1040-5488/14/9103-0278/0 VOL. 91, NO. 3, PP. 278Y283 OPTOMETRY AND VISION SCIENCE Copyright * 2014 American Academy of Optometry
ORIGINAL ARTICLE
Vision-Related Quality of Life in Patients with Infectious Keratitis Yimin Li*, Jiaxu Hong†, Anji Wei*, Xin Wang†, Yan Chen*, Xinhan Cui*, Xinghuai Sun†, Zuguo Liu†, and Jianjiang Xu†
ABSTRACT Purpose. To determine the vision-related quality of life (VR-QOL) in patients with infectious keratitis using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). Methods. Sixty-five patients with infectious keratitis (IK) were enrolled in the study. The NEI VFQ-25 scores and clinical and demographic data, including age, gender, pathogen, best corrected visual acuity (BCVA), and duration of the disease, were collected from the subjects. The subscale and composite scores were calculated and analyzed. Correlations between the VFQ-25 scores and the clinical and demographic features were also explored. Results. The mean age of enrolled subjects was 48.4 years (SD, 16.2), with 44 males (67.7%). The microbial pathogens were viruses (n = 48, 73.8%), fungi (n = 13, 20.0%), and bacteria (n = 4, 6.2%). The mean scores of each VFQ-25 subscale ranged from 31.9 (SD, 28.6) for role difficulties to 92.7 (SD, 13.1) for color vision; the mean composite score was 58.1 (SD, 19.2). Significant differences in scores were observed only in the subscale of dependency among educational levels and in the mental health subscale and the composite among the three pathogen groups. Multivariate regression analysis revealed that VFQ-25 composite score correlated significantly with the BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender. Conclusions. Infectious keratitis has extensive impacts on patients and VR-QOL. The BCVA of worse-seeing eye, duration, history of operation for IK treatment, and gender contributed independently to VR-QOL. Early treatment should be encouraged to obtain better visual prognosis and VR-QOL for patients with IK. (Optom Vis Sci 2014;91:278Y283) Key Words: infectious keratitis, vision-related quality of life, quality of life, NEI VFQ-25, best corrected visual acuity
I
nfectious keratitis (IK) is a potentially serious corneal infection and one of the more likely causes of visual impairment in contact lens wearers or especially working adults. The annual incidence of IK in the developed world has been increasing because of higher rates of contact lens use and is now two to 11 per 100,000 per year.1Y3 A study from Hong Kong found an annual incidence of 0.63 per 10,000 in nonYcontact lens wearers and 3.4 per 10,000 in contact lens wearers.2 The incidence of microbial keratitis in the developing world is considerably higher.1 Predisposing risk factors
*MD † MD, PhD Department of Ophthalmology, Eye, Ear, Nose, and Throat Hospital, School of Shanghai Medicine, Fudan University, Shanghai, China (YL, JH, AW, XW, YC, XC, XS, JX); State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Shanghai, China (XS); and Xiamen University, Fujian, China ( JH, ZL).
of microbial keratitis vary from one geographic region to another, including contact lens wear, surgical or nonsurgical trauma, preexisting corneal disease, and ocular surface disease, and various microorganisms can cause the disease.4 In both developing5 and developed6 countries, permanent visual dysfunction has been reported in a significant proportion of these patients. Generally, patients with this disease are initially involved in the acute phase, with ocular pain, sudden decreased vision, conjunctival injection, tearing, photophobia, and purulent discharge. If symptoms were not controlled completely for a period or relapsed, patients would not only suffer ocular discomfort but encounter more burden and disabilities in life because of visual impairment as well. Infectious keratitis is therefore a significant public health problem. To assess the complex effects caused by the disease, an appropriate instrument that could investigate both visual loss and vision-related quality of life (VR-QOL) is
Optometry and Vision Science, Vol. 91, No. 3, March 2014
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Vision-Related Quality of Life with Infectious KeratitisVLi et al.
necessary. Arguably, a comprehensive evaluation would facilitate diagnosis, treatment, and even public health policy of IK. As a generic VR-QOL instrument, the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) is devised to evaluate patients’ VF and VR-QOL.7 It is thus an appropriate comprehensive measurement for IK patients. Previous reports have demonstrated the reliability, validity, and feasibility of the Chinese version of the VFQ-25.8,9 It has been applied to following up various ocular diseases, including retinal vein occlusion, agerelated macular degeneration, diabetic retinopathy, retinal detachment, ocular chemical burns, glaucoma, and various ocular surgeries.9Y17 However, the existing literature is limited with respect to the VR-QOL in patients with IK. The purpose of this study was to determine the VR-QOL in patients with IK using the Chinese version of the NEI VFQ-25.
279
an experienced cornea specialist based on the composite clinical findings. Intraocular pressure was measured with a Goldmann applanation tonometer. The BCVA was assessed with Snellen equivalents, based on a standard refraction and testing protocol at a starting distance of 5 m, separately for both eyes. Participants who failed to read the largest letters at 5 m were tested at 1 m. Those who failed to read any letters were tested using counting fingers, hand movements, and light perception. To correlate VA with the questionnaire score, the Snellen VA was converted to its logMAR equivalent for statistical analysis. Based on the assumption that each progressively worse increment of off-the-chart vision was clinically significant and equivalent to a doubling of the visual angle, counting fingers, hand motion, light perception, and no light perception were assigned logMAR values of 2.0, 2.3, 2.6, and 2.9, respectively.18
Visual Function Questionnaire (VFQ-25) METHODS Subjects This prospective study initially enrolled 68 patients who presented with IK at the Department of Ophthalmology, Shanghai Eye, Ear, Nose, and Throat Hospital of Fudan University from February 1, 2010, to October 31, 2011. Three patients with bilateral IK were excluded from this analysis, and 65 subjects with unilateral IK were finally included into the analysis. Written informed consent was obtained from all patients after the nature of the study was explained to them. The diagnosis of IK was based on patient history and clinical examination, including measurement of visual acuity and slit lamp biomicroscopy by one corneal specialist. Corneal scrapings were taken for microbiological evaluation; and in suspected cases, a swab was obtained for detection of herpes virus by the polymerase chain reaction. The inclusion criteria were age 12 years and older, at least 1 month of clinical course to achieve relatively stable results of the visual outcome, and no other systemic or ocular disease that could potentially affect vision. Except for the driving subscale, there are no questions of NEI VFQ-25 related solely to an adult population, and of all the VR-QOL questionnaires in the Chinese language, it was the only available one for adolescents. Now that the driving subscale was eliminated in our statistical analysis (reasons are explained later), NEI VFQ-25 is suitable for younger patients in this study. Histories of ocular surgery (for treating IK at least 1 month before the interview), ocular trauma, clinical duration, and demographic features (age, gender, highest education level, and occupation) were recorded. Patients were excluded if they had received ocular operations not aimed at curing keratitis or had severe ocular trauma that caused complex ophthalmic problems other than IK. This study was approved by the ethics committee of the Shanghai Eye, Ear, Nose, and Throat Hospital of Fudan University and was carried out according to the tenets of the Declaration of Helsinki.
Ophthalmic Examination Every patient underwent a complete ophthalmologic examination, including slit lamp biomicroscopy, best corrected visual acuity (BCVA), tonometry, indirect ophthalmoscopy, corneal scraping, or in vivo confocal microscopy, if it was needed for developing a diagnosis. The diagnosis of type and pathogen associated with the disease were assessed by
Every subject was requested to fill out a Chinese version questionnaire of the NEI VFQ-25, which has been confirmed for its reliability and validity, on his or her own.8 Research staff explained the questionnaire to the subjects, and assistance was provided when necessary. For those participants who were unable to read because of poor eyesight, a single research staff member read the contents for them, in a neutral and uniform manner, and recorded their choices. Each completed questionnaire was checked for missing data by the staff member. The NEI VFQ-25 was used in the present study to assess the VR-QOL, with an additional question that was translated into Chinese. We chose item A8 from the NEI VFQ-39 to serve as an appendix to the no. 14 item because the response rate for item no.14 was rather low in the Chinese population, according to the instructions in the NEI VFQ-25 manual. The result of the appendix to the no.14 item was used to alleviate the impact of a high miss rate of this item on the validity and reliability of the whole questionnaire. Each item of the questionnaire was attributed to one of the 12 subscales, general health, general vision, near activities, ocular pain, distance activities, mental health, social functioning, role difficulties, driving, dependency, color vision, and peripheral vision, and was evaluated as our previous studies described.9 However, few Chinese in the area served drive and the response rate of driving subscale proved to be near zero; therefore, we eliminated the driving subscale in the statistical analysis.
Statistical Analysis Median scores and interquartile ranges were calculated for each subscale and composite score of the VFQ-25 questionnaire. The MannWhitney U test was performed to compare each subscale and composite score between male and female patients and with or without history of ocular surgery (only for treating IK). The Kruskal-Wallis test was performed for analysis of the median VFQ-25 scores among different age groups, educational levels, occupations, pathogens, and various duration of the disease. Spearman correlation was used to assess the relationship between the mean VFQ-25 scores and clinical features, including age, gender, BCVA of the better- or worse-seeing eye, duration, pathogen, and education level. Multivariate linear regression analysis was carried out to evaluate the relationship between clinical variables and the composite score. The covariates assessed were age,
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280 Vision-Related Quality of Life with Infectious KeratitisVLi et al. TABLE 1.
RESULTS
Demographic and clinical characteristics of all subjects Characteristics
All subjects, n = 68
Age, mean T SD (range), y G40 y, n G40È49 y, n G50È59 y, n Q60 y, n Male, n Education, n G = Primary Secondary 9 = Tertiary Occupation, n Labor work Peasant Office work Student Retired, housewife, or none Others Pathogen, n Virus Fungus Bacterium Duration of disease G1 y, n 1È4 y, n 5È9 y, n Q10 y, n
48.4 T 16.2 (12Y80) 15 15 15 20 44
Demographics of the Subjects Sixty-five eyes of 65 patients, suffering unilateral IK, were recruited into the study. The mean age of enrolled subjects was 48.4 years (SD, 16.2), with 44 males (67.7%). Thirty-eight patients (58.5%) had undergone surgery. Other demographic and clinical data are shown in Table 1.
Comparison of the VFQ-25 Subscales and the Composite Scores
19 28 18
Table 2 presents the comparison of subscale and composite scores between genders and among various age groups, occupations, educational levels, and pathogens in median (interquartile range). Among age groups, a significant difference was noted only in subscales of role difficulties, dependency, and peripheral vision (p G 0.05). Dependency was also found different (p G 0.05) among educational levels and peripheral vision (p G 0.05) among occupations and levels of education. Near activity (p G 0.05), mental health (p G 0.01), and composite score found disparity in patients infected by various pathogens. Between male and female, no significant difference was detected, with the exception of general health (p G 0.01). However, among patients with various durations of IK, significant differences were noted in most subscales and composite score, except for general health, general vision, ocular pain, and peripheral vision, as shown in Table 3.
14 13 7 5 19 7 48 13 4 15 19 11 20
gender, education level, occupation, duration of the disease, BCVA of the better- or worse-seeing eye, history of ocular operation for treatment of IK, and pathogen. A value of p G 0.05, determined using statistical software (version 18.0; PASW for Windows, Inc., Chicago, IL), was considered statistically significant in all analyses.
Correlation Analysis Table 4 shows the correlations between the NEI VFQ-25 scores and the BCVA of the better- and worse-seeing eyes. The composite score correlated strongly with the BCVA of the worse-seeing eye (Q = j0.446, p G 0.001). Overall, stronger
TABLE 2.
Comparison of subscale and composite scores between genders and among various age groups, occupation, educational level, and pathogens Subscale
Median scores (range) Age group* W2 (p) Occupation* W2 (p) Education level* W2 (p) Pathogen* W2 (p) Gender,† Z (p)
General health 70.0 (67.5Y80.0) General vision 50.0 (40.0Y60.0) Ocular pain 62.5 (43.8Y75.0) Near activity 58.3 (41.7Y85.4) Distance activity 75.0 (50.0Y91.7) Social function 87.5 (50.0Y100.0) Mental health 43.8 (18.8Y71.9) Role difficulties 25.0 (6.3Y62.5) Dependency 50.0 (29.2Y75.0) Color vision 100.0 (75.0Y100.0) Peripheral vision 75.0 (50.0Y100.0) Composite score 56.2 (42.5Y74.7)
1.6 (0.667) 4.9 (0.179) 4.2 (0.245) 3.6 (0.311) 2.9 (0.415) 2.0 (0.582) 5.4 (0.147) 7.9 (0.048)§ 9.7 (0.021)§ 4.8 (0.184) 10.4 (0.015)§ 6.5 (0.092)
3.93 (0.560) 6.57 (0.255) 2.52 (0.773) 4.52 (0.477) 8.83 (0.116) 4.70 (0.454) 3.76 (0.585) 7.08 (0.215) 10.34 (0.066) 7.29 (0.200) 13.01 (0.023)§ 6.74 (0.241)
0.615 (0.735) 3.34 (0.188) 1.50 (0.473) 2.44 (0.296) 5.62 (0.060) 3.19 (0.203) 4.96 (0.084) 5.00 (+0.082) 6.54 (0.038)§ 1.41 (0.494) 6.31 (0.043)§ 5.53 (0.063)
2.75 (0.253) 1.94 (0.378) 3.07 (0.216) 6.81 (0.033)§ 2.49 (0.288) 5.74 (0.057) 16.05 (G0.001)‡ 3.06 (0.216) 5.48 (0.064) 4.45 (0.108) 4.79 (0.091) 9.05 (0.011)§
*Kruskal-Wallis test. †Mann-Whitney U test. ‡p G 0.01. §p G 0.05. Optometry and Vision Science, Vol. 91, No. 3, March 2014
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j2.88 (0.004)‡ j1.18 (0.237) j0.42 (0.675) j0.32 (0.746) j1.25 (0.213) j0.01 (0.994) j1.34 (0.179) j1.44 (0.150) j1.65 (0.099) j1.50 (0.133) j0.18 (0.859) j1.23 (0.217)
Vision-Related Quality of Life with Infectious KeratitisVLi et al.
281
TABLE 3.
Analysis of subscale and composite scores among patients with various durations of infectious keratitis Subscale
G1 year Ave R (Mean T SD)
1 ~ 4 years Ave R (Mean T SD)
General health General vision Ocular pain Near activity Distance activity Social function Mental health Role difficulties Dependency Color vision Peripheral vision Composite score
34.2 (73.3 T 13.5) 37.1 (51.7 T 11.9) 25.7 (53.3 T 22.9) 17.9 (43.1 T 13.1) 22.2 (57.2 T 17.2) 17.8 (56.7 T 22.1) 22.4 (28.8 T 25.9) 19.1 (11.7 T 17.3) 20.9 (35.0 T 20.0) 24.1 (85.0 T 15.8) 28.3 (66.7 T 26.2) 18.3 (43.2 T 10.2)
39.3 (75.3 33.3 (49.2 33.8 (61.8 29.9 (57.7 33.3 (68.6 34.0 (78.9 29.1 (38.8 35.4 (33.6 34.0 (54.4 39.8 (98.7 33.9 (75.0 32.4 (57.1
T 16.7) T 20.2) T 23.7) T 26.7) T 25.8) T 20.9) T 25.3) T 22.5) T 21.9) T 5.7) T 23.6) T 16.3)
5 ~ 9 years Ave R (Mean T SD) 26.4 39.1 36.0 46.4 44.2 42.9 41.4 41.8 50.9 38.6 35.9 47.0
(70.0 (55.5 (65.9 (81.1 (84.1 (89.8 (57.4 (46.6 (80.3 (97.7 (77.3 (72.6
T 8.9) T 20.7) T 15.9) T 17.5) T 18.4) T 12.3) T 26.3) T 31.7) T 21.2) T 7.5) T 23.6) T 15.8)
Q10 years Ave R (Mean T SD) 29.8 (67.3 26.3 (41.5 36.1 (65.0 39.9 (72.9 34.7 (70.8 38.0 (81.3 40.0 (55.0 36.4 (37.5 31.3 (51.3 30.1 (90.0 34.1 (73.8 36.9 (62.4
T T T T T T T T T T T T
20.4) 23.7) 27.1) 25.2) 26.1) 25.8) 28.1) 32.2) 33.9) 15.0) 27.5) 21.7)
Total Mean (SD)
p value*
71.5 (16.3) 48.5 (20.1) 61.5 (23.5) 62.9 (25.7) 69.3 (24.1) 76.3 (24.1) 44.6 (28.3) 31.9 (28.6) 53.3 (29.0) 92.7 (13.1) 73.1 (25.1) 58.1 (19.2)
0.227 0.213 0.371 G0.001† 0.028‡ 0.002† 0.015‡ 0.008† 0.001† 0.006† 0.699 0.001†
*Kruskal-Wallis test. †p G 0.01. ‡p G 0.05. Ave R, average of the rank.
correlations were observed between most of the NEI VFQ-25 subscale scores and the BCVA of the worse-seeing eye, with the exception of general health, general vision, ocular pain, and color vision. By contrast, significant correlation between VFQ-25 scores and the BCVA of the better-seeing eye could only been seen for general vision (Q = j0.676, p G 0.001). Table 5 presents the correlations between VFQ-25 scores and age and duration of the disease. Only the subscale scores of peripheral vision showed a negative correlation with aging (Q = j0.294, p = 0.018), whereas the duration of the disease correlated positively with the scores of composite (Q = 0.382, p = 0.002), near activity (Q = 0.468, p G 0.001), distance activity (Q = 0.257, p = 0.039), social function (Q = 0.398, p = 0.001), mental health (Q = 0.380, p = 0.002), and role difficulties (Q = 0.325, p = 0.008).
Multivariate Analysis
TABLE 4.
TABLE 5.
Spearman correlations between the VFQ-25 scores and the BCVA for better- and worse-seeing eyes
Spearman correlations between the NEI VFQ-25 scores and age and duration of the disease
NEI VFQ-25 scores General health General vision Ocular pain Near activity Distance activity Social function Mental health Role difficulties Dependency Color vision Peripheral vision Composite score *p G 0.01. †p G 0.05.
BCVA (better-seeing eyes) Q j0.204 j0.676* j0.019 j0.180 j0.152 0.088 0.099 0.100 j0.081 0.080 j0.164 j0.069
p 0.138 G0.001 0.893 0.193 0.271 0.526 0.474 0.474 0.558 0.564 0.235 0.622
BCVA (worse-seeing eyes) Q j0.053 j0.172 j0.251 j0.441* j0.428* j0.275† j0.381* j0.259† j0.303† j0.119 j0.432* j0.446*
p 0.687 0.188 0.053 G0.001 0.001 0.033 0.003 0.046 0.019 0.365 0.001 G0.001
Results of the multivariate linear regression analysis are summarized in Table 6. The VFQ-25 composite score correlated significantly with the following independent variables: BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender.
DISCUSSION To the best of our knowledge, this was the first research that assessed the VR-QOL in patients with IK. This study demonstrated that IK patients have low to moderate NEI VFQ-25 composite scores when compared with the scores reported for other ocular diseases, including age-related macular degeneration,18 central
NEI VFQ-25 scores General health General vision Ocular pain Near activity Distance activity Social function Mental health Role difficulties Dependency Color vision Peripheral vision Composite score
Duration of the disease
Age Q
p
Q
j0.043 j0.134 0.064 j0.161 j0.138 j0.013 0.196 j0.021 0.035 0.017 j0.294† 0.001
0.735 0.286 0.612 0.200 0.271 0.920 0.117 0.869 0.780 0.891 0.018 0.992
j0.157 j0.191 0.195 0.468* 0.257† 0.398* 0.380* 0.325* 0.229 0.082 0.111 0.382*
*p G 0.01. †p G 0.05. Optometry and Vision Science, Vol. 91, No. 3, March 2014
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p 0.211 0.128 0.120 G0.001 0.039 0.001 0.002 0.008 0.066 0.514 0.377 0.002
282 Vision-Related Quality of Life with Infectious KeratitisVLi et al. TABLE 6.
Stepwise multivariate linear regression analysis on the potential clinical variables of VFQ-25 composite score in infectious keratitis patients Variables BCVA of worse-seeing eye Duration of the disease History of operation (for IK treatment) Gender
Standardized A
t
p
j0.491* 0.454* 0.251† j0.206†
j4.726 4.409 2.430 j2.041
G0.001 G0.001 0.019 0.047
*p G 0.01. †p G 0.05.
retinal vein occlusion,5 unilateral branch retinal vein occlusion,19 rhegmatogenous retinal detachment,15 proliferative diabetic retinopathy,12 Behcet uveitis, dry eye syndrome,20 and ocular chemical burns.8 Responses on the VFQ-25 correlated most strongly with the BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender. Most patients in this study suffered chronically, and more than half of them had undergone corneal operations; therefore, their relatively poor QOL scores for daily physical activities and psychological status were not surprising. The current study showed that patients with primary or a lower education level had the poorest scores in the subscale of dependency (Table 2). Similar results were found in patients with Behcet uveitis.21 A reasonable deduction is that patients who received less education also earned a lower income and tended to do different types of work for a living. At the same time, educated patients might be more capable of adjusting themselves psychologically to accept and deal with the disease, and they might also be more able to obtain more information and financial support to facilitate treatment.21 Patients with IK caused by viruses had significantly higher scores in composite and mental health when compared with those infected with fungi or bacteria (Table 2). The exact mechanism underlying this phenomenon is unknown; however, one possible explanation is that viral keratitis is generally featured with a relatively longer duration or less injury to the cornea compared with fungal and bacterial types. Patients with duration of the disease of less than 1 year had the lowest mean vision-specific NEI VFQ-25 subscale scores, particularly for dependency, role limitation, mental health, and social functioning limitation (Table 3). This result was in agreement with the findings of previous studies.22,23 Patients with a shorter duration of the disease usually suffer a sudden loss of independence, difficulties with social interactions, and considerable anxiety, whereas those with a longer
duration were able to endure long-standing poorer vision and had more time to adapt to their visual impairment.22,23 Our findings indicated that patients with IK in chronic phase, like patients with other chronic diseases, may become more used to their new vision state and their VR-QOL might improve. The BCVA of the worse-seeing eye strongly correlated with the composite score and a majority of the subscales, in line with previous reports.15,19,20 Nevertheless, a correlation between the BCVA of the better-seeing eye and VFQ-25 scores could only be seen in one of 12 items (the composite was included and driving was excluded; Table 4). Since 65 of 65 better-seeing eyes were patients with one eye involvement, the excellent visual acuity in the nonaffected eye does not appear to change the association of IK with lower VR-QOL scores. Correlations were also observed between the NEI VFQ-25 scores and the duration of the disease, and lack of time for adaptation might be the reason.22,23 Age was not correlated with the VFQ25 scores, with the exception of peripheral vision (Table 5), in agreement with similar findings in previous studies.11,23 Multivariate analysis confirmed that BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender were independent factors in patients with IK, whereas age, educational level, occupation, and pathogens of the disease were not relevant factors (Table 6). Table 7 summarizes the correlation between involved eye sides and BCVA in analysis in previous studies. It is shown that only one research that investigates unilateral branch retinal vein occlusion presented similar results to our study: a decrease in the VFQ-25 score is correlated with the involved eye visual acuity, even when good visual acuity is maintained in the uninvolved one.8 It is reasonable to deduce that, for patients with monocular disease, the BCVA of the involved eye contributed the most to their VR-QOL. All these findings suggest
TABLE 7.
Summary of the correlation between involved eye sides and BCVA in analysis in previous studies Disease Chemical burn Age-related macular degeneration Central retinal vein occlusion Branch retinal vein occlusion Proliferative diabetic retinopathy (comparison between pre- and post operation)
Involved eye sides in analysis
BCVA correlated
Author
Bilateral + unilateral Bilateral Bilateral + unilateral Unilateral Unilateral Preoperative Postoperative
Better- and worse-seeing eye Better-seeing eye Better-seeing eye N/A Worse-seeing eye Better-seeing eye Worse- and better-seeing eye
Le et al.9 Cahill et al.23 Deramo et al.11
BCVA, best corrected visual acuity. Optometry and Vision Science, Vol. 91, No. 3, March 2014
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Awdeh et al.19 Okamoto et al.13
Vision-Related Quality of Life with Infectious KeratitisVLi et al.
that IK patients should be treated and their visual function be protected as early as possible. Certain limitations of this study should be addressed. First, the sample size was relatively small and may have led to selection bias of the patients because this was a single-center study and most patients might have visited various hospitals before they came to see our cornea specialist. Second, only four cases induced by bacteria were included in the study, which might limit the power to detect significant differences in the comparison among pathogen groups. Finally, it was a prospective cross-sectional study, and we did not follow up the patients to explore the effects of medical or surgical treatments on VRQOL. These shortcomings might be resolved by further prospective investigations designed with a longer follow-up period. In conclusion, IK, an acute or chronic vision-impairing ocular disease, has extensive effects on patients’ visual function and VRQOL. The present study showed that NEI VFQ-25 could be a useful and valid approach for assessing patient-reported vision function outcomes and vision-related QOL, which had correlations with the BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender. Early treatment should be encouraged to obtain a better visual prognosis and VR-QOL for patients with unilateral IK.
ACKNOWLEDGMENTS Yimin Li and Jiaxu Hong contributed equally to the article and should be considered first coauthors. This work was supported by grants from the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China (81020108017); the Key Clinic Medicine Research Program, the Ministry of Health, China (2012Y2014); National Science and Technology Research Program, the Ministry of Science and Technology, China (2012BAI08B01); National Natural Science Foundation of China (81170817, 81200658); and Scientific Research Program, Science and Technology Commission of Shanghai Municipality, Shanghai, China (13441900900, 13430720400, 134119a8800, 13430710500). The sponsor or funding organization had no role in the design or conduct of this research. The authors declare that no financial relationship exists with the organization that sponsored the research. Received March 8, 2013; accepted October 2, 2013.
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8. Chan CW, Wong D, Lam CL, McGhee S, Lai WW. Development of a Chinese version of the National Eye Institute Visual Function Questionnaire (CHI-VFQ-25) as a tool to study patients with eye diseases in Hong Kong. Br J Ophthalmol 2009;93:1431Y6. 9. Le Q, Chen Y, Wang X, Li Y, Hong J, Xu J. Vision-related quality of life in patients with ocular chemical burns. Invest Ophthalmol Vis Sci 2011;52:8951Y6. 10. Hyman LG, Komaroff E, Heijl A, Bengtsson B, Leske MC. Treatment and vision-related quality of life in the early manifest glaucoma trial. Ophthalmology 2005;112:1505Y13. 11. Deramo VA, Cox TA, Syed AB, Lee PP, Fekrat S. Vision-related quality of life in people with central retinal vein occlusion using the 25-item National Eye Institute Visual Function Questionnaire. Arch Ophthalmol 2003;121:1297Y302. 12. Okamoto F, Okamoto Y, Fukuda S, Hiraoka T, Oshika T. Vision-related quality of life and visual function following vitrectomy for proliferative diabetic retinopathy. Am J Ophthalmol 2008;145:1031Y6. 13. Okamoto F, Okamoto Y, Hiraoka T, Oshika T. Vision-related quality of life and visual function after retinal detachment surgery. Am J Ophthalmol 2008;146:85Y90. 14. Miri A, Mathew M, Dua HS. Quality of life after limbal transplants. Ophthalmology 2010;117:638. 15. Berdeaux GH, Nordmann JP, Colin E, Arnould B. Vision-related quality of life in patients suffering from age-related macular degeneration. Am J Ophthalmol 2005;139:271Y9. 16. Okamoto Y, Okamoto F, Yamada S, Honda M, Hiraoka T, Oshika T. Vision-related quality of life after transsphenoidal surgery for pituitary adenoma. Invest Ophthalmol Vis Sci 2010;51:3405Y10. 17. Revicki DA, Rentz AM, Harnam N, Thomas VS, Lanzetta P. Reliability and validity of the National Eye Institute Visual Function Questionnaire-25 in patients with age-related macular degeneration. Invest Ophthalmol Vis Sci 2010;51:712Y7. 18. The ischemic optic neuropathy decompression trial (IONDT): design and methods. Control Clin Trials 1998;19:276Y96. 19. Awdeh RM, Elsing SH, Deramo VA, Stinnett S, Lee PP, Fekrat S. Vision-related quality of life in persons with unilateral branch retinal vein occlusion using the 25-item National Eye Institute Visual Function Questionnaire. Br J Ophthalmol 2010;94:319Y23. 20. Mizuno Y, Yamada M, Miyake Y. Association between clinical diagnostic tests and health-related quality of life surveys in patients with dry eye syndrome. Jpn J Ophthalmol 2010;54:259Y65. 21. Onal S, Savar F, Akman M, Kazokoglu H. Vision- and health-related quality of life in patients with Behcet uveitis. Arch Ophthalmol 2010;128:1265Y71. 22. Mangione CM, Lee PP, Gutierrez PR, Spritzer K, Berry S, Hays RD. Development of the 25-item National Eye Institute Visual Function Questionnaire. Arch Ophthalmol 2001;119:1050Y8. 23. Cahill MT, Banks AD, Stinnett SS, Toth CA. Vision-related quality of life in patients with bilateral severe age-related macular degeneration. Ophthalmology 2005;112:152Y8.
Jianjiang Xu Department of Ophthalmology Eye, Ear, Nose and Throat Hospital School of Shanghai Medicine Fudan University 83 Fenyang Rd Shanghai 200031 China e-mail: [email protected]
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ORIGINAL ARTICLE
Vision-Related Quality of Life in Patients with Infectious Keratitis Yimin Li*, Jiaxu Hong†, Anji Wei*, Xin Wang†, Yan Chen*, Xinhan Cui*, Xinghuai Sun†, Zuguo Liu†, and Jianjiang Xu†
ABSTRACT Purpose. To determine the vision-related quality of life (VR-QOL) in patients with infectious keratitis using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). Methods. Sixty-five patients with infectious keratitis (IK) were enrolled in the study. The NEI VFQ-25 scores and clinical and demographic data, including age, gender, pathogen, best corrected visual acuity (BCVA), and duration of the disease, were collected from the subjects. The subscale and composite scores were calculated and analyzed. Correlations between the VFQ-25 scores and the clinical and demographic features were also explored. Results. The mean age of enrolled subjects was 48.4 years (SD, 16.2), with 44 males (67.7%). The microbial pathogens were viruses (n = 48, 73.8%), fungi (n = 13, 20.0%), and bacteria (n = 4, 6.2%). The mean scores of each VFQ-25 subscale ranged from 31.9 (SD, 28.6) for role difficulties to 92.7 (SD, 13.1) for color vision; the mean composite score was 58.1 (SD, 19.2). Significant differences in scores were observed only in the subscale of dependency among educational levels and in the mental health subscale and the composite among the three pathogen groups. Multivariate regression analysis revealed that VFQ-25 composite score correlated significantly with the BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender. Conclusions. Infectious keratitis has extensive impacts on patients and VR-QOL. The BCVA of worse-seeing eye, duration, history of operation for IK treatment, and gender contributed independently to VR-QOL. Early treatment should be encouraged to obtain better visual prognosis and VR-QOL for patients with IK. (Optom Vis Sci 2014;91:278Y283) Key Words: infectious keratitis, vision-related quality of life, quality of life, NEI VFQ-25, best corrected visual acuity
I
nfectious keratitis (IK) is a potentially serious corneal infection and one of the more likely causes of visual impairment in contact lens wearers or especially working adults. The annual incidence of IK in the developed world has been increasing because of higher rates of contact lens use and is now two to 11 per 100,000 per year.1Y3 A study from Hong Kong found an annual incidence of 0.63 per 10,000 in nonYcontact lens wearers and 3.4 per 10,000 in contact lens wearers.2 The incidence of microbial keratitis in the developing world is considerably higher.1 Predisposing risk factors
*MD † MD, PhD Department of Ophthalmology, Eye, Ear, Nose, and Throat Hospital, School of Shanghai Medicine, Fudan University, Shanghai, China (YL, JH, AW, XW, YC, XC, XS, JX); State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Shanghai, China (XS); and Xiamen University, Fujian, China ( JH, ZL).
of microbial keratitis vary from one geographic region to another, including contact lens wear, surgical or nonsurgical trauma, preexisting corneal disease, and ocular surface disease, and various microorganisms can cause the disease.4 In both developing5 and developed6 countries, permanent visual dysfunction has been reported in a significant proportion of these patients. Generally, patients with this disease are initially involved in the acute phase, with ocular pain, sudden decreased vision, conjunctival injection, tearing, photophobia, and purulent discharge. If symptoms were not controlled completely for a period or relapsed, patients would not only suffer ocular discomfort but encounter more burden and disabilities in life because of visual impairment as well. Infectious keratitis is therefore a significant public health problem. To assess the complex effects caused by the disease, an appropriate instrument that could investigate both visual loss and vision-related quality of life (VR-QOL) is
Optometry and Vision Science, Vol. 91, No. 3, March 2014
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Vision-Related Quality of Life with Infectious KeratitisVLi et al.
necessary. Arguably, a comprehensive evaluation would facilitate diagnosis, treatment, and even public health policy of IK. As a generic VR-QOL instrument, the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) is devised to evaluate patients’ VF and VR-QOL.7 It is thus an appropriate comprehensive measurement for IK patients. Previous reports have demonstrated the reliability, validity, and feasibility of the Chinese version of the VFQ-25.8,9 It has been applied to following up various ocular diseases, including retinal vein occlusion, agerelated macular degeneration, diabetic retinopathy, retinal detachment, ocular chemical burns, glaucoma, and various ocular surgeries.9Y17 However, the existing literature is limited with respect to the VR-QOL in patients with IK. The purpose of this study was to determine the VR-QOL in patients with IK using the Chinese version of the NEI VFQ-25.
279
an experienced cornea specialist based on the composite clinical findings. Intraocular pressure was measured with a Goldmann applanation tonometer. The BCVA was assessed with Snellen equivalents, based on a standard refraction and testing protocol at a starting distance of 5 m, separately for both eyes. Participants who failed to read the largest letters at 5 m were tested at 1 m. Those who failed to read any letters were tested using counting fingers, hand movements, and light perception. To correlate VA with the questionnaire score, the Snellen VA was converted to its logMAR equivalent for statistical analysis. Based on the assumption that each progressively worse increment of off-the-chart vision was clinically significant and equivalent to a doubling of the visual angle, counting fingers, hand motion, light perception, and no light perception were assigned logMAR values of 2.0, 2.3, 2.6, and 2.9, respectively.18
Visual Function Questionnaire (VFQ-25) METHODS Subjects This prospective study initially enrolled 68 patients who presented with IK at the Department of Ophthalmology, Shanghai Eye, Ear, Nose, and Throat Hospital of Fudan University from February 1, 2010, to October 31, 2011. Three patients with bilateral IK were excluded from this analysis, and 65 subjects with unilateral IK were finally included into the analysis. Written informed consent was obtained from all patients after the nature of the study was explained to them. The diagnosis of IK was based on patient history and clinical examination, including measurement of visual acuity and slit lamp biomicroscopy by one corneal specialist. Corneal scrapings were taken for microbiological evaluation; and in suspected cases, a swab was obtained for detection of herpes virus by the polymerase chain reaction. The inclusion criteria were age 12 years and older, at least 1 month of clinical course to achieve relatively stable results of the visual outcome, and no other systemic or ocular disease that could potentially affect vision. Except for the driving subscale, there are no questions of NEI VFQ-25 related solely to an adult population, and of all the VR-QOL questionnaires in the Chinese language, it was the only available one for adolescents. Now that the driving subscale was eliminated in our statistical analysis (reasons are explained later), NEI VFQ-25 is suitable for younger patients in this study. Histories of ocular surgery (for treating IK at least 1 month before the interview), ocular trauma, clinical duration, and demographic features (age, gender, highest education level, and occupation) were recorded. Patients were excluded if they had received ocular operations not aimed at curing keratitis or had severe ocular trauma that caused complex ophthalmic problems other than IK. This study was approved by the ethics committee of the Shanghai Eye, Ear, Nose, and Throat Hospital of Fudan University and was carried out according to the tenets of the Declaration of Helsinki.
Ophthalmic Examination Every patient underwent a complete ophthalmologic examination, including slit lamp biomicroscopy, best corrected visual acuity (BCVA), tonometry, indirect ophthalmoscopy, corneal scraping, or in vivo confocal microscopy, if it was needed for developing a diagnosis. The diagnosis of type and pathogen associated with the disease were assessed by
Every subject was requested to fill out a Chinese version questionnaire of the NEI VFQ-25, which has been confirmed for its reliability and validity, on his or her own.8 Research staff explained the questionnaire to the subjects, and assistance was provided when necessary. For those participants who were unable to read because of poor eyesight, a single research staff member read the contents for them, in a neutral and uniform manner, and recorded their choices. Each completed questionnaire was checked for missing data by the staff member. The NEI VFQ-25 was used in the present study to assess the VR-QOL, with an additional question that was translated into Chinese. We chose item A8 from the NEI VFQ-39 to serve as an appendix to the no. 14 item because the response rate for item no.14 was rather low in the Chinese population, according to the instructions in the NEI VFQ-25 manual. The result of the appendix to the no.14 item was used to alleviate the impact of a high miss rate of this item on the validity and reliability of the whole questionnaire. Each item of the questionnaire was attributed to one of the 12 subscales, general health, general vision, near activities, ocular pain, distance activities, mental health, social functioning, role difficulties, driving, dependency, color vision, and peripheral vision, and was evaluated as our previous studies described.9 However, few Chinese in the area served drive and the response rate of driving subscale proved to be near zero; therefore, we eliminated the driving subscale in the statistical analysis.
Statistical Analysis Median scores and interquartile ranges were calculated for each subscale and composite score of the VFQ-25 questionnaire. The MannWhitney U test was performed to compare each subscale and composite score between male and female patients and with or without history of ocular surgery (only for treating IK). The Kruskal-Wallis test was performed for analysis of the median VFQ-25 scores among different age groups, educational levels, occupations, pathogens, and various duration of the disease. Spearman correlation was used to assess the relationship between the mean VFQ-25 scores and clinical features, including age, gender, BCVA of the better- or worse-seeing eye, duration, pathogen, and education level. Multivariate linear regression analysis was carried out to evaluate the relationship between clinical variables and the composite score. The covariates assessed were age,
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280 Vision-Related Quality of Life with Infectious KeratitisVLi et al. TABLE 1.
RESULTS
Demographic and clinical characteristics of all subjects Characteristics
All subjects, n = 68
Age, mean T SD (range), y G40 y, n G40È49 y, n G50È59 y, n Q60 y, n Male, n Education, n G = Primary Secondary 9 = Tertiary Occupation, n Labor work Peasant Office work Student Retired, housewife, or none Others Pathogen, n Virus Fungus Bacterium Duration of disease G1 y, n 1È4 y, n 5È9 y, n Q10 y, n
48.4 T 16.2 (12Y80) 15 15 15 20 44
Demographics of the Subjects Sixty-five eyes of 65 patients, suffering unilateral IK, were recruited into the study. The mean age of enrolled subjects was 48.4 years (SD, 16.2), with 44 males (67.7%). Thirty-eight patients (58.5%) had undergone surgery. Other demographic and clinical data are shown in Table 1.
Comparison of the VFQ-25 Subscales and the Composite Scores
19 28 18
Table 2 presents the comparison of subscale and composite scores between genders and among various age groups, occupations, educational levels, and pathogens in median (interquartile range). Among age groups, a significant difference was noted only in subscales of role difficulties, dependency, and peripheral vision (p G 0.05). Dependency was also found different (p G 0.05) among educational levels and peripheral vision (p G 0.05) among occupations and levels of education. Near activity (p G 0.05), mental health (p G 0.01), and composite score found disparity in patients infected by various pathogens. Between male and female, no significant difference was detected, with the exception of general health (p G 0.01). However, among patients with various durations of IK, significant differences were noted in most subscales and composite score, except for general health, general vision, ocular pain, and peripheral vision, as shown in Table 3.
14 13 7 5 19 7 48 13 4 15 19 11 20
gender, education level, occupation, duration of the disease, BCVA of the better- or worse-seeing eye, history of ocular operation for treatment of IK, and pathogen. A value of p G 0.05, determined using statistical software (version 18.0; PASW for Windows, Inc., Chicago, IL), was considered statistically significant in all analyses.
Correlation Analysis Table 4 shows the correlations between the NEI VFQ-25 scores and the BCVA of the better- and worse-seeing eyes. The composite score correlated strongly with the BCVA of the worse-seeing eye (Q = j0.446, p G 0.001). Overall, stronger
TABLE 2.
Comparison of subscale and composite scores between genders and among various age groups, occupation, educational level, and pathogens Subscale
Median scores (range) Age group* W2 (p) Occupation* W2 (p) Education level* W2 (p) Pathogen* W2 (p) Gender,† Z (p)
General health 70.0 (67.5Y80.0) General vision 50.0 (40.0Y60.0) Ocular pain 62.5 (43.8Y75.0) Near activity 58.3 (41.7Y85.4) Distance activity 75.0 (50.0Y91.7) Social function 87.5 (50.0Y100.0) Mental health 43.8 (18.8Y71.9) Role difficulties 25.0 (6.3Y62.5) Dependency 50.0 (29.2Y75.0) Color vision 100.0 (75.0Y100.0) Peripheral vision 75.0 (50.0Y100.0) Composite score 56.2 (42.5Y74.7)
1.6 (0.667) 4.9 (0.179) 4.2 (0.245) 3.6 (0.311) 2.9 (0.415) 2.0 (0.582) 5.4 (0.147) 7.9 (0.048)§ 9.7 (0.021)§ 4.8 (0.184) 10.4 (0.015)§ 6.5 (0.092)
3.93 (0.560) 6.57 (0.255) 2.52 (0.773) 4.52 (0.477) 8.83 (0.116) 4.70 (0.454) 3.76 (0.585) 7.08 (0.215) 10.34 (0.066) 7.29 (0.200) 13.01 (0.023)§ 6.74 (0.241)
0.615 (0.735) 3.34 (0.188) 1.50 (0.473) 2.44 (0.296) 5.62 (0.060) 3.19 (0.203) 4.96 (0.084) 5.00 (+0.082) 6.54 (0.038)§ 1.41 (0.494) 6.31 (0.043)§ 5.53 (0.063)
2.75 (0.253) 1.94 (0.378) 3.07 (0.216) 6.81 (0.033)§ 2.49 (0.288) 5.74 (0.057) 16.05 (G0.001)‡ 3.06 (0.216) 5.48 (0.064) 4.45 (0.108) 4.79 (0.091) 9.05 (0.011)§
*Kruskal-Wallis test. †Mann-Whitney U test. ‡p G 0.01. §p G 0.05. Optometry and Vision Science, Vol. 91, No. 3, March 2014
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j2.88 (0.004)‡ j1.18 (0.237) j0.42 (0.675) j0.32 (0.746) j1.25 (0.213) j0.01 (0.994) j1.34 (0.179) j1.44 (0.150) j1.65 (0.099) j1.50 (0.133) j0.18 (0.859) j1.23 (0.217)
Vision-Related Quality of Life with Infectious KeratitisVLi et al.
281
TABLE 3.
Analysis of subscale and composite scores among patients with various durations of infectious keratitis Subscale
G1 year Ave R (Mean T SD)
1 ~ 4 years Ave R (Mean T SD)
General health General vision Ocular pain Near activity Distance activity Social function Mental health Role difficulties Dependency Color vision Peripheral vision Composite score
34.2 (73.3 T 13.5) 37.1 (51.7 T 11.9) 25.7 (53.3 T 22.9) 17.9 (43.1 T 13.1) 22.2 (57.2 T 17.2) 17.8 (56.7 T 22.1) 22.4 (28.8 T 25.9) 19.1 (11.7 T 17.3) 20.9 (35.0 T 20.0) 24.1 (85.0 T 15.8) 28.3 (66.7 T 26.2) 18.3 (43.2 T 10.2)
39.3 (75.3 33.3 (49.2 33.8 (61.8 29.9 (57.7 33.3 (68.6 34.0 (78.9 29.1 (38.8 35.4 (33.6 34.0 (54.4 39.8 (98.7 33.9 (75.0 32.4 (57.1
T 16.7) T 20.2) T 23.7) T 26.7) T 25.8) T 20.9) T 25.3) T 22.5) T 21.9) T 5.7) T 23.6) T 16.3)
5 ~ 9 years Ave R (Mean T SD) 26.4 39.1 36.0 46.4 44.2 42.9 41.4 41.8 50.9 38.6 35.9 47.0
(70.0 (55.5 (65.9 (81.1 (84.1 (89.8 (57.4 (46.6 (80.3 (97.7 (77.3 (72.6
T 8.9) T 20.7) T 15.9) T 17.5) T 18.4) T 12.3) T 26.3) T 31.7) T 21.2) T 7.5) T 23.6) T 15.8)
Q10 years Ave R (Mean T SD) 29.8 (67.3 26.3 (41.5 36.1 (65.0 39.9 (72.9 34.7 (70.8 38.0 (81.3 40.0 (55.0 36.4 (37.5 31.3 (51.3 30.1 (90.0 34.1 (73.8 36.9 (62.4
T T T T T T T T T T T T
20.4) 23.7) 27.1) 25.2) 26.1) 25.8) 28.1) 32.2) 33.9) 15.0) 27.5) 21.7)
Total Mean (SD)
p value*
71.5 (16.3) 48.5 (20.1) 61.5 (23.5) 62.9 (25.7) 69.3 (24.1) 76.3 (24.1) 44.6 (28.3) 31.9 (28.6) 53.3 (29.0) 92.7 (13.1) 73.1 (25.1) 58.1 (19.2)
0.227 0.213 0.371 G0.001† 0.028‡ 0.002† 0.015‡ 0.008† 0.001† 0.006† 0.699 0.001†
*Kruskal-Wallis test. †p G 0.01. ‡p G 0.05. Ave R, average of the rank.
correlations were observed between most of the NEI VFQ-25 subscale scores and the BCVA of the worse-seeing eye, with the exception of general health, general vision, ocular pain, and color vision. By contrast, significant correlation between VFQ-25 scores and the BCVA of the better-seeing eye could only been seen for general vision (Q = j0.676, p G 0.001). Table 5 presents the correlations between VFQ-25 scores and age and duration of the disease. Only the subscale scores of peripheral vision showed a negative correlation with aging (Q = j0.294, p = 0.018), whereas the duration of the disease correlated positively with the scores of composite (Q = 0.382, p = 0.002), near activity (Q = 0.468, p G 0.001), distance activity (Q = 0.257, p = 0.039), social function (Q = 0.398, p = 0.001), mental health (Q = 0.380, p = 0.002), and role difficulties (Q = 0.325, p = 0.008).
Multivariate Analysis
TABLE 4.
TABLE 5.
Spearman correlations between the VFQ-25 scores and the BCVA for better- and worse-seeing eyes
Spearman correlations between the NEI VFQ-25 scores and age and duration of the disease
NEI VFQ-25 scores General health General vision Ocular pain Near activity Distance activity Social function Mental health Role difficulties Dependency Color vision Peripheral vision Composite score *p G 0.01. †p G 0.05.
BCVA (better-seeing eyes) Q j0.204 j0.676* j0.019 j0.180 j0.152 0.088 0.099 0.100 j0.081 0.080 j0.164 j0.069
p 0.138 G0.001 0.893 0.193 0.271 0.526 0.474 0.474 0.558 0.564 0.235 0.622
BCVA (worse-seeing eyes) Q j0.053 j0.172 j0.251 j0.441* j0.428* j0.275† j0.381* j0.259† j0.303† j0.119 j0.432* j0.446*
p 0.687 0.188 0.053 G0.001 0.001 0.033 0.003 0.046 0.019 0.365 0.001 G0.001
Results of the multivariate linear regression analysis are summarized in Table 6. The VFQ-25 composite score correlated significantly with the following independent variables: BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender.
DISCUSSION To the best of our knowledge, this was the first research that assessed the VR-QOL in patients with IK. This study demonstrated that IK patients have low to moderate NEI VFQ-25 composite scores when compared with the scores reported for other ocular diseases, including age-related macular degeneration,18 central
NEI VFQ-25 scores General health General vision Ocular pain Near activity Distance activity Social function Mental health Role difficulties Dependency Color vision Peripheral vision Composite score
Duration of the disease
Age Q
p
Q
j0.043 j0.134 0.064 j0.161 j0.138 j0.013 0.196 j0.021 0.035 0.017 j0.294† 0.001
0.735 0.286 0.612 0.200 0.271 0.920 0.117 0.869 0.780 0.891 0.018 0.992
j0.157 j0.191 0.195 0.468* 0.257† 0.398* 0.380* 0.325* 0.229 0.082 0.111 0.382*
*p G 0.01. †p G 0.05. Optometry and Vision Science, Vol. 91, No. 3, March 2014
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p 0.211 0.128 0.120 G0.001 0.039 0.001 0.002 0.008 0.066 0.514 0.377 0.002
282 Vision-Related Quality of Life with Infectious KeratitisVLi et al. TABLE 6.
Stepwise multivariate linear regression analysis on the potential clinical variables of VFQ-25 composite score in infectious keratitis patients Variables BCVA of worse-seeing eye Duration of the disease History of operation (for IK treatment) Gender
Standardized A
t
p
j0.491* 0.454* 0.251† j0.206†
j4.726 4.409 2.430 j2.041
G0.001 G0.001 0.019 0.047
*p G 0.01. †p G 0.05.
retinal vein occlusion,5 unilateral branch retinal vein occlusion,19 rhegmatogenous retinal detachment,15 proliferative diabetic retinopathy,12 Behcet uveitis, dry eye syndrome,20 and ocular chemical burns.8 Responses on the VFQ-25 correlated most strongly with the BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender. Most patients in this study suffered chronically, and more than half of them had undergone corneal operations; therefore, their relatively poor QOL scores for daily physical activities and psychological status were not surprising. The current study showed that patients with primary or a lower education level had the poorest scores in the subscale of dependency (Table 2). Similar results were found in patients with Behcet uveitis.21 A reasonable deduction is that patients who received less education also earned a lower income and tended to do different types of work for a living. At the same time, educated patients might be more capable of adjusting themselves psychologically to accept and deal with the disease, and they might also be more able to obtain more information and financial support to facilitate treatment.21 Patients with IK caused by viruses had significantly higher scores in composite and mental health when compared with those infected with fungi or bacteria (Table 2). The exact mechanism underlying this phenomenon is unknown; however, one possible explanation is that viral keratitis is generally featured with a relatively longer duration or less injury to the cornea compared with fungal and bacterial types. Patients with duration of the disease of less than 1 year had the lowest mean vision-specific NEI VFQ-25 subscale scores, particularly for dependency, role limitation, mental health, and social functioning limitation (Table 3). This result was in agreement with the findings of previous studies.22,23 Patients with a shorter duration of the disease usually suffer a sudden loss of independence, difficulties with social interactions, and considerable anxiety, whereas those with a longer
duration were able to endure long-standing poorer vision and had more time to adapt to their visual impairment.22,23 Our findings indicated that patients with IK in chronic phase, like patients with other chronic diseases, may become more used to their new vision state and their VR-QOL might improve. The BCVA of the worse-seeing eye strongly correlated with the composite score and a majority of the subscales, in line with previous reports.15,19,20 Nevertheless, a correlation between the BCVA of the better-seeing eye and VFQ-25 scores could only be seen in one of 12 items (the composite was included and driving was excluded; Table 4). Since 65 of 65 better-seeing eyes were patients with one eye involvement, the excellent visual acuity in the nonaffected eye does not appear to change the association of IK with lower VR-QOL scores. Correlations were also observed between the NEI VFQ-25 scores and the duration of the disease, and lack of time for adaptation might be the reason.22,23 Age was not correlated with the VFQ25 scores, with the exception of peripheral vision (Table 5), in agreement with similar findings in previous studies.11,23 Multivariate analysis confirmed that BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender were independent factors in patients with IK, whereas age, educational level, occupation, and pathogens of the disease were not relevant factors (Table 6). Table 7 summarizes the correlation between involved eye sides and BCVA in analysis in previous studies. It is shown that only one research that investigates unilateral branch retinal vein occlusion presented similar results to our study: a decrease in the VFQ-25 score is correlated with the involved eye visual acuity, even when good visual acuity is maintained in the uninvolved one.8 It is reasonable to deduce that, for patients with monocular disease, the BCVA of the involved eye contributed the most to their VR-QOL. All these findings suggest
TABLE 7.
Summary of the correlation between involved eye sides and BCVA in analysis in previous studies Disease Chemical burn Age-related macular degeneration Central retinal vein occlusion Branch retinal vein occlusion Proliferative diabetic retinopathy (comparison between pre- and post operation)
Involved eye sides in analysis
BCVA correlated
Author
Bilateral + unilateral Bilateral Bilateral + unilateral Unilateral Unilateral Preoperative Postoperative
Better- and worse-seeing eye Better-seeing eye Better-seeing eye N/A Worse-seeing eye Better-seeing eye Worse- and better-seeing eye
Le et al.9 Cahill et al.23 Deramo et al.11
BCVA, best corrected visual acuity. Optometry and Vision Science, Vol. 91, No. 3, March 2014
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Awdeh et al.19 Okamoto et al.13
Vision-Related Quality of Life with Infectious KeratitisVLi et al.
that IK patients should be treated and their visual function be protected as early as possible. Certain limitations of this study should be addressed. First, the sample size was relatively small and may have led to selection bias of the patients because this was a single-center study and most patients might have visited various hospitals before they came to see our cornea specialist. Second, only four cases induced by bacteria were included in the study, which might limit the power to detect significant differences in the comparison among pathogen groups. Finally, it was a prospective cross-sectional study, and we did not follow up the patients to explore the effects of medical or surgical treatments on VRQOL. These shortcomings might be resolved by further prospective investigations designed with a longer follow-up period. In conclusion, IK, an acute or chronic vision-impairing ocular disease, has extensive effects on patients’ visual function and VRQOL. The present study showed that NEI VFQ-25 could be a useful and valid approach for assessing patient-reported vision function outcomes and vision-related QOL, which had correlations with the BCVA of the worse-seeing eye, duration of the disease, history of operation (for IK treatment), and gender. Early treatment should be encouraged to obtain a better visual prognosis and VR-QOL for patients with unilateral IK.
ACKNOWLEDGMENTS Yimin Li and Jiaxu Hong contributed equally to the article and should be considered first coauthors. This work was supported by grants from the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China (81020108017); the Key Clinic Medicine Research Program, the Ministry of Health, China (2012Y2014); National Science and Technology Research Program, the Ministry of Science and Technology, China (2012BAI08B01); National Natural Science Foundation of China (81170817, 81200658); and Scientific Research Program, Science and Technology Commission of Shanghai Municipality, Shanghai, China (13441900900, 13430720400, 134119a8800, 13430710500). The sponsor or funding organization had no role in the design or conduct of this research. The authors declare that no financial relationship exists with the organization that sponsored the research. Received March 8, 2013; accepted October 2, 2013.
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Jianjiang Xu Department of Ophthalmology Eye, Ear, Nose and Throat Hospital School of Shanghai Medicine Fudan University 83 Fenyang Rd Shanghai 200031 China e-mail: [email protected]
Optometry and Vision Science, Vol. 91, No. 3, March 2014
Copyright © American Academy of Optometry. Unauthorized reproduction of this article is prohibited.
