ARTICLE
Surgical outcomes after intraocular lens implantation for posterior lenticonus–related cataract according to preoperative lens status Byung Joo Lee, MD, Jeong Hun Kim, MD, Young Suk Yu, MD
PURPOSE: To address the surgical outcomes of pediatric patients with cataracts associated with posterior lenticonus who required cataract extraction and intraocular lens (IOL) implantation according to preoperative lens status. SETTING: Department of Ophthalmology, Seoul National University Children’s Hospital, Seoul, South Korea. DESIGN: Comparative case series. METHODS: Patients who had cataract extraction and IOL implantation for posterior lenticonus were divided into 2 groups according to the preoperative lens status. Clinical features and visual outcomes in both groups were comparatively analyzed. RESULTS: Forty-seven eyes of 43 patients were studied. Thirty-five eyes had lens opacities localized to the posterior pole, and 12 eyes presented with total opacity of the lens. Preexisting posterior capsule defect was identified intraoperatively in 11 eyes with total lens opacity. Eyes with preexisting posterior capsule defects more frequently required ciliary sulcus fixation of the IOL (PZ.01). The mean follow-up after cataract extraction was 66.9 months G 35.9 (SD). The mean final corrected distance visual acuity of patients with total opacity (0.37 G 0.57 logMAR) was better than that of patients with posterior polar opacity (0.56 G 0.50 logMAR), with borderline significance (PZ.05). CONCLUSIONS: A preexisting posterior capsule defect, found most often in eyes that presented with total lens opacity, could be an obstacle to capsular bag fixation of the IOL. Posterior lenticonus patients with total lens opacity had marginally significantly better visual outcomes than patients with posterior polar opacity. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. J Cataract Refract Surg 2014; 40:217–223 Q 2013 ASCRS and ESCRS
Posterior lenticonus is a rare congenital lenticular anomaly1 characterized by localized protrusion of the posterior lens capsule and cortex. Although there are many theories of what causes posterior lenticonus, including posterior polar traction of the lens by a hyaloid artery remnant,2,3 aberrant hyperplasia of posterior lens fibers,4,5 and weakness of the posterior lens capsule,6,7 the exact pathogenesis of posterior lenticonus remains unclear. In patients with posterior lenticonus, the typical localized and oil droplet–shaped protrusion of the lens induces refractive errors of lenticular origin, such as myopia and a high degree of astigmatism. As the
Q 2013 ASCRS and ESCRS Published by Elsevier Inc.
disease progresses, lens opacification may occur at the conical protrusion6 and is one of the major causes of posterior lenticonus–related visual disturbance. Typically, the opacity of the lens arises from the posterior pole and involves the lens cortex and subcapsular area; however, involvement of the fetal nucleus has also been reported.8 Lens opacities associated with posterior lenticonus are not always localized within the posterior pole, and total cataracts have also been associated with posterior lenticonus.9 In these patients, leukocoria may be a presenting symptom of posterior lenticonus.10 The diagnosis of posterior lenticonus is not as difficult if posterior conical protrusion of the lens is
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apparent preoperatively. However, cortical cataracts or total lens opacity may accompany posterior lenticonus in some patients.10–12 In patients with an atypical presentation, intraoperative findings are crucial for the diagnosis of posterior lenticonus. In fact, according to a case series that retrospectively studied Korean patients with posterior lenticonus–associated cataracts,13 in 15 (32.6%) of 46 eyes, posterior lenticonus was first diagnosed during cataract extraction. If a preexisting, sharply bordered defect of the posterior capsule involving the posterior pole of the lens is detected after aspiration of the lens cortex, the diagnosis can be posterior lenticonus.4,6,7 Most cases of posterior lenticonus are unilateral,7 and in some cases the lens opacity may be present at birth.14 Although amblyopia is common among patients with posterior lenticonus, the visual prognosis of posterior lenticonus is favorable after cataract surgery and visual penalization.12,15 However, factors affecting the visual prognosis are largely uncertain in patients with posterior lenticonus. The aim of this study was to address surgical results after cataract surgery and posterior chamber intraocular lens (PC IOL) implantation for posterior lenticonus and to analyze the visual outcomes according to the preoperative lens status. PATIENTS AND METHODS A retrospective review of medical records at Seoul National University Children's Hospital from January 1999 to December 2010 was performed to identify patients who had cataract extraction and PC IOL implantation for posterior lenticonus complicated by cataract. Ethical approval was obtained from the Institutional Review Board, Seoul National University Hospital. Patients with a follow-up of less than 12 months after cataract extraction and whose Snellen corrected distance visual acuity (CDVA) could not be measured at the final follow-up examinations were excluded. The diagnosis of posterior lenticonus was made based on preoperative and intraoperative findings. Posterior lenticonus was diagnosed preoperatively if localized conical protrusion of the posterior lens cortex and posterior capsule was observed on the preoperative slitlamp biomicroscopic examination. The intraoperative diagnosis of posterior
Submitted: November 26, 2012. Final revision submitted: July 17, 2013. Accepted: July 17, 2013. From the Department of Ophthalmology (Lee, Kim, Yu), Seoul National University College of Medicine, and the Seoul Artificial Eye Center (Kim, Yu), Seoul National University Hospital Clinical Research Institute, Seoul, South Korea. Corresponding author: Young Suk Yu, MD, Department of Ophthalmology, Seoul National University College of Medicine, number 28 Yongon-Dong, Chongno-Gu, Seoul 110-744, South Korea. E-mail: [email protected].
lenticonus was made when a typical cone-shaped protrusion of the posterior capsule or a sharply bordered defect of the posterior capsule involving the posterior pole of the lens was detected after uneventful aspiration of the lens cortex.
Data Collection The following preoperative, intraoperative, and postoperative data were collected through a retrospective review of medical records. The preoperative data included sex, age at presentation, laterality of disease, family history of pediatric cataract, underlying disease, accompanying eye disease, presenting symptoms, preoperative horizontal ocular alignment, preoperative lens status, preoperative CDVA, and preoperative management (including penalization, pharmacologic dilation of pupil, and correction of refractive error). All patients were placed into groups according to the preoperative lens status. Patients who had lens opacity not localized to the posterior pole and who had no red reflex on dilated fundus examination were in the total opacity group. Others with lens opacity localized to the posterior pole were in the posterior polar opacity group. Intraoperative data, such as age at cataract extraction, intraoperative status of the posterior lens capsule, and position and type of IOL, were also collected. The preoperative CDVA and final Snellen CDVA were converted to the logMAR scale for statistical analysis. The CDVA of patients who preoperatively were able to perceive light only was not converted to the logMAR scale.16
Surgical Technique and Postoperative Management Some patients with unilateral small opacity localized to the posterior pole of the lens were initially treated with nonsurgical methods (occlusion therapy and/or pharmacological dilation of pupil). All these patients ultimately had cataract extraction due to unresponsiveness or poor compliance. All surgical procedures were performed by the same experienced pediatric ophthalmologist (Y.S.Y.). For cataract extraction, a mechanical anterior capsulorhexis, irrigation/aspiration (I/A) of the lens, posterior capsulotomy, and anterior vitrectomy were performed through a superior scleral tunnel incision. In patients expected to have adequate posterior capsule support after cataract extraction, the PC IOL was fixated in the capsular bag. If the patient had an intact anterior capsule rim in the absence of sufficient posterior capsule support, the PC IOL was implanted in the ciliary sulcus. Because poly(methyl methacrylate) (PMMA) IOLs have been proven in pediatric eyes, a 1-piece PMMA IOL was used for in-the-bag and for sulcus fixation. Over a study period of 11 years, 3 types of 1-piece PMMA IOLs (811 B, Pharmacia & Upjohn, Inc.; LK55 A, Lucid Korea Co., Ltd.; and MZ60BD, Alcon Surgical, Inc.) were available at each timepoint. From 2008, foldable IOLs with acrylate optics were used. A 1-piece acrylate IOL (SA60AT, Alcon Surgical, Inc.) was used for in-the-bag placement, and a 3-piece acrylate IOL with PMMA haptics (MA60BM, Alcon Surgical, Inc.) was used for sulcus placement because it was expected that only the 3-piece acrylate IOL with PMMA haptics would provide adequate tension for stable sulcus fixation. Figure 1 shows a diagram of the IOLs used in the study. The postoperative refraction was
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Figure 1. The IOLs used in this study.
targeted based on the patient's age at surgery, and the IOL power was calculated using the SRK II formula.17 Patients in need of cataract extraction who were younger than 24 months first had cataract extraction without IOL implantation and then had delayed secondary IOL implantation after 24 months of age. After cataract extraction, the patient received full correction of refractive errors. If monocular amblyopia development was noted during the postoperative follow-up, patients were treated with optical penalization. The secondary PC IOL was fixated in the capsular bag if the anterior capsule and posterior capsule of the lens were easily separable with a microvitreoretinal blade and the posterior capsule provided adequate alternative support. If the patient failed to satisfy any of the above conditions, the PC IOL was fixated in the ciliary sulcus.
Statistical Analysis Statistical analysis was performed using SPSS for Windows software (version 12.0, SPSS, Inc.). Factors that affected the surgeon's choice for IOL position were analyzed using the Fisher exact test. To address the visual outcomes according to the preoperative lens status, demographic data in both groups were analyzed with the chi-square test. The Fisher exact test was applied if 1 or more of the cells with expected frequencies of less than 5 were noted. The age at presentation and cataract extraction, follow-up period, and final CDVA in both groups were compared using the Mann-Whitney U test. The cutoff value of statistical significance was a P value of less than 0.05.
RESULTS Forty-seven eyes of 43 patients were included in the analysis. Most cases were unilateral (39 eyes of 39 unilateral cases; 8 eyes of 4 bilateral cases). Two bilateral cases had a family history of pediatric cataract. Two patients had underlying systemic disease; 1
bilateral case had cerebral palsy and 1 unilateral case had an atrial septal defect. Table 1 shows the preoperative characteristics of patients. Ocular misalignment and leukocoria were the 2 most common presenting symptoms. The preoperative CDVA in 24 eyes (23 patients) with visual acuities measurable with the Snellen chart ranged between 0.4 logMAR and 3.0 logMAR. In 20 patients (23 eyes) not able to cooperate with testing using the Snellen chart, the preoperative CDVA was measured with the fixation preference test. Conservative management was attempted before surgery in 12 unilateral cases with lens opacities in the posterior pole. The mean duration of nonsurgical treatment in these patients was 8.8 G 7.8 months. During uneventful cataract extraction, the typical sharp-bordered preexisting posterior capsule defect involving the posterior pole of the lens was observed in 12 eyes. Of the 12 eyes in the total opacity group, 11 were intraoperatively diagnosed with posterior lenticonus based on the finding of a typical preexisting posterior capsule defect. In the remaining 1 eye with total lens opacity, this typical feature was not found; however, localized conical bulging of the posterior capsule was observed after I/A of the lens cortex. Thirty-six eyes received simultaneous IOL implantation with cataract extraction, and 11 eyes received secondary IOL implantation after 24 months of age. In all cases, PC IOL implantation was successful using anterior or posterior capsule support without the need for suture fixation (Table 2). The presence of preexisting posterior capsule defects found in posterior lenticonus patients made it
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Table 1. Demographics. Parameter
Value
Laterality of posterior lenticonus (eyes/patients) Unilateral Bilateral Sex (patients) Male Female Family history of pediatric cataract (patients) Yes No Mean age (mo) G SD At presentation At cataract extraction Presenting symptoms, eyes (%) Ocular misalignment Incidentally found on routine checkup Leukocoria Photophobia Subjective decrease in vision Poor eye contact Preoperative CDVA With Snellen chart (logMAR) (24 eyes/23 patients) Mean G SD (22 eyes/21 patients) Light perception (eyes/patients) With fixation preference test (23 eyes/20 patients) Good (eyes) Moderate (eyes) Poor (eyes) Preoperative horizontal ocular alignment (patients) Orthotropia Heterotropia/heterophoria Exotropia/exophoria Esotropia/esophoria NA Preoperative lens status, eyes (%) Posterior polar opacity Total opacity
39/39 8/4 31 12 2 41 32.7 G 28.3 40.4 G 32.1 14 (29.8) 12 (25.5) 10 (21.3) 5 (10.6) 3 (6.4) 3 (6.4)
1.14 G 0.68 2/2
0 7 16
19 21 2 1 35 (74.5) 12 (25.5)
CDVA Z corrected distance visual acuity; NA Z not available
very difficult to implant a PC IOL in the capsular bag. However, capsular bag fixation of the IOL was performed safely in some eyes with a posterior capsule defect (Table 2). The decision to simultaneously implant a PC IOL and perform cataract surgery in patients with posterior lenticonus–associated cataract was not affected by the presence of a preexisting posterior capsule defect (PZ0.58, Fisher exact test). The CDVA at the final visit ranged between 0.1 logMAR and 2.0 logMAR (mean 0.51 logMAR G 0.52 [SD]). Of the 47 total eyes, 26 achieved a final CDVA of 20/40 or better. The mean follow-up after cataract
extraction was 66.9 G 35.9 months (range 12 to 144 months). Table 3 compares the demographic features, clinical features, and visual outcomes in the total opacity group and the posterior polar opacity group. There was no between-group difference in the laterality of the disease, preoperative horizontal ocular alignment, or mean follow-up after cataract extraction. There was no significant difference in the age at presentation between the 2 groups; however, the mean age at cataract surgery was significantly higher in the posterior polar opacity group, a finding that might be associated with the trial of initial nonsurgical treatment in some patients in the posterior polar opacity group. In eyes with total opacity, a preexisting posterior capsule defect was detected intraoperatively. However, 1 of 35 eyes in the posterior polar opacity group had a preexisting posterior capsule defect that was detected before surgery. Patients in the total opacity group had sulcus fixation of the PC IOL more frequently than the patients in the posterior polar opacity group. The mean CDVA in the total opacity group at the final visit was significantly better than in the posterior polar opacity group (Table 3 and Figure 2). The ratio of patients who achieved a final CDVA of 20/40 or better was also higher in the total opacity group; however, the Fisher exact test showed that the difference was not statistically significant. DISCUSSION Although amblyopia commonly accompanies posterior lenticonus in patients, it is well known that there is a generally favorable outcome in terms of visual prognosis after cataract surgery and treatment of amblyopia.12,18 Prognostic factors determining visual outcomes in posterior lenticonus patients are largely unknown. In our previous study,13 age at diagnosis
Table 2. Factors affecting the surgeon's choice of IOL position.
Factor Eyes (n) Primary versus secondary implantation of IOL, n (%) Primary implantation Secondary implantation Preexisting posterior capsule defect, n (%) Present Not present
Capsular Ciliary Sulcus P Bag Fixation Fixation Value* 32
15
29 (90.6) 3 (9.4)
7 (46.7) 8 (53.3) .01*
4 (12.5) 28 (87.5)
IOL Z intraocular lens; n Z number of eyes *Fisher exact test
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d .00*
8 (53.3) 7 (46.7)
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Table 3. Differences in clinical features and visual outcomes according to the preoperative lens status. Parameter Eyes (n) Mean age (mo) At presentation At cataract extraction Laterality of posterior lenticonus, n (%) Monocular Binocular Preoperative CDVA (logMAR) With Snellen chart Mean G SD (n) Light perception (n) With fixation preference test (n) Good Moderate Poor Preoperative horizontal ocular alignment, n (%) Orthotropia Heterotropia Exotropia/exophoria Esotropia/esophoria NA Posterior capsule defect as intraoperative finding, n (%) IOL implantation, n (%) Primary Secondary IOL position, n (%) Sulcus In the bag Final CDVA (logMAR) Mean G SD Median R20/40 Mean follow-up after cataract extraction (mo) G SD
Total Opacity
Posterior Polar Opacity
P Value
12
35
d
24.8 G 17.4 27.0 G 16.7
35.4 G 31.0 45.1 G 34.9
.21* .04* .33†
9 (75.0) 3 (25.0)
30 (85.7) 5 (14.3) d
2.50 G 0.71 (2) 2
1.00 G 0.52 (20) 0
0 0 8
0 7 8 .45z,x
6 (50.0)
14 (4.0)
6 (5.0) 0 0 11 (91.6%)
17 (48.6) 2 (5.7) 2 (5.7) 1 eye (2.9)
9 (75.0) 3 (25.0)
27 (77.1) 8 (22.9)
.00† .58†
.03† 7 (58.3) 5 (41.7)
8 (22.9) 27 (77.1)
0.37 G 0.57 0.16 8 (66.7) 69.4 G 32.1
0.56 G 0.50 0.3 18 (51) 66.1 G 37.5
.05* .28† .27*
CDVA Z corrected distance visual acuity; n Z number of eyes; NA Z not available *Mann-Whitney U test † Fisher exact test z Orthotropia versus heterotropia x Chi-square test
was significantly associated with visual outcome; however, no statistically significant association was found in another study.18 In our current study, 55.3% of patients achieved a final CDVA of 20/40 or better, a result that is comparable to findings in previous studies.12,15 An unexpected trend in this series was that patients with total lens opacities had a better final visual outcome than patients with posterior polar opacity. It has been reported that the development of a preexisting posterior capsule defect in patients with congenital cataract can result in a progression to total cataract and that this process is related to a rapid progression of lens opacity.19,20 Because long-standing total deprivation of visual stimulus is related to a poor visual prognosis in the pediatric population, we postulated
that the better mean visual acuity in patients with total opacity might imply an acute progression of this change (opacification of the lens). Earlier surgery in the total opacity group, which is presumably related to the early detection of cataract, may also be a factor in the better visual outcome. Initial conservative management in some patients in the posterior polar opacity group might be responsible for the late surgical intervention. It is known that inadequate capsule support in patients with posterior lenticonus sometimes makes it difficult to implant a PC IOL.21 According to our results, secondary implantation of the IOL and the presence of a preexisting posterior capsule defect made capsular bag fixation difficult. Because there was no association between the presence of a preexisting
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Figure 2. Comparison of the final CDVA after cataract extraction and IOL implantation. An asterisk denotes the Mann-Whitney U test (CDVA Z corrected distance visual acuity).
posterior capsule defect and the decision concerning simultaneous IOL implantation and cataract extraction, we surmise that a preexisting capsule defect alone could be an obstacle for capsular bag fixation of the IOL. Although posterior capsulotomy was performed in every patient, a preexisting posterior capsule defect was significantly associated with inadequate posterior capsule support for PC IOL implantation. This may be due to the eccentricity of the capsule defect from the posterior pole of the lens capsule. Patients with total lens opacity also required ciliary sulcus fixation of the PC IOL more frequently than patients with lens opacity confined to the posterior pole. Most patients who had preoperative total lens opacity tended to have a preexisting posterior capsule defect, which was in itself an obstacle for capsular bag fixation of the PC IOL, especially in cases with eccentric defects. However, it was possible to perform PC IOL implantation using anterior or posterior capsule support in every patient without the need for suture fixation of the IOL. In our study, 12 of 47 eyes with posterior lenticonus had total lens opacity at the preoperative examination. The diagnosis of posterior lenticonus was confirmed by intraoperative findings in those patients. There have been many suggestions about the pathogenesis of posterior lenticonus; however, controversy remains with respect to the development of the cone and lens opacity.2–5,7 In this study, of 12 eyes with total lens opacity, all eyes except 1 had a preexisting posterior capsule defect while only 1 of 35 eyes of patients with posterior polar opacity had a preexisting posterior capsule defect. If lens opacity in some posterior lenticonus patients starts from posterior polar opacity and progresses to total lens opacity, we can presume that once there is a preexisting posterior capsule defect, the development of total lens opacity is rapid. As mentioned, the unexpected good visual outcomes
in patients with total opacity may also be indirect evidence of acute onset of this change. Combined with the frequent association with a preexisting posterior capsule defect in patients with total lens opacity, this could provide a clue to a better understanding of the pathogenesis of cataract in posterior lenticonus. In conclusion, a considerable number of patients who had a confirmative diagnosis of posterior lenticonus after cataract surgery had total opacity of the crystalline lens at the preoperative examination. Careful inspection of the posterior capsule during surgery is necessary for intraoperative diagnosis of posterior lenticonus, especially in patients with total lens opacity. In addition, in posterior lenticonus patients, capsular bag fixation of the IOL is sometimes difficult because of a preexisting posterior capsule defect. However, in these cases, ciliary sulcus fixation using anterior capsule support is a safe alternative. When pediatric patients presenting with total lens opacity are intraoperatively diagnosed with posterior lenticonus, we can expect a favorable visual outcome with cataract surgery followed by amblyopia treatment. WHAT WAS KNOWN Although not that common, total cataracts are observed in some patients with posterior lenticonus. It is generally accepted that the visual prognosis of posterior lenticonus-associated cataract is fair. However, the factors determining the visual prognosis after cataract surgery for posterior lenticonus–associated cataract have not been clearly documented. WHAT THIS PAPER ADDS Unexpectedly, the final visual outcome of the patients with total lens opacity preoperatively was better than that of patients with posterior polar opacity. Patients with total opacity were more likely to have preexisting posterior capsule defect, which was an obvious obstacle to the capsular bag fixation of IOL. REFERENCES 1. Butler TH. Lenticonus posterior; report of six cases. Arch Ophthalmol 1930; 3:425–436 2. Kilty LA, Hiles DA. Unilateral posterior lenticonus with persistent hyaloid artery remnant [letter]. Am J Ophthalmol 1993; 116:104–106 3. Iwase T, Oveson BC. Pigment inside the lens associated with lenticonus. J Cataract Refract Surg 2011; 37:2222–2223 4. Franceschetti A, Rickli H. Posterior (eccentric) lenticonus; report of first case with clinical and histological findings. AMA Arch Ophthalmol 1954; 51:499–508 5. Makley TA Jr. Posterior lenticonus; report of a case with histologic findings. Am J Ophthalmol 1955; 39:308–312
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6. Khalil M, Saheb N. Posterior lenticonus. Ophthalmology 1984; 91:; 1429–1430, 43A 7. Crouch ER Jr, Parks MM. Management of posterior lenticonus complicated by unilateral cataract. Am J Ophthalmol 1978; 85:503–508 8. Singh D, Singh D. Posterior lenticonus with involvement of foetal nucleus. Br J Ophthalmol 1970; 54:136–137. Available at: http:// www.ncbi.nlm.nih.gov/pmc/articles/PMC1207650/pdf/brjopthal 00314-0064.pdf. Accessed October 26, 2013 9. Amaya L, Taylor D, Russell-Eggitt I, Nischal KK, Lengyel D. The morphology and natural history of childhood cataracts. Surv Ophthalmol 2003; 48:125–144 10. Fett D, Paez JH, Isenberg S. Infantile leukocoria caused by posterior lenticonus. Ann Ophthalmol 1984; 16:; 679–680, 684 11. Kalyanasundaram TS, Bearn MA. Surgical identification of posterior lenticonus. J Cataract Refract Surg 2002; 28: 1069–1070 12. Cheng KP, Hiles DA, Biglan AW, Pettapiece MC. Management of posterior lenticonus. J Pediatr Ophthalmol Strabismus 1991; 28:143–149; discussion 150 13. Kim MJ, Kim JH, Yu YS. [The surgical management of posterior lenticonus associated with pediatric cataract]. [Korean]. J Korean Ophthalmol Soc 2007; 48:649–654 14. Seidenberg K, Ludwig IH. A newborn with posterior lenticonus [letter]. Am J Ophthalmol 1993; 115:543–544 15. Parks MM. Visual results in aphakic children. Am J Ophthalmol 1982; 94:441–449 16. Holladay JT. Proper method for calculating average visual acuity. J Refract Surg 1997; 13:388–391. Available at: http://www.
17.
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docholladay.com/publications/propermethodforcalculating.pdf. Accessed October 26, 2013 Sanders DR, Retzlaff J, Kraff MC. Comparison of the SRK IIä formula and other second generation formulas. J Cataract Refract Surg 1988; 14:136–141 Travi GM, Schnall BM, Lehman SS, Kelly CJ, Hug D, Hirakata VN, Calhoun JH. Visual outcome and success of amblyopia treatment in unilateral small posterior lens opacities and lenticonus initially treated nonsurgically. J AAPOS 2005; 9:449–454 Vasavada AR, Praveen MR, Nath V, Dave K. Diagnosis and management of congenital cataract with preexisting posterior capsule defect. J Cataract Refract Surg 2004; 30:403–408 Vasavada AR, Praveen MR, Dholakia SA, Trivedi RH. Preexisting posterior capsule defect progressing to white mature cataract. J AAPOS 2007; 11:192–194 Simons BD, Flynn HW Jr. A pars plana approach for cataract surgery in posterior lenticonus. Am J Ophthalmol 1997; 124:695–696
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First author: Byung Joo Lee, MD Department of Ophthalmology, Seoul National University College of Medicine, Seoul, South Korea
Surgical outcomes after intraocular lens implantation for posterior lenticonus–related cataract according to preoperative lens status Byung Joo Lee, MD, Jeong Hun Kim, MD, Young Suk Yu, MD
PURPOSE: To address the surgical outcomes of pediatric patients with cataracts associated with posterior lenticonus who required cataract extraction and intraocular lens (IOL) implantation according to preoperative lens status. SETTING: Department of Ophthalmology, Seoul National University Children’s Hospital, Seoul, South Korea. DESIGN: Comparative case series. METHODS: Patients who had cataract extraction and IOL implantation for posterior lenticonus were divided into 2 groups according to the preoperative lens status. Clinical features and visual outcomes in both groups were comparatively analyzed. RESULTS: Forty-seven eyes of 43 patients were studied. Thirty-five eyes had lens opacities localized to the posterior pole, and 12 eyes presented with total opacity of the lens. Preexisting posterior capsule defect was identified intraoperatively in 11 eyes with total lens opacity. Eyes with preexisting posterior capsule defects more frequently required ciliary sulcus fixation of the IOL (PZ.01). The mean follow-up after cataract extraction was 66.9 months G 35.9 (SD). The mean final corrected distance visual acuity of patients with total opacity (0.37 G 0.57 logMAR) was better than that of patients with posterior polar opacity (0.56 G 0.50 logMAR), with borderline significance (PZ.05). CONCLUSIONS: A preexisting posterior capsule defect, found most often in eyes that presented with total lens opacity, could be an obstacle to capsular bag fixation of the IOL. Posterior lenticonus patients with total lens opacity had marginally significantly better visual outcomes than patients with posterior polar opacity. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. J Cataract Refract Surg 2014; 40:217–223 Q 2013 ASCRS and ESCRS
Posterior lenticonus is a rare congenital lenticular anomaly1 characterized by localized protrusion of the posterior lens capsule and cortex. Although there are many theories of what causes posterior lenticonus, including posterior polar traction of the lens by a hyaloid artery remnant,2,3 aberrant hyperplasia of posterior lens fibers,4,5 and weakness of the posterior lens capsule,6,7 the exact pathogenesis of posterior lenticonus remains unclear. In patients with posterior lenticonus, the typical localized and oil droplet–shaped protrusion of the lens induces refractive errors of lenticular origin, such as myopia and a high degree of astigmatism. As the
Q 2013 ASCRS and ESCRS Published by Elsevier Inc.
disease progresses, lens opacification may occur at the conical protrusion6 and is one of the major causes of posterior lenticonus–related visual disturbance. Typically, the opacity of the lens arises from the posterior pole and involves the lens cortex and subcapsular area; however, involvement of the fetal nucleus has also been reported.8 Lens opacities associated with posterior lenticonus are not always localized within the posterior pole, and total cataracts have also been associated with posterior lenticonus.9 In these patients, leukocoria may be a presenting symptom of posterior lenticonus.10 The diagnosis of posterior lenticonus is not as difficult if posterior conical protrusion of the lens is
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apparent preoperatively. However, cortical cataracts or total lens opacity may accompany posterior lenticonus in some patients.10–12 In patients with an atypical presentation, intraoperative findings are crucial for the diagnosis of posterior lenticonus. In fact, according to a case series that retrospectively studied Korean patients with posterior lenticonus–associated cataracts,13 in 15 (32.6%) of 46 eyes, posterior lenticonus was first diagnosed during cataract extraction. If a preexisting, sharply bordered defect of the posterior capsule involving the posterior pole of the lens is detected after aspiration of the lens cortex, the diagnosis can be posterior lenticonus.4,6,7 Most cases of posterior lenticonus are unilateral,7 and in some cases the lens opacity may be present at birth.14 Although amblyopia is common among patients with posterior lenticonus, the visual prognosis of posterior lenticonus is favorable after cataract surgery and visual penalization.12,15 However, factors affecting the visual prognosis are largely uncertain in patients with posterior lenticonus. The aim of this study was to address surgical results after cataract surgery and posterior chamber intraocular lens (PC IOL) implantation for posterior lenticonus and to analyze the visual outcomes according to the preoperative lens status. PATIENTS AND METHODS A retrospective review of medical records at Seoul National University Children's Hospital from January 1999 to December 2010 was performed to identify patients who had cataract extraction and PC IOL implantation for posterior lenticonus complicated by cataract. Ethical approval was obtained from the Institutional Review Board, Seoul National University Hospital. Patients with a follow-up of less than 12 months after cataract extraction and whose Snellen corrected distance visual acuity (CDVA) could not be measured at the final follow-up examinations were excluded. The diagnosis of posterior lenticonus was made based on preoperative and intraoperative findings. Posterior lenticonus was diagnosed preoperatively if localized conical protrusion of the posterior lens cortex and posterior capsule was observed on the preoperative slitlamp biomicroscopic examination. The intraoperative diagnosis of posterior
Submitted: November 26, 2012. Final revision submitted: July 17, 2013. Accepted: July 17, 2013. From the Department of Ophthalmology (Lee, Kim, Yu), Seoul National University College of Medicine, and the Seoul Artificial Eye Center (Kim, Yu), Seoul National University Hospital Clinical Research Institute, Seoul, South Korea. Corresponding author: Young Suk Yu, MD, Department of Ophthalmology, Seoul National University College of Medicine, number 28 Yongon-Dong, Chongno-Gu, Seoul 110-744, South Korea. E-mail: [email protected].
lenticonus was made when a typical cone-shaped protrusion of the posterior capsule or a sharply bordered defect of the posterior capsule involving the posterior pole of the lens was detected after uneventful aspiration of the lens cortex.
Data Collection The following preoperative, intraoperative, and postoperative data were collected through a retrospective review of medical records. The preoperative data included sex, age at presentation, laterality of disease, family history of pediatric cataract, underlying disease, accompanying eye disease, presenting symptoms, preoperative horizontal ocular alignment, preoperative lens status, preoperative CDVA, and preoperative management (including penalization, pharmacologic dilation of pupil, and correction of refractive error). All patients were placed into groups according to the preoperative lens status. Patients who had lens opacity not localized to the posterior pole and who had no red reflex on dilated fundus examination were in the total opacity group. Others with lens opacity localized to the posterior pole were in the posterior polar opacity group. Intraoperative data, such as age at cataract extraction, intraoperative status of the posterior lens capsule, and position and type of IOL, were also collected. The preoperative CDVA and final Snellen CDVA were converted to the logMAR scale for statistical analysis. The CDVA of patients who preoperatively were able to perceive light only was not converted to the logMAR scale.16
Surgical Technique and Postoperative Management Some patients with unilateral small opacity localized to the posterior pole of the lens were initially treated with nonsurgical methods (occlusion therapy and/or pharmacological dilation of pupil). All these patients ultimately had cataract extraction due to unresponsiveness or poor compliance. All surgical procedures were performed by the same experienced pediatric ophthalmologist (Y.S.Y.). For cataract extraction, a mechanical anterior capsulorhexis, irrigation/aspiration (I/A) of the lens, posterior capsulotomy, and anterior vitrectomy were performed through a superior scleral tunnel incision. In patients expected to have adequate posterior capsule support after cataract extraction, the PC IOL was fixated in the capsular bag. If the patient had an intact anterior capsule rim in the absence of sufficient posterior capsule support, the PC IOL was implanted in the ciliary sulcus. Because poly(methyl methacrylate) (PMMA) IOLs have been proven in pediatric eyes, a 1-piece PMMA IOL was used for in-the-bag and for sulcus fixation. Over a study period of 11 years, 3 types of 1-piece PMMA IOLs (811 B, Pharmacia & Upjohn, Inc.; LK55 A, Lucid Korea Co., Ltd.; and MZ60BD, Alcon Surgical, Inc.) were available at each timepoint. From 2008, foldable IOLs with acrylate optics were used. A 1-piece acrylate IOL (SA60AT, Alcon Surgical, Inc.) was used for in-the-bag placement, and a 3-piece acrylate IOL with PMMA haptics (MA60BM, Alcon Surgical, Inc.) was used for sulcus placement because it was expected that only the 3-piece acrylate IOL with PMMA haptics would provide adequate tension for stable sulcus fixation. Figure 1 shows a diagram of the IOLs used in the study. The postoperative refraction was
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Figure 1. The IOLs used in this study.
targeted based on the patient's age at surgery, and the IOL power was calculated using the SRK II formula.17 Patients in need of cataract extraction who were younger than 24 months first had cataract extraction without IOL implantation and then had delayed secondary IOL implantation after 24 months of age. After cataract extraction, the patient received full correction of refractive errors. If monocular amblyopia development was noted during the postoperative follow-up, patients were treated with optical penalization. The secondary PC IOL was fixated in the capsular bag if the anterior capsule and posterior capsule of the lens were easily separable with a microvitreoretinal blade and the posterior capsule provided adequate alternative support. If the patient failed to satisfy any of the above conditions, the PC IOL was fixated in the ciliary sulcus.
Statistical Analysis Statistical analysis was performed using SPSS for Windows software (version 12.0, SPSS, Inc.). Factors that affected the surgeon's choice for IOL position were analyzed using the Fisher exact test. To address the visual outcomes according to the preoperative lens status, demographic data in both groups were analyzed with the chi-square test. The Fisher exact test was applied if 1 or more of the cells with expected frequencies of less than 5 were noted. The age at presentation and cataract extraction, follow-up period, and final CDVA in both groups were compared using the Mann-Whitney U test. The cutoff value of statistical significance was a P value of less than 0.05.
RESULTS Forty-seven eyes of 43 patients were included in the analysis. Most cases were unilateral (39 eyes of 39 unilateral cases; 8 eyes of 4 bilateral cases). Two bilateral cases had a family history of pediatric cataract. Two patients had underlying systemic disease; 1
bilateral case had cerebral palsy and 1 unilateral case had an atrial septal defect. Table 1 shows the preoperative characteristics of patients. Ocular misalignment and leukocoria were the 2 most common presenting symptoms. The preoperative CDVA in 24 eyes (23 patients) with visual acuities measurable with the Snellen chart ranged between 0.4 logMAR and 3.0 logMAR. In 20 patients (23 eyes) not able to cooperate with testing using the Snellen chart, the preoperative CDVA was measured with the fixation preference test. Conservative management was attempted before surgery in 12 unilateral cases with lens opacities in the posterior pole. The mean duration of nonsurgical treatment in these patients was 8.8 G 7.8 months. During uneventful cataract extraction, the typical sharp-bordered preexisting posterior capsule defect involving the posterior pole of the lens was observed in 12 eyes. Of the 12 eyes in the total opacity group, 11 were intraoperatively diagnosed with posterior lenticonus based on the finding of a typical preexisting posterior capsule defect. In the remaining 1 eye with total lens opacity, this typical feature was not found; however, localized conical bulging of the posterior capsule was observed after I/A of the lens cortex. Thirty-six eyes received simultaneous IOL implantation with cataract extraction, and 11 eyes received secondary IOL implantation after 24 months of age. In all cases, PC IOL implantation was successful using anterior or posterior capsule support without the need for suture fixation (Table 2). The presence of preexisting posterior capsule defects found in posterior lenticonus patients made it
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Table 1. Demographics. Parameter
Value
Laterality of posterior lenticonus (eyes/patients) Unilateral Bilateral Sex (patients) Male Female Family history of pediatric cataract (patients) Yes No Mean age (mo) G SD At presentation At cataract extraction Presenting symptoms, eyes (%) Ocular misalignment Incidentally found on routine checkup Leukocoria Photophobia Subjective decrease in vision Poor eye contact Preoperative CDVA With Snellen chart (logMAR) (24 eyes/23 patients) Mean G SD (22 eyes/21 patients) Light perception (eyes/patients) With fixation preference test (23 eyes/20 patients) Good (eyes) Moderate (eyes) Poor (eyes) Preoperative horizontal ocular alignment (patients) Orthotropia Heterotropia/heterophoria Exotropia/exophoria Esotropia/esophoria NA Preoperative lens status, eyes (%) Posterior polar opacity Total opacity
39/39 8/4 31 12 2 41 32.7 G 28.3 40.4 G 32.1 14 (29.8) 12 (25.5) 10 (21.3) 5 (10.6) 3 (6.4) 3 (6.4)
1.14 G 0.68 2/2
0 7 16
19 21 2 1 35 (74.5) 12 (25.5)
CDVA Z corrected distance visual acuity; NA Z not available
very difficult to implant a PC IOL in the capsular bag. However, capsular bag fixation of the IOL was performed safely in some eyes with a posterior capsule defect (Table 2). The decision to simultaneously implant a PC IOL and perform cataract surgery in patients with posterior lenticonus–associated cataract was not affected by the presence of a preexisting posterior capsule defect (PZ0.58, Fisher exact test). The CDVA at the final visit ranged between 0.1 logMAR and 2.0 logMAR (mean 0.51 logMAR G 0.52 [SD]). Of the 47 total eyes, 26 achieved a final CDVA of 20/40 or better. The mean follow-up after cataract
extraction was 66.9 G 35.9 months (range 12 to 144 months). Table 3 compares the demographic features, clinical features, and visual outcomes in the total opacity group and the posterior polar opacity group. There was no between-group difference in the laterality of the disease, preoperative horizontal ocular alignment, or mean follow-up after cataract extraction. There was no significant difference in the age at presentation between the 2 groups; however, the mean age at cataract surgery was significantly higher in the posterior polar opacity group, a finding that might be associated with the trial of initial nonsurgical treatment in some patients in the posterior polar opacity group. In eyes with total opacity, a preexisting posterior capsule defect was detected intraoperatively. However, 1 of 35 eyes in the posterior polar opacity group had a preexisting posterior capsule defect that was detected before surgery. Patients in the total opacity group had sulcus fixation of the PC IOL more frequently than the patients in the posterior polar opacity group. The mean CDVA in the total opacity group at the final visit was significantly better than in the posterior polar opacity group (Table 3 and Figure 2). The ratio of patients who achieved a final CDVA of 20/40 or better was also higher in the total opacity group; however, the Fisher exact test showed that the difference was not statistically significant. DISCUSSION Although amblyopia commonly accompanies posterior lenticonus in patients, it is well known that there is a generally favorable outcome in terms of visual prognosis after cataract surgery and treatment of amblyopia.12,18 Prognostic factors determining visual outcomes in posterior lenticonus patients are largely unknown. In our previous study,13 age at diagnosis
Table 2. Factors affecting the surgeon's choice of IOL position.
Factor Eyes (n) Primary versus secondary implantation of IOL, n (%) Primary implantation Secondary implantation Preexisting posterior capsule defect, n (%) Present Not present
Capsular Ciliary Sulcus P Bag Fixation Fixation Value* 32
15
29 (90.6) 3 (9.4)
7 (46.7) 8 (53.3) .01*
4 (12.5) 28 (87.5)
IOL Z intraocular lens; n Z number of eyes *Fisher exact test
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d .00*
8 (53.3) 7 (46.7)
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Table 3. Differences in clinical features and visual outcomes according to the preoperative lens status. Parameter Eyes (n) Mean age (mo) At presentation At cataract extraction Laterality of posterior lenticonus, n (%) Monocular Binocular Preoperative CDVA (logMAR) With Snellen chart Mean G SD (n) Light perception (n) With fixation preference test (n) Good Moderate Poor Preoperative horizontal ocular alignment, n (%) Orthotropia Heterotropia Exotropia/exophoria Esotropia/esophoria NA Posterior capsule defect as intraoperative finding, n (%) IOL implantation, n (%) Primary Secondary IOL position, n (%) Sulcus In the bag Final CDVA (logMAR) Mean G SD Median R20/40 Mean follow-up after cataract extraction (mo) G SD
Total Opacity
Posterior Polar Opacity
P Value
12
35
d
24.8 G 17.4 27.0 G 16.7
35.4 G 31.0 45.1 G 34.9
.21* .04* .33†
9 (75.0) 3 (25.0)
30 (85.7) 5 (14.3) d
2.50 G 0.71 (2) 2
1.00 G 0.52 (20) 0
0 0 8
0 7 8 .45z,x
6 (50.0)
14 (4.0)
6 (5.0) 0 0 11 (91.6%)
17 (48.6) 2 (5.7) 2 (5.7) 1 eye (2.9)
9 (75.0) 3 (25.0)
27 (77.1) 8 (22.9)
.00† .58†
.03† 7 (58.3) 5 (41.7)
8 (22.9) 27 (77.1)
0.37 G 0.57 0.16 8 (66.7) 69.4 G 32.1
0.56 G 0.50 0.3 18 (51) 66.1 G 37.5
.05* .28† .27*
CDVA Z corrected distance visual acuity; n Z number of eyes; NA Z not available *Mann-Whitney U test † Fisher exact test z Orthotropia versus heterotropia x Chi-square test
was significantly associated with visual outcome; however, no statistically significant association was found in another study.18 In our current study, 55.3% of patients achieved a final CDVA of 20/40 or better, a result that is comparable to findings in previous studies.12,15 An unexpected trend in this series was that patients with total lens opacities had a better final visual outcome than patients with posterior polar opacity. It has been reported that the development of a preexisting posterior capsule defect in patients with congenital cataract can result in a progression to total cataract and that this process is related to a rapid progression of lens opacity.19,20 Because long-standing total deprivation of visual stimulus is related to a poor visual prognosis in the pediatric population, we postulated
that the better mean visual acuity in patients with total opacity might imply an acute progression of this change (opacification of the lens). Earlier surgery in the total opacity group, which is presumably related to the early detection of cataract, may also be a factor in the better visual outcome. Initial conservative management in some patients in the posterior polar opacity group might be responsible for the late surgical intervention. It is known that inadequate capsule support in patients with posterior lenticonus sometimes makes it difficult to implant a PC IOL.21 According to our results, secondary implantation of the IOL and the presence of a preexisting posterior capsule defect made capsular bag fixation difficult. Because there was no association between the presence of a preexisting
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Figure 2. Comparison of the final CDVA after cataract extraction and IOL implantation. An asterisk denotes the Mann-Whitney U test (CDVA Z corrected distance visual acuity).
posterior capsule defect and the decision concerning simultaneous IOL implantation and cataract extraction, we surmise that a preexisting capsule defect alone could be an obstacle for capsular bag fixation of the IOL. Although posterior capsulotomy was performed in every patient, a preexisting posterior capsule defect was significantly associated with inadequate posterior capsule support for PC IOL implantation. This may be due to the eccentricity of the capsule defect from the posterior pole of the lens capsule. Patients with total lens opacity also required ciliary sulcus fixation of the PC IOL more frequently than patients with lens opacity confined to the posterior pole. Most patients who had preoperative total lens opacity tended to have a preexisting posterior capsule defect, which was in itself an obstacle for capsular bag fixation of the PC IOL, especially in cases with eccentric defects. However, it was possible to perform PC IOL implantation using anterior or posterior capsule support in every patient without the need for suture fixation of the IOL. In our study, 12 of 47 eyes with posterior lenticonus had total lens opacity at the preoperative examination. The diagnosis of posterior lenticonus was confirmed by intraoperative findings in those patients. There have been many suggestions about the pathogenesis of posterior lenticonus; however, controversy remains with respect to the development of the cone and lens opacity.2–5,7 In this study, of 12 eyes with total lens opacity, all eyes except 1 had a preexisting posterior capsule defect while only 1 of 35 eyes of patients with posterior polar opacity had a preexisting posterior capsule defect. If lens opacity in some posterior lenticonus patients starts from posterior polar opacity and progresses to total lens opacity, we can presume that once there is a preexisting posterior capsule defect, the development of total lens opacity is rapid. As mentioned, the unexpected good visual outcomes
in patients with total opacity may also be indirect evidence of acute onset of this change. Combined with the frequent association with a preexisting posterior capsule defect in patients with total lens opacity, this could provide a clue to a better understanding of the pathogenesis of cataract in posterior lenticonus. In conclusion, a considerable number of patients who had a confirmative diagnosis of posterior lenticonus after cataract surgery had total opacity of the crystalline lens at the preoperative examination. Careful inspection of the posterior capsule during surgery is necessary for intraoperative diagnosis of posterior lenticonus, especially in patients with total lens opacity. In addition, in posterior lenticonus patients, capsular bag fixation of the IOL is sometimes difficult because of a preexisting posterior capsule defect. However, in these cases, ciliary sulcus fixation using anterior capsule support is a safe alternative. When pediatric patients presenting with total lens opacity are intraoperatively diagnosed with posterior lenticonus, we can expect a favorable visual outcome with cataract surgery followed by amblyopia treatment. WHAT WAS KNOWN Although not that common, total cataracts are observed in some patients with posterior lenticonus. It is generally accepted that the visual prognosis of posterior lenticonus-associated cataract is fair. However, the factors determining the visual prognosis after cataract surgery for posterior lenticonus–associated cataract have not been clearly documented. WHAT THIS PAPER ADDS Unexpectedly, the final visual outcome of the patients with total lens opacity preoperatively was better than that of patients with posterior polar opacity. Patients with total opacity were more likely to have preexisting posterior capsule defect, which was an obvious obstacle to the capsular bag fixation of IOL. REFERENCES 1. Butler TH. Lenticonus posterior; report of six cases. Arch Ophthalmol 1930; 3:425–436 2. Kilty LA, Hiles DA. Unilateral posterior lenticonus with persistent hyaloid artery remnant [letter]. Am J Ophthalmol 1993; 116:104–106 3. Iwase T, Oveson BC. Pigment inside the lens associated with lenticonus. J Cataract Refract Surg 2011; 37:2222–2223 4. Franceschetti A, Rickli H. Posterior (eccentric) lenticonus; report of first case with clinical and histological findings. AMA Arch Ophthalmol 1954; 51:499–508 5. Makley TA Jr. Posterior lenticonus; report of a case with histologic findings. Am J Ophthalmol 1955; 39:308–312
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6. Khalil M, Saheb N. Posterior lenticonus. Ophthalmology 1984; 91:; 1429–1430, 43A 7. Crouch ER Jr, Parks MM. Management of posterior lenticonus complicated by unilateral cataract. Am J Ophthalmol 1978; 85:503–508 8. Singh D, Singh D. Posterior lenticonus with involvement of foetal nucleus. Br J Ophthalmol 1970; 54:136–137. Available at: http:// www.ncbi.nlm.nih.gov/pmc/articles/PMC1207650/pdf/brjopthal 00314-0064.pdf. Accessed October 26, 2013 9. Amaya L, Taylor D, Russell-Eggitt I, Nischal KK, Lengyel D. The morphology and natural history of childhood cataracts. Surv Ophthalmol 2003; 48:125–144 10. Fett D, Paez JH, Isenberg S. Infantile leukocoria caused by posterior lenticonus. Ann Ophthalmol 1984; 16:; 679–680, 684 11. Kalyanasundaram TS, Bearn MA. Surgical identification of posterior lenticonus. J Cataract Refract Surg 2002; 28: 1069–1070 12. Cheng KP, Hiles DA, Biglan AW, Pettapiece MC. Management of posterior lenticonus. J Pediatr Ophthalmol Strabismus 1991; 28:143–149; discussion 150 13. Kim MJ, Kim JH, Yu YS. [The surgical management of posterior lenticonus associated with pediatric cataract]. [Korean]. J Korean Ophthalmol Soc 2007; 48:649–654 14. Seidenberg K, Ludwig IH. A newborn with posterior lenticonus [letter]. Am J Ophthalmol 1993; 115:543–544 15. Parks MM. Visual results in aphakic children. Am J Ophthalmol 1982; 94:441–449 16. Holladay JT. Proper method for calculating average visual acuity. J Refract Surg 1997; 13:388–391. Available at: http://www.
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docholladay.com/publications/propermethodforcalculating.pdf. Accessed October 26, 2013 Sanders DR, Retzlaff J, Kraff MC. Comparison of the SRK IIä formula and other second generation formulas. J Cataract Refract Surg 1988; 14:136–141 Travi GM, Schnall BM, Lehman SS, Kelly CJ, Hug D, Hirakata VN, Calhoun JH. Visual outcome and success of amblyopia treatment in unilateral small posterior lens opacities and lenticonus initially treated nonsurgically. J AAPOS 2005; 9:449–454 Vasavada AR, Praveen MR, Nath V, Dave K. Diagnosis and management of congenital cataract with preexisting posterior capsule defect. J Cataract Refract Surg 2004; 30:403–408 Vasavada AR, Praveen MR, Dholakia SA, Trivedi RH. Preexisting posterior capsule defect progressing to white mature cataract. J AAPOS 2007; 11:192–194 Simons BD, Flynn HW Jr. A pars plana approach for cataract surgery in posterior lenticonus. Am J Ophthalmol 1997; 124:695–696
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First author: Byung Joo Lee, MD Department of Ophthalmology, Seoul National University College of Medicine, Seoul, South Korea
