ORIGINAL STUDY
The Size of Subconjunctival Preparation Does Not Influence the Outcome of Trabeculectomy With Mitomycin C Joanna Wasielica-Poslednik, MD, Esther M. Hoffmann, MD, Daniel Herzog, MD, Shakhsanam Aliyeva, MD, Julia Lamparter, MD, and Norbert Pfeiffer, MD
Purpose: To compare the outcome of fornix-based trabeculectomy with mitomycin C (MMC) using 2 different sizes of subconjunctival preparation (36 mm2 compared with 72 mm2). Methods: Prospective, randomized interventional case series. Study population: Patients 18 to 85 years of age with open-angle glaucoma and progressive visual field defects under maximum tolerated medical therapy were randomized to undergo initial fornix-based trabeculectomy with MMC (0.2 mg/mL for 5 min) with subconjunctival preparation of 6 6 mm (group A) or 8 9 mm (group B). Main outcome parameters were: intraocular pressure (IOP), best-corrected visual acuity (BCVA), number of 5-fluorouracil (5-FU) injections, and laser suturolyses (SL). Results: Twenty-eight eyes of 26 patients were enrolled, including 14 eyes in group A and 14 in group B. At 12 months, IOP (mean ± SD) was 9.69 ± 2.5 mm Hg in group A and 9.93 ± 3.2 mm Hg in group B (P = 0.17) without glaucoma medication. Mean BCVA (logMAR) at month 12 was 0.29 ± 0.26 in group A and 0.26 ± 0.2 in group B (P = 0.71). Patients required 3.0 5-FU in group A and 4.1 ± 2.9 5-FU in group B (P = 0.16); 1.3 ± 1.1 SL and 1.8 ± 1.1 SL, respectively (P = 0.23). We noted 2 cases of intraocular hypotony in the 6 6 mm group (14.3%) and 1 in the 8 9 mm group (7.1%). Conclusions: There were no significant differences between study groups in mean IOP reduction, change in BCVA, or number of applied 5-FU and SL at 1-year follow-up. The area of subconjunctival preparation is only one of several factors playing a role in the outcome of trabeculectomy with MMC. Key Words: trabeculectomy, mitomycin C, subconjunctival preparation, glaucoma surgery
(J Glaucoma 2015;24:e75–e79)
E
ffective intraocular pressure (IOP) reduction is the only evidence-based intervention that positively influences glaucoma onset and outcome defined as visual field loss.1 Despite the introduction of modern antiglaucomatous medications in recent years, surgical methods remain a Received for publication September 14, 2013; accepted August 22, 2014. From the Department of Ophthalmology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany. Presented in part at the WOC 2010 XXXII International Congress of Ophthalmology (ICO), 108th DOG Congress (German Society of Ophthalmology). Disclosure: The authors declare no conflict of interest. Reprints: Joanna Wasielica-Poslednik, MD, Department of Ophthalmology, University Medical Center of the Johannes GutenbergUniversity Mainz, Langenbeckstr. 1, 55131 Mainz, Germany (e-mail: [email protected]). Copyright r 2014 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/IJG.0000000000000142
J Glaucoma
valuable therapeutic alternative or even IOP-reducing ultima ratio in many patients. Filtration surgery is still the most effective IOP-lowering method for open-angle glaucoma.2,3 Since its introduction, trabeculectomy has undergone numerous modifications to achieve a minimal complication rate through better postoperative IOP control. Growing knowledge of wound healing resulted in use of antifibroblastic drugs such as mitomycin C (MMC), which was proven to minimize the risk of subconjunctival scarring and to increase the success of trabeculectomy.4 Releasable sutures or cutting sutures with laser or with a needle enable control of postoperative IOP elevation.5,6 Fistulas are smaller and placed anteriorly to prevent ciliary body damage and iris incarceration.7 Several studies have evaluated the influence of the type of conjunctival incision— fornix-based versus limbus-based flaps—on bleb formation. Fornix-based flaps were found to provide more diffuse antifibrotic application and a better surgical view; they lead more frequently to diffuse bleb formation than limbusbased conjunctival incisions.8 The technique for trabeculectomy seems to be well described and investigated. However, the size of the subconjunctival preparation seems to remain a matter of controversy. Scar formation secondary to tissue injury remains the main cause of failure following trabeculectomy. It has been suggested that the larger the subconjunctival preparation, the better the outcome. Thus, Khaw described a conjunctival incision of B5 to 10 mm and a subconjunctival/sub-Tenon pocket measuring B10 to 15 mm posterior and 10 to 15 mm wide to allow a large area for antifibrotic treatment.9 Others propose a small incision trabeculectomy with a 2.5 mm wide conjunctival peritomy to minimize wound healing at the level of Tenon capsule.10 Ophir11 proposed a mini-trabeculectomy with a 3 mm fornix-based conjunctival flap. However, a comparison between a “standard” or large and a small approach has, to our knowledge, never been investigated. Thus, our study was designed to quantify the size of the subconjunctival preparation and to evaluate its influence on functional outcome. Motivated by experimental mini-trabeculectomy results—in the absence of large clinical trials—we pursued to investigate whether a “mini-subconjunctival preparation” would be superior, equal, or inferior to a large preparation.12–15 Might there be a higher accumulation of MMC in a small subconjunctival space and on the other hand—might MMC diffuse faster in the conjunctiva in a larger subconjunctival space? We hypothesized that there could be a difference in postoperative IOP reduction when first, the subconjunctival area preparation is standardized and second, differs between 2 experimental groups. To examine this we initiated a prospective, randomized clinical study in progressive glaucoma patients
Volume 24, Number 5, June/July 2015 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.glaucomajournal.com |
e75
Wasielica-Poslednik et al
J Glaucoma
Volume 24, Number 5, June/July 2015
undergoing trabeculectomy with MMC. We compared the outcome of trabeculectomy with a subconjunctival preparation area of 36 mm2 to one of double size (72 mm2).
METHODS The present prospective, randomized, interventional case series was carried out in accordance with the principles of the Declaration of Helsinki. The study was approved by our local Research Ethics Committee. All patients were evaluated at the Department of Ophthalmology of the University Medical Center, Johannes Gutenberg-University Mainz, Germany. Written informed consent was obtained from all participants before their study enrollment. Eligibility criteria were: white patients 18 to 85 years of age diagnosed with open-angle glaucoma and progressive visual field defects under maximum tolerated medical therapy. Exclusion criteria included: intraocular surgery (except for uncomplicated cataract surgery >6 mo before investigation), chronic conjunctivitis, conjunctival scarring, application of antiglaucomatous eye drops 4 weeks before surgery (according to our clinic’s preoperative standards), and history of uveitis. During the 4-week preoperative washout period, IOP elevation was combated with acetazolamide tablets (Diamox, maximum daily dose: 6 250 mg) with accompanying potassium supplementation. Dexamethasone eye drops were applied 5 times per day for the 5 days before surgery. Baseline demographics and ophthalmologic examination, including slit-lamp biomicroscopy, best-corrected visual acuity (BCVA) assessment, and IOP measurement were performed 1 day before surgery (at 2 PM ± 2 h) in all enrolled patients. Follow-up visits were scheduled 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively. Each examination included slit-lamp biomicroscopy, BCVA assessment, and IOP measurement. Postoperative interventions such as application of 5-fluorouracil (5-FU) and suturolyses (SL) as well as supplemental medical therapy and complications were documented at each follow-up visit. All IOP measurements were taken using Goldmann applanation tonometry after instilling oxybuprocain-HCl/ fluorescein-Na (Thilorbin) eye drops in both eyes in miosis. The tonometer pressure was set at 10 mm Hg before each measurement, and 2 measurements were taken. With a difference of >1 mm Hg, a third measurement was taken. The mean of all measurements was recorded. All baseline and follow-up examinations including IOP measurements were performed by the same examiner (J.W.-P.). The doctor who measured postoperative IOP was not explicitly blinded to the procedure as this information would have been accessible in the surgery record of the patient. However, at time of IOP measurement this information was not present in the patient’s charts. In addition, the patients of both study groups did appear by chance and not in a certain order. Study patients underwent fornix-based trabeculectomy augmented with MMC performed by 1 experienced surgeon (N.P.). They were randomized to receive fornix-based subconjunctival preparation of 6 6 or of 8 9 mm. Randomization was performed using a 1-block randomization list 1 day before surgery in each case. The area of subconjunctival preparation was restricted to the size of a sterile sponge stencil placed on the conjunctiva (Figs. 1, 2).
e76 | www.glaucomajournal.com
FIGURE 1. Subconjunctival preparation of 36 mm2. The area of subconjunctival preparation in group A was restricted to 6 6 mm large sponge stencil placed on the conjunctiva.
The conjunctiva was dissected with scissors along the stencil margin. The Tenon capsule was not removed due to the risk of thin bleb and fistulation. Study patients of both groups received the same amount of MMC (3 drops of MMC at a concentration of 0.2 mg/mL) on a 7 7 mm sponge according to the standards of our clinic. The sponge was then placed for 5 minutes in the priorly prepared subconjunctival space (6 6 mm in group A or 8 9 mm in group B). The sponge stencil (6 6 or 8 9 mm) was not equal to the MMC-saturated sponge (7 7 mm in all cases). According to the standards of our clinic, flap size was 4 4 mm and four 10-0 nylon sutures were placed in the scleral flap (2 loose edge sutures and 2 tense side sutures stitched tangentially through the scleral flap and the adjacent sclera to allow aqueous humor to flow posteriorly).
Statistics Statistical analysis of mean preoperative and postoperative IOP values as well as IOP reductions and BCVA in both groups was performed using the unpaired t test (SPSS, version 17.0; Microsoft Excel) and repeated measures ANOVA (SAS). Statistical significance was defined at P < 0.05 for a 95% confidence interval. The Mann-Whitney test was used to compare the number of postoperative 5-FUs and SLs applied in both groups.
RESULTS We enrolled 28 eyes of 26 patients (16 females and 10 males). Mean patient age was 68.8 years (± 7.97 SD; range, 51 to 85 y). We included 22 eyes with primary open-angle
FIGURE 2. Subconjunctival preparation of 72 mm2. The area of subconjunctival preparation in group B was restricted to 8 9 mm large sponge stencil placed on the conjunctiva.
Copyright
r
2014 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
J Glaucoma
Volume 24, Number 5, June/July 2015
Influence of Subconjunctival Preparation on Trabeculectomy
TABLE 1. Baseline and Follow-up IOP Measurements (Mean ± SD) in Group A and B With Corresponding P-values
TABLE 2. Baseline and 1-year Follow-up Visual Acuity in Group A and B (mean ± SD)
IOP (mm Hg)
Group A
Group B
P*
Median BCVA (logMAR)
Baseline Day 1 Day 7 Month 1 Month 3 Month 6 Month 12
25.1 ± 7.1 17.7 ± 6.2 8.7 ± 4.7 9.1 ± 2.1 9.8 ± 2.7 9.2 ± 2.3 9.7 ± 2.5
28.4 ± 11.5 19.2 ± 6.4 10.9 ± 5.1 12.1 ± 2.6 10.8 ± 2.8 10.4 ± 3.2 9.9 ± 3.2
0.24 0.89 0.7 0.33 0.88 0.49 0.17
Baseline Month 12
Group A: subconjuctival preparation 6 6 mm. Group B: subconjunctival preparation 8 9 mm. *Student unpaired t test (SPSS, version 17.0), group A versus group B. IOP indicates intraocular pressure.
glaucoma, 4 eyes with normal-tension glaucoma, and 2 eyes with pseudoexfoliation glaucoma. Twenty-six eyes were phakic and 2 eyes were pseudophakic. The study patients were not patients of specific risk. They were whites and received primary trabeculectomy with MMC in all cases. By randomization, 14 eyes were assigned to trabeculectomy with MMC with 6 6 mm subconjunctival preparation (group A) and 14 eyes to 8 9 mm subconjunctival preparation (group B). Baseline IOP (mean ± SD) was 25.07 ± 7.1 mm Hg in group A and 28.43 ± 11.5 mm Hg in group B (Table 1). Baseline BCVA (mean ± SD) was 0.32 ± 0.25 logMAR in group A and 0.2 ± 0.15 logMAR in group B. There were no significant differences in preoperative IOP measurements (P = 0.24) and BCVA (P = 0.18) between study groups. Surgery was uneventful in all cases. All enrolled patients completed all follow-up visits. Baseline and follow-up IOP in groups A and B, and corresponding P-values are reported in Table 1 and graphically presented in Figure 3. Mean IOP measurements did not differ significantly at any of the follow-up visits between study groups (P > 0.05). Group affiliation had no significant influence on mean IOP reduction (ie, IOP preoperative IOP at follow-up) at any of the follow-up visits (P > 0.05). Both methods led to a significant and sustained IOP reduction. At 12-month follow-up the IOP reduction was 63% in group A and 64% in group B. None of the patients required glaucoma medication or needling at any of the follow-up visits. We observed no significant difference between the groups in visual acuity at the 1-year follow-up visit (P = 0.71, Table 2). Group affiliation had no significant
Group A
Group B
P*
0.32 ± 0.25 0. 29 ± 0.26
0.2 ± 0.15 0.26 ± 0.2
0.18 0.71
Group A: subconjuctival preparation 6 6 mm. Group B: subconjunctival preparation 8 9 mm. *Repeated measures ANOVA. BCVA indicates best-corrected visual acuity.
influence on BCVA change (ie, preoperative BCVA BCVA at follow-up visit, P = 0.62). Patients were visited daily for 7 to 10 days. According to the standards of our clinic, the first suture lysis was performed if postoperative IOP was elevated in mid or high twenties and by flat bleb, which inflated after ocular massage. Further suture lyses were performed if the target IOP was not achieved. We applied 5-FU from the second postoperative day if the vascularity of the bleb was moderate and showed cork-screw vessels, unless we saw any hypotony symptoms. We did not apply 5-FU if IOP was
The Size of Subconjunctival Preparation Does Not Influence the Outcome of Trabeculectomy With Mitomycin C Joanna Wasielica-Poslednik, MD, Esther M. Hoffmann, MD, Daniel Herzog, MD, Shakhsanam Aliyeva, MD, Julia Lamparter, MD, and Norbert Pfeiffer, MD
Purpose: To compare the outcome of fornix-based trabeculectomy with mitomycin C (MMC) using 2 different sizes of subconjunctival preparation (36 mm2 compared with 72 mm2). Methods: Prospective, randomized interventional case series. Study population: Patients 18 to 85 years of age with open-angle glaucoma and progressive visual field defects under maximum tolerated medical therapy were randomized to undergo initial fornix-based trabeculectomy with MMC (0.2 mg/mL for 5 min) with subconjunctival preparation of 6 6 mm (group A) or 8 9 mm (group B). Main outcome parameters were: intraocular pressure (IOP), best-corrected visual acuity (BCVA), number of 5-fluorouracil (5-FU) injections, and laser suturolyses (SL). Results: Twenty-eight eyes of 26 patients were enrolled, including 14 eyes in group A and 14 in group B. At 12 months, IOP (mean ± SD) was 9.69 ± 2.5 mm Hg in group A and 9.93 ± 3.2 mm Hg in group B (P = 0.17) without glaucoma medication. Mean BCVA (logMAR) at month 12 was 0.29 ± 0.26 in group A and 0.26 ± 0.2 in group B (P = 0.71). Patients required 3.0 5-FU in group A and 4.1 ± 2.9 5-FU in group B (P = 0.16); 1.3 ± 1.1 SL and 1.8 ± 1.1 SL, respectively (P = 0.23). We noted 2 cases of intraocular hypotony in the 6 6 mm group (14.3%) and 1 in the 8 9 mm group (7.1%). Conclusions: There were no significant differences between study groups in mean IOP reduction, change in BCVA, or number of applied 5-FU and SL at 1-year follow-up. The area of subconjunctival preparation is only one of several factors playing a role in the outcome of trabeculectomy with MMC. Key Words: trabeculectomy, mitomycin C, subconjunctival preparation, glaucoma surgery
(J Glaucoma 2015;24:e75–e79)
E
ffective intraocular pressure (IOP) reduction is the only evidence-based intervention that positively influences glaucoma onset and outcome defined as visual field loss.1 Despite the introduction of modern antiglaucomatous medications in recent years, surgical methods remain a Received for publication September 14, 2013; accepted August 22, 2014. From the Department of Ophthalmology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany. Presented in part at the WOC 2010 XXXII International Congress of Ophthalmology (ICO), 108th DOG Congress (German Society of Ophthalmology). Disclosure: The authors declare no conflict of interest. Reprints: Joanna Wasielica-Poslednik, MD, Department of Ophthalmology, University Medical Center of the Johannes GutenbergUniversity Mainz, Langenbeckstr. 1, 55131 Mainz, Germany (e-mail: [email protected]). Copyright r 2014 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/IJG.0000000000000142
J Glaucoma
valuable therapeutic alternative or even IOP-reducing ultima ratio in many patients. Filtration surgery is still the most effective IOP-lowering method for open-angle glaucoma.2,3 Since its introduction, trabeculectomy has undergone numerous modifications to achieve a minimal complication rate through better postoperative IOP control. Growing knowledge of wound healing resulted in use of antifibroblastic drugs such as mitomycin C (MMC), which was proven to minimize the risk of subconjunctival scarring and to increase the success of trabeculectomy.4 Releasable sutures or cutting sutures with laser or with a needle enable control of postoperative IOP elevation.5,6 Fistulas are smaller and placed anteriorly to prevent ciliary body damage and iris incarceration.7 Several studies have evaluated the influence of the type of conjunctival incision— fornix-based versus limbus-based flaps—on bleb formation. Fornix-based flaps were found to provide more diffuse antifibrotic application and a better surgical view; they lead more frequently to diffuse bleb formation than limbusbased conjunctival incisions.8 The technique for trabeculectomy seems to be well described and investigated. However, the size of the subconjunctival preparation seems to remain a matter of controversy. Scar formation secondary to tissue injury remains the main cause of failure following trabeculectomy. It has been suggested that the larger the subconjunctival preparation, the better the outcome. Thus, Khaw described a conjunctival incision of B5 to 10 mm and a subconjunctival/sub-Tenon pocket measuring B10 to 15 mm posterior and 10 to 15 mm wide to allow a large area for antifibrotic treatment.9 Others propose a small incision trabeculectomy with a 2.5 mm wide conjunctival peritomy to minimize wound healing at the level of Tenon capsule.10 Ophir11 proposed a mini-trabeculectomy with a 3 mm fornix-based conjunctival flap. However, a comparison between a “standard” or large and a small approach has, to our knowledge, never been investigated. Thus, our study was designed to quantify the size of the subconjunctival preparation and to evaluate its influence on functional outcome. Motivated by experimental mini-trabeculectomy results—in the absence of large clinical trials—we pursued to investigate whether a “mini-subconjunctival preparation” would be superior, equal, or inferior to a large preparation.12–15 Might there be a higher accumulation of MMC in a small subconjunctival space and on the other hand—might MMC diffuse faster in the conjunctiva in a larger subconjunctival space? We hypothesized that there could be a difference in postoperative IOP reduction when first, the subconjunctival area preparation is standardized and second, differs between 2 experimental groups. To examine this we initiated a prospective, randomized clinical study in progressive glaucoma patients
Volume 24, Number 5, June/July 2015 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.glaucomajournal.com |
e75
Wasielica-Poslednik et al
J Glaucoma
Volume 24, Number 5, June/July 2015
undergoing trabeculectomy with MMC. We compared the outcome of trabeculectomy with a subconjunctival preparation area of 36 mm2 to one of double size (72 mm2).
METHODS The present prospective, randomized, interventional case series was carried out in accordance with the principles of the Declaration of Helsinki. The study was approved by our local Research Ethics Committee. All patients were evaluated at the Department of Ophthalmology of the University Medical Center, Johannes Gutenberg-University Mainz, Germany. Written informed consent was obtained from all participants before their study enrollment. Eligibility criteria were: white patients 18 to 85 years of age diagnosed with open-angle glaucoma and progressive visual field defects under maximum tolerated medical therapy. Exclusion criteria included: intraocular surgery (except for uncomplicated cataract surgery >6 mo before investigation), chronic conjunctivitis, conjunctival scarring, application of antiglaucomatous eye drops 4 weeks before surgery (according to our clinic’s preoperative standards), and history of uveitis. During the 4-week preoperative washout period, IOP elevation was combated with acetazolamide tablets (Diamox, maximum daily dose: 6 250 mg) with accompanying potassium supplementation. Dexamethasone eye drops were applied 5 times per day for the 5 days before surgery. Baseline demographics and ophthalmologic examination, including slit-lamp biomicroscopy, best-corrected visual acuity (BCVA) assessment, and IOP measurement were performed 1 day before surgery (at 2 PM ± 2 h) in all enrolled patients. Follow-up visits were scheduled 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively. Each examination included slit-lamp biomicroscopy, BCVA assessment, and IOP measurement. Postoperative interventions such as application of 5-fluorouracil (5-FU) and suturolyses (SL) as well as supplemental medical therapy and complications were documented at each follow-up visit. All IOP measurements were taken using Goldmann applanation tonometry after instilling oxybuprocain-HCl/ fluorescein-Na (Thilorbin) eye drops in both eyes in miosis. The tonometer pressure was set at 10 mm Hg before each measurement, and 2 measurements were taken. With a difference of >1 mm Hg, a third measurement was taken. The mean of all measurements was recorded. All baseline and follow-up examinations including IOP measurements were performed by the same examiner (J.W.-P.). The doctor who measured postoperative IOP was not explicitly blinded to the procedure as this information would have been accessible in the surgery record of the patient. However, at time of IOP measurement this information was not present in the patient’s charts. In addition, the patients of both study groups did appear by chance and not in a certain order. Study patients underwent fornix-based trabeculectomy augmented with MMC performed by 1 experienced surgeon (N.P.). They were randomized to receive fornix-based subconjunctival preparation of 6 6 or of 8 9 mm. Randomization was performed using a 1-block randomization list 1 day before surgery in each case. The area of subconjunctival preparation was restricted to the size of a sterile sponge stencil placed on the conjunctiva (Figs. 1, 2).
e76 | www.glaucomajournal.com
FIGURE 1. Subconjunctival preparation of 36 mm2. The area of subconjunctival preparation in group A was restricted to 6 6 mm large sponge stencil placed on the conjunctiva.
The conjunctiva was dissected with scissors along the stencil margin. The Tenon capsule was not removed due to the risk of thin bleb and fistulation. Study patients of both groups received the same amount of MMC (3 drops of MMC at a concentration of 0.2 mg/mL) on a 7 7 mm sponge according to the standards of our clinic. The sponge was then placed for 5 minutes in the priorly prepared subconjunctival space (6 6 mm in group A or 8 9 mm in group B). The sponge stencil (6 6 or 8 9 mm) was not equal to the MMC-saturated sponge (7 7 mm in all cases). According to the standards of our clinic, flap size was 4 4 mm and four 10-0 nylon sutures were placed in the scleral flap (2 loose edge sutures and 2 tense side sutures stitched tangentially through the scleral flap and the adjacent sclera to allow aqueous humor to flow posteriorly).
Statistics Statistical analysis of mean preoperative and postoperative IOP values as well as IOP reductions and BCVA in both groups was performed using the unpaired t test (SPSS, version 17.0; Microsoft Excel) and repeated measures ANOVA (SAS). Statistical significance was defined at P < 0.05 for a 95% confidence interval. The Mann-Whitney test was used to compare the number of postoperative 5-FUs and SLs applied in both groups.
RESULTS We enrolled 28 eyes of 26 patients (16 females and 10 males). Mean patient age was 68.8 years (± 7.97 SD; range, 51 to 85 y). We included 22 eyes with primary open-angle
FIGURE 2. Subconjunctival preparation of 72 mm2. The area of subconjunctival preparation in group B was restricted to 8 9 mm large sponge stencil placed on the conjunctiva.
Copyright
r
2014 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
J Glaucoma
Volume 24, Number 5, June/July 2015
Influence of Subconjunctival Preparation on Trabeculectomy
TABLE 1. Baseline and Follow-up IOP Measurements (Mean ± SD) in Group A and B With Corresponding P-values
TABLE 2. Baseline and 1-year Follow-up Visual Acuity in Group A and B (mean ± SD)
IOP (mm Hg)
Group A
Group B
P*
Median BCVA (logMAR)
Baseline Day 1 Day 7 Month 1 Month 3 Month 6 Month 12
25.1 ± 7.1 17.7 ± 6.2 8.7 ± 4.7 9.1 ± 2.1 9.8 ± 2.7 9.2 ± 2.3 9.7 ± 2.5
28.4 ± 11.5 19.2 ± 6.4 10.9 ± 5.1 12.1 ± 2.6 10.8 ± 2.8 10.4 ± 3.2 9.9 ± 3.2
0.24 0.89 0.7 0.33 0.88 0.49 0.17
Baseline Month 12
Group A: subconjuctival preparation 6 6 mm. Group B: subconjunctival preparation 8 9 mm. *Student unpaired t test (SPSS, version 17.0), group A versus group B. IOP indicates intraocular pressure.
glaucoma, 4 eyes with normal-tension glaucoma, and 2 eyes with pseudoexfoliation glaucoma. Twenty-six eyes were phakic and 2 eyes were pseudophakic. The study patients were not patients of specific risk. They were whites and received primary trabeculectomy with MMC in all cases. By randomization, 14 eyes were assigned to trabeculectomy with MMC with 6 6 mm subconjunctival preparation (group A) and 14 eyes to 8 9 mm subconjunctival preparation (group B). Baseline IOP (mean ± SD) was 25.07 ± 7.1 mm Hg in group A and 28.43 ± 11.5 mm Hg in group B (Table 1). Baseline BCVA (mean ± SD) was 0.32 ± 0.25 logMAR in group A and 0.2 ± 0.15 logMAR in group B. There were no significant differences in preoperative IOP measurements (P = 0.24) and BCVA (P = 0.18) between study groups. Surgery was uneventful in all cases. All enrolled patients completed all follow-up visits. Baseline and follow-up IOP in groups A and B, and corresponding P-values are reported in Table 1 and graphically presented in Figure 3. Mean IOP measurements did not differ significantly at any of the follow-up visits between study groups (P > 0.05). Group affiliation had no significant influence on mean IOP reduction (ie, IOP preoperative IOP at follow-up) at any of the follow-up visits (P > 0.05). Both methods led to a significant and sustained IOP reduction. At 12-month follow-up the IOP reduction was 63% in group A and 64% in group B. None of the patients required glaucoma medication or needling at any of the follow-up visits. We observed no significant difference between the groups in visual acuity at the 1-year follow-up visit (P = 0.71, Table 2). Group affiliation had no significant
Group A
Group B
P*
0.32 ± 0.25 0. 29 ± 0.26
0.2 ± 0.15 0.26 ± 0.2
0.18 0.71
Group A: subconjuctival preparation 6 6 mm. Group B: subconjunctival preparation 8 9 mm. *Repeated measures ANOVA. BCVA indicates best-corrected visual acuity.
influence on BCVA change (ie, preoperative BCVA BCVA at follow-up visit, P = 0.62). Patients were visited daily for 7 to 10 days. According to the standards of our clinic, the first suture lysis was performed if postoperative IOP was elevated in mid or high twenties and by flat bleb, which inflated after ocular massage. Further suture lyses were performed if the target IOP was not achieved. We applied 5-FU from the second postoperative day if the vascularity of the bleb was moderate and showed cork-screw vessels, unless we saw any hypotony symptoms. We did not apply 5-FU if IOP was
