Limbus-based vs fornix-based conjunctival flap in combined glaucoma and cataract surgery with adjunctive mitomycin C

The Japan Glaucoma Society guidelines for glaucoma 5th edition

We are pleased to bring you the 5th edition of the Glaucoma Clinical Practice Guidelines. Clinical practice guidelines are based on evidence (scientific grounds). It is a document that presents the treatment that is the most appropriate for the patient. "Glaucoma Clinical Guidelines" was first published in 2003. This was the first guideline for glaucoma treatment in Japan. The principle of glaucoma treatment is to lower intraocular pressure. Means for lowering intraocular pressure includes drugs, lasers, and surgery; Glaucoma is a disease that should be considered as a complex syndrome rather than a single condition. Therefore, the actual medical treatment is not as simple as one word. This time we set the Clinical Questionnaire with a focus on glaucoma treatment. We hope that you will take advantage of the 5th edition.

Fornix-based versus limbal-based conjunctival trabeculectomy flaps for glaucoma

BACKGROUND

Glaucoma is one of the leading largely preventable causes of blindness in the world. It is usually  addressed first medically with topical intraocular pressure-lowering drops or by laser trabeculoplasty. In cases where such treatment fails, glaucoma-filtering surgery such as trabeculectomy, is commonly considered. Surgeons can differ in their technique when performing trabeculectomy, for example, the choice of the type of the conjunctival flap (fornix- or limbal-based). In a fornix-based flap, the surgical wound is performed at the corneal limbus; while in a limbal-based flap, the incision is further away. Many studies in the literature compare fornix- and limbal-based trabeculectomy with respect to outcomes and complications.

OBJECTIVES

To assess the comparative effectiveness of fornix- versus limbal-based conjunctival flaps in trabeculectomy for adult glaucoma, with a specific focus on intraocular pressure (IOP) control and complication rates (adverse effects).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2021, Issue 3); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 23 March 2021. There were no restrictions to language or year of publication.

SELECTION CRITERIA

We included RCTs comparing the benefits and complications of fornix- versus limbal-based trabeculectomy for glaucoma, irrespective of glaucoma type, publication status, and language. We excluded studies on children less than 18 years of age, since wound healing is different in this age group and the rate of bleb scarring postoperatively is high.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as per Cochrane criteria.  MAIN RESULTS: We did not identify any new eligible studies for this review update. As presented in the original review, we included six trials with a total of 361 participants. Two studies were conducted in the USA and one each in Germany, Greece, India, and Saudi Arabia. The participants of four trials had open-angle glaucoma; one study included participants with primary open-angle or primary closed-angle glaucoma, and one study did not specify the type of glaucoma. Three studies used a combined procedure (phacotrabeculectomy). Trabeculectomy with mitomycin C (MMC) was performed in four studies, and trabeculectomy with 5-fluorouracil (5-FU) was performed in only one study. None of the included trials reported trabeculectomy failure at 24 months. Only one trial reported the failure rate of trabeculectomy as a late complication. Failure was higher among participants randomised to the limbal-based surgery: 1/50 eyes failed trabeculectomy in the fornix group compared with 3/50 in the limbal group (Peto odds ratio  0.36, 95% confidence interval (CI) 0.05 to 2.61)); therefore we are very uncertain as to the relative effect of the two procedures on failure rate. Four studies including 252 participants provided measures of mean IOP at 12 months. In the fornix-based surgeries, mean IOP ranged from 12.5 to 15.5 mmHg and similar results were noted in limbal-based surgeries with mean IOP ranging from 11.7 to 15.1 mmHg without significant difference. Mean difference was 0.44 mmHg (95% CI -0.45 to 1.33; 247 eyes) and 0.86 mmHg, (95% CI -0.52 to 2.24; 139 eyes) at 12 and 24 months of follow-up, respectively. Neither of these pooled analyses showed a statistically significant difference in IOP between groups (moderate certainty evidence). One trial reported number of anti-glaucoma medications at 24 months of follow-up with no difference noted between surgical groups. However, three trials reported the mean number of anti-glaucoma medications at 12 months of follow-up without significant difference in the mean number of postoperative IOP-lowering medications between the two surgical techniques. Mean difference was 0.02, (95% CI -0.15 to 0.19) at 12 months of follow-up (high certainty evidence). Because of the small numbers of events and total participants, the risk of many reported adverse events was uncertain and those that were found to be statistically significant may have been due to chance. For risk of bias assessment: although all six trials were randomised selection bias was mostly unclear, with unclear random sequence generation in four of the six studies and unclear allocation concealment in five of the six studies. Attrition bias was encountered in only one trial which also suffered from reporting bias. All other trials had an unclear risk of reporting bias as there was no access to study protocols. All included trials were judged to have high risk of detection bias due to lack of masking of the outcomes. Trabeculectomy is quite a standard procedure and unlikely to induce bias due to surgeon 'performance', hence performance bias was not evaluated.

AUTHORS' CONCLUSIONS

The main result of this review was that there was uncertainty as to the difference between fornix- and limbal-based trabeculectomy surgeries due to the small number of events and confidence intervals that cross the null. This also applied to postoperative complications, but without any impact on long-term failure rate between the two surgical techniques.

Study of the Efficacy and Safety of Contact Lens Used in Trabeculectomy

Purpose

To investigate the efficacy and safety of soft bandage contact lens used in trabeculectomy.

Methods

This was a prospective, randomized study which enrolled 200 glaucoma patients (200 eyes). Patients were randomized into Group 1, using contact lens after trabeculectomy, and Group 2, without contact lens. The primary outcome measurement was the comparison of success rates at 12 months after surgery. Qualified surgical success was defined as a postoperative intraocular pressure (IOP) value of 6–21 mmHg with or without topical antiglaucoma medication use at the last follow-up visit. Complete success was defined as the IOP between 6 and 21 mmHg without any antiglaucoma medication at the last follow-up visit. Postoperative data included IOP values, best-corrected visual acuity (BCVA), number of antiglaucoma medications, complications related to surgery, and bleb characteristics.

Results

There were statistically significant differences between Groups 1 and 2 in mean IOP values at 3, 6, and 12 months after surgery (P < 0.05). The 12-month life table rates for qualified surgical success were 94.7% and 86.3% in Groups 1 and 2, respectively (P=0.045). The 12-month life table rates for complete surgical success were 89.6% and 80.0% in Groups 1 and 2, respectively (P=0.042). At 12 months after surgery, the mean numbers of antiglaucoma medications were 0.3 ± 0.4 and 0.5 ± 0.6, respectively. (P=0.001). At the 12-month visit, the maximal bleb area was significantly different between groups (P=0.044), with Group 1 exhibiting a more diffused bleb area. Encysted blebs were observed in 7 (7%) eyes in Group 1 and 17 (17%) eyes in Group 2, with statistically significant differences (P=0.030). The 12-month life table rates for qualified surgical success were 94.7% (91 eyes) and 86.3% (82 eyes) in Groups 1 and 2, respectively (P=0.045).

Conclusions

Bandage contact lens is a safe and effective device after fornix-based trabeculectomy.

Fornix-Based Trabeculectomy Conjunctival Closure: Winged Sutures versus Modified Wise Closure

PURPOSE

To compare the midterm safety and efficacy profile of winged sutures versus modified Wise closure for fornix-based trabeculectomy.

DESIGN

Retrospective comparative study.

PARTICIPANTS

Consecutive cases that underwent fornix-based trabeculectomy by a single surgeon between January 5, 2015, and May 8, 2017.

METHODS

Potential cases were identified using the Current Procedural Terminology code, and their charts were reviewed thoroughly. Only 1 eye per patient was included. Demographic and clinical data were collected.

MAIN OUTCOME MEASURES

Primary outcomes were bleb leak and subsequent surgical revision rates. Secondary outcomes included intraocular pressure (IOP), number of glaucoma medications (NGM), visual acuity (VA), and other complications.

RESULTS

A total of 313 patients were identified, 157 with winged sutures and 156 with modified Wise closure. Baseline demographic and clinical characteristics were similar between the 2 groups. Twenty-six cases (16.6%) of winged sutures and 10 cases (6.4%) of modified Wise group developed bleb leak (P = 0.007), but only a total of 10 eyes needed bleb revision (P = 0.336). Other complications were similar in rates between the groups (P > 0.05). At 6 months, the modified Wise group had significantly greater IOP reduction (-3.10±1.29 [standard error], P = 0.016). Number of glaucoma medications reduction and VA evolution were similar between the 2 groups (P > 0.05).

CONCLUSIONS

Fornix-based trabeculectomy with either closure technique was effective in lowering IOP and NGM with comparable safety profile at 6 months. Furthermore, modified Wise closure provided larger IOP reduction and lower bleb leak rate, suggesting a potential superiority to winged sutures. Our study was limited by mitomycin C (MMC) delivery method change near the time of conjunctival closure change, although MMC delivery methods did not show significance in any outcome model.

Fornix-Based Versus Limbal-Based Conjunctival Trabeculectomy Flaps for Glaucoma: Findings From a Cochrane Systematic Review

PURPOSE

To compare effectiveness of fornix- and limbal-based conjunctival flaps in trabeculectomy surgery.

DESIGN

Systematic review.

METHODS

Setting: CENTRAL, MEDLINE, LILACS, ISRCTN registry, ClinicalTrials.gov, WHO, and ICTRP were searched to identify eligible randomized controlled trials (RCTs).

STUDY POPULATION

RCTs in which benefits and complications of fornix- vs limbal-based trabeculectomy for glaucoma were compared in adult glaucoma patients.

OBSERVATION PROCEDURE

We followed Cochrane methodology for data extraction.

MAIN OUTCOME MEASURES

Proportion of failed trabeculectomies at 24 months, defined as the need for repeat surgery or uncontrolled intraocular pressure (IOP) >22 mm Hg, despite topical/systemic medications.

RESULTS

The review included 6 trials with a total of 361 participants, showing no difference in effectiveness between fornix-based vs limbal-based trabeculectomy surgery, although with a high level of uncertainty owing to low event rates. In the fornix-based and limbal-based surgery, mean IOP at 12 months was similar, with ranges of 12.5-15.5 mm Hg and 11.7-15.1 mm Hg, respectively. Mean difference was 0.44 mm Hg (95% CI -0.45 to 1.33) and 0.86 mm Hg (95% CI -0.52 to 2.24) at 12 and 24 months of follow-up, respectively. Mean number of postoperative glaucoma medications was similar between the 2 groups. Mean difference was 0.02 (95% CI -0.15 to 0.19) at 12 months. As far as postoperative complications, an increased risk of shallow anterior chamber was observed in the limbal-based group.

CONCLUSION

Similar efficacy of trabeculectomy surgery with respect to bleb failure or IOP control was observed in both types of conjunctival flap incisions. A significant difference was detected in the risk of postoperative shallow anterior chamber, which was increased in the limbal-based group.

Fornix-based versus limbal-based conjunctival trabeculectomy flaps for glaucoma

BACKGROUND

Glaucoma is one of the leading largely preventable causes of blindness in the world. It usually is addressed first medically with topical intraocular pressure-lowering drops or by laser trabeculoplasty. In cases where such treatment fails, glaucoma-filtering surgery is considered, most commonly trabeculectomy surgery with variations in technique, for example, the type of conjunctival flap (fornix- or limbal-based). In a fornix-based flap, the surgical wound is performed at the corneal limbus; while in a limbal-based flap, the incision is further away. Many studies in the literature compare fornix- and limbal-based trabeculectomy with respect to outcomes and complications.

OBJECTIVES

To assess the comparative effectiveness of fornix- versus limbal-based conjunctival flaps in trabeculectomy for adult glaucoma, with a specific focus on intraocular pressure (IOP) control and complications (adverse effects).

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2015), EMBASE (January 1980 to October 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 23 October 2015.We reviewed the bibliographic references of identified randomised controlled trials (RCTs) in order to find trials not identified by the electronic searches. We contacted researchers and practitioners active in the field of glaucoma to identify other published and unpublished trials.

SELECTION CRITERIA

We included RCTs comparing the benefits and complications of fornix- versus limbal-based trabeculectomy for glaucoma, irrespective of glaucoma type, publication status, and language. We excluded studies on children less than 18 years of age, since wound healing is different in this age group and the rate of bleb scarring postoperatively is high.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. We contacted study authors for additional information.The primary outcome was the proportion of failed trabeculectomies at 24 months. Failure was defined as the need for repeat surgery or uncontrolled IOP (more than 22 mmHg), despite additional topical/systemic medications. Needling and 5-fluorouracil (5-FU) injections were allowed only during the first six months postoperatively; additional needling or 5-FU injections were considered as failure. Mean post-operative IOP at 12 and 24 months also was recorded.

MAIN RESULTS

The review included six trials with a total of 361 participants. Two studies were conducted in America and one each in Germany, Greece, India, and Saudi Arabia. The participants of four trials had open-angle glaucoma; one study included participants with primary open-angle or primary closed-angle glaucoma, and one study did not specify the type of glaucoma. Three studies used a combined procedure (phacotrabeculectomy). Trabeculectomy with mitomycin C (MMC) was performed in four studies, and trabeculectomy with 5-fluorouracil (5-FU) was performed in only one study.None of the included trials reported trabeculectomy failure at 24 months. Only one trial reported the failure rate of trabeculectomy as a late complication. Failure was higher among participants randomised to the limbal-based surgery: 1/50 eyes failed trabeculectomy in the fornix group compared with 3/50 in the limbal group (risk ratio (RR) 0.33, 95% confidence interval (95% CI) 0.04 to 3.10); therefore we are very uncertain as to the relative effect of the two procedures on failure rate.Four studies including 252 participants provided measures of mean IOP at 12 months. In the fornix-based surgeries, mean IOP ranged from 12.5 to 15.5 mmHg and similar results were noted in limbal-based surgeries with mean IOP ranging from 11.7 to 15.1 mmHg without significant difference. Mean difference was 0.44 mmHg (95% CI -0.45 to 1.33) and 0.86 mmHg, (95% CI -0.52 to 2.24) at 12 and 24 months of follow-up, respectively. Neither of these pooled analyses showed a statistically significant difference in IOP between groups (moderate quality of evidence).One trial reported number of anti-glaucoma medications at 24 months of follow-up with no difference noted between surgical groups. However, three trials reported the mean number of anti-glaucoma medications at 12 months of follow-up without significant difference in the mean number of postoperative IOP-lowering medications between the two surgical techniques. Mean difference was 0.02, (95% CI -0.15 to 0.19) at 12 months of follow-up (high quality of evidence).Because of the small numbers of events and total participants, the risk of many reported adverse events were uncertain and those that were found to be statistically significant may have been due to chance.For risk of bias assessment: although all six trials were randomised selection bias was mostly unclear, with unclear random sequence generation in four of the six studies and unclear allocation concealment in five of the six studies. Attrition bias was encountered in only one trial which also suffered from reporting bias. All other trials had an unclear risk of reporting bias as there was no access to study protocols. All included trials were judged to have high risk of detection bias due to lack of masking of the outcomes. Trabeculectomy is quite a standard procedure and unlikely to induce bias due to surgeon 'performance', hence performance bias was not evaluated.

AUTHORS' CONCLUSIONS

The main result of this review was that there was uncertainty as to the difference between fornix- and limbal-based trabeculectomy surgeries due to the small number of events and confidence intervals that cross the null. This also applied to postoperative complications, but without any impact on long-term failure rate between the two surgical techniques.

Limbus- versus fornix-based trabeculectomy for open-angle glaucoma eyes with prior ocular surgery: the Collaborative Bleb-Related Infection Incidence and Treatment Study

We compared the surgical successes of limbus- and fornix-based trabeculectomies in open-angle glaucoma (OAG) eyes that had prior ocular surgery in the Collaborative Bleb-Related Infection Incidence and Treatment Study (CBIITS), Japan. From the 1,098 glaucoma eyes in 34 clinical centers in CBIITS, 195 OAG eyes that had undergone previous trabeculectomy and/or lens extraction were included. Limbus- or fornix-based trabeculectomy with mitomycin C were performed. Surgical failure (IOP ≥ 21, 18, or 15 mmHg for criterion A, B or C, respectively; <20% decrease from baseline; reoperation for glaucoma; or loss of light perception vision) was counted. There were 106 and 89 eyes treated with limbus- and fornix-based trabeculectomies, respectively. At 3 years, IOP (mean ± SD) was 12.5 ± 5.9 and 14.1 ± 6.4 mmHg and the cumulative probabilities of failure during 3 years were 30.2% and 50.5% for criterion A, 40.3% and 57.4% for criterion B, and 57.9% and 65.8% for criterion C in the limbus- and the fornix-based group, respectively. Fornix-based incisions were associated with surgical failure in Cox-proportional multivariable analysis for criterion A [relative risk (RR) = 1.96], and B [RR = 1.60]. Limbus-based trabeculectomy had a higher probability of success in OAG eyes with prior ocular surgery.

Fornix-based versus limbus-based conjunctival flap in trabeculectomy: a quantitative evaluation of the evidence

Objective

To evaluate the efficacy and tolerability of limbus-based (LBCF) compared with fornix-based conjunctival flaps (FBCF) for trabeculectomy in the treatment of patients with uncontrolled glaucoma.

Methods

A comprehensive literature meta-analysis was performed according to the Cochrane Collaboration methodology to identify controlled clinical trials comparing LBCF with FBCF in trabeculectomy. The efficacy measures were the weighted mean differences (WMDs) for intraocular pressure reduction (IOPR), the reduction in glaucoma medications, and the relative risks (RRs) for success rates. Tolerability estimates were measured by RR for adverse events. The pooled effects were calculated using the random effects model.

Results

Sixteen controlled clinical trials meeting the predefined criteria were included in the meta-analysis. A total of 1,825 eyes from 1,392 patients with medically uncontrolled glaucoma were included. The WMD of the IOPR from baseline was 1.12 (95% CI: −0.88 to 3.12) when comparing LBCF with FBCF. LBCF was associated with numerically greater but non-significant IOP lowering efficacy than FBCF (P = 0.270). LBCF was comparable with FBCF in the reduction of glaucoma medication, with a WMD of 0.15 (−0.05 to 0.36) at the follow-up endpoint (P = 0.141). The pooled RR comparing LBCF with FBCF were 1.08 (0.94, 1.23) for the complete success rate and 1.01 (0.92, 1.10) for the qualified success rate. Rates of adverse events did not differ significantly between LBCF and FBCF.

Conclusions

There is no significant difference in IOP lowering, number of glaucoma medications, or proportion of patients who reached the IOP target between LBCF and FBCF trabeculectomy. Both incision techniques may contribute equally to adverse events.

Comparison of fornix- and limbus-based conjunctival flaps in mitomycin C trabeculectomy with laser suture lysis in Japanese glaucoma patients

PURPOSE

To analyze the results of mitomycin C (MMC) trabeculectomy and laser suture lysis using either fornix-based (FB) or limbus-based (LB) conjunctival flaps.

METHODS

Eighty-two Japanese glaucoma patients were treated by MMC trabeculectomy, with 38 eyes receiving an FB conjunctival flap and 44 eyes receiving an LB conjunctival flap. Postoperative intraocular pressure (IOP), the probability of success, and complications were compared between the FB and LB groups.

RESULTS

The IOP of the FB group decreased from 21.6+/-7.90 mmHg to 9.75+/-3.23 mmHg at 12 months postoperation, and the IOP of the LB group decreased from 21.3+/-6.77 mmHg to 9.30+/-3.16 mmHg. The postoperative IOPs were similar in the two groups at all postoperative time points. A life-table analysis (Kaplan-Meier method) showed that the survival rate was similar in the two groups but tended to be lower in the early postoperative period in the FB group. Complications were similar also, with the exception of increased leakage in the FB group.

CONCLUSIONS

MMC trabeculectomy results were similar between FB and LB conjunctival flaps, in agreement with previous reports. However, increased care may be warranted when an FB flap is used in MMC trabeculectomy.

Fornix vs limbal-based trabeculectomy with mitomycin C

PURPOSE

To compare the effectiveness of limbus- and fornix-based conjunctival flaps in patients undergoing trabeculectomy with mitomycin-C augmentation.

METHODS

A retrospective review of the records of 71 consecutive eyes of 59 patients who underwent trabeculectomy with mitomycin C. All the patients had at least 6 months of follow-up. The first 35 eyes underwent surgery with a limbal-based flap, whereas all subsequent surgeries were by fornix-based procedures.

RESULTS

No significant difference was detected between the groups with regard to patient demographics, preoperative visual field and intraocular pressure parameters, postoperative intraocular pressures at day 1, months 1, 3, and 6 postoperatively, need for intervention, need for supplementary glaucoma medication, and final visual acuity. There were four cases of overdrainage and hypotony in the limbal-based group, whereas none occurred in the fornix-based group. In all 83% percent of eyes in the limbal-based group achieved intraocular pressures off medication of less than 18 mmHg, whereas 94% of the fornix based group obtained such IOP control. One patient in the limbal-based group developed late postoperative endophthalmitis.

CONCLUSION

Trabeculectomy with MMC augmentation is a safe and effective procedure for reduction of IOP and visual rehabilitation whether a fornix- or a limbal-based conjunctival flap is utilised. In this series, there was a greater risk of excessive drainage with subsequent hypotonous complications when surgery was undertaken by a limbal-based procedure.

Protocol for mitomycin C use in glaucoma surgery

PURPOSE

To evaluate the results of a protocol described for mitomycin C (MMC) use in trabeculectomy or combined surgery (phacoemulsification and trabeculectomy).

METHODS

A total of 143 eyes (60 trabeculectomies and 83 combined surgeries) of 124 patients were divided into four groups: group 1 (without MMC); group 2 (with 0.1 mg/ml MMC); group 3 (with 0.2 mg/ml MMC), and group 4 (with 0.4 mg/ml MMC). Two-minute MMC was used in every case in groups 2, 3 and 4. The results were analysed after 1 year of follow-up. Intraocular pressure (IOP) and complications were evaluated. Successful IOP control was defined when IOP was <21 mmHg and <16 mmHg if advanced glaucoma was present, always without additional medical treatment.

RESULTS

Mean preoperative IOP decreased from 24.60 mmHg (SD 1.40 mmHg) to 13.47 mmHg (SD 0.37 mmHg) (p < 0.00001), 12 months postoperatively. Control in IOP was achieved in 79.02% of eyes. No significant differences were found in final mean IOP values (p > 0.196) or in postoperative complications (p > 0.120) in groups 2, 3 and 4.

CONCLUSION

With the protocol described, a selection of concentration of MMC has been made in different clinical forms of glaucoma. No significant differences in IOP control and postoperative complications were noticed among the groups.

Early postoperative trabeculectomy leakage: incidence, time course, severity, and impact on surgical outcome

AIM

To establish the incidence, time course, and severity of conjunctival wound leakage following trabeculectomy, and also to establish whether early wound leakage adversely affects the ultimate outcome of the surgery.

METHOD

A prospective, observational case series of sequential trabeculectomies performed in a single institution over a 12 month period. Datasets on 286 operations were analysed. A fornix based conjunctival flap was used in 254 cases and a limbus based conjunctival flap in 41 cases. At every postoperative visit trabeculectomies were assessed for four grades of leakage (none; mild; moderate; severe), and for success or failure at the 6 month follow up post surgery. Pressure was applied to the trabeculectomy bleb to record the maximum rates of leakage and improve kappa statistics. Study clinicians were validated with respect to their scoring of leaks before starting the study.

RESULTS

169 of the 286 trabeculectomies (59%) showed leakage at some stage postoperatively. 159 of 245 fornix based flaps (65%) leaked compared with 10 of 41 limbus based flaps (24%). Median time to leak was 3.5 (range 0-408) days. Median duration of leakage was 14 (range 2-457) days. 14 (5%) of trabeculectomies failed completely. A further 40 (14%) were a partial failure. In total, 23 of 117 (20%) without postoperative leaks partially or completely failed compared with 31 of 169 (18%) with leaks. Cross tabulation of partial and complete failure by leak shows no evidence of an adverse effect of leaking on the outcome (chi(2) = 1.81, p = 0.4).

CONCLUSIONS

There is no evidence to support the hypothesis that early postoperative leakage of fornix based conjunctival flaps affects the outcome of trabeculectomy.

Effect of technique on intraocular pressure after combined cataract and glaucoma surgery: An evidence-based review

TOPIC

To analyze the literature pertaining to the techniques used in combined cataract and glaucoma surgery, including the technique of cataract extraction, the timing of the surgery (staged procedure versus combined procedure), the anatomic location of the operation, and the use of antifibrosis agents.

CLINICAL RELEVANCE

Cataract and glaucoma are both common conditions and are often present in the same patient. There is no agreement concerning the optimal surgical management of these disorders when they coexist.

METHODS/LITERATURE REVIEWED

Electronic searches of English language articles published since 1964 were conducted in Pub MED and CENTRAL, the Cochrane Collaboration's database. These were augmented by a hand search of six ophthalmology journals and the reference lists of a sample of studies included in the literature review. Evidence grades (A, strong; B, moderate; C, weak; I, insufficient) were assigned to the evidence that involved a direct comparison of alternative techniques.

RESULTS

The preponderance of evidence from the literature suggests a small (2-4 mmHg) benefit from the use of mitomycin-C (MMC), but not 5-fluorouracil (5-FU), in combined cataract and glaucoma surgery (evidence grade B). Two-site surgery provides slightly lower (1-3 mmHg) intraocular pressure (IOP) than one-site surgery (evidence grade C), and IOP is lowered more (1-3 mmHg) by phacoemulsification than by nuclear expression in combined procedures (evidence grade C). There is insufficient evidence to conclude either that staged or combined procedures give better results or that alternative glaucoma procedures are superior to trabeculectomy in combined procedures.

CONCLUSIONS

In the literature on surgical techniques and adjuvants used in the management of coexisting cataract and glaucoma, the strongest evidence of efficacy exists for using MMC, separating the incisions for cataract and glaucoma surgery, and removing the nucleus by phacoemulsification.

Comparison of surgical outcomes of combined viscocanalostomy and cataract surgery with combined trabeculotomy and cataract surgery

PURPOSE

To compare the outcomes of combined viscocanalostomy, phacoemulsification, and intraocular lens (IOL) implantation with combined trabeculotomy, phacoemulsification, and IOL implantation in patients with primary open-angle glaucoma (POAG).

DESIGN

Nonrandomized clinical trial.

METHODS

Fifty-seven eyes (57 POAG patients) that underwent viscocanalostomy, phacoemulsification, and intraocular lens (IOL) implantation between March 2000 and April 2001 and were followed for over 6 months postoperatively comprised the viscocanalostomy (VCS) group. Fifty-seven of 105 eyes (105 POAG patients) that underwent trabeculotomy, phacoemulsification, and IOL implantation between April 1995 and February 2000 and were followed for over 6 months and < 2 years comprised the trabeculotomy (LOT) group. The reductions of postoperative intraocular pressure (IOP) and antiglaucoma medication use in both groups were compared. Best-corrected visual acuity (VA) and complication rates were secondary outcomes. The success probabilities related to postoperative IOP level in both groups were evaluated by Kaplan-Meier life-table analysis with log-rank test.

RESULTS

Significant reductions of IOP and antiglaucoma medication use occurred in both groups up to 1 year postoperatively, but were not significantly different between the two groups. The success probabilities of the VCS group for IOP control under 21, 17, and 15 mm Hg were 95%, 74%, and 44%, respectively, at 6 months, 95%, 67%, and 32% at 1 year, and not significantly different from the LOT group. All eyes in the VCS group had VA equal to or better than baseline 3 months postoperatively. The incidences of postoperative fibrin reaction (14 eyes, 25%) and microperforations of the Descemet membrane (14 eyes, 25%) in the VCS group were higher than in the LOT group (P =.0004 and P <.0001, respectively).

CONCLUSIONS

Intraocular pressure reduction and VA improvement after the two procedures were similar in Japanese patients with POAG and cataract.

Methodologic rigor of clinical trials on surgical management of eyes with coexisting cataract and glaucoma

OBJECTIVE

To assess the methodologic quality of published studies of the surgical management of coexisting cataract and glaucoma.

DESIGN

Literature review and analysis.

METHOD

We performed a systematic search of the literature to identify all English language articles pertaining to the surgical management of coexisting cataract and glaucoma in adults. Quality assessment was performed on all randomized controlled trials, nonrandomized controlled trials, and cohort studies. Overall quality scores and scores for individual methodologic domains were based on the evaluations of two experienced investigators who independently reviewed articles using an objective quality assessment form.

MAIN OUTCOME MEASURES

Quality in each of five domains (representativeness, bias and confounding, intervention description, outcomes and follow-up, and statistical quality and interpretation) measured as the percentage of methodologic criteria met by each study.

RESULTS

Thirty-six randomized controlled trials and 45 other studies were evaluated. The mean quality score for the randomized, controlled clinical trials was 63% (range, 11%-88%), and for the other studies the score was 45% (range, 3%-83%). The mean domain scores were 65% for description of therapy (range, 0%-100%), 62% for statistical analysis (range, 0%-100%), 58% for representativeness (range, 0%-94%), 49% for outcomes assessment (range, 0%-83%), and 30% for bias and confounding (range, 0%-83%). Twenty-five of the studies (31%) received a score of 0% in the bias and confounding domain for not randomizing patients, not masking the observers to treatment group, and not having equivalent groups at baseline.

CONCLUSIONS

Greater methodologic rigor and more detailed reporting of study results, particularly in the area of bias and confounding, could improve the quality of published clinical studies assessing the surgical management of coexisting cataract and glaucoma.

Two-site phacotrabeculectomy with intraoperative mitomycin-C: fornix- versus limbus-based conjunctival opening in fellow eyes

To prospectively compare the influence of fornix-based and limbus-based conjunctival flaps on the final outcome and complications of 2-site phacotrabeculectomy with mitomycin-C in fellow eyes of patients with bilateral open-angle glaucoma (OAG). Glaucoma Unit, Department of Ophthalmology, University of Crete, Crete, Greece.Twenty-two patients with bilateral primary OAG and 8 patients with bilateral exfoliative glaucoma had 2-site phacotrabeculectomy in both eyes. Eyes were randomly assigned to the fornix-based flap or limbus-based flap group by the use of random tables. The intraocular pressure (IOP) decreased significantly in both groups (P <.01); however, there was no statistically significant difference between the groups in the amount of IOP decrease or the number of postoperative antiglaucoma medications after a 1-year follow-up. Faster improvement in visual acuity was observed in the fornix-based group during the first week. The mean time of surgery was 3.5 minutes less in the fornix-based group. An increased incidence of fibrin exudation, pupillary membrane formation, and capsule opacification was found in eyes with exfoliative glaucoma. The early bleb leakage was 3 times more frequent in the fornix-based group. The type of conjunctival flap in a 2-site phacotrabeculectomy did not seem to influence the final outcome. The main advantage of the fornix-based conjunctival flap is the shorter surgical time and the relatively faster improvement in vision postoperatively. The main disadvantage is more frequent early bleb leakage.

Comparison of long-term incidence of posterior capsular opacification between phacoemulsification and phacotrabeculectomy

PURPOSE

To investigate the long-term incidence of posterior capsular opacification after phacoemulsification compared with phacotrabeculectomy with or without adjunctive subconjunctival mitomycin C.

METHODS

This was a retrospectively conducted long-term, observational, case-control study. One hundred eyes of 100 cataract patients who underwent phacoemulsification and posterior chamber intraocular lens implantation and 100 eyes of 100 primary open-angle glaucoma patients with cataract that underwent phacotrabeculectomy and posterior chamber intraocular lens implantation, matched with respect to age, intraocular lens type, prevalence of diabetes mellitus, and length of follow-up. The main outcome measure was the rate of clinically significant posterior capsular opacification as determined by slit-lamp biomicroscopy and necessity to perform neodynium:yttrium aluminum garnet (Nd:YAG) capsulotomy and as calculated by Kaplan-Meier survival analysis. Postoperative visual acuity and maintenance of intraocular pressure control were also measured.

RESULTS

There was no significant difference in the rate of posterior capsular opacification requiring Nd:YAG capsulotomy between the phacoemulsification and phacotrabeculectomy groups (P =.77). However, a significant difference in the rate of posterior capsular opacification was found between those patients without diabetes mellitus and those with a preoperative diagnosis of diabetes mellitus (P =.016). Also, survival analysis comparing use of mitomycin C with no use of mitomycin C in the phacotrabeculectomy group showed a higher survival in the mitomycin C subgroup (P =.03).

CONCLUSION

There was no significant difference in long-term posterior capsular opacification between phacoemulsification and phacotrabeculectomy in the study population. Intraoperative, adjunctive use of mitomycin C in the phacotrabeculectomy group and the presence of diabetes mellitus in the overall patients were beneficial (protective) factors against posterior capsular opacification.

Combined surgery in the treatment of patients with cataract and primary open-angle glaucoma

The literature on combined surgery in the treatment of patients with cataract and primary open-angle glaucoma was comprehensively studied, and all aspects and variations of the combined procedure were assessed. Phacoemulsification has improved the success rate and reduced the complication rate previously associated with extracapsular cataract extraction combined with trabeculectomy. A mean reduction in intraocular pressure (IOP) of 5 to 8 mm Hg can be achieved. One- and 2-site techniques appear to be similarly effective. Phacotrabeculectomy augmented with mitomycin-C achieves a lower IOP than phacotrabeculectomy alone but has a higher complication rate. The use of 5-fluorouracil is not as effective as mitomycin-C and has a variable influence on the results. The development of new techniques that combine nonpenetrating glaucoma surgery with phacoemulsification offers interesting surgical alternatives, but no long-term results have been reported.

Combined cataract and glaucoma surgery

The management of cataract in glaucoma patients has been continuously changing over the past decade. Extracapsular cataract extraction has been replaced by small-incision phacoemulsification with foldable lenses, and in glaucoma surgery, adjunctive antifibrotic therapy based on risk factors for failure has become standard. Furthermore, new techniques in filtering and nonfiltering surgery have been suggested. The techniques, however, change so fast that well-controlled studies with a follow-up of more than 12 months are increasingly seldom. The purpose of this paper is to review the current literature and to point out some new ideas for the future investigation.

Fornix-based trabeculectomy with Wise's suture technique in Chinese patients

OBJECTIVE

To assess the safety and efficacy of fornix-based trabeculectomy with Wise's suture technique in Chinese subjects.

DESIGN

A retrospective noncomparative case series.

PARTICIPANTS

Forty-eight eyes of 44 Chinese subjects that underwent fornix-based trabeculectomy combined with intraoperative 0.4 mg/ml mitomycin-C for 3 to 5 minutes were studied.

INTERVENTION

Conjunctival wound closure of all eyes was with the Wise's technique using 9-0 nylon suture to prevent leakage at the corneolimbal interface.

MAIN OUTCOME MEASURES

The success rate, with or without antiglaucoma medication, the complication rate, and the longevity of the drainage blebs were analyzed.

RESULTS

At a mean follow-up period of 21.8 +/- 4.5 months, 75% (36 eyes) had postoperative intraocular pressure of 21 mmHg or less. Of these, 23 eyes (47.9%) required no antiglaucoma medication, 7 eyes (14.6%) required one medication, 3 eyes (6.3%) required two medications, and 3 eyes (6.3%) required three medications. Ten eyes (21%) had early wound leak. Two eyes (4.2%) required surgical repair. Two eyes (4%) had hypotonous maculopathy. No other major complications were encountered.

CONCLUSIONS

Fornix-based trabeculectomy with adjunctive mitomycin-C using Wise's suture technique appears to be both safe and effective in Chinese subjects.

Combined cataract surgery, intraocular lens implantation, and viscocanalostomy

PURPOSE

To describe 2 techniques of combined viscocanalostomy and phacoemulsification and report the results.

SETTING

Gimbel Eye Centre, Calgary, Alberta, Canada.

METHODS

Combined viscocanalostomy, phacoemulsification, and intraocular lens implantation was performed in 83 eyes. A shared scleral incision was made in 46 eyes and a clear corneal incision separate from the viscocanalostomy site, in 37 eyes. A retrospective review of these cases was performed.

RESULTS

Intraocular pressure (IOP) was significantly lower in both groups 2 and 8 weeks and 6 months postoperatively. The decline in IOP postoperatively over time was also comparable. There were no cases of hypotony, choroidal detachment, filtrating bleb, or postoperative cystoid macular edema in either group. Complications included IOP spikes in 2 eyes in the shared-incision group at 1 day (to 43 and 30 mm Hg, respectively). In early shared-incision cases, there was 1 obvious Descement's puncture in 1 eye and a torn scleral flap requiring extra suturing in another eye.

CONCLUSION

Combined viscocanalostomy, cataract extraction, and IOL implantation was safe and efficacious in lowering IOP whether a shared scleral incision or a separate clear corneal incision was used for phacoemulsification.

Cataract surgery in the glaucoma patient: advances and modifications

Cataract removal in the glaucoma patient is a less arduous task today than it was a decade ago, because of technological advances and modifications in surgical technique. These technological advances include excellent phacoemulsification instrumentation. Useful modifications in surgical technique include the use of combined phacotrabeculectomy with antimetabolite supplementation, when necessary. Anticipated advances in the next decade include superior viscoelastics and the widespread availability of capsular tension rings.

Phacotrabeculectomy: limbus-based versus fornix-based conjunctival flaps in fellow eyes

OBJECTIVE

To compare the effectiveness of limbus-based and fornix-based conjunctival flaps in fellow eyes of the same patients undergoing combined trabeculectomy with phacoemulsification.

DESIGN

Prospective, nonrandomized comparative (fellow eye) study.

PARTICIPANTS

Forty-four patients and 88 fellow eyes.

INTERVENTION

Limbus-based conjunctival flap with phacotrabeculectomy was performed in one eye, and a fornix-based conjunctival flap with phacotrabeculectomy was performed in the fellow eyes of the same patients. The patients were followed up for a minimum of 1 year postoperatively for each eye.

MAIN OUTCOME MEASURES

Preoperative and postoperative visual acuity, intraocular pressure, number of antiglaucoma medications, interventions, and complications were studied.

RESULTS

At last follow-up visit, visual acuity improved to 20/40 or better in 88.6% of the limbus-based group and 79.6% of the fornix-based group. Preoperatively, the mean intraocular pressure in the limbus-based group was 21.4 +/- 4.8 mmHg on a mean of 2.4 +/- 1.2 glaucoma medications; in the fornix-based group, it was 21.4 +/- 4.3 mmHg on a mean of 2.3 +/- 1.1 medications. Mean intraocular pressure decreased to 15.3 +/- 3.3 mmHg (P < 0.01) on a mean of 0.2 +/- 0.5 glaucoma medications in the limbus-based group (P < 0.01). In the fornix-based group, mean intraocular pressure at last follow-up visit decreased to 15.3 +/- 4.7 mmHg (P < 0.01) on a mean of 0.2 +/- 0.5 medications (P < 0.01). Postoperative interventions and complications were not statistically different between the two groups.

CONCLUSION

With phacotrabeculectomy, limbus-based and fornix-based conjunctival flaps are equally effective in improving visual acuity and lowering intraocular pressure. This variation in conjunctival flap orientation was equally effective in fellow eyes of the same patients, with no difference in postoperative complications or outcomes.

The risk profile of glaucoma filtration surgery

Glaucoma surgery has evolved over the past 30 years from the full-thickness procedure to the guarded filtration procedure. However, many of the risks and complications attendant with the full-thickness procedure, including endophthalmitis, hypotony, cataract progression, and filtration failure, continue to plague the glaucoma surgeon performing the guarded filtration procedure, although at lower incidences. With proper modification of technique, such as with postoperative bleb titration and use of adjunctive antifibrotic therapy based on prognosticators for failure, the success rates of trabeculectomy reoperations can approach those of primary trabeculectomy. Such risk factors for failure include African-American race, higher preoperative intraocular pressures, previously failed filters, younger age, and uveitic and neovascular glaucomas. In this paper, we review a number of studies that analyze the risks, complications, and long-term results of glaucoma filtration surgery and discuss different surgical recommendations based on risk factors for failure as well as for performing concomitant cataract and glaucoma surgery.

Management of coincident glaucoma and cataract

Phacoemulsification for visually significant cataract and trabeculectomy for uncontrolled glaucoma are two of the most commonly performed ophthalmic surgeries. Many articles pertaining to cataract extraction in the glaucoma patient have been published during the 1-year scanning period of this periodical. This discussion reviews the recent literature as it pertains to the management of coincident cataract and glaucoma. Important topics addressed by the recent literature include long-standing controversies such as limbus-based versus fornix-based approaches to trabeculectomy and one-site versus two-site approaches to combined surgery, as well as innovative techniques in cataract and glaucoma surgery. This article also addresses perhaps the most controversial issue with regard to coincident cataract and glaucoma surgery, that is, the indications for the procedure. It should be noted that this article is not a comprehensive review but rather discusses the literature published within the 1-year scanning period.