The role of needle revision and 5-fluorouracil application over the filtration site in the management of bleb failure after trabeculectomy: a prospective study

The role of primary needle revision after Ahmed glaucoma valve (AGV) implantation

PURPOSE

To evaluate the efficacy and safety of primary needle revision after Ahmed Glaucoma Valve (AGV) implantation in comparison with glaucoma medication use.

METHODS

In this interventional case series, 23 eyes of 23 patients who underwent AGV implantation were enrolled. Needle revision was performed when the intraocular pressure was higher than the target pressure before glaucoma medications. Using a 30-gauge needle, the Tenon's capsule over the plate was incised and the bleb was reformed. Patients were examined on a postoperative day one, weekly (for four weeks), and every 1-3 months. Two criteria were used to define cumulative success as a minimum 20% reduction in IOP and 5 < IOP ≤ 21 mmHg (Criteria A) or 5 < IOP ≤ 18 mmHg (Criteria B) without (Complete success) or with (Qualified success) glaucoma medication.

RESULTS

In this pilot study, we enrolled 23 patients with a mean age of 53.8 ± 12.4 years (25-78 years) who underwent AGV implantation and a one-year follow-up period. The mean number of primary needle revision was 2.2 ± 1.6 (1-6). One year postoperatively, the cumulative success rate was 91.4% and 86.9% based on Criteria A and B, respectively. The average of preoperative IOP was 28.26 ± 8.86 mmHg (range 15-46 mmHg), reaching 13.78 ± 3.54 mmHg (range 8-20) at the end of the one-year follow-up. (P < 0.001) The mean preoperative medication significantly decreased from a median of 4 (range 3-4) at baseline to 2 (range 1-4) after the one-year follow-up (P < 0.001). One patient experienced leakage over the plate, which was successfully treated via conservative management.

CONCLUSION

This pilot study showed that primary needle revision is a safe and effective method for controlling IOP after AGV implantation with a lower need for medication.

Comparison of Efficacy and Safety of Bleb Needle Revision With and Without 5-Fluorouracil for Failing Trabeculectomy Bleb

PRéCIS:: Bleb needle revision with and without 5-FU showed similar success rates over the course of a long-term follow-up. A greater total number of needle revisions was identified as a risk factor for procedural failure.

PURPOSE

The purpose of the study was to investigate the efficacy and safety of bleb needle revision with adjunctive 5-fluorouracil (5-FU) subconjunctival injection in large-scaled patients with failing trabeculectomy bleb.

MATERIALS AND METHODS

A retrospective chart review was performed on a total of 113 eyes of 106 subjects who had undergone trabeculectomy followed by needle revision and been followed up for at least 6 months. The subjects were divided into 2 groups according to whether they had also undergone concurrent adjunctive 5-FU subconjunctival injection. Two definitions of failure were derived irrespective of IOP-lowering medication use and were assessed at each follow-up visit: (1) IOP>21 mm Hg or >85% of preoperative IOP or reoperation for glaucoma, (2) IOP>18 mm Hg or >80% of preoperative IOP or reoperation for glaucoma.

RESULTS

A total of 78 eyes of 73 subjects underwent the simple needle revision procedure and 35 eyes of 33 subjects underwent needle revision with subconjunctival 5-FU injection. There was no significant adverse event for either group and no significant IOP difference in any of the observational periods between them (P=0.867). There was also no statistically significant difference in the total number of IOP-lowering medications between the groups (P=0.199). The success rate at 24 months after the first needle revision was 45.6% (95% CI: 33.7, 56.7) in simple revision group and 44.6% (95% CI: 27.7, 60.2) in 5-FU needle revision group by failure 1, 36.3% (95% CI: 25.4, 47.2) and 32.9% (95% CI: 18.0, 48.6) by failure 2, respectively. A greater total number of needle revisions was the significant risk factors for needle revision failure (HR=2.25 and P=0.001 according to failure 2).

CONCLUSIONS

Bleb needle revision with 5-FU subconjunctival injection is a safe procedure for failing trabeculectomy bleb. Bleb needle revision with and without 5-FU were equally likely to succeed.

The relationship of bleb morphology and the outcome of needle revision with 5-fluorouracil in failing filtering bleb

To investigate the risk factors for failure of needling revision with 5-fluorouracil (5-FU) and to identify the correlation of outcomes of needling revision and the morphological features of dysfunctional filtration blebs using Moorfields bleb grading system.This retrospective, nonrandomized, comparative case-control study included 41 consecutive patients (41 eyes) who underwent 5-FU needling revision for failed or failing filtration blebs between July 2012 and August 2014 in Chang Gung Memorial Hospital, a referral center in Taiwan. The main outcome measures were the bleb survival and the correlation factors of bleb morphology before revision. The secondary outcome measure was the identification of any study factor associated with bleb failure.Forty-one eyes of 41 patients were included in this study. The most frequent glaucoma diagnoses were 10 cases (24%) of neovascular glaucoma and 8 cases (19%) of chronic open-angle glaucoma. Survival of bleb at 6, 12, and 24 months was 42%, 39%, and 23%. Fourteen cases (34%) maintained overall success at the last follow-up, with an average follow-up of 22.7 ± 9.4 months (range: 12-48 months). The central bleb area and height were significantly different between the successful needling group and the failed needling group (P = 0.03 and 0.04, respectively). Further trend test confirmed that smaller central bleb extension and flatter height were associated with a higher chance of failure (P = 0.02 and 0.02, respectively). Time from initial trabeculectomy to needling of less than 4 months and higher intraocular pressure (IOP) in the first postoperative week also led to significantly higher risk for failure (P = 0.01 and 0.03, respectively).A small central area and the flat height of dysfunctional blebs were more likely to fail after the needle revision. Cautious case selections, taking account of the time from the initial filtering surgery and postoperative IOP, may improve the surgical outcome.

Outcomes: Trabeculectomy Bleb Needle Revision With 5-Fluorouracil

PURPOSE

To evaluate outcomes of trabeculectomy bleb needle revision with 5-fluorouracil augmentation performed in the operating theater.

METHODS

Retrospective study of all patients undergoing trabeculectomy bleb needle revisions in the operating theater performed by a single surgeon in a metropolitan hospital in Australia. A total of 51 needle revisions were performed on 33 eyes over a mean follow-up time of 1.81±1.56 years.

RESULTS

A total of 29% achieved intraocular pressure (IOP) ≤20 mm Hg off all glaucoma medications, and an additional 39% achieved qualified success with the addition of glaucoma medications, giving overall success of 68%. Analyzing success rate for target IOP≤16 mm Hg, 24% achieved target off all glaucoma medications, 35% achieved qualified success with the addition of glaucoma medications, giving an overall success rate of 59%. There was a statistically significant improvement in IOP, as compared with preoperative levels, at all timepoints postoperatively (P<0.05). However, number of glaucoma medications remained unchanged (P>0.05) contributing to the high percentage of qualified successes. Visual acuity remained unchanged and there were no major postoperative complications. The Kaplan-Meier survival shows a survival rate of 60% with IOP≤20 mm Hg and 40% for IOP≤16 mm Hg at 5 years.

CONCLUSIONS

Trabeculectomy needle revision is a useful option for the management of elevated IOP in the presence of a failed or failing trabeculectomy bleb. However, as with trabeculectomy, there tends to be a failure rate over time. This often leads to reinstitution of glaucoma medications and/or further needle revisions to maintain IOPs at target level. The procedure itself is minimally invasive with an acceptable safety profile.

The Effect of Everolimus on Scar Formation in Glaucoma Filtering Surgery in a Rabbit Model

PURPOSE

To investigate the efficiency of everolimus on the prevention of postoperative scar in a rabbit model of glaucoma filtering surgery in comparison with mitomycin-C (MMC).

MATERIALS AND METHODS

Thirty New Zealand albino rabbits were randomly assigned into 3 groups, each including ten rabbits: an everolimus group (Group 1), a MMC group (Group 2), and a sham group (Group 3). A limbal-based trabeculectomy was performed on the right eyes of all the rabbits. For 28 days following surgery, the eyes were evaluated in terms of intraocular pressure (IOP), morphological and biomicroscopic changes, and complications in the bleb. On the 28th day, four eyes randomized from each group were enucleated and histologically and immunohistochemically analyzed. Transforming growth factor-β1 (TGF-β1), metalloproteinase (MMP-2, MMP-9), and proliferative cell nuclear antigen (PCNA) expressions in each group were evaluated. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method was used for apoptosis.

RESULTS

Bleb survival was statistically significantly longer for a period in Group 1 compared to Group 2. When postoperative IOPs of three groups were measured, it was seen that there is significant IOP reduction in all three groups. However, there were increases in the mean IOP values beginning from the 5th day in Group 2 and from the 3rd day in Group 3 while in Group 1 mean IOP values began to increase beginning from 10th day and the mean IOP values in Group 1 remained at a lower level in comparison to the other groups for 28 days (p < 0.05). The expressions of TGF-β1, MMP-2, MMP-9, and PCNA were reduced in Group 1 compared to other groups. TUNEL positive apoptotic cells were significantly increased in Group 1 compared to other groups (p < 0.05).

CONCLUSION

Everolimus appears to suppress the proliferation of fibroblast and thus may provide an effective treatment strategy in glaucoma filtering surgery.

Comparison of Subconjunctival Mitomycin C and 5-Fluorouracil Injection for Needle Revision of Early Failed Trabeculectomy Blebs

Background. To compare the efficacy of needle revision with 5-fluorouracil (5-FU) and mitomycin C (MMC) on dysfunctional filtration blebs shortly after trabeculectomy. Methods. It is a prospective randomized study comparing needle revision augmented with MMC or 5-FU for failed trabeculectomy blebs. Results. To date 71 patients (75 eyes) have been enrolled, 40 eyes in the MMC group and 35 in the 5-FU group. 68 patients (72 eyes) have completed 12-month follow-up, 38 eyes in the MMC group and 34 in the 5-FU group. The mean IOP before and that after needle revision in the MMC group were 26.5 ± 4.3 mmHg and 11.3 ± 3.4 mmHg, respectively (P < 0.05), and in the 5-FU group were 27.1 ± 3.8 mmHg and 10.9 ± 3.4 mmHg, respectively (P < 0.05). At 12-month follow-up, complete success rates were 57.5% for MMC group and 34.3% for 5-FU group (P = 0.042; log-rank test) and 75% and 60% (P = 0.145; log-rank test), respectively, for the qualified success. Complication rates between the two groups were not statistically different (P > 0.05). Conclusions. Needle revision and subconjunctival MMC injection were more effective than needling and subconjunctival 5-FU injection for early dysfunctional filtration blebs after trabeculectomies.

Intra-bleb hematoma and hyphema following digital ocular compression

We report successful outcome of a huge post- trabeculectomy intra-bleb hematoma and hyphema that occurred following digital ocular compression. The patient was a 64-year-old lady suffering from bilateral primary angle closure glaucoma and cataract. She was on anti-platelet therapy. She underwent single-site phacoemulsification, intra-ocular lens implantation and trabeculectomy with mitomycin C in the right eye. The trabeculectomy was under-filtering. She was asked to perform digital ocular compression thrice daily. On 15^th post-operative day, she presented with a huge intra-bleb hematoma and hyphema. The hematoma did not respond to conservative measures and was drained to prevent bleb failure. We recommend caution in the consideration of digital ocular compression in patients on prophylactic anti-coagulation.

Efficacy of repeated 5-fluorouracil needling for failing and failed filtering surgeries based on simple gonioscopic examination

Purpose

To evaluate the success rate of a modified bleb needling technique in eyes with previous glaucoma surgery that had elevated intraocular pressure.

Methods

A retrospective study of 24 eyes of 24 patients that underwent repeated bleb needling performed for failing and failed blebs on slit lamp with 5-fluorouracil (5-FU) injections on demand. This was performed after gonioscopic examination to define levels of filtration block.

Results

There was significant reduction of mean IOP from 36.91 mmHg to 14.73 mmHg at the final follow-up (P < 0.001). The overall success rate was 92%.

Conclusion

Repeated needling with adjunctive 5-FU proved a highly effective, safe alternative to revive filtration surgery rather than another medication or surgery.

Comparison of needle revision with subconjunctival bevacizumab and 5-fluorouracil injection of failed trabeculectomy blebs

PURPOSE

To evaluate the efficacy and complications of bevacizumab versus 5-fluorouracil (5-FU)-augmented bleb needling of failed filtration blebs following trabeculectomy.

METHODS

Twenty-seven eyes of 27 patients with bleb failure were included. Patients were randomly assigned to receive either 5-FU or bevacizumab. Needling was performed in the operating room under sterile conditions. After the needling procedure, a viscoelastic material was injected subconjunctivally around the bleb area to avoid the entrance of 5-FU or bevacizumab into the anterior chamber. Bevacizumab (1.25 mg/0.1 mL) was injected into 12 eyes and 5-FU injected into 15 eyes subconjunctivally. All of the patients were controlled weekly until a filtration bleb was maintained. Intraocular pressure (IOP), bleb appearance, and complications were noted in each group. Success was defined as absolute if the IOP 21 mmHg or less without any medication or surgical intervention at last visit, and qualified if the IOP 21 mmHg or less with topical antiglaucomatous medications. The patients were followed from 11 to 26 (median, 17) months.

RESULTS

The IOP decreased, from 31.2±3.2 mmHg to 16.1±2.1 mmHg, in the bevacizumab group on the first postoperative day. The IOP was within normal limits in 1 (8.3%) patient without medication and controlled with topical antiglaucomatous drops in 2 (16.7%) patients. The total success rate was 25% at the time of the last visit. Success was not achieved in 9 (75%) eyes. The IOP was 32.0±4.6 mmHg preoperatively and 12.2±2.6 mmHg on the first postoperative day in the 5-FU injected patients. The total success rate was 80%; 8 (53.3%) eyes showed absolute success, whereas 4 (26.7%) eyes showed a qualified success. A statistically significant difference between groups in terms of success rates was observed (P=0.04).

CONCLUSIONS

Subconjunctival 5-FU application is a more effective therapy than bevacizumab application for needling procedures in failed trabeculectomy blebs.

Single needle revision of failing filtration blebs: a retrospective comparative case series with 5-fluorouracil and mitomycin C

PURPOSE

To assess the success of needling in failed filtration blebs and the potential benefit of using either 5-fluorouracil (5-FU) or mitomycin C (MMC).

METHODS

In this retrospective, comparative observational case series, 107 eyes that underwent needle revision with either 5-FU or MMC between July 2003 and May 2008 at Wills Eye Institute were selected. Exclusion criteria included follow-up less than 1 month and a history of glaucoma drainage device. Intraocular pressure (IOP) and number of glaucoma medications were recorded preoperatively and postoperatively. Success was defined as >20% decrease in IOP if glaucoma medications were resumed or <10% decrease in IOP if medications were not resumed post needling or fewer medications than pre needling.

RESULTS

Sixty-five patients received 5-FU and 42 patients received MMC for needling. Mean IOP changed from 23.9 mmHg to 13.8 mmHg in the MMC group and from 23.3 mmHg to 13.02 mmHg in the 5-FU group (both p<0.001). Mean glaucoma medications changed from 1.7 to 0.7 in the MMC group and 2.0 to 0.8 in the 5-FU group (both p<0.001) at the end of follow-up. After a mean follow-up of 14.5 months, overall survival was 49.5%. Mean time to failure was 7.7 months. There was a moderately weak association between survival and the immediate postoperative IOP (r=0.262, p=0.01). In comparing MMC and 5-FU, there was no statistically significant difference in survival rate (p=0.267).

CONCLUSIONS

Bleb needling may be a safe and effective means of prolonging bleb survival. The only factor associated with success was the immediate postoperative IOP. There was no apparent difference between the use of 5-FU and MMC in this population. A prospective study may provide further confirmation of this finding.

Late needling of flat filtering blebs with adjunctive mitomycin C: efficacy and safety for the corneal endothelium

PURPOSE

To assess the efficacy of needle revision using mitomycin C (MMC) for reviving failed filtering blebs during the late postoperative period and its safety for the corneal endothelium.

DESIGN

Prospective interventional case series.

PARTICIPANTS

We recruited 125 eyes from 98 patients with uncontrolled glaucoma. All had at least 1 failed trabeculectomy, a flat filtering bleb, and a patent internal ostium on gonioscopy. The average time between the last trabeculectomy and needle revision was 5.3±5.3 years (range, 6 months to 30 years).

INTERVENTION

Needling revision with a subconjunctival injection of 8 μg of MMC.

MAIN OUTCOME MEASURES

Intraocular pressure (IOP) and number of hypotensive medications at latest visit, central corneal thickness (CCT), corneal endothelial cell density (ECD), coefficient of variation of cell size (CV), and hexagonality before and after needling.

RESULTS

We performed 186 needling procedures on 125 eyes (mean, 1.5±0.6 procedures/eye). Seventy-three eyes (58.4%) were needled once, 44 eyes (35.2%) were needled twice, 7 eyes (5.6%) were needled 3 times, and 1 eye (0.8%) was needled 4 times. We reestablished aqueous flow and obtained a raised bleb in 115 eyes (92%). After an average follow-up of 20.8±12.0 months, the mean IOP decreased from 20.1±5.2 mmHg preoperatively to 13.2±6.8 mmHg (P<0.001), and the mean number of hypotensive medications per eye decreased from 2.4±1.1 to 0.8±1.3 (P<0.001) at the latest visit. The overall success rate (IOP ≤16 mmHg) was 76% (58.4% without medication and 17.6% with hypotensive medications). Kaplan-Meier survival rates were 91.2% at the 1-month follow-up, 84.5% at 6 months, 81.0% at 1 year, 74.6% at 2 years, and 66.3% at 3 years. We studied the corneal endothelium in 42 eyes of 36 patients. There was no statistically significant difference between preoperative CCT, ECD, CV, or hexagonality and postoperative measurements at 1 week and 1, 3, 6, and 12 months.

CONCLUSIONS

Needling revision with adjunctive MMC is effective for reviving flat filtering blebs and controlling IOP, even several years after the original trabeculectomy, and seems to be safe for the corneal endothelium.

Moving the goal posts definitions of success after glaucoma surgery and their effect on reported outcome

PURPOSE

To determine (1) the extent to which the definition of success of glaucoma surgery varies in the literature and (2) the degree to which the reported outcome after trabeculectomy is affected by the criteria used to define success.

DESIGN

A systematic review of the literature and application of definitions to a retrospective cohort.

PARTICIPANTS

A cohort of 100 patients who previously underwent trabeculectomy.

METHODS

A literature search was performed of PubMed using the search term trabeculectomy for a 5-year period. Studies presenting original data relating to longitudinal intraocular pressure (IOP) control after glaucoma surgery were included. The definitions of success and failure used were documented for each publication. Each IOP-related definition of success was applied to a cohort of patients who previously underwent trabeculectomy. Success rates were derived for each published definition up to 36 months after surgery.

MAIN OUTCOME MEASURES

Intraocular pressure measured by Goldmann applanation tonometry.

RESULTS

From 100 publications meeting the inclusion criteria, 92 distinct IOP-related definitions of success were identified. Using these definitions, success rates for this series of 100 trabeculectomies varied between 36.0% and 98.0% after 3 years of follow-up.

CONCLUSIONS

Over a recent 5-year period, there were nearly as many different definitions of success after glaucoma surgery as publications on the subject. The definition used markedly affects the quoted success rate after trabeculectomy, making interpretation of and comparison between published results extremely difficult. Standardization of published outcome parameters after glaucoma surgery is essential to allow meaningful comparisons between different study reports.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

[Late needling with 5-fluorouracil when scarring of filtering bleb seems imminent]

BACKGROUND

Evaluation of needling and 5-fluorouracil (5-FU) injections more than 4 months after preceding filtration surgery.

PATIENTS AND METHOD

Retrospective analysis of 17 eyes in 14 patients who underwent needling of the filtering bleb and administration of 5-FU by injection at least 4 months after trabeculectomy (TE) with mitomycin C (MMC; same surgeon throughout). Complete success was defined as a reduction of intraocular pressure (IOP) by >30% from the baseline value without further medication and, in cases of primary open-angle glaucoma, IOP of 18 mmHg. The mean period of follow-up was 8.1 months (3-24 months).

RESULTS

One to four needlings (Ø 1.6) with one to five injections (Ø 3.1) of 5-FU were performed as required according to clinical need an average of 31.3 months (4-108 m) after TE. The mean baseline IOP was 25 mmHg (+/-SD 6.02; median 25 mmHg). After needling and 5-FU injection the mean IOD at the last hospital visit was 13.64 mmHg (+/-SD 5.2, median 13 mmHg; p<0,001). Complete success was achieved in 82.4% of these cases. The mean reduction in IOP was 11.2 mmHg (0-22 mmHg). In the cases with successful outcome (14 of 17 eyes) the mean IOP reduction from baseline was 55%. Three eyes required further treatment. Complications encountered were hyphaema (2 cases), subconjunctival bleeding (1 case) and corneal erosion (3 cases).

CONCLUSION

Late needling and injections of 5-FU can restore filtering bleb function even over 4 months after initial surgery. The high success rate and low incidence of complications together with the simple procedure justify regarding this approach as an alternative that can be used before passing on to more invasive interventions.

Rescue of failed filtering blebs with ab interno trephination

We evaluated the effectiveness of ab interno automated trephination as a technique for rescuing failed mature filtering blebs. A retrospective chart review of 40 failed blebs of 38 patients who had a posttrephination follow-up period of at least 3 months was done. With success defined as intraocular pressure (IOP) <21 mm Hg and at least a 20% reduction from baseline on the same or fewer number of pretrephination medications, 30/40 eyes (75%) fit these criteria over the entire course of follow-up. Among all 40 eyes, there was a significant reduction of IOP from pretrephination to 3 months (P<.001). The percentage of patients requiring 2 or more medications declined from 90% pretrephination to 21% at 3 months (P<.0001), and was stable thereafter. Some patients were able to eliminate all medications. Patients who did not meet the criteria of success regained successful IOP control with other modalities of management. Complications were few. We believe that ab interno trephination is an excellent option for rescuing selected failed filtering blebs.

Prospective evaluation of preoperative factors associated with successful mitomycin C needling of failed filtration blebs

PURPOSE

To study the long-term effectiveness and factors involved in successful needling of failed filtration blebs with mitomycin C (MMC).

MATERIALS AND METHODS

We conducted a prospective, nonrandomized comparative trial that included 34 consecutive patients (34 eyes) who underwent mitomycin C needling of a failed filtering bleb after trabeculectomy followed by a 0.01 mL injection of mitomycin C (0.2 mg/ml). The success of the needling revision was defined as absolute if the intraocular pressure (IOP) was < 21 mm Hg without antiglaucoma medications and qualified if the IOP was < 21 mm Hg with antiglaucoma medications. Preoperative and perioperative factors were evaluated for an association with postoperative success using Kaplan-Meier survival analysis.

RESULTS

The mean follow-up was 14.2 +/- 9.8 months. The mean preoperative IOP was 25.5 +/- 4.4 mm Hg, which decreased to 11.1, 13.4, 15.8, 16.7, 14.9, 14.1, 13.9, and 13 on postoperative day 1, postoperative week 1, and after 1, 3, 6, 9, 12, and 24 months, respectively (P = 0.001 for each comparison). At the final visit, success was absolute in 15 eyes (44.1%) and qualified in 14 eyes (41.2%). The success rates were 90% and 75% at 1 and 2 years, respectively. The success of the needling procedure was highly correlated with glaucoma filtration surgery performed less than 4 months previously (Kaplan-Meier analysis, log-rank test P = 0.006).

CONCLUSIONS

Mitomycin C needling revision appears to have a high long-term success rate. Surgery performed less than 4 months previously contributes to the success of the initial mitomycin C needling procedure.

Is intraocular pressure in the early postoperative period predictive of antimetabolite-augmented filtration surgery success?

PURPOSE

To determine whether intraocular pressure (IOP) in the early postoperative period after trabeculectomy or combined phacoemulsification-trabeculectomy, augmented with antimetabolite, correlates with IOP at one year in surgeries considered to be successful at that time point.

DESIGN

Retrospective case series.

METHODS

A chart review of antimetabolite-augmented surgical procedures done by DJG and JBS between January 1994 and November 2000 identified 82 primary or secondary trabeculectomies and 53 combined phacoemulsification-trabeculectomies with at least one year of follow-up. The success rate for each surgical subgroup was calculated and IOP on postoperative days (POD +/- SD) 1, 7 (+/-2), 30 (+/-5), 90 (+/-10), and 180 (+/-20) was correlated with IOP at one year (POY 1, between month 12 and 15) using linear regression. IOP at each time point was compared among eyes that achieved success at one year with and without the use of IOP-lowering agents.

RESULTS

Of the 82 eyes having undergone antimetabolite-augmented trabeculectomies and the 53 eyes having undergone combined surgeries with at least one year of follow-up, the surgical success rates at POY 1 were 87.8% (72 of 82 eyes) and 92.5% (49 of 53 eyes). Of these, 42 eyes (58.3%) from 39 patients in the trabeculectomy group and 27 eyes (55.1%) from 24 patients in the combined surgery group did not require glaucoma medications at one year postsurgically, and were considered complete surgical successes. Mean preoperative IOP mm Hg +/- SD was 26.0 +/- 8.5 for the trabeculectomy group and 18.2 +/- 4.5 for the phaco-trabeculectomy group. Postoperative IOP at POD 1, POD 7, POD 30, POD 90, POD 180, and POY 1 respectively for the eyes undergoing trabeculectomy were 13.9 +/- 10.4, 9.5 +/- 6.2, 12.0 +/- 5.5, 12.0 +/- 5.2, 12.8 +/- 5.9, and 12.1 +/- 4.3, and for the combined surgery group were 20.8 +/- 12.5, 9.7 +/- 5.7, 12.2 +/- 5.4, 11.1 +/- 3.4, 11.6 +/- 4.6, and 10.3 +/- 4.3. Intraocular pressure on postoperative day one correlated poorly with intraocular pressure at POY 1 for the trabeculectomy group (R2 = 0.0788), and not at all for the combined procedures group (R2 = 0.018). The correlation was slightly better for intraocular pressure at postoperative day 90 for the trabeculectomy group (R2 = 0.546), and at postoperative day 180 for the combined group (R2 = 0.37), but still rather low. Eyes requiring glaucoma medication use at POY 1 in the trabeculectomy group had higher (P < 0.009) intraocular pressure at POD 30 and at all subsequent visits than eyes not requiring these medications. Eyes requiring glaucoma medication use at POY 1 in the phaco-trabeculectomy group had higher (P < 0.0025) intraocular pressure at POD 30, POD 180, and POY 1 than eyes not requiring these medications.

CONCLUSION

Intraocular pressure in the early postoperative period correlates very poorly with intraocular pressure one year after successful antimetabolite-augmented trabeculectomy or combined cataract extraction and trabeculectomy. Starting one month after glaucoma surgery, intraocular pressure is substantially lower in eyes that will ultimately not require the use of ocular hypotensive agents to achieve clinical success one year postoperatively.