Long-term intraocular pressure control of eyes that developed encapsulated blebs following trabeculectomy

Usefulness of Eye Deformation in the Corvis ST Measurement to Predict Postoperative Hypotony Complications in Glaucoma

PURPOSE

This study aimed to investigate the usefulness of measuring biomechanical parameters using the Corvis ST to predict the occurrence of hypotony maculopathy and choroidal detachment (CD) following trabeculectomy or bleb needling revision with mitomycin C.

DESIGN

Clinical cohort study.

METHODS

This study included 100 eyes of 100 patients who underwent trabeculectomy (88 eyes of 88 patients) or bleb needling (12 eyes of 12 patients) with mitomycin C. A significant predictor of hypotony complications was identified from (1) operation (trabeculectomy or bleb needling), (2) age, (3) sex, (4) disease type (primary open-angle glaucoma, exfoliation glaucoma or other), (5) lens status (phakia or pseudophakia), (6) preoperative Goldmann applanation tonometry (GAT) intraocular pressure (IOP), (7) preoperative central corneal thickness (CCT), (8) preoperative axial length (AL), (9) preoperative anterior chamber depth, (10) "Min IOP" (IOP value when hypotony complications occurred, otherwise the minimum IOP during 3 months from trabeculectomy or bleb needling), (11) preoperative corneal curvature, and (12-24) 12 Corvis ST parameters using multivariate logistic regression.

RESULTS

There were 13 and 21 eyes developed hypotony maculopathy and CD, respectively. Male gender, greater preoperative GAT IOP, and greater highest concavity deflection Amplitude were significant predictors of the occurrence of hypotony maculopathy (P < .05). On the other hand, shorter AL, thinner CCT, greater preoperative GAT IOP and pseudophakia were significant predictors of the occurrence of CD (P < .05).

CONCLUSIONS

A careful attention should be paid to the occurrence of hypotony maculopathy with male gender and greater highest concavity deflection Amplitude despite higher preoperative GAT IOP. Different risk factors were identified; shorter AL, thinner CCT, greater preoperative GAT IOP, and pseudophakia.

Bleb Needling with Mitomycin C as Adjunctive Therapy in Failing Blebs: A Retrospective Study

PURPOSE

To evaluate the effects and complications related to use of mitomycin C (MMC) as an adjunctive therapy in bleb needling.

METHODS

Retrospective review of the records of patients affected by open-angle glaucoma who underwent a bleb revision as a treatment for failed trabeculectomy. All subjects underwent surgery with a fornix-based approach to incision. Full baseline data for each patient included a comprehensive ocular and medical history, the patient's Snellen visual acuity test results, and Goldmann applanation tonometry test results. Data were reported following observations occurring at 6, 12, 18, 24, and 30 months. In addition, the number and timing of needling with or without MMC subconjunctival injections and any short- and long-term complications were observed.

RESULTS

We included 101 patients, 56 (55.4%) male and 45 (44.6%) female. The mean age was 69.81 ± 16.19 years (range 28-92). Statistically significant effects of needling and needling and MMC (p values <0.05) in the decrease in intraocular pressure were observed. Three (2.9%) patients presented hypotony at the last follow-up visit. No other complications were observed.

CONCLUSIONS

Needling bleb revision augmented with the use of MMC appears to be a more useful tool in the management of failing bleb.

Long-term outcome of mitomycin C-augmented needle revision of trabeculectomy blebs for late trabeculectomy failure

OBJECTIVES

To describe the 3-year outcomes of mitomycin C (MMC)-augmented bleb needling procedures following late trabeculectomy failure.

METHODS

A retrospective, observational chart review of 44 eyes that underwent MMC-augmented bleb needling following late trabeculectomy failure. The primary outcome measure was IOP at 3 years post-operatively. Secondary outcome measures were the number of topical glaucoma medications and success rate at 3 years. Success was defined on the basis of IOP (≤21 mmHg and ≥5 mmHg with a reduction of ≥ 20% from pre-operative baseline), need for ocular hypotensive medications, and need for further laser or surgical intervention.

RESULTS

Mean IOP was reduced from 19.8 mmHg preoperatively to 13.9 mmHg (29.5% reduction) at 3 years. By the 3-year time point, 26 eyes (59.1%) had met one or more of the criteria for failure. A lower immediate post-operative IOP was found to be associated with greater likelihood of success.

CONCLUSIONS

Bleb needling augmented with MMC can achieve a significant reduction in IOP in eyes with late trabeculectomy failure. By 3 years however, 59% of eyes were classified as failures, with half requiring further glaucoma surgery or laser. Patients undergoing this procedure should therefore be warned of the likelihood of requiring further intervention, and a repeat antimetabolite-augmented trabeculectomy or glaucoma tube shunt surgery in the first instance can be considered instead.

Bleb needling outcomes for failed trabeculectomy blebs in Asian eyes: a 2-year follow up

AIM

To describe the outcomes of bleb needling in primary glaucoma in an Asian tertiary eye centre over a 2y period. To compare the success rates between primary angle-closure glaucoma (PACG) and primary open angle glaucoma (POAG). Lastly, to identify factors associated with success of bleb needling.

METHODS

This was a retrospective review of 227 patients who underwent bleb needling between June 2009 and June 2011 in Singapore National Eye Centre. The 5-fluorouracil (5-FU) augmented bleb needling was performed either at the slit lamp or in the operating theatre. Repeat bleb needlings were performed as necessary. Complete success was defined as maintenance of intraocular pressure (IOP) ≥6 mm Hg and ≤21 mm Hg, in the absence of further surgery or use of antiglaucoma medication. Qualified success met the above criteria with or without use of antiglaucoma medications.

RESULTS

One hundred and seventy-five eyes completed the two-year follow up. Sixty-nine percent of participants had POAG and 31% had PACG. The mean interval between filtering surgery and bleb needling was 299.9±616.4d for POAG and 167.1±272.2d for PACG. Mean needling attempts were 1.9±1.4 and 2±1.6 for POAG and PACG respectively. In general, there was a statistically significant reduction of IOP ranging from 21.9% to 26.8% from month 1 through to month 24. The complete success rates at month 6 were 70.0% for POAG and 65.7% for PACG. At month 12, this decreased to 62.2% for POAG and PACG and at month 24, 57.9% for POAG and 63.0% for PACG respectively. The qualified success rates at month 6 for POAG and PACG were 23.8% and 29.9% respectively, 32.2% and 29.2% at month 12, and 34.7% and 29.6% at month 24. The success rates between POAG and PACG were not significantly different (P>0.05 for complete and qualified success at months 6, 12 and 24). An increased number of needlings and higher pre-needling IOP were associated with failure.

CONCLUSION

The 5-FU augmented bleb needling within one year of trabeculectomy in Asian eyes can provide clinically significant IOP lowering of more than 20% for 2y. POAG and PACG had similar complete success rates (58% and 63% respectively). Factors associated with greater risk of procedure failure included increased number of needlings and higher pre-needling IOP. Asian eyes have a greater propensity for scarring but bleb needling, if performed in a timely manner can rescue bleb function.

Needling for encapsulated trabeculectomy filtering blebs

BACKGROUND

Encapsulation of a filtering bleb following trabeculectomy may lead to elevation of intraocular pressure, prompting further medical or surgical intervention. It has been suggested that needling of an encapsulated bleb may be effective in re-establishing drainage and lowering intraocular pressure.

OBJECTIVES

The objective of this review was to assess the effects of needling encapsulated blebs on intraocular pressure.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 1), MEDLINE (January 1950 to February 2012), EMBASE (January 1980 to February 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to February 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the 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. The electronic databases were last searched on 14 February 2012.

SELECTION CRITERIA

We included randomised and quasi-randomised in which bleb needling was compared with any form of antiglaucoma medication in people with encapsulated trabeculectomy blebs. The primary outcome was mean intraocular pressure measured in millimetres of mercury at day one, one week, one month and at last available follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

One trial, which randomised 25 eyes to either needling or medical treatment, met the inclusion criteria. At one day post-treatment, mean intraocular pressure was lower in the needling group (16.28 mmHg, standard deviation 5.9) than the medical group (19.45 mmHg, standard deviation 3.75). The difference was not statistically significant. At all other follow-up points, mean intraocular pressure was consistently higher in the needling group than the medical group, although the differences were not statistically significant. However, only one needled bleb remained successful at the end of follow-up compared to 10 out of the 11 blebs managed conservatively. This difference was statistically highly significant.

AUTHORS' CONCLUSIONS

Evidence from one small trial suggests that needling of encapsulated trabeculectomy blebs is not better than medical treatment in reducing intraocular pressure.

Needling for encapsulated trabeculectomy filtering blebs

BACKGROUND

Encapsulation of a filtering bleb following trabeculectomy may lead to elevation of intraocular pressure, prompting further medical or surgical intervention. It has been suggested that needling of an encapsulated bleb may be effective in re-establishing drainage and lowering intraocular pressure.

OBJECTIVES

The objective of this review is to assess the effects of needling encapsulated blebs on intraocular pressure.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group trials register) on The Cochrane Library (Issue 2 2003), MEDLINE (1966 to March 2003), EMBASE (1980 to May 2003) and LILACS (Latin American and Caribbean Health Sciences ) (June 2003). There were no language or date restrictions in the searches.

SELECTION CRITERIA

We included randomised and quasi-randomised in which bleb needling was compared with any form of antiglaucoma medication in people with encapsulated trabeculectomy blebs. The primary outcome was mean intraocular pressure measured in millimetres of mercury at day one, one week, one month and at last available follow-up.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

One trial, which randomised 25 eyes to either needling or medical treatment, met the inclusion criteria. At one day post-treatment, mean intraocular pressure was lower in the needling group (16.28 mm Hg, standard deviation 5.9) than the medical group (19.45 mm Hg, standard deviation 3.75). The difference was not statistically significant. At all other follow-up points, mean intraocular pressure was consistently higher in the needling group than the medical group, although the differences were not statistically significant. However, only one needled bleb remained successful at the end of follow-up compared to 10 out of the 11 blebs managed conservatively. This difference was statistically highly significant.

REVIEWERS' CONCLUSIONS

Evidence from one small trial suggests that needling of encapsulated trabeculectomy blebs is not better than medical treatment in reducing intraocular pressure.