[Risk factors for trabeculectomy failure]

Outcome of combined single-loop fixation of intraocular lens with Ahmed glaucoma valve implantation

A late adolescent girl presented with medically uncontrolled glaucoma and aphakia post-fire-cracker injury to the right eye. She underwent single-loop fixation of the posterior chamber intraocular lens (IOL) and Ahmed glaucoma valve (AGV) implantation with reduction of intraocular pressure (IOP) in the immediate postoperative period. She sustained second trauma 6 days later resulting in tube retraction and an IOP of 38 mm Hg. An anterior repositioning of the tube-plate complex was performed and IOP remained under control for 5 months. She then developed a tenon cyst and the IOP rose to 24 mm Hg, for which topical timolol and dorzolamide and digital massage were administered. The IOP was in the lower teens, sans medication and aided vision of 0.50 LogMAR at the 1 year follow-up. This case highlights the outcomes of single-loop fixation of IOL with AGV in a post-traumatic setting and subsequent management of complications.

Discomfort During Instillation Of Antihypertensives And Ocular Surface Condition In Glaucoma Patients

Background — An increase in the frequency of manifestations of dry eye syndrome (DES), against the background of hypotensive therapy, leads to a decrease in treatment adherence. After reformulation in the composition of a preservative-free preparation of a carbonic anhydrase inhibitor (CAI) (sodium benzoate was added), patient complaints of burning sensation during instillation became more frequent, which was the reason for our study. Objective — To evaluate the effect of sodium benzoate on the course of DES during local hypotensive therapy of glaucoma. Methods and Results — Group 1 consisted of 21 eyes with glaucoma receiving hypotensive therapy, Group 2 (20 eyes) included patients with suspected glaucoma not receiving therapy. Patients underwent standard diagnostic methods and examination of the ocular surface condition: tear break-up time test sensu Norn, Schirmer test, vital staining with lissamine green, and a survey based on the Ocular Surface Disease Index (OSDI) questionnaire. When a preservative-free CAI in combination therapy was replaced with the CAI containing sodium benzoate, no statistically significant change in IOP occurred after four weeks of treatment (p> 0.05). In both groups, the indicators characterizing the ocular surface condition did not change statistically significantly over the observation period. Conclusion — Replacement of preservative-free CAI in combination therapy of glaucoma with CAI with sodium benzoate does not lead to statistically significant changes in intraocular pressure. The ocular surface condition does not change statistically significantly over a month of observation. Instillation discomfort is not related to the pH of the preparation.

Effects of Lidocaine on Mitomycin C Cytotoxicity

PURPOSE

Intra-Tenon or subconjunctival injection of a solution of mitomycin C (MMC) and 1% preservative-free lidocaine (as an anesthetic) has gained popularity for its use in trabeculectomy, a filtering surgery for glaucoma. To our knowledge, no studies have analyzed the impact of lidocaine on the cytotoxic effects of MMC in this setting. This study was conducted to evaluate in vitro fibroblast cytotoxicity to a solution of MMC (0.2 mg/ml) and 1% preservative-free lidocaine.

DESIGN

Experimental study.

PARTICIPANTS

Nonhuman subject research.

METHODS

Cultured human conjunctival fibroblasts were incubated in phosphate-buffered saline (PBS) (control), MMC (0.2 mg/ml), a mixture of 0.2 mg/ml MMC + 1% preservative-free lidocaine, or 1% preservative-free lidocaine. Samples were taken at 2, 5, 10, 30, and 60 minutes, and a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay with photoabsorbance testing was used to assess conjunctival cell viability.

MAIN OUTCOME MEASURE

Mean photoabsorbance.

RESULTS

Mean photoabsorbance across all time intervals was 0.680 for solutions incubated in PBS, 0.642 for MMC, 0.612 for MMC + 1% preservative-free lidocaine, and 0.605 for 1% preservative-free lidocaine. A 2-way analysis of variance analyzing solution, time, and solution-time interaction on photoabsorbance showed that PBS was least cytotoxic and an optimal control for this study. Tukey post hoc comparisons showed that MMC was more cytotoxic than PBS (P < 0.001). However, both MMC + 1% preservative-free lidocaine and 1% preservative-free lidocaine were more cytotoxic than MMC and PBS (P < 0.01 for all). No significant differences in cytotoxicity comparing lidocaine-containing solutions were observed.

CONCLUSIONS

In this in vitro study, we found an increase in cytotoxicity when MMC (0.2 mg/ml) was combined with 1% preservative-free lidocaine. We note that lidocaine did not inhibit MMC cytotoxicity and exhibited a significant cytotoxic effect on its own.

Observational Outcomes of Initial Trabeculectomy With Mitomycin C in Patients of African Descent vs Patients of European Descent: Five-Year Results

Importance

There is evidence that patients of African descent (AD) experience higher surgical failure rate after trabeculectomy without antimetabolites.

Objective

To compare outcomes of initial trabeculectomy with mitomycin C in AD patients with those of patients of European descent (ED) and to identify prognostic factors for failure.

Design, Setting, and Participants

In this retrospective matched cohort study, 135 eyes of 105 AD patients were matched with 135 eyes of 117 ED patients by age (within 5 years), surgeon, lens status, and follow-up time (within 1 year) from a single tertiary academic center.

Interventions

Initial trabeculectomy with mitomycin C.

Main Outcomes and Measures

Criteria A, B, and C defined qualified success rates as final intraocular pressure of 18 mm Hg or less, 15 mm Hg or less, and 12 mm Hg or less, respectively, in addition to 20% or more, 25% or more, and 30% or more reduction of intraocular pressure or reduction of 2 or more medications. Kaplan-Meier survival curves were compared with log-rank test in AD and ED patients, and Cox proportional hazard models were used to estimate the influence of race/ethnicity on surgical success accounting for confounding variables.

Results

Of the 105 AD patients, 56 (53.3%) were female, and the mean (SD) age was 67.5 (10.4) years; of the 117 ED patients, 64 (54.7%) were female, and the mean (SD) age was 68.2 (10.0) years. For AD patients compared with ED patients, the qualified success rates at 5 years for criteria A were 61% and 67%, respectively (difference, 7.3%; 95% CI, 4.4-10.4); for criteria B, 43% and 60% (difference, 17.6%; 95% CI, 15.2-20.0); and for criteria C, 25% and 40% (difference, 15.8%; 95% CI, 11.1-20.5). On multivariable Cox regression analyses, AD was associated with higher failure rate with criteria B and C for qualified success and with all criteria for complete success (ie, no need for medications). Incidence of bleb leaks was higher in the AD group (29 vs 11 eyes; P = .002). Additionally, AD patients required additional glaucoma surgeries more often than ED patients (47 vs 26 eyes; P = .004).

Conclusions and Relevance

African descent was associated with higher failure rates and higher incidence of bleb leaks after initial trabeculectomy with mitomycin C compared with European descent. If this is subsequently shown to be a cause and effect, the findings need to be considered when surgical treatment of glaucoma is contemplated in AD patients.

Outcomes and Complications of Scleral-Fixated Intraocular Lens Combined with Ahmed Tube Surgery

Background

To evaluate the outcome and complications of transscleral suture-fixated posterior chamber intraocular lens (PCIOL) implantation combined with Ahmed glaucoma valve (AGV) surgery in Asian eyes.

Design

This was a retrospective study that included 22 eyes from 22 participants. The surgeries were performed at Singapore's National University Hospital. Participants underwent an Ahmed tube surgery, together with transscleral suture-fixated posterior chamber intraocular lens.

Main Outcome Measures

Complete success was defined as 6 ≤ intraocular pressure (IOP) ≤ 21 mmHg without medications at the last follow-up visit, with no reoperation required and no progression to no perception of light (NPL).

Results

At the last follow-up, there was a significant reduction in mean IOP (22.4 ± 6.5 mmHg versus 13.9 ± 3.9 mmHg; p < 0.001) and mean number of intraocular pressure-lowering medications (2.45 ± 1.30 versus 0.05 ± 0.21; p < 0.001). There was no significant change in visual acuity [1.43 ± 1.21 (LogMAR) versus 1.09 ± 1.31 (p = 0.204)]. Sixteen eyes (72.7%) achieved complete success. The 3 commonest complications were bullous keratopathy, choroidal detachment, and displacement of intraocular lens.

Conclusion and Relevance

This technique showed good success for intraocular pressure control and vision preservation. Postoperative complications were relatively common although most were self-limiting. Patients at increased risk of trabeculectomy failure may be suitable for this procedure.

Homocysteine in tear fluid of patients with pseudoexfoliation glaucoma

PURPOSE

To evaluate homocysteine (Hcy) concentrations in tear fluid and plasma and their association with B-vitamin levels in patients with pseudoexfoliation glaucoma (PEXG).

PATIENTS AND METHODS

Reflex tear and blood samples were obtained in 30 patients with PEXG and 30 controls. Hcy levels were determined by high-performance liquid chromatography.

RESULTS

Hcy was detected in all tear fluid samples of patients with PEXG and controls. Statistical analysis with t tests showed that patients with PEXG had significantly higher Hcy levels both in tear fluid (237+/-133 nmol/L vs. 128+/-54 nmol/L; P<0.001) and in plasma (14.51+/-4.43 micromol/L vs. 10.22+/-2.77 micromol/L; P<0.001) than control subjects. Hcy in tear fluid correlated significantly with Hcy in plasma (r=0.438, P=0.015) and with serum B12 levels (r=-0.424, P=0.019) in patients with PEXG, but not in controls.

CONCLUSIONS

The study suggests increased Hcy levels in tear fluid and plasma of patients with PEXG. Further investigations are needed to evaluate the possible clinical role of Hcy in ocular surface and systemic disorders associated with PEXG.

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

PURPOSE

To evaluate the long-term intraocular pressure (IOP) control of eyes that developed an encapsulated bleb (EB) following trabeculectomy.

METHODS

Between 1994 and 1995, 25 eyes developed EBs and were randomized to medical treatment or needling without adjunct antimetabolites. Among the 25 patients who developed an EB, 21 were followed for at least 6 months. A control group of 21 consecutive eyes, which underwent trabeculectomy during the same period and that did not develop EBs was retrospectively selected. Success was defined as IOP <21 mmHg with or without medications. Kaplan-Meier survival analysis was performed to compare the groups.

RESULTS

Among the 21 eyes that developed EBs, 12 (57%) had undergone transconjunctival needling and nine (43%) had received medical treatment. Mean follow-ups were 30.0 +/- 14.0 months, 33.3 +/- 18.5 months, and 37.4 +/- 2.6 months for the needling, medical treatment, and control groups, respectively (P = 0.19). Kaplan-Meier survival curves demonstrated that the control group showed a significantly lower chance of failure than both the needling and the medical treatment groups (P < 0.0001).

CONCLUSION

Encapsulated blebs may be associated with an increased risk for surgical failure.

Comparative effects of TGF-β1 and TGF-β2 on extracellular matrix production, proliferation, migration, and collagen contraction of human Tenon's capsule fibroblasts in pseudoexfoliation and primary open-angle glaucoma

PURPOSE

To comparatively investigate the effects of TGF-beta(1) and TGF-beta(2) on extracellular matrix production, proliferation, migration, and collagen contraction of cultured human Tenon's capsule fibroblasts derived from patients with pseudoexfoliation (PEX) syndrome, PEX glaucoma, primary open-angle glaucoma (POAG), and cataract.

METHODS

Tenon's capsule fibroblasts obtained from four groups of patients were cultured and stimulated with different concentrations (0.1-10 ng ml(-1)) of TGF-beta(1) or TGF-beta(2) for up to 14 days. Cell proliferation was determined with the WST-1 colorimetric assay, cell migration by using the Transwell assay system, and collagen contraction by computerised analysis of three-dimensional collagen lattices and immunohistochemistry for alpha-smooth muscle actin expression. Expression and synthesis of extracellular matrix components (fibronectin, collagen types I and III) was assessed by enzyme-linked immunosorbent assays, by real-time RT-PCR, and by transmission electron microscopy.

RESULTS

Both TGF-beta(1) and TGF-beta(2) in pathophysiological concentrations of 0.1-5 ng ml(-1) stimulated cell proliferation, migration, collagen contraction, alpha-smooth muscle actin expression as well as mRNA expression and secretion of fibronectin, collagen type I, and collagen type III by Tenon's fibroblasts derived from all groups of patients. TGF-beta stimulation occurred in a concentration-dependent manner with different peak activities associated with different fibroblast functions. There was some variability among the different groups of patients with an increased response of cells derived from PEX and POAG patients as compared to cataract patients. Although no statistically significant differences were found between both TGF-beta isoforms, TGF-beta(1) had a more pronounced stimulatory effect on expression and synthesis of extracellular matrix components including the production of elastic microfibrils, particularly in cells derived from patients with PEX syndrome/glaucoma.

CONCLUSIONS

These findings suggest a significant contribution of TGF-beta(1) in addition to TGF-beta(2) to the conjunctival scarring process following glaucoma filtration surgery. Due to its pronounced fibrogenic potential, TGF-beta(1) may become another focus for targeting drug therapy, particularly in patients with PEX glaucoma.

Surgical strategies in patients with combined cataract and glaucoma

PURPOSE OF REVIEW

In the elderly population, the combined presence of cataract and glaucoma is a frequent condition. In this situation, several surgical options are possible: cataract surgery only and later maybe trabeculectomy, trabeculectomy only and later maybe cataract surgery, or combined cataract and glaucoma surgery. This review compares the different surgical options on the basis of their achievable postoperative intraocular pressure (IOP) level and success and complication rates.

RECENT FINDINGS

The impression of better IOP regulation with trabeculectomy than with phacotrabeculectomy has been recently confirmed by an evidence-based review. Contrary to this finding, the success of deep sclerectomy or trabeculotomy does not seem to be compromised by simultaneous phacoemulsification. In eyes with previous glaucoma-filtering surgery, cataract surgery with clear corneal incision has no effect on mean IOP but increases the 3-year failure probability. For phacotrabeculectomy, moderate evidence of a beneficial effect of MMC on IOP regulation and only weak evidence for separating the incisions has been recently reported by another evidence-based review.

SUMMARY

The choice of the preferred surgical method depends on the target pressure, the amount of glaucomatous damage, and the grade of visual disturbance caused by the cataract. Phacotrabeculectomy combined with mitomycin C achieves the best IOP lowering of all types of combined cataract and glaucoma surgery currently possible but is associated with potentially sight-threatening complications. In the absence of a low target pressure, phacotrabeculotomy or the combination of phacoemulsification with viscocanalostomy or deep sclerectomy may be the therapy of choice.

Efficacy and safety of contact transscleral diode laser cyclophotocoagulation for advanced glaucoma

BACKGROUND

This prospective study was conducted to evaluate the efficacy and safety of transscleral diode laser cyclophotocoagulation in refractory, advanced glaucoma.

PATIENTS AND METHODS

One hundred eyes of 100 patients with advanced glaucoma refractory to medical treatment were consecutively treated by transscleral diode laser cyclophotocoagulation. Success was defined as a final intraocular pressure between 5 and 21 mm Hg in eyes with a visual acuity of more than hard movements, relief of pain in eyes with a visual acuity of hand movements or less including blind eyes, and reduction of carbonic anhydrase inhibitor use in all eyes.

RESULTS

Ninety-three patients were followed up for 1 year after initial treatment. The overall success rate was 74.2%. Of 60 eyes with a visual acuity of more than hand movements, intraocular pressure between 5 and 21 mm Hg was achieved in 41 (68.3%) eyes. Relief of pain was achieved in 28 (84.8%) of 33 eyes. Reduction of systemic carbonic anhydrase inhibitor use was highly significant (P < 0.0001). Within 1 year, 173 laser procedures (mean, 1.9 per patient) were performed. The probability of success increased significantly (P = 0.004) with the age of the patients, from 55% for patients younger than the age of 50 years to 83% for patients older than the age of 50 years. Previous ocular surgery decreased the success probability from 95% to 68% (P = 0.02). A high success rate was achieved in inflammatory glaucoma (75%), primary open-angle glaucoma (89.5%), and neovascular glaucoma (86.7%). The results were relatively poor in traumatic glaucoma (57.1%), aphakic glaucoma (57.1%), and congenital or juvenile glaucoma (62.5%). No significant relationship between loss of visual acuity and failure of treatment (P = 0.3) could be detected. No phthisis bulbi or persistent hypotonia developed.

CONCLUSIONS

Transscleral diode laser cyclophotocoagulation is an effective and safe method for the treatment of advanced, refractory glaucoma. However, repeated treatments are often necessary. Success of treatment depends on the age of patients, previous surgery, and the type of glaucoma.