Prevalence of primary angle-closure disease in retinitis pigmentosa

To determine the prevalence of primary angle?closure disease (PACD) in patients with retinitis pigmentosa (RP). Methods: This was a retrospective review of the electronic medical records of all RP patients over the age of 10 years attending the Genetics Eye Clinic of a tertiary?care hospital during a 7?year period. Information regarding age, gender, vision, refraction, lens, intraocular pressure (IOP), type of RP, and inheritance pattern using pedigree charts for all patients were obtained. Patients with a shallow anterior chamber, high IOP, or glaucomatous optic discs were referred to the glaucoma department where they underwent additional IOP measurements, a gonioscopy, and disc evaluation by a glaucoma specialist. The prevalence of PACD was determined. Results: A total of 618 RP patients were examined during the study period, of which 95.1% had typical RP. The prevalence of primary angle?closure suspects was 2.9%, primary angle closure was 0.65%, and primary angle?closure glaucoma (PACG) was 2.27%. In contrast, the prevalence of primary open?angle glaucoma was 1.29%. The prevalence of PACG in those older than 40 years was 3.8% (95% confidence interval: 1.6–6.0). Conclusion: The prevalence of PACG in RP patients over 40 years was higher than that found in the general population of a similar age (3.8% vs. 0.8%). In our cohort of RP patients, 5.9% had PACD. Hence, gonioscopy is warranted in all RP patients to identify this condition and treat it appropriately.

Comparison of long-term outcomes of trabeculectomy and risk factors for failure in eyes post penetrating keratoplasty or Descemet’s stripping endothelial keratoplasty

Purpose: To evaluate the outcomes of trabeculectomy, graft survival, and risk factors for failure in post penetrating keratoplasty (PK) and Descemet’s stripping endothelial keratoplasty (DSEK) eyes. Methods: We reviewed charts of eyes that underwent trabeculectomy for post keratoplasty glaucoma PK [25 eyes] and DSEK [14 eyes] between 1993 and 2019. The demographics, clinical features, and surgical outcomes were evaluated. Success of trabeculectomy was defined as complete when the intraocular pressure (IOP) was >5 and ?21 mmHg without antiglaucoma medications (AGM) and qualified with AGM. Clear and compact graft was considered for graft success. Results: Median (interquartile range [IQR] preoperative IOP in post?PK eyes and post?DSEK eyes was comparable, 32 (28–38) vs. 31.5 (25–36) mmHg, P = 0.38). Median number of preoperative AGMs was comparable (P = 0.78). Median postoperative follow?up was longer in post?PK, compared with post?DSEK, 2.5 (1.3–3.3) vs. 1 (0.3–2.9) years (P = 0.05). Kaplan–Meier survival estimates for complete and qualified success of trabeculectomy at 3 years were 23.7% and 73.3%, respectively, for PK and 45.8% and 71.6%, respectively, for DSEK. Kaplan–Meier survival estimates for graft survival were 91.8% up to 3 years for PK and 100% until 2 years and 77.8% at 3 years for DSEK. Higher IOP prior to trabeculectomy was a risk factor for failure of trabeculectomy (P = 0.03) and older age was a risk factor for graft failure (P = 0.05) in PK eyes. Number of prior corneal surgeries (P = 0.05) was associated with failure of trabeculectomy and graft failure in post?DSEK eyes. Conclusion: Trabeculectomy had moderate qualified success in post?PK and DSEK eyes at 3 years. Higher pretrabeculectomy IOP and higher number of prior corneal surgeries were significantly associated with failure of trabeculectomy in PK and DSEK eyes, respectively

Outcomes of trabeculectomy in eyes with refractory acute primary angleclosure in Indian eyes

Purpose: To report the outcomes of trabeculectomy in eyes with refractory acute primary angle?closure attack. Methods: Patients with acute primary angle?closure attack and who underwent trabeculectomy for medically uncontrolled intraocular pressure within 2 months of presentation were retrospectively analyzed. Primary outcome was intraocular pressure (IOP). Secondary outcome measures were visual acuity, number of antiglaucoma medication (AGM), complications, and risk factors for failure of trabeculectomy. Results: Thirty?five eyes of 31 patients with median (interquartile range) follow?up of 3 (0.5, 9) years were included in the study. Median age at presentation was 55 (47, 60) years. Median duration of symptoms at presentation was 10 (4, 16) days and median time from presentation to surgery was 13 (6, 25) days. Median IOP reduced from 42 (36, 46) to 13 (12, 16) mmHg (P < 0.001) and median number of AGM reduced from 3 (1, 3) to 0 (0, 0) after trabeculectomy at the end of 1 year. The probability of complete and qualified success was 88% (95% confidence interval [CI]: 72%–95%) and was 97% (95% CI: 81%–99%) at 1 year, respectively. Failure was noted in six eyes. Subsequent cataract surgery was needed in 13 eyes (37%) with a median duration from trabeculectomy being 6.75 (1, 11) years. None of the preoperative, intraoperative, or postoperative factors tested were associated with failure (P > 0.10 for all associations on Cox proportional hazard regression analysis). Conclusion: In medically unresponsive cases of acute primary angle?closure attack, primary trabeculectomy seems safe and effective in Indian eyes

Rectifying calibration error of Goldmann applanation tonometer is easy.

Purpose: Goldmann applanation tonometer (GAT) is the current Gold standard tonometer. However, its calibration error is common and can go unnoticed in clinics. Its company repair has limitations. The purpose of this report is to describe a self‑taught technique of rectifying calibration error of GAT. Materials and Methods: Twenty‑nine slit‑lamp‑mounted Haag‑Streit Goldmann tonometers (Model AT 900 C/M; Haag‑Streit, Switzerland) were included in this cross‑sectional interventional pilot study. The technique of rectification of calibration error of the tonometer involved cleaning and lubrication of the instrument followed by alignment of weights when lubrication alone didn’t suffice. We followed the South East Asia Glaucoma Interest Group’s definition of calibration error tolerance (acceptable GAT calibration error within ±2, ±3 and ±4 mm Hg at the 0, 20 and 60‑mm Hg testing levels, respectively). Results: Twelve out of 29 (41.3%) GATs were out of calibration. The range of positive and negative calibration error at the clinically most important 20‑mm Hg testing level was 0.5 to 20 mm Hg and ‑0.5 to ‑18 mm Hg, respectively. Cleaning and lubrication alone sufficed to rectify calibration error of 11 (91.6%) faulty instruments. Only one (8.3%) faulty GAT required alignment of the counter‑weight. Conclusions: Rectification of calibration error of GAT is possible in‑house. Cleaning and lubrication of GAT can be carried out even by eye care professionals and may suffice to rectify calibration error in the majority of faulty instruments. Such an exercise may drastically reduce the downtime of the Gold standard tonometer.

Choroidal thickness profile in healthy Indian subjects.

Purpose: The aim was to study choroidal thickness (CT) and its profile based on location in healthy Indian subjects using Cirrus high definition (HD) optical coherence tomography. Materials and Methods: A total of 211 eyes of 115 healthy subjects with no retinal or choroidal disease were consecutively scanned using Cirrus HD 1 line raster scan mode without pupillary dilation. Eyes with any ocular disease or axial length (AXL) >24 mm or <20 mm were excluded. Experienced technician measured CT from the lower border of the retinal pigment epithelium (RPE) to the lower border of choroid. CT was measured from the posterior edge of the RPE to the choroid/sclera junction at 500‑μm intervals up to 3000 μm temporal and nasal to the fovea. Generalized estimating equations were used to evaluate the correlation between CT at various locations and age, AXL, spherical equivalent, and macular thickness. Results: Mean age was 42.8 ± 13.6 years. Mean AXL was 22.84 ± 0.78 mm. Median spherical equivalent was 0.16 ± 0.64 D. Mean central macular thickness was 216.4 ± 30.03 μm. Choroidal was thinnest nasally and thickest subfoveally. On multivariate regression, age was the most significant factor affecting subfoveal CT (P = 0.000). Regression analysis showed an approximate decrease in CT of 1.18 μm every year. Conclusions: Our study provides CT profile in Indian healthy subjects in various age groups. CT depends on its location, subfoveal being the thickest and nasal being the thinnest. Age is a critical factor, which is negatively correlated with CT.

Outcomes of trabeculectomy in microspherophakia.

Purpose: To report the outcomes of trabeculectomy in eyes with glaucoma in microspherophakia. Materials and Methods: In a retrospective non-comparative case series, we analyzed 29 eyes of 18 patients with glaucoma in microspherophakia, who underwent primary trabeculectomy between 1998 and 2012. Success was defi ned as complete if the intraocular pressure (IOP) was ≤21 and >5 mm Hg without any antiglaucoma medication and qualifi ed if IOP ≤21 and >5 mm Hg with or without antiglaucoma medications. Eyes not falling into qualifi ed success criteria were labeled as failure. Results: The median age at the time of trabeculectomy was 23 years (inter quartile range: 12, 28). The mean IOP reduced from 31.1 ± 8.6 mm Hg to 14.6 ± 4.4 mm Hg after trabeculectomy over a median follow up of 77 months (P < 0.001). The probability of complete success was 96% (95% CI: 77-99%) at one year, 88% (95% CI: 67-96%) at 2 years, which was maintained till 7 years and decreased to 79% (95% CI: 50-92%) at 8 years. The probability of qualifi ed success was 100% till 7 years and decreased to 90% (95% CI: 47-98%) at 8 years. The median number of postoperative medications reduced from 2 to 0 postoperatively (P < 0.001). Five eyes (21%) developed post-operative shallow anterior chamber (AC) requiring anterior chamber reformation, with 2 of these eyes needing lensectomy for resolution of this complication. Conclusion: Primary trabeculectomy had good success rate in glaucoma associated with microspherophakia. Post-operative shallow AC was a frequent complication needing additional intervention.

Contralateral intraocular pressure lowering effect of prostaglandin analogues.

Background: Though the use of prostaglandin analogues (PGA) for reduction of intraocular pressure (IOP) has shown a marked increase, studies evaluating the contralateral eff ects of PGA are limited. Aims: To evaluate if PGA treatment in one eye has an eff ect on the IOP of the untreated fellow eye. Design: Retrospective study. Materials and Methods: Thirty patients of open-angle glaucoma with no previous antiglaucoma treatment underwent 24-hour diurnal IOP phasing. They subsequently were started on a uniocular trial with PGA, and had offi ce diurnal IOP measurements 6 weeks later. Twenty-four hour diurnal consisted of 8 IOP readings over 24 hours and offi ce diurnal consisted of 4 IOP readings between 8 AM and 6 PM at 3 hourly intervals. Statistical Analysis: IOPs of the fellow eye during the offi ce diurnal were compared with IOPs at similar time points during the 24-hour diurnal using paired t-tests. Results: Mean (± standard deviation) IOP in the treated eye reduced (P < 0.001) from 17.17 ± 3.2 mm Hg at baseline to 13.7 ± 2.4 mm Hg at 6 weeks, while that in the untreated eye reduced from 16.4 ± 3.1 mm Hg to 14.8 ± 2.7 mm Hg (P = 0.01). The decrease in IOP in the untreated fellow eye was statistically signifi cant at 8 AM (2.7 mm Hg, P = 0.003) and 11 AM (2.3 mm Hg, P = 0.01) but not so at 2 PM (1.2 mm Hg, P = 0.10) and 5 PM (0.9 mm Hg, P = 0.19). The amount of IOP reduction in the untreated eye was signifi cantly associated with the magnitude of IOP reduction in the treated eye (β = 0.69, P = 0.008). Conclusion: Uniocular PGA treatment tends to reduce the IOP of the untreated fellow eye.

Outcomes of trabeculectomy in juvenile open angle glaucoma.

Purpose: This study was aimed at reporting the outcomes of trabeculectomy in primary juvenile open angle glaucoma (JOAG). Design: This study was a retrospective noncomparative case series. Materials and Methods: We included 60 eyes of 41 JOAG patients who underwent primary trabeculectomy without mitomycin-C (MMC) between 1995 and 2007. The primary outcome was success, defined as complete, if intraocular pressure (IOP) was >5 and ≤21 mmHg without medications or qualified if IOP was >5 and ≤21 mmHg with or without antiglaucoma medications. Secondary outcome measures were mean and percentage IOP reduction, complications, and risk factors for the failure of trabeculectomy. Results: The mean (±standard deviation) age at presentation was 24.1 ± 6.8 years (range, 12–35). Mean follow-up was 67 ± 41 months (range, 12–156). At 1 year, the probability of complete success was 92% (n = 56, 95% CI: 81–96%), at 3 years it was 89% (n = 47, 95% CI: 78–95%), and at the end of 5 years, it was 80% (n = 34, 95% CI: 65–89%). The probability of qualified success was 100% (n = 60) at 1 year, 98% (n = 51, 95% CI: 87–100%) at 3 years, and 96% (n = 36, 95% CI: 84–99%) at the end of 5 years. The mean IOP reduced from 35 ± 10 to 13 ± 2.5 mmHg (P < 0.001) after trabeculectomy. There was no serious postoperative complication. Young age was the only significant risk factor associated with the failure (odds ratio = 0.89, P = 0.03). Conclusion: Primary trabeculectomy without MMC has good success rates in JOAG.

Scanning the macula for detecting glaucoma.

Background: With the advent of spectral domain optical coherence tomography (SDOCT), there has been a renewed interest in macular region for detection of glaucoma. However, most macular SDOCT parameters currently are thickness parameters which evaluate thinning of the macular layers but do not quantify the extent of area over which the thinning has occurred. We therefore calculated a new macular parameter, “ganglion cell complex surface abnormality ratio (GCC SAR)” that represented the surface area over which the macular thickness was decreased. Purpose: To evaluate the ability of SAR in detecting perimetric and preperimetric glaucoma. Design: Retrospective image analysis. Materials and Methods: 68 eyes with perimetric glaucoma, 62 eyes with preperimetric glaucoma and 165 control eyes underwent GCC imaging with SDOCT. SAR was calculated as the ratio of the abnormal to total area on the GCC signifi cance map. Statistical Analysis: Diagnostic ability of SAR in glaucoma was compared against that of the standard parameters generated by the SDOCT soft ware using area under receiver operating characteristic curves (AUC) and sensitivities at fi xed specifi cities. Results: AUC of SAR (0.91) was statistically signifi cantly bett er than that of GCC average thickness (0.86, P = 0.001) and GCC global loss volume (GLV; 0.88, P = 0.01) in diff erentiating perimetric glaucoma from control eyes. In diff erentiating preperimetric glaucoma from control eyes, AUC of SAR (0.72) was comparable to that of GCC average thickness (0.70, P > 0.05) and GLV (0.72, P > 0.05). Sensitivities at specifi cities of 80% and 95% of SAR were comparable (P > 0.05 for all comparisons) to that of GCC average thickness and GLV in diagnosing perimetric and preperimetric glaucoma. Conclusion: GCC SAR had a bett er ability to diagnose perimetric glaucoma compared to the SDOCT soft ware provided global GCC parameters. However, in diagnosing preperimetric glaucoma, the ability of SAR was similar to that of soft ware provided global GCC parameters.

Comparison of outcomes of trabeculectomy with mitomycin C vs. ologen implant in primary glaucoma.

Purpose: To compare the safety and efficacy of trabeculectomy with Ologen implant vs. trabeculectomy with Mitomycin C (MMC). Materials and Methods: In a prospective, randomized, pilot study, 39 eyes of 33 subjects with medically uncontrolled primary glaucoma, aged 18 years or above underwent trabeculectomy either with MMC (20 eyes) or with Ologen implant (19 eyes). The primary outcome measure was cumulative success probability, defined as complete if the intraocular pressure (IOP) was > 5 and ≤ 21 mm Hg without anti-glaucoma medications or additional surgery and qualified if an IOP was > 5 and ≤ 21 mm Hg with or without anti-glaucoma medications. Results: Mean (± standard deviation) follow-up in Ologen group was 19.1 ± 8.1 months, and in MMC group was 18.0 ± 8.4 months. Mean IOP reduction at 6 months was significantly lower (P = 0.01) in the MMC group (11.9 ± 2.9 mm Hg) as compared to Ologen group (14.6 ± 2.7 mm Hg). However, at 12 months (P = 0.81) and 24 months (P = 0.32), the mean IOP was similar between the 2 groups. Complete success probability at the end of 6 months in Ologen group was 100% (95% confidence interval: 59.1 - 99.0) was similar (P = 0.53) to that in MMC group (93.8%, 95% CI: 63.2 - 99.1). The incidences of early post-operative complications were similar in the 2 groups, except hyphema, which was significantly more in Ologen group (P = 0.02). Conclusion: In this pilot study, the success of trabeculectomy and complications were similar in both Ologen and MMC groups at the end of 6 months.

Evaluation of blotchy pigments in the anterior chamber angle as a sign of angle closure.

Background: Blotchy pigments in the anterior chamber (AC) angle are considered diagnostic of primary angle closure (PAC). But there are no reports either on the prevalence of blotchy pigments in AC angles or the validity of this sign. Aims: To determine the prevalence of blotchy pigments in AC angles and to evaluate their relationship with glaucomatous optic neuropathy (GON) in eyes with occludable angles. Setting and Design: Cross-sectional, comparative study. Materials and Methods: Gonioscopy was performed in 1001 eyes of 526 subjects (245 eyes of 148 consecutive, occludable angle subjects and 756 eyes of 378 non-consecutive, open angle subjects), above 35 years of age. Quadrant-wise location of blotchy pigments was documented. Statistical Analysis: Odds of blotchy pigments in occludable angles against that in open angles were evaluated. Relationship of GON with blotchy pigments in occludable angle eyes was evaluated using a multivariate model. Results: Prevalence of blotchy pigments in occludable angles was 28.6% (95% CI, 22.9-34.3) and in open angles was 4.7% (95% CI, 3.2-6.3). Blotchy pigments were more frequently seen in inferior (16%) and superior quadrants (15%) of occludable angles, and inferior quadrant of open angles (4%). Odds of superior quadrant blotchy pigments in occludable angles were 33 times that in open angles. GON was seen in 107 occludable angle eyes. Blotchy pigments were not significantly associated with GON (odds ratio = 0.5; P = 0.1). Conclusions: Blotchy pigments were seen in 28.6% of occludable angle eyes and 4.7% of open angles eyes. Presence of blotchy pigments in the superior quadrant is more common in occludable angles. Presence of GON in occludable angle eyes was not associated with blotchy pigments.

Role of imaging in glaucoma diagnosis and follow-up.

The purpose of the review is to provide an update on the role of imaging devices in the diagnosis and follow-up of glaucoma with an emphasis on techniques for detecting glaucomatous progression and the newer spectral domain optical coherence tomography instruments. Imaging instruments provide objective quantitative measures of the optic disc and the retinal nerve fiber layer and are increasingly utilized in clinical practice. This review will summarize the recent enhancements in confocal scanning laser ophthalmoscopy, scanning laser polarimetry, and optical coherence tomography with an emphasis on how to utilize these techniques to manage glaucoma patients and highlight the strengths and limitations of each technology. In addition, this review will briefly describe the sophisticated data analysis strategies that are now available to detect glaucomatous change overtime.