Posterior corneal morphological changes in primary congenital glaucoma

Purpose: To compare posterior corneal morphology between older treated and younger untreated children with primary congenital glaucoma (PCG) using anterior segment optical coherence tomography (ASOCT) and intraoperative OCT (iOCT), respectively. Methods: In this comparative study, ASOCT of older PCG children were compared with iOCT of younger untreated PCG patients. Differences between the two groups with respect to posterior corneal morphology were studied. Results: Observed morphological patterns within posterior cornea in older treated (age: 72–300 months) children (87 eyes) included Descemet’s membrane (DM) excrescences (70%), thickened DM (35%), intracameral twin protuberances (92%), and DM detachment (26%). Changes within pre?Descemet’s layer (PDL) (28%) included thickening, breaks, and detachments. Extent of Haab’s striae was associated with thickness of DM/PDL complex (P = 0.008) when analyzed in the treated group. In contrast, in the untreated group (n = 53 eyes, age 1–63 months), posterior corneal changes were limited to diffuse hyper?reflectivity of the DM/PDL complex, with absence of DM tears. Conclusion: Posterior cornea thickens and Haab’s striae become more circumscribed in eyes of older treated children compared to untreated PCG eyes, probably reflecting a healing response of posterior cornea over time.

Intracameral vent and flush technique for silicone oil blockade in Ahmed glaucoma valve

The presence of emulsified silicone oil in the eye can lead to many complications, glaucoma being one of the most common. Adequate IOP control is difficult to achieve with medical management alone; surgical intervention is often required. Glaucoma drainage device implantation is often the preferred line of surgical intervention in such cases due to trabeculectomy failure from emulsified silicone oil droplets and associated conjunctival scarring. However, the silicone tube of Ahmed glaucoma valve (AGV) may attract the silicone oil droplets, causing blockade of the tube with persistent raised IOP postoperatively. We report one such case where post?AGV silicone oil tube occlusion was treated with semi?conservative surgical management instead of revising the entire surgery or implantation of another drainage device. Our surgical technique of intracameral “vent and flush” offers rapid and effective IOP control in such cases. Postoperatively, normal IOP was achieved. Patency of tube continued to be maintained along with normalization of IOP on subsequent follow?ups.

Validating the use of U-tool as a novel method for measuring the corneal diameter in infants screened for congenital glaucoma

Purpose: The Castroviejo caliper is routinely used for measuring the corneal diameter in patients with primary congenital glaucoma, but needs an examination under anesthesia (EUA) or sedation. A simple U?shaped tool was devised to aid in the estimation of the corneal diameters of patients in settings where an ophthalmic caliper is not available or EUA is not feasible. Methods: Infants presenting to the congenital glaucoma clinic posted for EUA were recruited. The demographic details of the patients such as age, sex, and diagnosis were noted. A simple U?shaped tool was devised using three Schirmer strips or a printable ruler. Before the patient underwent a EUA, the corneal diameters were measured using the U?tool. During EUA, corneal diameters were measured using the Castroviejo caliper. Results: The mean age of infants was 6.7 ± 3.39 months (R = 1–12). The mean corneal diameter measured using the U?tool was 13.29 ± 1.33 mm and with Castroviejo caliper was 13.18 ± 1.39 mm. The difference between the corneal diameters measured using the two techniques was ?0.114 mm with the Bland–Altman plot 95% Limits of agreement (LoA) from ?0.965 to 0.737 mm. Corneal diameters measured with both instruments had a good correlation (Pearson’s correlation coefficient = 0.95, P < 0.001). Conclusion: U?tool can be used for screening congenital glaucoma by first?contact physicians or optometrists. It can also be used by ophthalmologists when EUA is delayed

Socioeconomics of long‑term glaucoma therapy in India.

Purpose: To determine the socioeconomic impact of long‑term glaucoma therapy. Materials and Methods: One hundred and fifty consecutive glaucoma patients on medical therapy, following up at our glaucoma service for at least 6 months were recruited. A questionnaire regarding monthly income, cost of glaucoma medications prescribed, availability of medications, travel time, time spent in review clinics, compliance, education status, medical insurance and systemic or local side‑effects was administered. Results: The patients seen at the tertiary government hospital had an average monthly income of Rs. 10,912/‑ (range: Rs. 500/‑ to Rs. 50,000/‑) with approximately 56% of the patients having an income of less than Rs. 5000/month. The expenditure on anti‑glaucoma medications ranged from 0.3% in high income group to 123% of their monthly gross income in low income group (P < 0.0001). The total expenditure including travel, stay, and loss of wages of patients and accompanying persons ranged from 1.6% in high income group to 137% of the monthly income in low income group (P < 0.0001). Mean time required for a glaucoma clinic visit was 15.66 h, (range: 6–96 h/month). About 2.7% experienced systemic side‑effects and 21.3% had complaints of ocular adverse effects. About 90% of the patients were compliant. 92% were not covered by any insurance plan/government reimbursement for their treatment. Conclusions: Medical therapy for glaucoma is an economic burden to many patients and should be individualized, according to the socioeconomic status, availability of drugs and the required distance to travel to reach the specialist clinics.

Bilateral intraocular dirofilariasis.

Ocular dirofilariasis mostly presents as a subconjunctival or eyelid lesion.[1] Intraocular dirofilarial infestation is rare.[2,3] We report a case of a young woman who was accidentally detected to have a live motile worm in the anterior segment in one eye and a cystic lesion on the optic disc in the other eye. To our knowledge, bilateral intraocular dirofilariasis has never been reported.

Comparative evaluation of RetCam vs. gonioscopy images in congenital glaucoma.

Purpose: To compare clarity, exposure and quality of anterior chamber angle visualization in congenital glaucoma patients, using RetCam and indirect gonioscopy images. Design: Cross‑sectional study Participants. Congenital glaucoma patients over age of 5 years. Materials and Methods: A prospective consecutive pilot study was done in congenital glaucoma patients who were older than 5 years. Methods used are indirect gonioscopy and RetCam imaging. Clarity of the image, extent of angle visible and details of angle structures seen were graded for both methods, on digitally recorded images, in each eye, by two masked observers. Outcome Measures: Image clarity, interobserver agreement. Results: 40 eyes of 25 congenital glaucoma patients were studied. RetCam image had excellent clarity in 77.5% of patients versus 47.5% by gonioscopy. The extent of angle seen was similar by both methods. Agreement between RetCam and gonioscopy images regarding details of angle structures was 72.50% by observer 1 and 65.00% by observer 2. Conclusions: There was good agreement between RetCam and indirect gonioscopy images in detecting angle structures of congenital glaucoma patients. However, RetCam provided greater clarity, with better quality, and higher magnification images. RetCam can be a useful alternative to gonioscopy in infants and small children without the need for general anesthesia.

Determinants of severity at presentation among young patients with early onset glaucoma.

Aim: The aim of this study was to evaluate the clinical, socio‑economic, and demographic factors associated with the severity at presentation among juvenile primary open angle glaucoma (JOAG) patients. Materials and Methods: Age at diagnosis, family history, baseline intraocular pressure (IOP), access to health‑care, socio‑economic status, and glaucoma awareness among 80 unrelated JOAG patients presenting between 10 years and 40 years of age were analyzed for their association with the severity at presentation. Severity at presentation was graded based on worse eye visual field using the advanced glaucoma intervention study score and on binocular visual field defects at presentation. Results: Patients with a positive family history presented 4 years earlier (P = 0.045, confidence interval [CI]: 0.09‑8.8) compared to those without a family history. Lower socio‑economic status (Odds ratio [OR] 5.7, P = 0.01, CI: 1.5‑22), and higher baseline IOP (OR 7, P = 0.003, CI: 1.9‑26) were associated with severe glaucomatous visual field defect at presentation. A negative family history was associated with a 10 times likelihood of presenting with a severe glaucomatous field defect (OR 0.1, P = 0.007, CI: 0‑0.5). Conclusions: Clinical, socio‑economic, and demographic factors are contributory to the severity at presentation among young patients with early onset glaucoma. Presence of a family history is associated with an earlier presentation among these patients and a reduced risk of the severe presentation

Scanning electron microscopy of the trabecular meshwork: Understanding the pathogenesis of primary angle closure glaucoma.

Purpose: To study ultrastructural changes of the trabecular meshwork in acute and chronic primary angle closure glaucoma (PACG) and primary open angle glaucoma (POAG) eyes by scanning electron microscopy. Materials and Methods: Twenty-one trabecular meshwork surgical specimens from consecutive glaucomatous eyes after a trabeculectomy and five postmortem corneoscleral specimens were fixed immediately in Karnovsky solution. The tissues were washed in 0.1 M phosphate buffer saline, post-fixed in 1% osmium tetraoxide, dehydrated in acetone series (30-100%), dried and mounted. Results: Normal trabecular tissue showed well-defined, thin, cylindrical uveal trabecular beams with many large spaces, overlying flatter corneoscleral beams and numerous smaller spaces. In acute PACG eyes, the trabecular meshwork showed grossly swollen, irregular trabecular endothelial cells with intercellular and occasional basal separation with few spaces. Numerous activated macrophages, leucocytes and amorphous debris were present. Chronic PACG eyes had a few, thickened posterior uveal trabecular beams visible. A homogenous deposit covered the anterior uveal trabeculae and spaces. Converging, fan-shaped trabecular beam configuration corresponded to gonioscopic areas of peripheral anterior synechiae. In POAG eyes, anterior uveal trabecular beams were thin and strap-like, while those posteriorly were wide, with a homogenous deposit covering and bridging intertrabecular spaces, especially posteriorly. Underlying corneoscleral trabecular layers and spaces were visualized in some areas. Conclusions: In acute PACG a marked edema of the endothelium probably contributes for the acute and marked intraocular pressure (IOP) elevation. Chronically raised IOP in chronic PACG and POAG probably results, at least in part, from decreased aqueous outflow secondary to widening and fusion of adjacent trabecular beams, together with the homogenous deposit enmeshing trabecular beams and spaces.

Neuroprotection in glaucoma.

Glaucoma is a neurodegenerative disease characterized by loss of retinal ganglion cells and their axons. Recent evidence suggests that intraocular pressure (IOP) is only one of the many risk factors for this disease. Current treatment options for this disease have been limited to the reduction of IOP; however, it is clear now that the disease progression continues in many patients despite effective lowering of IOP. In the search for newer modalities in treating this disease, much data have emerged from experimental research the world over, suggesting various pathological processes involved in this disease and newer possible strategies to treat it. This review article looks into the current understanding of the pathophysiology of glaucoma, the importance of neuroprotection, the various possible pharmacological approaches for neuroprotection and evidence of current available medications.

Comparison of the diagnostic ability of Moorfield’s regression analysis and glaucoma probability score using Heidelberg retinal tomograph III in eyes with primary open angle glaucoma.

Purpose: To compare the diagnostic performance of the Heidelberg retinal tomograph (HRT) glaucoma probability score (GPS) with that of Moorfield’s regression analysis (MRA). Materials and Methods: The study included 50 eyes of normal subjects and 50 eyes of subjects with early-to-moderate primary open angle glaucoma. Images were obtained by using HRT version 3.0. Results: The agreement coefficient (weighted k) for the overall MRA and GPS classification was 0.216 (95% CI: 0.119 – 0.315). The sensitivity and specificity were evaluated using the most specific (borderline results included as test negatives) and least specific criteria (borderline results included as test positives). The MRA sensitivity and specificity were 30.61 and 98% (most specific) and 57.14 and 98% (least specific). The GPS sensitivity and specificity were 81.63 and 73.47% (most specific) and 95.92 and 34.69% (least specific). The MRA gave a higher positive likelihood ratio (28.57 vs. 3.08) and the GPS gave a higher negative likelihood ratio (0.25 vs. 0.44).The sensitivity increased with increasing disc size for both MRA and GPS. Conclusions: There was a poor agreement between the overall MRA and GPS classifications. GPS tended to have higher sensitivities, lower specificities, and lower likelihood ratios than the MRA. The disc size should be taken into consideration when interpreting the results of HRT, as both the GPS and MRA showed decreased sensitivity for smaller discs and the GPS showed decreased specificity for larger discs.

Bilateral iridocorneal endothelial syndrome in a young girl with Down's syndrome.

We describe the occurrence of bilateral iridocorneal endothelial (ICE) syndrome with glaucoma in a young girl with Down's syndrome. A 16-year-old girl with Down's syndrome was found to have secondary glaucoma in the right eye with features of progressive iris atrophy in both eyes. She was uncontrolled on maximum tolerable medical therapy for glaucoma. She underwent an uneventful trabeculectomy with mitomycin-C in her right eye. Scanning electron microscopy of the trabecular meshwork obtained in this case is described.

Post-penetrating keratoplasty glaucoma.

Post-penetrating keratoplasty (post-PK) glaucoma is an important cause of irreversible visual loss and graft failure. The etiology for this disorder is multifactorial, and with the use of new diagnostic equipment, it is now possible to elucidate the exact pathophysiology of this condition. A clear understanding of the various mechanisms that operate during different time frames following PK is essential to chalk out the appropriate management algorithms. The various issues with regard to its management, including the putative risk factors, intraocular pressure (IOP) assessment post-PK, difficulties in monitoring with regard to the visual fields and optic nerve evaluation, are discussed. A step-wise approach to management starting from the medical management to surgery with and without metabolites and the various cycloablative procedures in cases of failed filtering procedures and excessive perilimbal scarring is presented. Finally, the important issue of minimizing the incidence of glaucoma following PK, especially through the use of oversized grafts and iris tightening procedures in the form of concomitant iridoplasty are emphasized. It is important to weigh the risk-benefit ratio of any modality used in the treatment of this condition as procedures aimed at IOP reduction, namely trabeculectomy with antimetabolites, and glaucoma drainage devices can trigger graft rejection, whereas cyclodestructive procedures can not only cause graft failure but also precipitate phthisis bulbi. Watchful expectancy and optimal time of intervention can salvage both graft and vision in this challenging condition.

Current profile of secondary glaucomas.

PURPOSE: To study the current profile of secondary glaucomas for their incidence and to identify risk factors. Materials and Methods: In this retrospective chart review, 2997 patients newly diagnosed and referred with glaucoma to our tertiary glaucoma center in the year 2005 were included. Evaluation of all cases was done on the basis of a detailed history and recorded examination including vision, intraocular pressure (IOP), anterior segment examination, gonioscopy and fundus evaluation by glaucoma specialists. Demographic data, etiology of secondary glaucoma, and any other significant findings were noted. RESULTS: Of 2997 referred patients, 2650 had glaucoma or were glaucoma suspects. Of all glaucoma patients or glaucoma suspects, 579 patients (21.84%) had secondary glaucoma. Age distribution was as follows: 25% were between 0-20 years; 27% were between 21-40 years; 30% were between 41-60 years and 18% were > 60 years. The male female ratio was 2.2. Frequent causes of secondary glaucoma were post - vitrectomy 14%, trauma 13%, corneo-iridic scar 12%, aphakia 11%, neovascular glaucoma 9%. Post-vitrectomy glaucoma eyes had vitreous substitutes in 83% cases of which 66% eyes had retained silicone oil for more than three months. Vision <or=20/200 was present in 63% eyes, 57% eyes had baseline IOP > 30 mm Hg. Of all traumatic glaucoma patients, 71% cases were < 30 years of age. Fifty per cent had baseline IOP of> 30 mm Hg and vision <or=20/200. CONCLUSIONS: Most patients with secondary glaucoma have poor vision (<or=20/200) with high IOP and advanced fundus changes at presentation.

Transconjunctival penetration of mitomycin C.

AIMS: The study was performed to estimate transconjunctival penetration of mitomycin C (MMC) to Tenon's tissue following application over the intact conjunctiva before routine trabeculectomy. SETTINGS AND DESIGN: Institution-based case series. MATERIALS AND METHODS: In 41 eyes of 41 patients, MMC (0.4 mg/ml for 3 min) was applied over the intact conjunctiva before beginning trabeculectomy. Tenon's capsule directly beneath the site of application was excised during trabeculectomy and was homogenized, centrifuged and MMC concentrations were analyzed using high-performance liquid chromatography (HPLC). Statistical Analysis Used: Statistical analysis was performed using STATA 8.0 version software (STATA Corporation, Houston, TX, USA). In this study, P -values less than 0.05 were considered as statistically significant. RESULTS: The average weight of the sample of Tenon's tissue excised was 5.51+/-4.42 mg (range: 0.9-17.1) and the average estimated MMC concentration found to be present in Tenon's tissue using HPLC was 18.67+/-32.36 x 10(-6) moles/kg of the tissue (range: 0.38-197.05 x 10(-6)). In 36 of the 41 patients (87.80%), the MMC concentration reached above 2 x 10(-6) moles/kg of the tissue concentration required to inhibit human conjunctival fibroblasts. CONCLUSIONS: Mitomycin C does permeate into the subconjunctival tissue after supraconjunctival application for 3 min. Application of MMC over the conjunctiva may be a useful alternative to subconjunctival or subscleral application during routine trabeculectomy and as an adjunct for failing blebs.

Inherited partial aniridia, microcornea with high myopia and Bergmeister's papilla: A new phenotypic expression.

We describe a rare case of familial partial aniridia with high myopia and Bergmeister papilla in five members of a family. Cataract surgery was performed on the proband wherein a brown black spherophakic lens was extracted.

Inter-instrument agreement and influence of central corneal thickness on measurements with Goldmann, pneumotonometer and noncontact tonometer in glaucomatous eyes.

PURPOSE: This study was conducted to compare the intraocular pressure (IOP) measurements by the Goldman applanation tonometer (GAT), non contact tonometer (NCT) and the ocular blood flow (OBF) pneumotonometer in different IOP ranges in glaucomatous eyes. The effect of central corneal thickness (CCT) on IOP measurement in chronic glaucomatous eyes using the three different tonometers was also evaluated. MATERIALS AND METHODS: IOP measurements of 130 eyes of primary glaucoma patients were performed using GAT by an ophthalmologist while NCT and OBF-pneumotonometer measurements were performed by an experienced optometrist. The IOP values were compared amongst the three instruments in the three different IOP ranges (0-18 mmHg, > 18 to 25 mmHg, > 25 mmHg). CCT was also measured in all patients. RESULTS: The mean of paired difference between GAT and NCT was 0.9 +/- 3.1 mmHg while that between GAT and OBF-pneumotonometer was 0.3 +/- 3.4 mmHg. The OBF-pneumotonometer and NCT were more affected by corneal thickness (0.41 mmHg and 0.4 mmHg / 10 micro corneal thickness respectively) while GAT was the least affected by corneal thickness (0.3 mmHg / 10 micro corneal thickness) though the difference was not statistically significant ( P =0.42). CONCLUSION: With appropriate correction for corneal thickness the NCT and OBF-pneumotonometer can be used as reliably as GAT in following up glaucomatous patients.

Pulsatile ocular blood flow among normal subjects and patients with high tension glaucoma.

PURPOSE: To estimate pulsatile ocular blood flow (POBF) among normal subjects and to compare various parameters in eyes of primary open angle glaucoma with high intraocular pressure (IOP). METHODS: POBF was estimated in 95 eyes of 95 normal subjects above the age of 40 years and in 35 eyes of 35 primary open angle glaucoma patients using the OBF system (OBF Labs Ltd., UK). Correlation of age, gender, IOP, pulse amplitude, pulse volume and pulse rate with POBF was studied. POBF values were measured in glaucomatous patients before IOP control and one month later after control of IOP to < 22 mmHg. RESULTS: The mean POBF among normal subjects was 1382.2 +/- 413 ml/min (range 636-2291 m/min). Females had a significantly higher mean POBF (1512 +/- 347 ml/min) than males (1193 +/- 312 ml/min). The mean IOP among normal subjects was 12.6 mmHg and in glaucoma patients, 29.1 mmHg. Mean POBF in glaucomatous eyes with initially elevated IOP was 718.9 +/- 322.6 ml/min, which improved after IOP control to 1129 +/- 291 ml/min. IOP had a strong (P < .01) negative correlation with POBF (r = -0.667) CONCLUSIONS: POBF among eyes of normal subjects in this study is higher than reported among Caucasian eyes. Primary open angle glaucoma eyes with high IOP have significantly reduced ocular blood flow. Therapy aimed at lowering IOP has a positive effect onocular haemodynamics.