Clinical, ultrasonographic and optical coherence tomography correlation of optic nerve head cupping in glaucoma patients

Purpose: To ascertain if ultrasound (USG) B-scan examination of the optic nerve head (ONH) can be a useful tool to diagnose and quantify glaucomatous cupping. Methods: A cross-sectional observational study of 48 eyes of 48 patients with clear ocular media and cup-disc ratio of (CDR) ?0.6 were included. The disc was studied by + 90D examination, USG B-scan and ONH Optical coherence tomography (OCT) by three masked observers. Observer-1 assessed the clinical CDR, observer-2recordedopticcup diameter on USG B-scan and observer-3performed ONH OCT to note the software computed average CDR. Measurements of cupping obtained by these 3 methods were compared and their relative strengths determined. The interdependency between variables was further studied using regression analysis. Results: Clinically assessed disc ratios of 0.6, 0.7, 0.8, 0.9, and total corresponded to USG cup measures of 1.02 ± 0.11 mm, 1.23 ± 0.14 mm, 1.35 ± 0.072 mm, 1.45 ± 0.084 mm, 1.75 ± 0.15 mm and OCT average CDR of 0.62 ± 0.087, 0.68 ± 0.060, 0.75 ± 0.078, 0.81 ± 0.036, 0.89 ± 0.038, respectively. There was an excellent correlation between the three arms, with Pearson's co-efficient (r) of 0.87, P < 0.001 between clinical and USG cupping; r = 0.89, P < 0.001 between clinical and OCT cupping; and r = 0.88, P < 0.001 between USG and OCT cupping. A relation of y = 1.64x + 0.03 was obtained between them, where y stands for USG cup diameter and x stands for the observed clinical CDR. Conclusion: Ultrasonographic measurement of optic cup diameter corresponds well to clinical ONH cupping. Therefore, it can reliably be used in quantifying ONH cupping in cases of media opacities which preclude optic disc visualization.

Suprachoroidal hemorrhage after removal of releasable suture with globe massage post-trabeculectomy

A 19-year-old female, having aniridia with secondary glaucoma, presented with uncontrolled intraocular pressure (IOP) in the right eye (RE) on maximal topical and systemic medications. On examination, RE had a subluxated cataractous lens with advanced cupping. She underwent trabeculectomy with mitomycin C. On postoperative day 1, as the IOP was 32 mmHg, one releasable suture was removed followed by gentle bleb massage. On postoperative day 2, suprachoroidal hemorrhage was noted, for which the patient underwent two drainage procedures. Hemorrhagic choroidals resolved completely 4 weeks after drainage.

Therapeutic potential of valproic acid in advanced glaucoma: A pilot study

Purpose: Oral valproic acid (VPA) used as an anticonvulsant has been shown to improve contrast threshold sensitivities in patients receiving it on long-term. This study aimed to evaluate the efficacy of oral VPA in improving visual function in eyes with advanced stage glaucoma. Methods: In this prospective randomized study, 31 patients (n = 31 eyes) with advanced stage glaucoma (with an intraocular pressure <16 mmHg) in at least one eye received oral VPA 500 mg once a day for 3 months and 33 patients (n = 33 eyes) continued on glaucoma therapy. Patients were followed up at 3 and 12 months (to evaluate the legacy effect of the drug). Blood VPA concentrations were measured at 3 months. Following parameters were assessed at baseline, 3 months and 12 months: log of the minimum angle of resolution (LogMAR) visual acuity, mean deviation on visual fields, and multifocal electroretinogram (ERG). Results: Median LogMar visual acuity in the VPA group improved from 0.3 at baseline to 0.18 and 0.18 at 3 and 12 months, respectively (P < 0.01). In comparison, the median visual acuity in control group at baseline was 0.18 and showed neither worsening nor improvement over 3 and 12 months (P = 0.56). The improvement in VPA group was significant compared to the control group (P < 0.01; Wilcoxon Signed-rank test). An improvement in one line was experienced in 11 out of 31 eyes in the VPA group compared to 1 out of 33 eyes among controls (P = 0.003). No significant improvement was noted in the mean deviation, and the multifocal ERG (Latency and amplitudes) in the VPA-treated patients. The average blood VPA concentration measured at 3 months of therapy was 26 � 8.9 ?g/ml (range 8� ?g/ml) which is much lower than that achieved during anticonvulsant therapy. None of the patients complained of any adverse effects that required stopping VPA therapy. Conclusion: A 3 months oral VPA therapy results in some improvement in visual acuity in a subgroup of eyes with advanced glaucoma and the effect was seen to persist 9 months after the drug was stopped.

Simplifying “target” intraocular pressure for different stages of primary open-angle glaucoma and primary angle-closure glaucoma

Lowering of intraocular pressure is currently the only therapeutic measure for Glaucoma management. Many longterm, randomized trials have shown the efficacy of lowering IOP, either by a percentage of baseline, or to a specified level. This has lead to the concept of 'Target” IOP, a range of IOP on therapy, that would stabilize the Glaucoma/prevent further visual field loss, without significantly affecting a patient's quality of life. A clinical staging of Glaucoma by optic nerve head evaluation and perimetric parameters, allows a patient's eye to be categorized as having – mild, moderate or severe Glaucomatous damage. An initial attempt should be made to achieve the following IOP range for both POAG or PACG after an iridotomy. In mild glaucoma the initial target IOP range could be kept as 15-17 mmHg, for moderate glaucoma 12-15 mmHg and in the severe stage of glaucomatous damage 10-12 mmHg. Factoring in baseline IOP, age, vascular perfusion parameters, and change on perimetry or imaging during follow up, this range may be reassessed over 6 months to a year. “Target” IOP requires further lowering when the patient continues to progress or develops a systemic disease such as a TIA. Conversely, in the event of a very elderly or sick patient with stable nerve and visual field over time, the target IOP could be raised and medications reduced. An appropriate use of medications/laser/surgery to achieve such a “Target” IOP range in POAG or PACG can maintain visual fields and quality of life, preventing Glaucoma blindness.

Cumulative effect of risk factors on short-term surgical success of mitomycin augmented trabeculectomy.

CONTEXT: Risk factors for failure of trabeculectomy may have a cumulative effect on the outcome. AIMS: To study the effect of preoperative ocular risk factors on the surgical outcome of trabeculectomy augmented with 2 commonly used doses of Mitomycin C. SETTINGS AND DESIGN: In a prospective cohort study, cases were recruited over an 18 month period. 92 eyes of 83 patients with one to three known risk factors for failure of trabeculectomy underwent Mitomycin-C (MMC) augmented trabeculectomy. METHODS AND MATERIAL: Trabeculectomy was done with a randomly chosen MMC dose of 0.2 mg/ml or 0.4 mg/ml. All cases were followed up for a period of at least 3 months. Surgical success was defined as the lowering of intraocular pressure (IOP) below 21 mmHg during the follow up period. STATISTICAL ANALYSIS USED: Chi square test, paired t test, odds ratio, effect size. RESULTS: Eyes with two or three risk factors (out of aphakic glaucoma, failed trabeculectomy, neovascular glaucoma, post uveitic glaucoma, traumatic glaucoma, adherent leucoma, juvenile glaucoma, prolonged medical therapy, steroid induced glaucoma, post penetrating keratoplasty glaucoma and developmental glaucoma) had a significantly poorer surgical success rate (88% and 78%) than eyes with one risk factor (100%). 0.4 mg/ml MMC used sub-sclerally had a statistically similar effect on lowering the IOP as 0.2 mg/ml in all groups. The rate of complications was significantly higher in the 0.4 mg/ml subgroup. CONCLUSIONS: The presence of more than one preoperative ocular risk factor, affects the surgical success of MMC augmented trabeculectomy in high-risk cases. Because of the significantly higher rate of complications with the higher dose of MMC, this should be used sparingly, only in cases with more than two risk factors.

The trabecular meshwork in acute and chronic angle closure glaucoma.

PURPOSE: To determine the effect of acute and chronic primary angle closure glaucoma (PACG) on the trabecular meshwork. METHODS: Trabecular specimens of 16 consecutive patients with primary angle closure glaucoma (PACG)--6 acute PACG eyes, and 10 chronic PACG eyes without an acute attack--were studied by light and electron microscopy. RESULTS: Acute PACG: The trabecular meshwork revealed a generalised oedema and an accumulation of pigment in the widened trabecular spaces and Schlemm's canal. Attenuated trabecular endothelial cells appeared to be devoid of subcellular components. Chronic PACG: In chronic PACG eyes the trabecular architecture had lost its regular arrangement, with fewer and narrower trabecular spaces and fusion of the trabecular beams in areas. There were numerous electron-dense bodies in the trabecular tissues, both within the trabecular beams and in the extracellular spaces, which had a banded fibrillar structure. An overall loss of endothelial cells was noted; the remaining cells were crowded together and were polymorphic. Melanin pigment was present both within the stroma and in the endothelial cells. CONCLUSIONS: Pigment accumulation in the trabecular spaces and within the cells and a noninflammatory degeneration appeared to be the primary changes in the trabecular meshwork after acute angle closure glaucoma. In chronic PACG eyes, there was evidence of loss of endothelial cells and reactive repair processes. These changes were present in areas away from visible peripheral anterior synechiae. A gonioscopic evaluation of the extent of peripheral anterior synechiae alone may not reflect the extent of trabecular meshwork damage in acute and chronic PACG. Patients experiencing an acute attack of PACG require a long-term follow up, because the intraocular pressure (IOP) may rise later, due to ongoing changes compromising the outflow facility, or due to the effects of aging in the trabecular meshwork.

Assessing the role of subconjunctival versus intrascleral application of mitomycin C in high-risk trabeculectomies.

PURPOSE: To compare the efficacy and safety of subconjunctival and intrascleral applications of mitomycin C (MMC) in trabeculectomy for high-risk glaucomas. METHODOLOGY: A randomized prospective clinical study was conducted on 41 consecutive eyes with a high risk of glaucoma surgery failure. Patients were randomized to trabeculectomy and application of subconjunctival MMC or to trabeculectomy and application of intrascleral MMC. MMC solution 0.2 mg/ml was applied for 3 minutes under the conjunctival flap overlying the proposed site of trabeculectomy in Group I (n=21), or intrasclerally under the superficial scleral flap in Group II (n=20) RESULTS: After a follow-up of one year, the intraocular pressure (IOP) decreased from a mean basal IOP of 33.0 +/- 8.4 mm Hg to 12.56 +/- 2.54 mm Hg in Group I and from 30.9 +/- 6.6 mm Hg to 11.6 +/- 2.21 mm Hg in Group II. The IOP was 6-21 mmHg, without medication, in 90.5 % of the eyes in Group I and 75 % of the eyes Group II. Ocular hypotony, hypotony maculopathy, choroidal detachment and a shallow anterior chamber were more frequent with the intrascleral application of MMC during trabeculectomy, but the difference was not statistically significant. The overall success of the surgery at one year, i.e., achieving an IOP of 6-21 mmHg and a stable vision, (reduction in visual acuity of < or = 2 lines), was 90.5% in Group I and 75 % in Group II. CONCLUSION: No significant difference was seen in overall success or complication between subconjunctival and intrascleral application of MMC-augmented trabeculectomies in glaucomatous eyes at high risk of surgical failure.

Visual field assessment in glaucoma: comparative evaluation of manual kinetic Goldmann perimetry and automated static perimetry.

PURPOSE: To compare the detection and assessment of progression of visual field defects in primary open-angle glaucoma with manual suprathreshold perimetry on Goldmann perimeter and automated static threshold perimetry on Humphery visual field (HVF) analyzer. METHODS: 105 eyes of 54 patients of primary open-angle glaucoma were followed up with 3-monthly perimetry on Goldmann perimeter and HVF analyzer, for a period of 9 months. RESULTS: HVF analyzer picked up visual field defects in 48 (46%) eyes whereas Goldmann perimeter picked up visual field defects in 26 (25%) eyes. HVF analyzer demonstrated progression in 14 eyes whereas Goldmann perimeter detected progression in 7 eyes during follow up of 9 months. CONCLUSIONS: HVF analyzer is superior to Goldmann perimeter to document and to demonstrate progression of visual field defects in primary open-angle glaucoma.

Albendazole therapy for a recurrent orbital hydatid cyst.

Till recently, the treatment of a multiloculated hydatid cyst in the confines of the orbit was every ophthalmologist's nightmare. Over the last decade, two benzimidazole compounds, mebendazole and albendazole, have been tested clinically for use in the chemotherapy of hydatid disease.

The role of artificial drainage devices in glaucoma surgery.

The use of artificial drainage devices (ADDs) or "setons" in glaucoma surgery is generally restricted to patients with refractory glaucoma at high risk for failure from conventional filtration surgery. ADDs, both valved and nonvalved are currently available in this country. Recently, some of these devices have been propogated as primary treatment even for primary glaucomas. This article examines the role of ADDs in the modern management of the glaucomas. Specific indications for ADDs and methods to reduce the complication of overfiltration are discussed. The use of antimitotics, such as 5-fluorouracil or mitomycin, with traditional filtration has decreased the indications for ADDs. The literature and our experience confirm that currently there is no role for use of ADDs as a primary procedure in most glaucomas.

Profile of the subtypes of angle closure glaucoma in a tertiary hospital in north India.

A prospective study of 500 consecutive patients of primary angle closure glaucoma was undertaken to study the clinical profile of the three subtypes: acute, subacute, and chronic. A record of age and sex distributions, symptomatology, the best corrected visual acuity, gonioscopy, visual fields, methods of control of intraocular pressure, and status of the second eye was maintained. Statistical analysis of these parameters and the subtypes of angle closure glaucoma was carried out using the chi-square test. Angle closure glaucoma constituted 45.9% of all primary adult glaucomas seen. 24.8% of these had acute angle closure glaucoma, 31.2% subacute, and 44% chronic glaucoma. Angle closure glaucoma occurred maximally in the sixth decade and females constituted 51.4% of those affected. The difference in symptoms among the subtypes was significant (p < 0.001). More than 80% of the chronic eyes had no significant symptoms. Visual field defects specific for glaucoma were seen in only 15.1% of chronic glaucoma eyes. Bilaterality was commonest in subacute angle closure glaucoma (95.5%) and least in acute angle closure 35.5%. Nd YAG iridotomy alone or with topical medication controlled the intraocular pressure in 48.3% of acute angle closure glaucoma, 78.8% of subacutes, and 30% of chronic eyes. Statistically, each parameter reviewed was significantly different among the subtypes. There are considerable differences as well as an overlap of clinical features in the subtypes of angle closure glaucoma, which suggest some anatomical differences or dissimilar pathogenic mechanisms in these eyes.

A comparative evaluation of pilocarpine 1% and clonidine 0.125% versus timolol 0.5%.

All the presently available antiglaucoma medications have either local or systemic adverse effects. Combinations of drugs are being used not only to increase the effectivity and compliance but also to decrease the incidence and magnitude of side effects. The single dose response of open angle glaucoma eyes to pilocarpine 1%, clonidine 0.125%, a combination of pilocarpine 1% and clonidine 0.125%, and timolol 0.5% was studied in a double blind, masked, cross over study. Over a period of twelve hours the effectivity of the combination of pilocarpine 1% and clonidine 0.125% was significantly more than that of either drug alone and was found to be similar to that of timolol 0.5%. No local or systemic adverse effects were seen.

Clinico-biochemical study of experimental complicated cataracts.

Clinically observed complicated cataracts, generally do not have a definite causal factor. We studied the effects of E. coli toxin injected suprachoroidally, to simulate the effect of toxins released by extraocular organisms on the lens. 79.2% of eyes had a definable cataract at the end of the 6th week of observation. The biochemical changes portrayed an increased oxidative activity in the lens, evidenced by a fall in glutathione concentration, and the consequent tertiary reorientation of proteins to increase insoluble proteins, forming a cataract.

The additive influence of nevus flammeus and the nevus of Ota on congenital glaucoma.

Nevus flammeus and nevus of Ota are commonly encountered dermatological conditions, but both individually, are only occasionally associated with glaucoma. The occurrence of isolated nevus flammeus along with nevus of Ota in the same patient is also extremely rare. We are presenting two unusual cases, both having a nevus of Ota, together with nevus flammeus and severe congenital glaucoma.

Secondary juvenile glaucomas in India.

A comparative retrospective study of 164 cases of juvenile secondary gla as presenting to the glaucoma service in 1984 and 100 cases in 1988, to the changes brought about by health education and innovations in ophthalmic care is undertaken.

Medical and socio-economic aspects of long term therapy of open angle glaucoma.

Hundred patients of open angle glaucoma (OAG) who were on any one of the three drugs pilocarpine, timolol and epinephrine--for an average period of 3.3 years were chosen. Proforma regarding socio-economic status and the patients' reaction to long-term medication were recorded. Though the objective and subjective effects of long term medication were negligible the financial constraints were considerable. More than 70% patient would prefer laser's and surgery because of the cumbersome schedule and financial burden. The visit to the clinic was a time consuming process suggesting a lack of adequate glaucoma follow-up at the peripheral level. The study reflects a need for reorientation of glaucoma management.

Congenital nystagmus with head posture (a modified approach in surgical management).

The surgical methods for correction of an abnormal head posture in congenital nystagmus presently in use, do not correct the head posture adequately and in some cases produce a postoperative tropia. We felt that this may be related to the arbitrary quantities of surgery suggested by various workers. We have observed that surgery on the medial rectus is approximately one and a half times as effective as on the lateral. Using this ratio, excellent results have been obtained in 5 cases which are reported herein.

Role of 5 fluorouracil in the management of failed glaucoma surgery.

Filtering surgery for glaucoma usually controls the intraocular pressure adequately. However, in glaucoma patients with aphakia, neovascularisation of iris, previous failed filtering surgeries and relatively young patients, results of surgery leave much scope for improvement. Most failures of filtering surgery are related to extra-ocular factors. Histopathological studies of eyes after failed filtering operations have suggested that proliferation of fibroblasts and deposition of collagen constitute a barrier to filteration. There is also a positive correlation between success of filtering surgery and inhibition of fibroblast growth by the patients aqueous humour. Thus agents inhibiting fibroblast proliferation should play an important role in increasing the success rate of filtering surgery. 5 Fluorouracil is a pyrimidine analogue which has been utilised for over 15 years as an antimetabolite in cancer therapy. Its efficiency in inhibiting fibroblast proliferation in vitro and in rabbit eyes has been proved beyond doubt. We undertook a pilot project to estimate the efficiency of the subconjunctival 5 FU to increase the changes of success in problematic cases of glaucoma in pigmented eyes.