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.

Protein mediated cholesterol absorption in locusts Schistocerca gregaria (Forskal) and Locusta migratoria (Linn).

Absorption and transport of 3H cholesterol from the midgut to hemolymph and other tissues was studied in the locusts Schistocerca gregaria and Locusta migratoria. S. gregaria are able to absorb dietary cholesterol in the midgut and release into the hemolymph in vivo and into the incubation medium in virto. Certain proteins of midgut origin are involved in the absorption and release of cholesterol. The proteins designated as cholesterol binding proteins (CBP's) were fractionated by gel filtration chromatography using Sepharose CL-6B-200 column. Presence of a protein and its binding with cholesterol is confirmed by TCA precipitation after subsequent incubation of midgut in the incubation medium. Cholesterol binding with the proteins was also confirmed in native polyacrylamide gel electrophoresis. Biosynthesis of this protein takes place in the midgut which is inhibited by a protein synthesis inhibitor, cycloheximide. It also inhibits absorption and release of cholesterol from the midgut. The cholesterol binding activity was associated with a peak containing proteins ranging from molecular weights of 17-32 kDa in SDS-PAGE gels. Treatment of midgut with cycloheximide resulted in reduced cholesterol binding activity. Dilipidation of mucin and transport in presence of bile salts yielded a higher cholesterol binding activity. Although the absorption and release of cholesterol was observed in the hemolymph of both sexes, the ovary exhibited higher cholesterol binding as compared to testis.

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.

Inhibitory effect of 1-benzyl-5[(C)-2,6-dimethyl-1,5-heptadienyl] imidazole (KK-42) on desert locust, Schistocerca gregaria forsk.

Imidazole compound KK-42 was tested for its inhibitory effect on Schistocerca gregaria. The compound caused 80% mortality after 19 days of treatment with 100 microg of KK-42/insect. It also caused the production of deformed adults at even lower doses. Ecdysteroid content, when estimated by RIA, declined due to KK-42 treatment in both haemolymph and ovaries of the insect. Reduction in ecdysteroid titer was maximum at 100 microg of KK-42/insect. The value estimated by RIA was 0.34 ng/pL haemolymph as compared to 0.97 ng/microL in case of controls. Similarly,ecdysteroid content of ovaries detected was 0.48 ng/mg in treated ones as compared to 0.61 ng/mg in controls. Histological studies, however, revealed no alteration in the ovarian tissues due to KK-42 treatment.

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.

Contact trans-scleral diode laser cyclophotocoagulation treatment for refractory glaucomas in the Indian population.

PURPOSE: This study aimed to evaluate the clinical efficacy of contact diode trans-scleral cyclophotocoagulation (TSCPC) for treatment of refractory glaucomas. METHOD: Fifty two eyes of 52 patients, (post-penetrating keratoplasty glaucoma: 16 eyes; adherent leucoma with secondary glaucoma: 8 eyes; aphakic glaucoma: 6 eyes; neovascular glaucoma: 6 eyes; narrow angle glaucoma: 6 eyes; and other secondary glaucomas: 10 eyes) were followed up from 3.5-18 months (average 12 months) after TSCPC. The treatment parameters using the contact G probe were--energy: 3-4J; area: 40 spots spread over 360 degrees; site: 1.2-1.5 mm posterior to limbus. Retreatments (22 eyes; 42%) were given whenever intraocular pressure (IOP) exceeded 22 mmHg despite maximum tolerable topical therapy. RESULTS: IOP decreased from a baseline of 44.7 (+/- 7.3) mmHg to 15 (+/- 3.7) mmHg at first week and was 15.2 +/- (8.2) mmHg at the last follow up. Successful control of IOP (< 22 mmHg) occurred in 30 (58%) eyes after a single treatment and in 48 (92%) eyes following retreatment. Complications included reduction in visual acuity from light perception (LP) only to no light perception (NLP) in two eyes and phthisis bulbi in one eye. CONCLUSION: Contact trans-scleral diode laser cyclophotocoagulation is effective in lowering IOP in eyes with intractable glaucoma with few side effects in Indian subjects.

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.

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.

A modified technique of anterior peribulbar anaesthesia.

A modified technique of peribulbar anaesthesia consisting of a single injection of anaesthetic solution with a 26G, half inch insulin needle was evaluated in 50 eyes. The operative procedures included extracapsular cataract extraction with intraocular lens implantation in 20 eyes, intracapsular lens extraction in 20 eyes, and trabeculectomy in 10 eyes. Complete anaesthesia was obtained in 45 eyes (90%). No significant complications were observed except for mild to moderate conjunctival chemosis in 40 eyes (80%). The technique is easy to learn, safe, effective and relatively economical.

Argon laser iridoplasty: a primary mode of therapy in primary angle closure glaucoma.

Argon laser iridoplasty was performed in 40 eyes of 33 patients of primary angle closure glaucoma. There were 12 male and 21 female patients. The mean ages of the male and female patients were 51 years and 48.4 years respectively. Forty eyes were divided into two groups. Group I consisted of ten eyes of subacute angle closure glaucoma and group II included thirty eyes of chronic angle closure glaucoma. Argon laser iridoplasty was performed with Coherent 9000 model using laser settings of spot size 200 micron, duration 0.2 second and power 0.7 watt. A total of 80 spots were applied over 360 degree circumference. The intraocular pressure control (below 22 mm Hg) was achieved after iridoplasty in all the eyes (100%) in group I, where as in group II the intraocular pressure was controlled in 70% eyes. The follow up period varied from 3 months to one year with a mean of eight months. The success rate with iridoplasty was directly related to the extent of peripheral anterior synechiae, optic disc cupping and presence of visual field changes.

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.

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.

Assessment of visual evoked response in chronic simple glaucoma.

1. The largest number of VEP abnormalities were found in check size 16 and alterate 1.88 cycles/sec. 2. With check size 32 and alt/sec. 1.88. (a) Delayed latency (BA) was found in 18.2% eyes without field defect (statistically nearly significant). (b) Delayed latency (BA) was found in 38.5% eyes with field defect (statistically significant (P less than 0.05). 3. When the check size 16 and alt. rate 1.88 cycles/sec. delayed VEP latency (BA) was found in 23.1% eyes with glaucomatous field defect (which is statistically significant (P less than 0.05). 4. When the check size is 32 and alt/sec. 7.5 delayed VEP latency (BT) was found in 30.2% eyes with glaucomatous field defect (showing statistically significant mean difference).