Limbal autografting: comparison of results in the acute and chronic phases of ocular surface burns

PURPOSE

To compare outcomes of limbal autograft transplantation (LAT) in the acute and chronic phases of ocular surface burns.

METHODS

Retrospective analysis of case records of 16 consecutive patients who underwent LAT for ocular surface burns, at our institute, between April 1994 and March 1997.

RESULTS

Limbal autograft transplantation was successful in reconstructing the corneal surface and restoring ocular comfort in 15 (93.8%) eyes. Limbal autografting failed to reconstruct the ocular surface in one patient undergoing surgery 2 weeks after grade IV alkali burns. In 13 eyes with counting fingers or worse vision, functional success (visual acuity >20/400) was attained after LAT in nine (69.2%) eyes. Visual acuity > or = 20/80 was achieved in two (25%) of eight eyes undergoing surgery for a persistent epithelial defect (PED) and five of six (83.3%) eyes undergoing surgery after the epithelial defect had healed (p = 0.03). Nine patients underwent simultaneous superior and inferior limbal autografting. Mean epithelial healing time in six of these patients undergoing surgery in the acute phase of injury (<4 months) was 15+/-6.1 days. In three patients undergoing a similar procedure in the chronic phase of injury, the healing time was 8.3+/-6.7 days.

CONCLUSIONS

Limbal autograft transplantation is successful in reconstructing the corneal surface and restoring ocular comfort after ocular surface burns. Surgery in the acute phase of injury (<4 months), in the presence of a PED, could result in delayed corneal reepithelialization and poorer visual prognosis. If performed in the acute phase of injury, LAT should be performed after adequate limbal vascularization and resolution of surface inflammation in the recipient eye, avoiding graft placement over ischemic limbus.

Conjunctival-limbal autografts for primary and recurrent pterygia: technique and results

Our technique of pterygium excision with conjunctival-limbal autografting is described and the safety and efficacy of the procedure in India is analysed. Case records of 51 consecutive patients (53 eyes) who underwent surgery at our institute between November 1992 and September 1994 were retrospectively analysed. Recurrence was defined as fibrovascular tissue crossing the corneoscleral limbus onto clear cornea in the area of previous pterygium excision. 2 (3.8%) of the 53 pterygia (primary 36; recurrent 17) recurred, after a mean follow up of 18.9 +/- 12.1 months (range: 1.5-43 months). Both recurrences occurred within a year of follow up, in patients who were < or = 40 years of age. No major operative or postoperative complications were encountered. The inclusion of limbal tissue in conjunctival autografts following pterygium excision appears to be essential to ensure low recurrence rates. The technique is safe, simple and inexpensive and is recommended for the management of both primary and recurrent pterygia in Indian eyes.

Corneoscleral epithelial cysts: evidence of developmental etiology

PURPOSE

To describe the clinical features, histopathology, surgical management and possible etiopathogenesis of corneoscleral epithelial cysts.

METHODS

Three patients with corneoscleral epithelial cysts underwent surgical ablation of the cysts. Material obtained during surgery was subjected to histopathologic analysis.

RESULTS

At last follow-up (mean, 6.3 months), none of the cysts had recurred. All patients had improved visual acuity. Histopathology revealed the occurrence of glandular elements suggestive of lacrimal tissue in one of the cysts.

CONCLUSION

The presence of ectopic lacrimal tissue suggests a developmental etiology for such cysts. Marsupialization of the scleral portion of the cyst and chemical ablation of the lining epithelium of the corneal cyst with 20% trichloroacetic acid appears to be a safe and effective technique in the surgical management of corneoscleral epithelial cysts.

Capsulorhexis in eyes with phacomorphic glaucoma

Phacomorphic glaucoma is a common condition in developing countries. Extracapsular cataract extraction with a sulcus-fixated intraocular lens (IOL) is associated with increased intraoperative and postoperative complications in this condition. We developed a technique that allows a safe, controlled capsulorhexis in the presence of the shallow anterior chamber, increased anterior capsule convexity, and high intralenticular pressure seen in eyes with phacomorphic glaucoma. The intumescent cataracts are decompressed by filling the anterior chamber with viscoelastic; a 30 gauge needle is then used to aspirate liquid cortex, which facilitates a controlled capsulorhexis. This allows safe phacoemulsification of the cataract and in-the-bag IOL implantation.

Posterior keratoconus. An expanded classification scheme based on corneal topography

OBJECTIVE

The purpose of the study was to evaluate corneal changes in posterior keratoconus.

DESIGN

A retrospective review.

RESULTS

Distinct topographic patterns were identified. Generalized posterior keratoconus showed uniform corneal steepening. Localized central and paracentral posterior keratoconus showed corneal steepening, and localized peripheral posterior keratoconus showed corneal flattening overlying the area of corneal change. The changes in central and paracentral posterior keratoconus appear to progress with an increase in patient age. Unilateral disease may have more amblyogenic potential.

CONCLUSIONS

Posterior keratoconus manifests significant corneal surface alterations. The distinct topographic patterns seen probably warrant a further classification of localized posterior keratoconus into central-paracentral and peripheral varieties.

Photorefractive keratectomy: the Sankara Nethralaya experience

BACKGROUND AND OBJECTIVE

Excimer laser photorefractive keratectomy (PRK) is quickly establishing itself as a dependable treatment modality for the correction of myopia. We review in this report our experience with the Summit OmniMed UV200 excimer laser (Summit Technology, Inc., Waltham, MA) in the treatment of low to high degrees of myopia.

PATIENTS AND METHODS

We retrospectively analyzed the results of excimer laser PRK in 139 eyes of 127 patients treated between November 1993 and August 1994.

RESULTS

The study population was comprised of 75 males and 52 females with a mean ago of 26.9 +/- 6.21 years (range, 19 to 52 years). All patients were followed for at least six months and the mean follow-up was 11.7 +/- 3.63 months (range, 6 to 22 months). Mean pre-operative myopia was -8.23 +/- 3.32 diopters (D) (-2.63 to -19.50 D). Of 139 eyes, 101 (72.7%) had a pre-operative myopia greater than -6.00 D; and 32 (23.0%) had a pre-operative myopia greater than -10.00 D. At last follow-up, 73 (52.5%) eyes were within +/-1.00 D of emmetropia, 92 (66.2%) eyes had an uncorrected visual acuity of > or = 6/12, and 12 (8.6%) eyes lost 2 or more lines of spectacle corrected visual acuity. Severe corneal haze (grade 3 to 4) was seen in 20 (14.4%) eyes at last follow-up. Complications encountered in this series included steroid response in 15 (10.8%) eyes, and reactivation of herpes simplex keratitis in one (0.7%) eye. Statistical analysis reveals that the only risk factor independently associated with regression > or = 2.00 D following PRK is the occurrence of severe corneal haze (grade 3 and 4).

CONCLUSION

Excimer laser PRK appears to be a safe and predictable method for the treatment of myopia < 6.00 D. With higher degrees of myopia the results appeared to be more guarded, mainly due to the healing pattern of the cornea following single zone myopic ablations.

Effect of cotrimoxazole (Bactrim) on cholesterol metabolism

Male albino rats when treated with antimicrobial cotrimoxazole (trimethoprim+sulphamethaoxazole) showed an elevation of plasma high density lipoprotein (HDL) cholesterol and lecithin cholesterol acyl transferase activity (LCAT). Very low density lipoprotein and low density lipoprotein (VLDL+S4, 5LDL) cholesterol levels were decreased. However, total blood cholesterol and aortic cholesterol levels were normal. There was decreased synthesis of cholesterol and its content in the liver. Intestinal cholesterol mobilisation (studied using [U-14C]glucose) towards lymph was normal in spite of decreased synthesis by intestines. Decreased fecal excretion of bile acids and neutral sterols and normal intestinal contribution may be mainly involved in the blood cholesterol homeostasis.

Ocular chlamydial infections. Clinicomicrobiological correlation

We report the results of conjunctival scrapings done in 234 eyes of 127 patients presenting with acute, chronic, or recurrent conjunctivitis. Although some patients had the classic features of superior pannus, Herbert's pits, conjunctival follicles, and tarsal distortions, others presented in a more subtle fashion mimicking allergic, viral, and bacterial diseases of the eyes. These scrapings were subjected to rapid diagnostic techniques and culture studies for the identification of chlamydial infections. The correlation between the clinical and laboratory diagnosis was studied. Of the 127 patients, 44 were culture positive for Chlamydia. Of these, only 19 had been clinically suspected to have chlamydial ocular disease, whereas the others were diagnosed to have bacterial, viral, allergic, or other diseases. This higher rate of Chlamydia detection is probably a reflection of endemicity of this infection in India. This article highlights the possible underdiagnosis of chlamydial ocular disease in the outpatient department and emphasizes the importance of microbiological evaluation in patients with atypical or chronic ocular surface disease.

A simple device for the concentration and detection of enterovirus, hepatitis E virus and rotavirus from water samples by reverse transcription-polymerase chain reaction

A simultaneous concentration of enteroviruses, hepatitis E virus, and rotavirus from drinking water samples through a filtration column filled with granular activated carbon (GAC) was achieved. Urea-arginine phosphate buffer (UAPB) as an eluent at pH 9.0 was used for effective desorption and elution of viruses from GAC. Further concentration of viruses with magnesium chloride enabled nucleic acid extraction, cDNA synthesis, amplification with a specific set of primers for enterovirus, hepatitis E virus and rotavirus. Polymerase chain reaction (PCR) products were then confirmed by Southern transfer and hybridization with the relevant probes. The efficacy of the protocol was established with 100 1 of water samples seeded with poliovirus-1, providing 74% recovery in granular activated carbon based UAPB-RT-PCR. The GAC-based method for concentration of viruses from water samples was preferred, despite its somewhat lower efficacy compared to 80% in membrane filter based UAPB-RT-PCR protocol, due to the specific requirements of short-time and savings in cost of analyses. The protocol was used for the detection of waterborne viruses from 24 drinking water sources in urban areas of New Delhi. Direct isolation of viruses from water samples revealed that the 4 samples were positive for enteroviruses, two for hepatitis E virus, and 10 samples for rotavirus. One sample was positive for both hepatitis E virus and rotavirus, and another for all the 3 types of viruses.

Effect of two anterior capsulotomy techniques on the corneal endothelium

We performed a prospective, randomized, clinical study to assess the effect of two anterior capsulotomy techniques on the corneal endothelium. Specular microscopy was done preoperatively and postoperatively in 57 patients having manual extracapsular cataract surgery with a can-opener capsulotomy or with a retained anterior capsule flap. The mean percentage of cell loss following the can-opener capsulotomy was 0.43 (P = .22). There was no statistically significant alteration in endothelial morphology after surgery. The cell loss with a retained anterior capsule flap was zero. However, there was a statistically significant difference in polymegathism (P = .024) and pleomorphism (P = .045) after surgery. A comparison of the two techniques showed no statistically significant difference in cell loss or in pleomorphism. The statistically significant difference in polymegathism (P = .01) was not clinically significant. Our findings indicate that, when carefully performed, both methods of anterior capsulotomy for manual extracapsular cataract surgery are safe for the corneal endothelium.