Choroidal neovascular membrane associated with melanocytoma of the optic nerve.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
K V Chalam
Publications and source records attributed to K V Chalam.
Suction-assisted one-piece self-retaining wide-angle contact lens for vitrectomy.
INTRODUCTION: We have developed a suction-assisted one-piece self-retaining wide-angle contact lens for vitrectomy. DESIGN: The wide-angle contact lens is a one-piece lens without the case, making it lightweight. The contact inferior surface is enhanced by four quadrant plate extensions. A metal housing is attached to the side of the plate extension with an opening at the inferior surface. A negative suction device is attached to the housing of the lens. METHOD OF USE: A drop of viscoelastic is placed between the lens and the cornea. Suction created by a syringe device holds the contact lens on the cornea. CONCLUSION: This specially designed lens is lightweight and eliminates the need for a skilled assistant to stabilize the contact lens. It provides a stable well-centered view of the peripheral fundus during vitreous surgery.
Contact Lenses↗
Autoclavable two-piece noncased wide-angle contact lens system for vitrectomy.
PURPOSE: To describe an autoclavable wide-angle two-piece noncased contact lens system (two lenses: equatorial and wider-angle lens) for vitrectomy. DESIGN: The inferior lens is made of an autoclavable plastic with a concave contact surface of 7.7 mm and the superior lens is a convex glass lens. The superior lens is mounted on the inferior one to make the lens assembly. RESULT: The equatorial lens has a power of +81 D and a field of view of 80-96 degrees, while the wider-angle lens power is +151 D and the field 110-120 degrees. The lens is kept on the cornea upon a drop of viscoelastic substance. An assistant holds it with a conventional lens holder. The lens is easy to sterilize by autoclaving and does not require expensive gas sterilization or potentially injurious chemical sterilization. CONCLUSION: This lens system provides a panoramic wide-angle view of the retina during vitreous surgery. The autoclaving makes this lens system cost-effective and fast to reuse.
Contact Lenses↗
Congenital retinal macrovessel causes reduced retinal sensitivity at the macula.
PURPOSE: To report a case of reduced macular sensitivity at the macula due to congenital retinal macrovessel as measured by liquid crystal display (LCD) microperimetry. METHODS: Case report. RESULTS: We present a patient with normal visual acuity OU, with fundus OS revealing a congenital retinal macrovessel. LCD microperimetry of the macular area OS revealed reduced sensitivity of the superior retina (median sensitivity, 13.0 dB) compared to the inferior retina (median sensitivity, 15.0 dB) based on numerical values of the sensitivity. Such a difference of sensitivity was not found in OD which had a normal fundus ezamination. CONCLUSIONS: The patient's congenital macrovessel may be causing a relative angioscotoma with reduced retinal sensitivity in the superior half of the macula as compared to the inferior half.
Aged↗
Evaluation of glutaraldehyde and povidone iodine for sterilization of wide-field contact vitrectomy lenses.
BACKGROUND AND OBJECTIVE: Wide-field vitrectomy contact lenses are currently sterilized with ethylene oxide gas, and other lenses with autoclaving. To maintain a large inventory or possibly run the risk of loss of lens quality with repeated autoclaving, glutaraldehyde 2% and povidone iodine 5% solution were evaluated as possible sterilizing agents. MATERIALS AND METHODS: Ethylene oxide presterilized lenses were contaminated with known concentrations (10(5) organisms/mL) of bacteria (S. epidemidis, P. aeruginosa, B. subtilis), and fungi (A. flavus, C. albicans) for 5 minutes. The test lenses were treated with glutaraldehyde or povidone iodine for 5, 10, 30, 60, and 120 minutes, and controls with sterilized water for a similar duration. Following treatment, both test and control lenses were sampled with sterile cotton swabs. The swabs were cultured for bacteria (tryptone soya broth 48 hours), and fungi (Saubourd's dextrose broth 5 days). RESULTS: The culture was negative for both glutaraldehyde- and povidone iodine-treated lenses against all organisms at all time points except B subtilis, which needed 120 minutes treatment. CONCLUSION: Two hours contact time with glutaraldehyde 2% or providone iodine 5% can sterilize vitrectomy contact lenses against common bacteria and fungi without affecting lens quality.
Bacteria↗
A curved vitrectomy probe.
A curved vitrectomy probe for better accessibility of the peripheral retina in phakic eyes is described. The specially designed curved vitrectomy probe has a 20-gauge pneumatic cutter. The radius of curvature at the shaft is 19.4 mm and it is 25 mm long. The ora serrata is accessed through a 3.0- or 4.0-mm sclerotomy in phakic eyes without touching the crystalline lens. Use of this instrument avoids inadvertent trauma to the clear lens in phakic eyes requiring vitreous base excision. This curved vitrectomy instrument complements wide-angle viewing systems and endoscopes for safe surgical treatment of peripheral retinal pathology in phakic eyes.
Equipment Design↗
Liquid crystal display microperimetry in idiopathic subretinal fibrosis.
A 46-year-old woman presented with a history of decreased vision. On examination, best-corrected visual acuity was 20/30 in both eyes. Fundus evaluation of the right eye revealed subretinal fibrosis of the macula involving the fovea. The fundus of the left eye was normal. Fluorescein angiography confirmed the diagnosis. At 10 months of follow-up, the patient was asymptomatic and the visual acuity was stable at 20/25 in both eyes. Liquid crystal display microperimetry showed comparable retinal sensitivity in both eyes (P> .05). However, the right eye revealed unstable fixation compared to the left eye. Idiopathic subretinal fibrosis should be considered in the differential diagnosis of patients with subretinal fibrosis. Liquid crystal display microperimetry is a useful tool in evaluating these patients.
Diagnosis, Differential↗
Suction-assisted two-piece cased wide-angle contact lens for vitrectomy.
The conventional two-piece cased wide-angle contact lens is modified to enhance its contact system by four quadrant plate extensions. A metal housing attached to the side of the plate has an opening at the inferior surface. A suction device is attached to the housing. Suction created by the device holds the contact lens on the cornea. This lens reduces the need for a skilled assistant to stabilize the contact lens. It provides a stable, well-centered view of the peripheral fundus during vitreous surgery.
Equipment Design↗
Successful management of melanocytoma-associated choroidal neovascularization with photodynamic therapy.
PURPOSE: To report the efficacy of photodynamic therapy in treatment of choroidal neovascular membrane (CNV) associated with melanocytoma of the optic disc. METHODS: A middle-aged man with visual acuity of 20/200 in right eye was treated with photodynamic therapy for juxtafoveal classic CNV overlying the papillomacular bundle. CNV was secondary to ocular melanocytoma, a rare event. RESULTS: At the 6-month follow-up, a scarred CNV with final visual acuity of 20/30 was noted clinically and angiographically. Tomography revealed high reflective scar tissue with flat macula and microperimetry showed restoration of retinal sensitivity over the papillomacular bundle. CONCLUSIONS: Photodynamic therapy effectively resolved CNV that involved papillomacular bundle (secondary to melanocytoma) and restored retinal function in papillomacular bundle.
Choroidal Neovascularization↗