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Biomedical subjects

Eugene S Lit

Publications and source records attributed to Eugene S Lit.

5 recordsLinked to original sources

Lamina puncture for central retinal vein occlusion: results of a pilot trial.

OBJECTIVE: To evaluate the effect of treatment by lamina puncture, a novel procedure to create a perivascular opening within the optic nerve head by a transvitreal approach, on visual acuity after central retinal vein occlusion (CRVO) in older patients. METHODS: The patients comprised a nonrandomized, consecutive, interventional case series of older patients being seen with CRVO. Patients 65 years or older with CRVO and a visual acuity of 20/200 or worse were treated with vitrectomy and lamina puncture of the optic disc. Preoperative visual acuity, clinical examination results, and fluorescein angiography results were compared with postoperative results. RESULTS: Twenty patients (12 men and 8 women), an average age of 72 years, were enrolled. The mean duration of CRVO was 5.4 months; 14 eyes had nonischemic CRVO when first seen, while 6 had substantial ischemia. The mean preoperative visual acuity was in the counting fingers range, and the mean postoperative visual acuity was also in the counting fingers range. Complications included 5 eyes with iris neovascularization, of which 4 progressed to neovascular glaucoma; also, preoperative ischemia seemed to predispose to neovascular complications. CONCLUSION: Lamina puncture does not restore visual acuity in older patients with CRVO.

Aged↗

In vivo rabbit eyecup preparation for use in retinal research.

PURPOSE: To develop an in vivo rabbit eyecup preparation that preserves neuronal and vascular connections with normal posterior segment contour, permitting direct access to the retina and facilitating retinal microsurgical and neuroscience research. METHODS: Cyanoacrylate glue was applied to the anterior sclera of six Dutch-belted rabbits before open-sky vitrectomy. The glue was used to harden the compliant scleral wall and to fix it to the surrounding periorbital tissues. RESULTS: A normal contour of the posterior segment was retained in all cases. Vitrectomy under air was successfully accomplished and an extensive removal of the vitreous gel was achieved. Fluorescein angiography revealed normal vascular patency of the retinal vessels after vitrectomy. CONCLUSIONS: The proposed modification of the rabbit eyecup retains the normal neurovascular connections and configuration of the retina, making it suitable for retinal microsurgical maneuvers or any procedures in which easy access to anatomically undisturbed retina is required.

Animals↗

Retinal microvascular surgery: a feasibility study.

PURPOSE: To evaluate the feasibility of microvascular surgery at the level of the retinal vasculature. METHOD: Porcine eyes were used, and eyecups were prepared under an operating microscope. Several classic microvascular maneuvers were explored, such as vascular puncturing, catheterization, mobilization, intravascular injections, and various combinations of the same. Instruments used ranged from disposable 30-gauge needles to an Er:YAG laser. Commercially available 10-0 nylon sutures, fine polyimide tubes, and custom-made fine glass tubes were used for vascular catheterization. RESULTS: Puncturing, mobilization, catheterization, and intravascular injection of retinal arteries and veins were possible. The connection of two remote retinal vessels with a fine tube was also achieved with the combination of these maneuvers. CONCLUSIONS: The feasibility of performing several microvascular maneuvers on retinal arteries and veins was demonstrated in porcine eyes. Further experimentation and development of these findings in a living animal model could lead to the development of such microvascular maneuvers in humans.

Anastomosis, Surgical↗

Lamina puncture: pars plana optic disc surgery for central retinal vein occlusion.

OBJECTIVE: To determine the feasibility of creating a perivascular space adjacent to the central retinal vein at the level of the lamina cribrosa as a potential method of reestablishing perfusion in central retinal vein occlusion. METHODS: Various designs for a puncture instrument, or lamina puncture lancet, were investigated in cadavers, pigs that had undergone enucleation, and in vivo rabbit eyes. RESULTS: A lancet with a sharp cutting edge on one side and an opposing blunt edge is repeatedly able to create a perivascular space with limited optic nerve fiber damage. CONCLUSIONS: Lamina puncture is technically feasible, and evaluation in carefully selected patients appears warranted.

Animals↗