Biomedical subjects
Publications and source records attributed to M B Raizman.
We measured intraoperative intraocular pressure in nine eyes of six patients, 34 to 55 years old, undergoing rectus muscle recession or resections and found sustained intraocular pressures of 77 to 84 mm Hg in the five eyes (three patients) affected by thyroid ophthalmopathy. Smaller increases were noted in the four eyes without muscle restrictions.
We recently studied members from a family with autosomal dominant iris coloboma. All affected members had either unilateral or bilateral iris coloboma and bilateral peripheral corneal changes indistinguishable from those seen in aniridia. The corneal changes consisted of well-demarcated pannus-like growths extending from the limbus onto the peripheral cornea for 360 degrees without any stromal vascularization. In one adolescent member, bilateral lenticular opacities limited to the meridian of the colobomata were seen. No members had primary glaucoma, macular or optic disc hypoplasia, nystagmus, or extraocular malformations. The coexistence of iris coloboma and aniridia-like corneal changes may imply that ocular coloboma and aniridia comprise a continuous spectrum of the same developmental defect or, alternatively, such corneal changes constitute a nonspecific manifestation of iris developmental defects in general.
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This multicenter, double-masked, randomized, parallel-group study compared the efficacy and safety of ketorolac tromethamine 0.5% ophthalmic solution with levocabastine 0.05% and ketorolac tromethamine vehicle in patients with seasonal allergic conjunctivitis. One drop of ketorolac, levocabastine, or vehicle was instilled in each eye four times daily for 6 weeks. In the majority of efficacy variables, ketorolac produced the greatest improvements, followed by levocabastine and vehicle. Ketorolac was significantly more effective (P < .05) than vehicle in reducing mean itching scores, palpebral hyperemia, bulbar hyperemia, and edema. Patients treated with ketorolac reported significant improvements (P < .05) in their ability to sleep and to concentrate on work, compared with those who received vehicle. No significant differences were noted among the treatment groups in safety or tolerability. Ketorolac tromethamine 0.5% ophthalmic solution instilled four times daily is effective and safe in reducing the signs and symptoms of seasonal allergic conjunctivitis.
Exposure of the eye to airborne particles in patients predisposed to allergy often results in the signs and symptoms of allergic conjunctivitis such as red, itchy eyes and ocular discharge. The mediators of these allergic symptoms include histamine, inflammatory substances such as prostaglandins, and other products of arachidonic acid metabolism (ie, leukotrienes). Ketorolac tromethamine is a nonsteroidal anti-inflammatory agent that inhibits the activity of cyclooxygenase, one of the two major enzymes responsible for the conversion of arachidonic acid to inflammatory substances. A multicenter patient survey was performed to evaluate the effectiveness of topical ketorolac tromethamine in treating the symptoms of allergic conjunctivitis. After ocular administration of ketorolac tromethamine, 90% (246/272) of patients reported that their eyes felt better. Eighty-four percent (173/206) of respondents rated ketorolac tromethamine as good to excellent in relieving their overall symptoms of ocular allergy, and 86% (217/251) of patients found the study drug produced good to excellent relief of their ocular itching usually within minutes to 1 hour of administration. Results of this survey found ketorolac tromethamine is effective in relieving ocular itching, the hallmark symptom of allergic conjunctivitis. In addition, these results provide further evidence that the products of arachidonic acid metabolism contribute to the symptoms of allergic conjunctivitis.
Herpes zoster ophthalmicus occurs worldwide, usually in healthy adults, but, increasingly in patients who are immunocompromised. After primary varicella infection (chickenpox), the virus lies dormant in the sensory ganglion until it becomes reactivated as zoster. Involvement of the ophthalmic branch of the trigeminal nerve is characterized early by corneal dysesthesia and dendritiform keratopathy, and these are self-limited. However, smoldering disease may cause pathological changes in the ocular structures through direct invasion of virus, secondary inflammation, and alterations of autoimmune mechanisms. Antiviral agents have demonstrated some success in resolving early signs and symptoms, but their role in preventing and treating late complications remains to be fully studied. Until a definitive antiviral agent is established, the benefits of steroid use in certain acute inflammatory processes outweight its risk of reducing host immunity. Corneal complications of herpes zoster ophthalmicus sometimes require surgical intervention.
BACKGROUND: This study evaluates epithelialization, clarity, intraocular inflammation, and fibroblast ingrowth of a collagen corneal allograft derived from rabbit dermis. METHODS: Dermal collagen fibers were dispersed intact and chemically modified to make them soluble. The allografts consisted of a fibrous, opaque peripheral zone and a central clear area. Twelve New Zealand white rabbits underwent penetrating keratoplasty with implantation of an allograft. The grafts were evaluated daily for clarify, anterior segment inflammation, and extent of reepithelialization with a slit-lamp microscope. RESULTS: Epithelialization of the fibrous peripheral zone of the graft ranged from 0% to 90%. The central clear area did not epithelialize in any of the animals. Fibroblasts migrated into the peripheral zone in all eyes. Complications included ulceration of the central clear area in two eyes. There was no ulceration or leakage at the graft-host interface and no synechia, fibrous, or inflammatory retrocorneal membranes in any of the eyes. CONCLUSIONS: Our study is the first to describe the method of modifying dermal type I collagen into a clear corneal allograft. Survival of the corneal collagen allograft beyond 1 month may be limited by several factors including lack of epithelialization of the central clear area.
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BACKGROUND AND OBJECTIVE: A prospective study was performed to assess the effect of trephination on corneal curvature. MATERIALS AND METHODS: Thirty-seven fresh porcine globes with intact corneal epithelium were used. Radius of curvature, central dioptric power, and powers and axes of the steepest and flattest meridians were obtained using a vertically mounted computerized videokeratography unit. Following 8-mm vacuum trephination of the central donor corneas, the said parameters were reassessed on the resultant buttons. No globes with epithelial defects were included in the study. RESULTS: The mean corneal radius of curvature (mm) increased from 8.68 +/- 0.79 to 10.46 +/- 3.24 (P = .005), the central dioptric power (D) decreased from 39.36 +/- 3.84 to 36.31 +/- 10.15 (P = .08), and the total corneal asphericity (D) increased from 5.03 +/- 2.99 to 7.47 +/- 3.42 (P = .0001). No significant changes in the axes of the steepest and the flattest meridians were noted following trephination. CONCLUSION: Trephination leads to significant corneal flattening and increased asphericity. Corneal topography can be used successfully as a research tool for whole globes and trephined buttons.