Retinal toxicity of intravitreal genistein in a rabbit model.

PURPOSE: The purpose of this study was to evaluate the preclinical safety of intravitreal genistein in rabbit eyes over a short-term period. METHODS: Twelve New Zealand albino rabbits were selected for this study. Four concentrations of genistein (LC Laboratories, Woburn, MA) were prepared: 24 mg/0.1 mL, 135 mg/0.1 mL, 270 mg/0.1 mL, and 540 mg/0.1 mL. Each concentration was injected intravitreally in one eye of three rabbits. As a control, the vehicle solution was injected into the other eye of each animal. Retinal safety of intravitreal genistein was studied with electroretinography and histologic examination in rabbits. Electroretinography recordings were made before the injection and 3 weeks after the injection. Eventually, the rabbits were killed and the retinas were examined by light microscopy. Immunohistochemical staining with caspase-3 and caspase-9 was also performed to evaluate apoptotic expression in all study and control eyes. RESULTS: Electroretinography studies showed no significant difference between control and genistein-injected eyes at any of the doses in the rabbit model. Histologic examination showed no retinal abnormality in the rabbits injected with different concentrations of genistein. Immunohistochemical staining with caspase-3 and caspase-9 showed no different apoptotic protein expression in any study or control eyes. CONCLUSION: Our results indicate that genistein is a safe intravitreal drug in the rabbit model up to 540 mg. If proven safe and efficacious in human studies, intravitreal injection of genistein could be considered a treatment alternative for ocular neovascularisation in selected cases.

Limbal anaesthesia versus topical anaesthesia for clear corneal phacoemulsification.

PURPOSE: To compare the safety and clinical efficacy provided by limbal anaesthesia with topical anaesthesia in cataract surgery. METHODS: A total of 117 consecutive patients undergoing routine cataract surgery were randomly assigned to receive limbal or topical anaesthesia. Limbal anaesthesia was administered with a cellulose ophthalmic sponge soaked in preservative-free lidocaine hydrochloride 4% applied to the temporal perilimbal area for 45 seconds immediately before surgery. For topical anaesthesia lidocaine 4% was instilled in each patient at 10-min intervals four times before surgery. We studied phaco time, perioperative pain, visual outcome and intraoperative complications. The level of intraoperative pain was scored on a scale of 1-10, where 1 = no pain and 10 = severe pain. RESULTS: 55 patients (91.6%) in the topical group and 54 patients (94.7%) in the limbal group tolerated the procedure well, giving pain scores of 1-3, with no statistical difference. No patients in either group required supplemental anaesthesia and no intraoperative complications were recorded. No eyes had epithelial defects at the end of surgery or at postoperative check-ups. CONCLUSION: Limbal anaesthesia in cataract surgery is safe and the two anaesthesia techniques do not present differences in the degree of analgesia achieved.

Ocular cicatricial pemphigoid, keratomycosis, and intravenous immunoglobulin therapy.

PURPOSE: To report the case of a patient developing fungal keratitis in the context of uncontrolled ocular cicatricial pemphigoid (OCP), which, despite intravenous immunoglobulin (IVIg) and other immunomodulatory therapy, progressed to end-stage pemphigoid, with corneal opacification, ankyloblepharon, and xerosis. Keratoprosthesis (KPro) restored functional vision for the patient. METHODS: A 39-year-old man presented with uncontrolled CP and corneal ulcer in the left eye. Conjunctival biopsy diagnosed OCP; corneal scraping and biopsy diagnosed the cause of the corneal ulcer. OCP was treated with systemic steroids, immunosuppressive drugs, and IVIg. Visual rehabilitation was accomplished with Ahmed valve and a type II Dohlman KPro. RESULTS: Immunohistology of the biopsied conjunctiva showed IgG at the epithelial basement membrane zone, confirming the clinical diagnosis of OCP. Microbiologic studies of the corneal biopsy specimen were negative for Acanthamoeba and herpes but positive for Aspergillus niger. The patient's keratomycosis resolved with topical antifungal therapy. Treatment with Dapsone, intravenous-pulse steroid, oral cyclophosphamide, and intravenous immunoglobulin (IVIg) failed to control the OCP, with resultant complete conjunctivization of the cornea. Keratoprosthesis improved the patient's visual acuity from hand movements to 20/20. CONCLUSIONS: Patients with uncontrolled OCP are at increased risk of corneal infection. The difficulty in diagnosing keratomycosis and the relatively rare occurrence of OCP explain the uniqueness of our reported case. OCP may progress to "end-stage" disease despite therapy. Keratoprosthesis can restore vision in selected otherwise seemingly hopeless cases.