Effect of topical anesthetic agents and ethanol on corneoepithelial wound healing in an ex vivo whole-globe porcine model.

PURPOSE: To assess the impact of topical anesthetic agents and ethanol on ocular surface wound healing using an ex vivo whole-globe porcine model. SETTING: Department of Ophthalmology, Inselspital, University of Bern, Bern, Switzerland. DESIGN: Experimental study. METHODS: Standardized corneoepithelial lesions (5.0 mm diameter, 40 µm depth) were created with excimer laser light in freshly enucleated porcine eyes. The globes (6 per group) were exposed to different concentrations of ethanol (2.0% to 99.0%), cocaine (2.0% to 10.0%), procaine hydrochloride (0.4%), tetracaine (0.5% to 1.0%), or lidocaine (2.0%), 3 drops/hour for 3 hours. Control solutions were physiologic saline, balanced salt solution, and tissue-culture medium. After 20 to 26 hours, wound-healing response was compared by measuring the diameter of each corneoepithelial lesion. RESULTS: The mean diameter of corneoepithelial lesions exposed to physiologic saline decreased from 4.78 mm ± 0.19 (SD) to 4.44 ± 0.17 mm between 20 and 26 hours. After 24 hours, the mean lesion size, compared with physiological saline, was larger after cocaine 5.0% (5.20 ± 0.26 mm) and 10.0% (5.39 ± 0.12 mm), tetracaine 0.5% (5.59 ± 0.35 mm) and 1.0% (5.55 ± 0.27 mm), and procaine hydrochloride 0.4% (5.76 ± 0.12 mm), but not after lidocaine 2.0% (5.01 ± 0.17 mm). Balanced salt solution, tissue-culture medium, ethanol 2.0% to 99.0%, and cocaine 2.0% did not inhibit the wound-healing response. CONCLUSIONS: In an ex vivo whole-globe porcine model, lidocaine 2.0% and cocaine 2.0% were the least toxic anesthetic agents. At all concentrations, ethanol had no impact on wound healing. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Retinal vascular occlusion after vitrectomy with retrobulbar anesthesia-observational case series and survey of literature.

BACKGROUND: Severe postoperative loss of vision has been occasionally reported as a rare complication of retrobulbar anesthesia, and several possible causes have been proposed in the literature. In this work, our own and other investigators' experiences with these complications are surveyed with a view to identifying its pathophysiology. PATIENTS: This observational case series refers to six patients who presented during a 3-month period with occlusion of either the central artery itself (n = 3) or a branch thereof (n = 3) 2-14 days after uneventful vitreoretinal surgery following retrobulbar anesthesia with a commercial preparation of mepivacaine (1% Scandicain®, Astra Chemicals, Sweden) containing methyl- and propyl parahydroxybenzoate as preservatives. RESULTS: Three of the patients carried risk factors, which were medically controlled. In three individuals, vasoocclusion was observed after a second vitreoretinal intervention, which was performed 3-12 months after uneventful primary surgery. Good visual recovery was observed in only one instance. CONCLUSIONS: In patients who were anesthetized with preservative-free mepivacaine, no vasoocclusion occurred. In individuals who were anesthetized with mepivacaine containing the preservatives methyl- and propyl parahydroxybenzoate, a tenfold increase in the incidence of eyes requiring re-operation was documented, with a 2- to 14-day lapse in the onset of vasoocclusion. These findings reveal a possible implication of preservatives contained in the local anesthetic solution for the vasoocclusive events. Due to this potential hazard, the use of preservative-free preparations of local anesthesia in ocular surgery is emphasized in order to prevent this sight-threatening complication.

Conjunctival proliferation after a mild pepper spray injury in a young child.

PURPOSE: To report a case of conjunctival proliferation in a 2.5-year-old boy after initial evidence of a mild chemical injury after ocular exposure to pepper spray (oleoresin capsicum). METHODS: Case report with ophthalmologic and histologic findings. RESULTS: A child presented with mild conjunctival injection and chemosis without any corneal erosion after direct exposure to pepper spray. Three weeks later, a significant conjunctival proliferation was found at the limbus, which was refractory to treatment with topical corticosteroids. Finally, proliferative tissue was surgically excised without clinical recurrence during 2 months of follow-up. CONCLUSIONS: We hypothesize that the young age of the patient may have been an important factor for the severe conjunctival proliferation in comparison to a mainly uncomplicated course of pepper spray injuries in most adults. We recommend the use of topical antiinflammatory treatment even in apparently mild pepper spray injuries, especially in young children.

Dietary tocopherol supplementation after trabeculectomy and phacotrabeculectomy: double-blind randomized placebo-controlled trial.

PURPOSE: The vitamin E compound alpha-tocopherol inhibits fibroblast growth in vitro. To evaluate its potential benefit in preventing failure of glaucoma filtration surgery, we prospectively investigated the outcome of filtering surgery with postoperative dietary alpha-tocopherol supplementation. PATIENTS AND METHODS: Thirty-nine patients (39 eyes) with primary open-angle glaucoma or pseudoexfoliative glaucoma were randomly assigned to two post-(phaco)-trabeculectomy treatment groups. Daily oral intake of 300 mg alpha-tocopheryl-acetate (absorbed as alpha-tocopherol in the intestine) for 2 months was compared to a placebo preparation in a double-blind trial. The follow-up time was 1 year. Success was defined as intraocular pressure (IOP)