Methicillin-resistant Staphylococcus aureus ulcerative keratitis after laser in situ keratomileusis.

We report the first case of methicillin-resistant Staphylococcus aureus (MRSA) ulcerative keratitis after routine bilateral laser in situ keratomileusis. Within 24 hours of initial ulceration the lamellar flap melted, disintegrating into necrotic fragments. Recognition of lamellar flap infections followed by immediate medical and surgical management is critical to preserving vision.

Fungal and parasitic infections of the eye.

The unique structure of the human eye as well as exposure of the eye directly to the environment renders it vulnerable to a number of uncommon infectious diseases caused by fungi and parasites. Host defenses directed against these microorganisms, once anatomical barriers are breached, are often insufficient to prevent loss of vision. Therefore, the timely identification and treatment of the involved microorganisms are paramount. The anatomy of the eye and its surrounding structures is presented with an emphasis upon the association of the anatomy with specific infection of fungi and parasites. For example, filamentous fungal infections of the eye are usually due to penetrating trauma by objects contaminated by vegetable matter of the cornea or globe or, by extension, of infection from adjacent paranasal sinuses. Fungal endophthalmitis and chorioretinitis, on the other hand, are usually the result of antecedent fungemia seeding the ocular tissue. Candida spp. are the most common cause of endogenous endophthalmitis, although initial infection with the dimorphic fungi may lead to infection and scarring of the chorioretina. Contact lens wear is associated with keratitis caused by yeasts, filamentous fungi, and Acanthamoebae spp. Most parasitic infections of the eye, however, arise following bloodborne carriage of the microorganism to the eye or adjacent structures.

Ocular gelfoam disc-applicator for pupillary dilation in humans.

This study investigates a gelfoam disc device as an alternative topical ophthalmic drug delivery system for pupillary dilation in humans. Gelfoam (Pharmacia & Upjohn) discs were impregnated with 0.60 mg of tropicamide racemate and 1.7 mg of 1-phenylephrine hydrochloride by an ethanol solvent evaporation method. Twenty randomly selected human subjects received baseline examinations, including blood pressure, pulse rate and biomicroscopy of the ocular surface. One impregnated gelfoam disc was placed in the inferior fornix of a randomly selected eye. Simultaneously, the fellow eye was treated with two topically administered drops, one from a phenylephrine hydrochloride 2.5% solution and one from a tropicamide 1% solution. A single, masked observer measured the pupillary diameter in both eyes at various time intervals under constant ambient conditions. Administration of the topical drops was repeated in the fellow eye. At maximum pupillary dilation, the disc was removed, and a post-dilation biomicroscopic exam was performed. Blood pressure and pulse rate were rechecked. The gelfoam-treated eyes' median change in dilation diameter was approximately 25% greater (a two-fold increase in pupillary area) (p< 0.001) at 15.2 min (median time to maximum dilation) than the topically treated fellow eyes. The median change in systolic blood pressure (+1.0 mmHg) and diastolic blood pressure (-1.0 mmHg) was not statistically significant (p>0.1). The average pulse rate was decreased 7 beats per minute (p=0.004). A gelfoam disc may serve as an ophthalmic drug delivery system for pupillary dilation or as a model for other multiple-dose topical drugs.

Serum tryptase: an indicator of anaphylaxis following fluorescein angiography.

BACKGROUND: Anaphylaxis is a potentially fatal complication of fluorescein angiography. It is diagnosed by clinical signs. Serum beta-tryptase serves as a specific indicator of mast cell activation and of anaphylactic shock that can be detected by radioimmunoassay. METHOD: This is a report on a 48-year-old woman who developed anaphylaxis during fluorescein angiography. This study investigates the role of beta-tryptase in anaphylactic shock resulting from intravenous fluorescein angiogram. RESULTS: A serum sample of beta-tryptase collected at the time of an adverse reaction to fluorescein angiography was determined by radioimmunassay to be elevated above 20 ng/ml (normal level <1 ng/ml). This indicates massive mast cell activation and anaphylactic shock. CONCLUSION: This case is the first in which elevated levels of beta-tryptase in serum indicated that the systemic adverse reaction to fluorescein was mast cell dependent. Additionally, beta-tryptase levels can be assayed to detect anaphylactic reactions several hours after a precipitating event.

Formulation and in vivo evaluation of ocular insert containing phenylephrine and tropicamide.

A Gelfoam based ocular device containing 1.7 mg of phenylephrine and 0.6 mg of tropicamide was formulated and evaluated for pupillary dilation in rabbits. The manufacturing procedure is fairly simple and the required excipients are inexpensive. The in vivo results show that the mydriatic response produced by the proposed device is larger and longer lasting than that produced by eyedrops with an equivalent amount of phenylephrine and tropicamide. The results reported in this study, along with those of previous studies, imply that Gelfoam(R) is a versatile drug carrier for either local or systemic drug delivery via the ophthalmic route.