Immunohistochemical properties of human optic nerve glioma. Evidence of type 1 astrocyte origin.

The peroxidase-antiperoxidase method was used to study ten surgically obtained human optic nerve gliomas (pilocytic astrocytomas). All tissues were formalin fixed and paraffin embedded. Primary antisera included glial fibrillary acidic protein (GFAP), HNK-1 (type 1 astrocyte precursor marker), A2B5 (type 2 astrocyte precursor marker), S-100, vimentin, myelin basic protein (MBP), laminin, keratin, cytokeratin, epithelial membrane antigen (EMA), and neuron-specific enolase (NSE). Neoplastic astrocytes in optic nerve gliomas stained with GFAP, HNK-1, S-100, and vimentin. Oligodendrocytes and myelin sheaths stained for MBP, and NSE stained surviving axons in the tumors. Neoplastic astrocytes did not stain for A2B5, keratin, cytokeratin, EMA, or laminin. These results suggest that human optic nerve gliomas (pilocytic astrocytomas) arise from type 1 astrocytes.

Topical fluoroquinolones: antimicrobial activity and in vitro corneal epithelial toxicity.

To assess the potential of fluoroquinolones as topical antimicrobial agents, we evaluated in vitro the antimicrobial activity of five fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, pefloxacin, and temafloxacin), as well as gentamicin, tobramycin, and cefazolin against 96 isolates of common bacterial corneal pathogens. Ciprofloxacin and temafloxacin were the most active quinolones [minimal inhibitory concentration inhibiting 90% of stains (MIC90) of 1 microgram/ml], followed by ofloxacin (MIC90 2 micrograms/ml), and norfloxacin and pefloxacin (MIC90s 4 micrograms/ml). In contrast, gentamicin and tobramycin MIC90s were 32 and 64 micrograms/ml, respectively; cefazolin MIC90 was greater than 2048 micrograms/ml. The corneal epithelial cytotoxicity of the fluoroquinolones also was evaluated utilizing an in vitro assay of 3H-thymidine uptake of rabbit corneal epithelial cell cultures. The least to greatest toxicity of the fluoroquinolones were as follows: ciprofloxacin and temafloxacin less than norfloxacin less than ofloxacin less than pefloxacin. Our study suggests that the fluoroquinolones, especially ciprofloxacin and temafloxacin, possess excellent in vitro activity against common bacterial corneal pathogens and are less toxic to the corneal epithelium than the aminoglycosides.

Antimicrobial activity and in vitro corneal epithelial toxicity of antimicrobial agents for gram-positive corneal pathogens.

We assessed in vitro the antimicrobial activity of four agents (vancomycin, teicoplanin, mupirocin, and imipenem) which are effective against Gram-positive cocci causally associated with bacterial keratitis, as well as their corneal epithelial cytotoxicity. Minimal inhibitory concentrations inhibiting 90% of strains (MIC90s) against 10 strains each of methicillin-susceptible and -resistant Staphylococcus aureus and Staphylococcus epidermidis, penicillin-susceptible and -resistant Streptococcus pneumoniae, and viridans group streptococci were as follows: vancomycin (MIC90s 0.25-2 micrograms/ml), teicoplanin (MIC90s 0.25-4 micrograms/ml, mupirocin (MIC90s 0.12-4 micrograms/ml), and imipenem (MIC90s 0.008-0.25 micrograms/ml, except for methicillin-resistant staphylococci with MIC90 of 16 micrograms/ml). Cytotoxicity was assayed by uptake of 3H-thymidine by rabbit corneal epithelial cell cultures at drug concentrations of 12.5-100 mg/ml for vancomycin and teicoplanin, 1-8 mg/ml for mupirocin and 0.125-8 mg/ml for imipenem, with exposure times of 5, 30 and 60 min. Cytotoxicity was as follows: imipenem < mupirocin < vancomycin < or = teicoplanin. Resistance to methicillin-resistant S. aureus and S. epidermidis for imipenem and resistance to S. epidermidis and cytotoxicity for teicoplanin limit their consideration for suspected Gram-positive keratitis. On the other hand, vancomycin and mupirocin, because of their excellent therapeutic indices, should be considered for this indication.

The painful eye: external and anterior segment causes.

When a patient presents to a medical practitioner with a painful eye, the initial history is extremely valuable in determining the cause of the complaint. The patient should be questioned specifically about the onset and duration of symptoms; description of the pain; exacerbating and mitigating factors; associated pruritus, discharge, or photophobia; and any previous occurrences. It is important to inquire about the patient's past medical history, past ocular history (including surgeries, trauma, contact lens wear, and family history of glaucoma), systemic and ocular medications, and allergies. A careful examination of the patient's skin, face, eyelids, conjunctiva, sclera, cornea, and anterior chamber should be performed. In this article, the authors describe a variety of external diseases and anterior segment causes of a painful eye, many of which can be diagnosed from the initial history. The article works systematically, beginning externally with the eyelids and conjunctiva and progressing internally toward the cornea and anterior chamber.

Phototherapeutic keratectomy for recurrent erosion syndrome in anterior basement membrane dystrophy.

PURPOSE: To determine the outcome of patients who received phototherapeutic keratectomy (PTK) for recurrent erosion syndrome due to anterior basement membrane dystrophy (ABMD). DESIGN: A retrospective, noncomparative case series. PARTICIPANTS: Forty-eight eyes of 43 consecutive patients who underwent PTK for recurrent erosions occurring in ABMD at the Hunkeler Eye Center from 1991 to April 1995. All patients had previously failed at least one method of medical or surgical treatment for recurrent erosions and had slit-lamp findings of ABMD on initial evaluation. INTERVENTION: The eyes each underwent manual superficial keratectomy and PTK with the Summit Omnimed excimer laser. MAIN OUTCOME MEASURES: Data were analyzed by a retrospective chart review for 1, 3, 6, and 12 months for the 36 eyes with at least 12 months of follow-up data available. They were analyzed for preoperative and postoperative visual acuity, change in spherical equivalent, recurrence rate, and patient satisfaction. RESULTS: The preoperative mean visual acuity was not statistically significantly different at 1 month after PTK. Statistically significant improvement in mean visual acuity was present at 3, 6, and 12 months. Recurrence of symptoms of recurrent erosion was present in 5 (13.8%) of 36 eyes during the 12-month follow-up period, which was managed with repeat PTK over the area of the cornea initially treated with PTK; 1 of 5 required a third PTK treatment. All recurrences presented within 6 months of PTK or repeat PTK. The mean dioptric change in spherical equivalent was not statistically significant. Patient satisfaction levels after PTK for recurrent erosions in ABMD were assessed in 21 (58%) of 36 patients on a scale of 0 to 5 (5 = most satisfied); the mean response was 4.14 of 5. CONCLUSIONS: Phototherapeutic keratectomy is an effective treatment for recurrent erosions occurring in the setting of ABMD, is well tolerated, and may improve visual acuity. The rate of recurrence of erosions in ABMD treated with PTK is low during a 12-month follow-up period.