Scattered UV irradiation during VISX excimer laser keratorefractive surgery.

PURPOSE: To evaluate the potential occupational health hazards associated with scattered ultraviolet (UV) radiation during photorefractive keratectomy (PRK) using the VISX Star S3 excimer laser. SETTING: The Laser Vision Center, National Naval Medical Center, Bethesda, Maryland, USA. METHODS: Intraoperative radiometric measurements were made with the Ophir Power/Energy Meter (LaserStar Model PD-10 with silicon detector) during PRK treatments as well as during required calibration procedures at a distance of 20.3 cm from the left cornea. These measurements were evaluated using a worst-case scenario for exposure, and then compared with the American Conference of Governmental Industrial Hygeinists (ACGIH) Threshold Value Limits (TVL) to perform a risk/hazard analysis. RESULTS: During the PRK procedures, the highest measured value was 248.4 nJ/pulse. During the calibration procedures, the highest measured UV scattered radiation level was 149.6 nJ/pulse. The maximum treatment time was 52 seconds. Using a worst-case scenario in which all treatments used the maximum power and time, the total energy per eye treated was 0.132 mJ/cm2 and the total UV radiation at close range (80 cm from the treated eye) was 0.0085 mJ/cm2. With a workload of 20 patients, the total occupational exposure at 80 cm to actinic UV radiation in an 8-hour period would be 0.425 mJ/cm2. CONCLUSIONS: The scattered actinic UV laser radiation from the VISX Star S3 excimer laser did not exceed occupational exposure limits during a busy 8-hour workday, provided that operating room personnel were at least 80 cm from the treated eye. While the use of protective eyewear is always prudent, this study demonstrates that the trace amounts of scattered laser emissions produced by this laser do not pose a serious health risk even without the use of protective eyewear.

Epicorneal aspergilloma after penetrating keratoplasty.

PURPOSE: To report an epicorneal aspergilloma in a postkeratoplasty patient with a bandage soft contact lens. METHODS: Case report of a 77-year-old postkeratoplasty patient who presented with an epicorneal mass under a bandage soft contact lens placed for a nonhealing epithelial defect. On removal of the contact lens, a 4 x 4-mm placoid mass fell free from the corneal surface and was sent for culture and histopathology. RESULTS: Gram stain demonstrated septated branching hyphae, and cultures confirmed the diagnosis of Histopathologic sections of the epicorneal mass revealed a full-thickness aspergilloma. CONCLUSION: Contact lens removal and aggressive antimycotic treatment resulted in epithelial healing and resolution of the keratomycosis. The patient remained stable for 6 months followed by a successful repeat penetrating keratoplasty.

Overview of refractive surgery.

Patients with myopia, hyperopia and astigmatism can now reduce or eliminate their dependence on contact lenses and eyeglasses through refractive surgery that includes radial keratotomy (RK), photorefractive keratectomy (PRK), laser-assisted in situ keratomileusis (LASIK), laser thermal keratoplasty (LTK) and intrastromal corneal rings (ICR). Since the approval of the excimer laser in 1995, the popularity of RK has declined because of the superior outcomes from PRK and LASIK. In patients with low-to-moderate myopia, PRK produces stable and predictable results with an excellent safety profile. LASIK is also efficacious, predictable and safe, with the additional advantages of rapid vision recovery and minimal pain. LASIK has rapidly become the most widely performed refractive surgery, with high patient and surgeon satisfaction. Noncontact Holium: YAG LTK provides satisfactory correction in patients with low hyperopia. ICR offers patients with low myopia the potential advantage of removal if the vision outcome is unsatisfactory. Despite the current widespread advertising and media attention about laser refractive surgery, not all patients are good candidates for this surgery. Family physicians should be familiar with the different refractive surgeries and their potential complications.

Effective steroid-sparing treatment for peripheral ulcerative keratitis and pyoderma gangrenosum.

OBJECTIVE: To report a patient with a rare clinical presentation of marginal keratitis and pyoderma gangrenosum (PG) that responded to the steroid-sparing agent azathioprine. DESIGN: Interventional case report. METHODS: Case report and MEDLINE review of the medical literature on PG-associated peripheral ulcerative keratitis (PUK) and its treatment. RESULTS: A patient with a biopsy-proven history of PG developed an explosive episode of PUK. The ocular inflammation was minimally responsive to topical therapy and required significant long-term oral steroids for control. The patient's active skin lesions and marginal keratitis responded dramatically to systemic oral azathioprine. Since the initiation of treatment with azathioprine, there have been no subsequent recurrences of PG or marginal keratitis. CONCLUSIONS: PUK may be associated with other inflammatory conditions, such as PG and arthritis. Systemic azathioprine may successfully control ocular and extraocular conditions and should be considered in the clinical setting of topical therapy failure and/or extraocular inflammatory conditions.

Pellucid marginal degeneration with superior corneal thinning.

PURPOSE: Pellucid marginal degeneration is a noninflammatory thinning disorder typically involving the inferior cornea. We describe a patient with superior corneal thinning similar to classic pellucid marginal degeneration. METHODS: An 80-year-old man was evaluated for high astigmatism. RESULTS: The right superior cornea had a prominent band of thinning with ectasia. Both inferior corneas had characteristic zones of thinning without inflammation. CONCLUSIONS: Superior pellucid marginal corneal degeneration should be considered in the differential diagnosis of superior corneal ectatic disorders.

Possible consequences of shaking hands with your patients with epidemic keratoconjunctivitis.

PURPOSE: We evaluated patients' hands as a possible vector for the spread of epidemic kerato-conjunctivitis. METHODS: The hands and conjunctivitis of 26 patients with epidemic keratoconjunctivitis and the hands of 26 uninfected control patients were cultured for infectious adenovirus. RESULTS: In 12 (46%) of 26 patients with epidemic keratoconjunctivitis, cultures from the hands were positive for adenovirus, whereas cultures from the hands of all uninfected control patients were negative. CONCLUSIONS: Simultaneous coinfection of patients' hands and eyes with adenovirus may contribute to office epidemics. Ophthalmologists and coworkers should not shake the hands of patients suspected of having epidemic keratoconjunctivitis unless properly gloved.

Fluoroquinolones in the treatment of bacterial keratitis.

PURPOSE: We evaluated the potential role of three topical fluoroquinolones in the treatment of bacterial keratitis by means of a laboratory database. METHODS: Antibiotic susceptibilities were determined for 153 isolates from patients with bacterial keratitis. Results were analyzed for each fluoroquinolone individually and in combination with cefazolin. RESULTS: Predicted susceptibility to each cefazolin-fluoroquinolone combination (98.7%) was superior to that for single-agent therapy with ofloxacin (88.2%), ciprofloxacin (82.3%), or norfloxacin (80.4%) (P = .0002). A cefazolin-fluoroquinolone combination (98.7%) was comparable to a cefazolin-gentamicin combination (97.4%). CONCLUSIONS: Combination therapy with cefazolin and a fluoroquinolone offers a reasonable alternative for the treatment of bacterial keratitis. Single-agent therapy with fluoroquinolones for vision-threatening bacterial keratitis is not advised.