Prevalence of sleep apnea syndrome and high-risk characteristics among keratoconus patients.

PURPOSE: To determine the prevalence and risk factors for sleep apnea in a keratoconus population. METHODS: Ninety-two keratoconus patients and 92 controls were classified as high risk or low risk for sleep apnea, using the Berlin Questionnaire (BQ) or individual history of sleep apnea. Logistic regression was used to investigate the risk factors associated with high risk of sleep apnea in keratoconus patients and controls. RESULTS: Of the 92 keratoconus patients, 18 (19.6%) had a positive known history for sleep apnea, and 49 (53.3%) were categorized to be at high risk by the BQ. Of the 92 control patients, 6 (6.5%) had a positive known history for sleep apnea, and 25 (27.2%) were categorized to be at high risk by the BQ. In keratoconus patients, body mass index was the only risk factor for sleep apnea, whereas in control patients, age, body mass index, and family history of sleep apnea were the risk factors for sleep apnea. CONCLUSIONS: Keratoconus patients are at increased risk for sleep apnea, and different risk factors are associated with sleep apnea in keratoconus patients and controls. Ophthalmologists should consider screening keratoconus patients for obstructive sleep apnea, if appropriate.

Multiple drug-resistant Alcaligenes xylosoxidans keratitis in a sanitation worker.

PURPOSE: To report a case of daily wear soft contact lens-associated keratitis caused by Alcaligenes xylosoxidans in a portable toilet sanitation worker. METHODS: A previously healthy 30-year-old man presented with bilateral decreased vision, redness, and irritation, beginning 1 week earlier. The patient had been treated with moxifloxocin for 1 week before presentation without improvement. Bacterial staining cultures were performed from corneal scrapings, contact lenses, contact lens case, and solution. Preliminary culture results and antibiotic sensitivities were generated using an automated identification system. Positive results from the contact lens, case, and solution were confirmed using polymerase chain reaction (PCR). RESULTS: The contact lenses, contact lens case, and solution cultures revealed heavy growth of A. xylosoxidans. These findings were confirmed by PCR. The organism was found to be resistant to aminoglycosides, fluoroquinolones, and cephalosporins. The patient was started on polymyxin B or trimethoprim. After 21 days of treatment, the infection completely resolved with a final spectacle-corrected visual acuity of 20/25. CONCLUSIONS: To our knowledge, this is the first case report of a corneal infection caused by A. xylosoxidans, which was isolated and identified from a contact lens, case, and solution using culture and PCR technique as well the first description of ocular surface disease resolution after the treatment with topical polymyxin B or trimethoprim. A. xylosoxidans should be considered as uncommon but potential pathogen capable of infectious spread through contaminated contact lens solution.

Correlation between clinical suspicion and polymerase chain reaction verification of infectious vitritis.

PURPOSE: To compare polymerase chain reaction (PCR) results to presumptive clinical diagnosis in patients with vitritis. DESIGN: Retrospective review of PCR laboratory records from vitreous samples. METHODS: Fifty consecutive laboratory records of vitreous samples sent for PCR testing were reviewed. Three reviewers with uveitis training ranked the clinical suspicion of a specific diagnosis using a classification system (scale of 1 to 4) and were masked to the PCR results. RESULTS: The degree of clinical suspicion of a particular diagnosis was significantly associated with a positive PCR result (P = .048). Higher clinical suspicion was significantly more associated with a positive PCR result compared with cases with lower clinical suspicion (P = .01). CONCLUSIONS: If the clinical suspicion of a specific diagnosis is low, the PCR for any infectious etiology is unlikely to be positive.

Reduction of preoperative conjunctival bacterial flora with the use of mupirocin nasal ointment.

PURPOSE: To determine whether the use of mupirocin ointment for preoperative eradication of nasal bacterial carriage was effective in reducing conjunctival bacterial flora. METHODS: Prospective, double-arm, blinded clinical trial of 37 eyes of 37 patients undergoing intraocular surgery (cataract extraction or pars plana vitrectomy) randomized to either control or mupirocin treatment groups. Treated patients received mupirocin nasal ointment twice daily for 5 days prior to surgery. Nasal cultures were obtained in all patients. All patients received a standard 5% povidone-iodine preparation before the surgical procedure, and conjunctival cultures were obtained in all patients before and after the povidone-iodine preparation. RESULTS: All 37 patient nasal swabs were positive for bacterial growth (cultures were obtained prior to the use of mupirocin ointment in the treatment group). One of 15 eyes (6.7%) in the treatment group had positive conjunctival cultures prior to povidone-iodine preparation, compared with nine of 22 eyes (41%) in the control group (P < .05). Even after povidone-iodine preparation, eight of 22 eyes (36%) in the control group demonstrated persistent positive cultures, whereas one (6.7%) of the treatment eyes exhibited growth (P < .05). CONCLUSIONS: Prophylactic use of mupirocin nasal ointment resulted in significant reduction of conjunctival flora with or without preoperative topical 5% povidone-iodine preparation. The use of mupirocin nasal ointment prior to intraocular surgery or intravitreal injections is a novel method for reducing conjunctival contamination rates, which theoretically should reduce the incidence of endophthalmitis.

Cytomegalovirus retinitis after intravitreous triamcinolone in an immunocompetent patient.

PURPOSE: To report the case of a 75-year-old man with diabetes who developed cytomegalovirus (CMV) retinitis after intravitreous injection of triamcinolone acetonide (IVTA). DESIGN: Observational case report. METHODS: Review of medical records. RESULTS: A 75-year-old man with diabetic macular edema developed arcuate retinal whitening after IVTA. A presumptive diagnosis of viral retinitis was made, and a vitrectomy was performed. Polymerase chain reaction of the vitreous was positive for CMV DNA. An infectious disease consultant found no signs of systemic CMV infection, and laboratory examination revealed that the patient was HIV negative. The patient responded well to intravitreal ganciclovir and oral valganciclovir, but when therapy was discontinued, the retinitis recurred and CMV DNA was again detected in the vitreous. The retinitis once again responded to antiviral therapy. CONCLUSIONS: CMV retinitis can occur after local immunosuppression with IVTA. Clinicians should be aware of this rare complication of IVTA.

Feasibility of eliminating ocular Chlamydia trachomatis with repeat mass antibiotic treatments.

CONTEXT: Mass antibiotic administrations for ocular chlamydial infection play a key role in the World Health Organization's trachoma control program. Mathematical models suggest that it is possible to eliminate trachoma locally with repeat mass treatment, depending on the coverage level of the population, frequency of mass treatments, and rate that infection returns into a community after each mass treatment. Precise estimates of this latter parameter have never been reported. OBJECTIVE: To determine the rate at which chlamydial infection returns to a population after mass treatment and to estimate the treatment frequency required for elimination of ocular chlamydia from a community. DESIGN, SETTING, AND PARTICIPANTS: Longitudinal cohort study of 24 randomly selected villages from the Gurage Zone in Ethiopia conducted February 2003 to October 2003. A total of 1332 children aged 1 to 5 years were monitored for prevalence of ocular chlamydial infection pretreatment and 2 and 6 months posttreatment. INTERVENTIONS: All individuals older than 1 year were eligible for single-dose oral azithromycin treatment. Pregnant women were offered tetracycline eye ointment. MAIN OUTCOME MEASURES: Prevalence of ocular chlamydial infection, measured by polymerase chain reaction, in children aged 1 to 5 years, in each of 24 villages at each time point was used to estimate the rate of return of infection and the treatment frequency necessary for elimination. RESULTS: The prevalence of infection was 56.3% pretreatment (95% confidence interval [CI], 47.5%-65.1%), 6.7% 2 months posttreatment (95% CI, 4.2%-9.2%), and 11.0% 6 months posttreatment (95% CI, 7.3%-14.7%). Infection returned after treatment at an exponential rate of 12.3% per month (95% CI, 4.6%-19.9% per month). The minimum treatment frequency necessary for elimination was calculated to be once every 11.6 months (95% CI, 7.2-30.9 months), given a coverage level of 80%. Thus, biannual treatment, already being performed in some areas, was estimated to be more than frequent enough to eventually eliminate infection. CONCLUSION: The rate at which ocular chlamydial infection returns to a community after mass treatment suggests that elimination of infection in a hyperendemic area is feasible with biannual mass antibiotic administrations and attainable coverage levels.

Ocular oxygen consumption: estimates using vitreoperfusion in the cat.

PURPOSE: Little is known about the ocular oxygen consumption rate (QO2) in human diseases. Alterations in QO2 must occur in many conditions, such as retinal ischemia. We present a method of estimating QO2 that eventually could be used in patients during vitrectomy surgery. METHODS: We performed vitreoperfusion (i.e., perfusion of the vitreous cavity after vitrectomy) in 14 cat eyes with no ocular blood flow. The solution contained nutrients at a high partial pressure of oxygen (PO2). In eight eyes, the retinas were undisturbed (Group 1), and in six eyes, we excised the retinas (Group 2). We estimated QO2 in both groups on the basis of the temporal decline of PO2 in the vitreoperfusion solution according to a pharmacokinetic model. RESULTS: The mean and standard deviation of QO2 was 3.2 +/- 0.8 microL/min in Group 1 and 0.4+/- 0.7 microL/min in Group 2, with the difference being the retinal contribution, 88%. In Group 1, metabolism, bulk flow, and diffusion accounted for 82, 13, and 5%, respectively, of the oxygen loss from the vitreoperfusion solution. CONCLUSION: We estimated ocular oxygen consumption by means of vitreoperfusion. Eventually, the pathophysiology of human diseases may be clarified by similar measurements during vitrectomy.