Nonarteritic ischemic optic neuropathy. The impact of tobacco use.

BACKGROUND: Numerous associations to anatomic variation and systemic vascular disease have been made to anterior ischemic optic neuropathy (AION) but exogenous agents have not been emphasized. The authors studied the effect that smoking had in the development of AION. The relevance of other intraocular and systemic vascular disease to AION also is discussed. METHODS: Over a 10-year period (January 1980-May 1990), nonarteritic AION was diagnosed in 148 patients, 137 of whom were included in this analysis. FINDINGS: Of the 137 patients identified with nonarteritic AION, 28 smokers were statistically younger, at 51 years of age, compared with 83 nonsmokers whose mean age was 64 years (P = 0.005). CONCLUSIONS: Cigarette smoking is an important risk factor in the development of AION. Cessation of smoking appears to reduce the risk of AION to that of the nonsmoking population.

Comparison of the accuracy of computerized videokeratography and keratometry for use in intraocular lens calculations.

We compared the accuracy of keratometry and computerized videokeratography (CVK) for use in intraocular lens calculations. We studied 48 eyes of 45 patients having phacoemulsification and posterior chamber lens implantation. Computerized videokeratography was performed with the EyeSys Corneal Analysis System (ECAS). Using the SRK II, SRK/T, and Holladay formulas, we evaluated predictive accuracy calculated with keratometric values and four values derived from ECAS measurements. For each formula, the use of one of the CVK parameters resulted in lower mean absolute errors between actual and predicted postoperative refractive errors and higher percentages of cases with power prediction errors < 0.5 and < 1.0 diopters. Computerized videokeratography may provide a more accurate corneal curvature value than keratometry for use in intraocular lens calculations.

Computerized digital image analysis of retinal vessel density: application to normoxic and hyperoxic rearing of the newborn rat.

Because of the inherent nature of existing techniques for vascular assessment of the retina, quantitative rigor has been difficult to attain. Computer imaging has now made possible measurement of oxygen-induced alterations in retinal blood vessels that is precise, accurate and repeatable. Newborn rats were exposed to 80% oxygen for 14 days as an animal model for retinopathy of prematurity (ROP). Ink perfusion, followed by retinal dissection, yielded silhouettes of the retinal vascular network. These images were digitized and enhanced by the MegaVision 1024XM imaging system in order to facilitate measuring extent of vasculature and capillary density. Mean grey levels, or 'mu', were 33.1 +/- 3.4 and 20.1 +/- 3.5 for room air- and oxygen-reared rats, respectively. These values are directly proportional to the fraction of the overall image that is vascular material, and, therefore, describe the extent of vaso-obliteration resulting from the oxygen exposure. The values were subsequently converted to square millimeters of vessel area to facilitate comparison to past and future studies. Oxygen rearing does not effect retinal area, but decreases retinal artery and vein diameter and decreases the linear extent of vessels toward the retinal periphery.

Visual results and complications of phacoemulsification with intraocular lens implantation performed by ophthalmology residents.

The authors retrospectively analyzed the visual outcome and incidence of complications of 181 consecutive cases of phacoemulsification performed by eight third-year ophthalmology residents. A posterior chamber intraocular lens was implanted in 179 of these eyes. Vitreous loss occurred in 5.5% of cases. The overall incidence of posterior capsule rupture was 9.9%; of the 18 posterior capsular ruptures, 72% were detected during cortical removal and 22% during nuclear emulsification. Postoperative follow-up for 177 eyes was at least 2 months, and 70% were followed for 6 months or longer. Final best corrected visual acuity of 20/40 or better was obtained in 92.6% of eyes. These results are comparable with previous reports of residents' experience in performing planned extracapsular cataract extraction. With appropriate training and faculty supervision, residents learning to perform phacoemulsification and intraocular lens implantation can achieve acceptable results.

Pharmacy-coordinated program that encourages physician reporting of adverse drug reactions.

A pharmacy-coordinated program for encouraging physician reporting of adverse drug reactions (ADRs) is described. The ADR surveillance program at the Medical Center Hospital of Vermont, a 500-bed tertiary-care hospital, is in its fifth year. Key elements are close interaction between physicians and pharmacists, feedback, program promotion, and financial incentive. The program is promoted chiefly to house staff physicians. A physician may identify a suspected ADR, or he or she may be alerted by a pharmacist. The physician completes the first part of a form, which requests information on the patient, the severity of the reaction, the actions taken, and any predisposing factors. A pharmacist reviews the incident independently and in consultation with the reporter and then completes the second part of the form, which asks the pharmacists to assess the probability that the drug caused the ADR and to classify the reaction. A summary is sent to the physician and may be reported to the FDA and the manufacturer. Each report earns the reporter a $5 stipend. Information from the ADR forms is entered into a dBASEIII PLUS computer program for later retrieval and analysis. During a 12-month period, 175 ADR reports (out of a total of 249 reports) were received from house staff members, compared with about 4 voluntary reports received annually before the program began. The ADR surveillance program has increased physician reporting of ADRs and produced a reliable database that can be used to influence hospital policy and promote education.