Relationship of Bell phenomenon with Salzmann nodular degeneration.

PURPOSE: To determine the relationship of Bell phenomenon with the presence and the location of Salzmann nodular degeneration. METHODS: This is a noninterventional observational case series study. We reviewed the medical records of 10 patients with Salzmann nodules between 2001 and 2012. The mean age of participants was 60 years with 8 women and 2 men. A complete history and eye examination was performed with regular follow-up visits to document the progression of the disease. The data collected were as follows: age, gender, Snellen visual acuity, manifest refraction, Salzmann nodule location, presence of Bell or inverse Bell phenomenon, treatment, and associated conditions. Slit-lamp pictures to document the location of the Salzmann nodules and the direction of the Bell phenomenon were obtained. RESULTS: Five patients had inferior Salzmann nodules with a normal Bell phenomenon and 5 patients had superior nodules with inverse Bell phenomenon. Nine of 10 patients had moderate to severe meibomian gland disease and dry eye syndrome as associated conditions. Two of the patients underwent removal of the nodules with lamellar keratectomy and 1 with phototherapeutic keratectomy, all with mitomycin-C application and without recurrence of the nodules at 1 year of follow-up. CONCLUSIONS: In all 10 patients the direction of the globe rotation during a normal or inverse Bell phenomenon was directly correlated to the location of the Salzmann nodules. Specifically, patients with inverse Bell phenomenon presented with superior nodule formation, whereas patients with a normal Bell phenomenon presented with inferior nodules.

Complications in resident-performed phacoemulsification cataract surgery at New Jersey Medical School.

AIM: To describe the complications related to cataract surgery performed by phacoemulsification technique by third-year ophthalmology residents at New Jersey Medical School, who are trained to perform phacoemulsification without any prior experience with extracapsular extraction. DESIGN: Retrospective, observational case series. METHODS: A retrospective chart review of 755 patients who underwent cataract surgery by third-year residents between July 2000 and June 2005 at the Institute of Ophthalmology and Visual Science was performed. Details of intraoperative complications (posterior capsular rupture, vitreous loss, subluxation of lens fragments into the vitreous, extracapsular cases converted to phacoemulsification, retinal detachment, vitreous haemorrhage and haemorrhagic choroidals) of the cases done by phacoemulsification technique were recorded. Results were analysed and compared with complication rates reported from other residency programmes and from experienced ophthalmologists. RESULTS: Of 755 cataract surgeries, 719 were performed using phacoemulsification technique. Posterior capsule disruption occurred in 48 (6.7%), vitreous loss in 39 (5.4%) and dislocated lenticular fragments in 7 (1.0%) of 719 cases that underwent phacoemulsification technique. Subsequent pars plana lensectomy was required in 5 (0.7%) cases; 1 case (0.1%) experienced retinal detachment and haemorrhagic choroidal detachment. CONCLUSION: The residents can perform phacoemulsification well with a very low complication rate, without prior training with extracapsular cataract extraction technique.

Noninvasive determination of intraocular pressure (IOP) in nonsedated mice of 5 different inbred strains.

BACKGROUND: Noninvasive intraocular pressure (IOP) measurement in mice is critically important for understanding the pathophysiology of glaucoma. Rebound tonometry is one of the methods that can be used for obtaining such measurements. We evaluated the ability of the rebound tonometer (RT) to determine IOP differences among various mouse strains and whether differences in corneal thickness may affect IOP measurements in these animals. MATERIALS AND METHODS: Five different commonly used mouse strains (BALB/C, CBA/CAHN, AKR/J, CBA/J, and 129P3/J) were used. IOP was measured in eyes from 12 nonsedated animals (6 male and 6 female) from each strain at 2 to 3 months of age using the RT. IOPs were measured in all animals, on 2 different days between 10 AM and 12 PM. Subsequently, a number of eyes from each strain were cannulated to provide a calibration curve specific for that strain. Tonometer readings for all strains were converted to apparent IOP values using the calibration data obtained from the calibration curve of the respective strain. For comparison purposes, IOP values were also obtained using the C57BL/6 calibration data previously reported. IOP for the 5 strains, male and female animals, and the different occasion of measurement were compared using repeat measures analysis of variance. The central corneal thickness (CCT) of another group of 8 male animals from each of the 5 strains was also measured using an optical low coherence reflectometry (OLCR) pachymeter modified for use with mice. CCT values were correlated to mean IOPs of male animals and to the slopes and intercept of individual strain calibration curves. RESULTS: Noninvasive IOP measurements confirm that the BALB/C strain has lower and the CBA/CAHN has higher relative IOPs than other mouse strains while the AKR/J, the CBA/J, and the 129P3/J strains have intermediate IOPs. There is a very good correlation of apparent IOP values obtained by RT with previously reported true IOPs obtained by cannulation. There was a small but statistically significant difference in IOP between male and female animals in 2 strains (129P3/J and AKR/J) with female mice having higher relative IOPs. No correlation between CCT and IOP was detected. CCT did not correlate with any of the constants describing the calibration curves in the various strains. CONCLUSIONS: Noninvasive IOP measurement in mice using the RT can be used to help elucidate IOP phenotype, after prior calibration of the tonometer. CCT has no effect on mouse IOP measurements using the RT.

Ultrasound biomicroscopy of the rat eye: effects of cholinergic and anticholinergic agents.

BACKGROUND: Over the past few years the rat has gained prominence as an animal model for the study of glaucoma. However, no systematic study of the angle structures and the effects of medications on angle anatomy in the rat has been reported to date. We investigated the normal rat anterior segment anatomy in vivo using ultrasound biomicroscopy (UBM) and determined the effect of both cholinergic and anticholinergic medications on angle structures. METHODS: Fourteen eyes of seven 2-month-old female Wistar rats were imaged using an ultrasound biomicroscope and a modified eyecup. Baseline measurements of the anterior chamber depth (ACD), trabecular-iris angle (TIA), iris thickness at the thickest point near the pupillary margin (IT), angle-opening distance (AOD) (distance between the posterior corneal surface and anterior iris surface measured at 200 microm from the scleral spur), corneal thickness (CT) and irido-zonular distance (IZD) were obtained. Imaging was repeated 30 min after instillation of one drop of cyclopentolate 1% and 48 h later 30 min after pilocarpine 1% instillation. The same measurements were obtained and compared to baseline values. RESULTS: Baseline values for all parameters recorded were not significantly different among contralateral eyes. After instillation of either pilocarpine or cyclopentolate, ACD was the only parameter that did not change significantly from baseline. In contrast, TIA, AOD, IZD, and IT were significantly different among the three groups. Post-hoc analysis (Bonferroni test) revealed differences among all three groups of eyes for TIA and AOD. A difference was also found between the pilocarpine-treated group and the other two groups for IZD and IT. A very small difference detected between the pilocarpine-treated group and the baseline measurements for CT was caused by the zero variance of measurements in the former group. Although both pilocarpine and cyclopentolate induced angle narrowing, inspection of the ultrasonic images revealed a differential effect. Pilocarpine caused a "pupillary block-like" picture, while cyclopentolate caused crowding of the iris base in the angle. CONCLUSIONS: Baseline characteristics of the normal rat anterior chamber anatomy were established. Both cyclopentolate and pilocarpine cause angle narrowing in the rat eye, by different mechanisms.