Rajesh K. Shetty

Outbreak of toxic anterior segment syndrome following cataract surgery associated with impurities in autoclave steam moisture

BACKGROUND Toxic anterior segment syndrome (TASS), a complication of cataract surgery, is a sterile inflammation of the anterior chamber of the eye. An outbreak of TASS was recognized at an outpatient surgical center and its affiliated hospital in December 2002. METHODS Medical records of patients who underwent cataract surgery during the outbreak were reviewed, and surgical team members who participated in the operations were interviewed. Potential causes of TASS were identified and eliminated. Feedwater from autoclave steam generators and steam condensates were analyzed by use of spectroscopy and ion chromatography. RESULTS During the outbreak, 8 (38%) of 21 cataract operations were complicated by TASS, compared with 2 (0.07%) of 2,713 operations performed from January 1996 through November 2002. Results of an initial investigation suggested that cataract surgical equipment may have been contaminated by suboptimal equipment reprocessing or as a result of personnel changes. The frequency of TASS decreased (1 of 44 cataract operations) after reassignment of personnel and revision of equipment reprocessing procedures. Further investigation identified the presence of impurities (eg, sulfates, copper, zinc, nickel, and silica) in autoclave steam moisture, which was attributed to improper maintenance of the autoclave steam generator in the outpatient surgical center. When impurities in autoclave steam moisture were eliminated, no cases of TASS were observed after more than 1,000 cataract operations. CONCLUSION Suboptimal reprocessing of cataract surgical equipment may evolve over time in busy, multidisciplinary surgical centers. Clinically significant contamination of surgical equipment may result from inappropriate maintenance of steam sterilization systems. Standardization of protocols for reprocessing of cataract surgical equipment may prevent outbreaks of TASS and may be of assistance during outbreak investigations.

Violation of the ISNT rule in nonglaucomatous pediatric optic disc cupping.

PURPOSE To determine whether nonglaucomatous optic disc cupping in children violates the ISNT rule (which states that for normal optic discs the neuroretinal rim width is greatest in the order inferior >or= superior >or= nasal >or= temporal). METHODS Digital ocular fundus photographs from a random cohort of children with large optic disc cups of nonglaucomatous origin were analyzed in masked fashion by using computer graphic software. The diameter and perimeter of each optic disc and optic cup and the width of the neuroretinal rim were drawn and measured. Measurements were compared to a random cohort of normal pediatric optic discs. RESULTS The ISNT rule was intact in 9 (16%) of 55 eyes of nonpremature children with nonglaucomatous cupping, in 6 (21%) of 28 eyes of children with a history of prematurity and nonglaucomatous cupping, and in 35 (73%) of 48 eyes with normal discs. CONCLUSIONS Violation of the ISNT rule occurs with greater frequency in the pediatric population with large optic disc cups of nonglaucomatous origin, compared with the pediatric population with normal optic discs. In discs with small cups, neuroretinal rim width conforms to the overall oval shape of the disc, which is usually greatest in vertical dimension, whereas discs with large cups possess greater variability of relative neuroretinal rim width around the disc, greater relative vertical cup/disc ratio versus horizontal cup/disc ratio, and lower predictability of the ISNT rule.

Visual recovery following Mycobacterium chelonae endophthalmitis.

Following uncomplicated cataract surgery, a patient receiving etanercept for psoriatic arthritis developed Mycobacterium chelonae endophthalmitis. Vitrectomy, capsulectomy, and intraocular lens removal was followed by intravitreal amikacin, topical gatifloxacin, intravenous imipenem, and oral clarithromycin for six months. The patient achieved a final corrected visual acuity of 20/20. Etanercept has been implicated in the development of numerous, severe granulomatous infections, though not previously with M. chelonae. This represents the first reported case of visual recovery following M. chelonae endophthalmitis.

Comparing the measurement of diurnal fluctuations in intraocular pressure in the same day versus over different days in glaucoma

Purpose. To compare the measurement of diurnal fluctuations in intraocular pressure (IOP) in the same day versus over different days in primary open-angle glaucoma. Methods. Twenty-five eyes from 25 patients with primary open-angle glaucoma were submitted to a diurnal curve on the same day, 5 measurements, 2.5 hours apart, from 8:00 AM to 6:00 PM. For the measurements on different days, we randomly selected one time point from the diurnal curve for each patient. All patients were then instructed to return every 3–7 days to complete all 5 measurements. The maximum, minimum, and IOP fluctuation were compared between the 2 methods. Results. The IOP fluctuation (maximum-minimum) was similar when we measured the IOP on different days (5.0±2.6 mmHg vs 4.0±1.2 mmHg, p=0.08). There was no difference regarding the minimum or maximum IOP assessed in the diurnal curve or over different days. There was a high correlation for the maximum IOP (r=0.863, p<0.001) and the minimum IOP (r=0.708, p<0.001) by either method of measuring during the same day or different days, as well as for all measurements (8:00 AM: r=0.718, p<0.001; 10:30 AM: r=0.479, p=0.01; 1:00 PM: r=0.628, p=0.001; 3:30 PM: r=0.757, p<0.001; and 6:00 PM: r=0.910, p<0.001). Conclusions. IOP fluctuation in primary open-angle glaucoma can be assessed using IOP measures on different days, at different time points, which strongly correlate to a diurnal curve.

Use of Rituximab for Periocular and Intraocular Mucosa-associated Lymphoid Tissue Lymphoma

The clinical efficacy of rituximab therapy in systemic mucosa-associated lymphoid tissue (MALT) lymphoma with both periocular and intraocular involvement is described. Ophthalmic examination and radiologic imaging demonstrated tumor with bilateral periorbital, lacrimal, and subconjunctival infiltration, a pseudohypopyon in one eye, and extensive systemic lymph node involvement. Lymph node biopsy confirmed the pathologic findings of a low-grade MALT lymphoma. The patient had a complete remission within 3 months of starting rituximab therapy. A recurrence 6 months later remitted with a second round of rituximab therapy and the patient remained tumor-free at 1 year.

Combined ab externo and ab interno revision of failed filtering blebs with adjunctive mitomycin C.

Purpose: To report the results of combined ab externo and ab interno revision with mitomycin C (MMC) of failed filtering blebs in glaucoma patients. Methods: Glaucoma patients with a failed trabeculectomy who had undergone internal and external revision with MMC in the last 6 years with at least 12 months of follow-up were considered. All study patients followed the same protocol in the operating room: injection of 0.2 mL of MMC (0.4 mg/mL) 2 cm lateral from the bleb followed by internal revision with an iris spatula and external revision with a 26-G × ½” needle. Success was defined as an intraocular pressure (IOP) ≥6 mm Hg and ≤18 mm Hg with (qualified) or without (absolute) any ocular hypotensive drugs. Results: The study included 25 eyes of 22 glaucoma patients. Mean age was 65.2 ± 10.5 years. Mean follow-up was 26.9 ± 10.3 months. The IOP was reduced from 24.5 ± 6.0 mm Hg preoperatively to 10.0 ± 3.3 mm Hg at the last visit (p<0.001). The number of ocular hypotensive medications was reduced from 1.8 ± 1.0 to 0.2 ± 0.6 (p<0.001). There was no change in visual acuity (0.83 ± 0.75 vs 0.83 ± 0.74, p = 0.7). Three patients developed choroidal detachment, another eye had a transient hypotony with maculopathy, and 2 patients developed cataract. Absolute success was achieved in 80% of eyes, and qualified success in 16% of eyes. Conclusions: Combined ab externo and ab interno revision with MMC can be an effective technique to revitalize failed filtering blebs in glaucoma patients with minimal complications.