Faculty Bibliography

BACKGROUND AND OBJECTIVE: To evaluate the effectiveness of combined phacoemulsification and trabeculectomy with mitomycin-C with respect to visual rehabilitation and control of intraocular pressure in patients with coexisting cataract and glaucoma. PATIENTS AND METHODS: The authors retrospectively studied 20 consecutive cases of phacoemulsification with posterior chamber intraocular lens implantation combined with trabeculectomy using mitomycin-C. They included in their study 20 eyes of 19 patients with primary open-angle glaucoma, pseudoexfoliation glaucoma, inflammatory glaucoma, chronic angle-closure glaucoma, and normal tension glaucoma. RESULTS: After a mean postoperative follow-up time of 14.4 +/- 3.1 months, intraocular pressure was reduced from a preoperative mean of 19.2 +/- 6.1 mm Hg to a postoperative mean of 13.4 +/- 3.9 mm Hg (P = .0004). The number of required intraocular pressure-lowering medications dropped from a preoperative mean of 2.3 +/- 0.7 medications to 0.2 +/- 0.4 medications postoperatively (P < .0001), with only 4 eyes requiring the restarting of a single medication each. Mean log(10) (minimum angle of resolution) visual acuity improved from a preoperative 0.66 +/- 0.53 (Snellen 20/91) to a postoperative 0.30 +/- 0.40 (Snellen 20/40) (P<.0005). The most frequent complication was a bleb leak (8 of 20 eyes [40%]), usually occurring early and responding to conservative management. One eye with later-onset bleb leak incurred endophthalmitis. In another eye, hypotony with maculopathy developed. CONCLUSIONS: Phacoemulsification combined with trabeculectomy using mitomycin-C appears to be an effective approach to the management of cataract in patients with glaucoma. It offers potential for good improvement in visual acuity as well as long-term control of intraocular pressure with reduced or no dependence on medications. Potential vision-threatening complications of this procedure, specifically hypotony maculopathy and late-onset bleb leaks, should be considered in the decision to use mitomycin-C.

OBJECTIVE: To evaluate optical coherence tomography (OCT), a novel noncontact and noninvasive imaging technique, for the diagnosis and quantitative characterization of epiretinal membranes. METHODS: Optical coherence tomography is similar to an ultrasound B-scan, except that light rather than sound is used, which enables higher resolution. Over a 2-year period, OCT was used to examine 186 eyes of 160 patients who had a diagnosis of an epiretinal membrane. Optical coherence tomograms were correlated with visual acuity, slit-lamp biomicroscopy, fluorescein angiography, and funds photography. RESULTS: Based on OCT, the epiretinal membrane was clearly separated from the retina with focal points of attachment in 49 eyes and globally adherent (no observed separation) in 125 eyes. Globally adherent membranes were associated with the following features: macular pseudohole (32 eyes), a difference in optical reflectivity between the membrane and retina (65 eyes), and/or a visible membrane tuft or edge (92 eyes). The membrane was undetectable on OCT in 12 eyes. The membrane thickness (mean +/- standard deviation) was 61 +/- 28 microns in the 169 eyes in which the thickness could be measured with OCT. Mean central macular thickness measured with OCT correlated with visual acuity (R2 = 0.73). CONCLUSION: Optical coherence tomography was able to provide a structural assessment of the macula that was useful in the preoperative and postoperative evaluation of epiretinal membrane surgery. Quantitative measurements and the assessment of membrane adherence with OCT may be useful in characterizing the surgical prognosis of eyes with an epiretinal membrane.

PURPOSE: Optical coherence tomography (OCT) is a new technology that uses near-infrared light in an interferometer to produce approximately 10-microns resolution cross-sectional images of the tissue of interest. The authors performed repeated quantitative assessment of nerve fiber layer thickness in individuals with normal and glaucomatous eyes, and they evaluated the reproducibility of these measurements. METHODS: The authors studied 21 eyes of 21 subjects by OCT. Each subject underwent five repetitions of a series of scans on five separate occasions within a 1-month period. Each series consisted of three circular scans around the optic nerve head (diameters, 2.9, 3.4, and 4.5 mm). Each series was performed separately using internal (fixation with same eye being studied) and external (fixation with contralateral eye) fixation techniques. The eye studied and the sequence of testing were assigned randomly. RESULTS: Internal fixation (IF), in general, provides a slightly higher degree of reproducibility than external fixation (EF). Reproducibility was better in a given eye on a given visit than from visit to visit. Reproducibility as measured by intraclass correlation coefficients were as follows: circle diameter (CD), 2.9 mm, 0.51/0.57 (normal/glaucoma) (IF), 0.43/0.54 (EF); CD, 3.4 mm, 0.56/0.52 (IF), 0.43/0.61 (EF); CD, 4.5 mm, 0.53/0.43 (IF), 0.42/0.49 (EF). CONCLUSIONS: Nerve fiber layer thickness can be reproducibly measured using OCT. Internal is superior to external fixation; each circle diameter tested provides adequate reproducibility.