Marc F. Lieberman

Histologic Studies of the Vasculature of the Anterior Optic Nerve

Thirty-one normal human anterior optic nerves were studied in thin serial sections and their vessels stained by standard histologic stains and a new modification of the silver reticulin stain. The retrolaminar cribrosa was profusely supplied by centripetal and longitudinal vessels of pial origin; small branches of the central retinal artery were also seen. Longitudinal continuity of small vessels extended from the retrolaminar nerve to the retinal surface. This system freely anastomosed with three transverse systems; a significant anteriolar input from short posterior ciliary arteries in the sclera to the lamina cribrosa; smaller short posterior ciliary branches and occasional choroidal capillaries to the prelaminar portion; and branches derived from the central retinal artery in and around the disk. Vessels entering the prelaminar region at the level of the choroid were mainly derived from scleral branches of short posterior ciliary vessels entering through the border tissue of Elschnig, rather than from choroidal branches of ciliary arteries. Venous drainage for the anterior optic nerve was primarily through the central retinal vein, although alternate smaller paths to surrounding tissues were also identified.

Embolic Ischemic Optic Neuropathy

On examining the postmortem enucleated eyes of a 68-year-old man, we found the left eye had focal infarction 3 mm behind the lamina cribrosa caused by thromboembolic compromise of three discrete pial and pial-derived arterioles. The optic nerve had been destroyed focally, whereas the retinal and choroidal tissue supplied by a similarly occluded vessel had been preserved. We diagnosed nonarteritis ischemic optic neuropathy.

Midterm follow-up results of combined phacoemulsification, lens implantation, and mitomycin-C trabeculectomy procedure.

Purpose:This study evaluates the visual, refractive, perimetric, and intraocular pressure (IOP) results following combined phacoemulsification, lens implantation, and trabeculectomy with mitomycin-C. Methods:Twenty-nine consecutive eyes of 26 patients with cataract and glaucoma that had undergone combined phacoemulsification, posterior chamber lens implantation, and limbus-based trabeculectomy with mitomycin-C applied after the cataract removal and trabeculectomy had a minimal follow-up time of 12 months (mean follow-up 20 ± 6.3 months). Each eye was evaluated for visual acuity, corneal astigmatism. IOP, bleb persistence, optic nerve stability, visual field status, and complications. Goldmann visual fields were assessed by a semi-quantitative method and threshold static perimetry by statistical indices of diffuse damage (mean deviation) and focal loss (corrected pattern standard deviation). The preoperative and postoperative results were compared by Students t-test. Results:All eyes that were free of pre-existing macular disease demonstrated significant improvement in visual acuity by at least 4.5 lines of Snellen acuity. Postoperative astigmatism was negligible (0.29 diopters). The average IOP reduction was 6.5 mm Hg, with the one year or more average of 13.4 mm Hg on virtually no antiglaucoma medicines (0.2 ± 0.5). Functioning filtering blebs persisted in 86% of eyes. Of 11 patients tested with pre- and postoperative Goldmann perimetry, only two showed visual field defect progression despite IOPs <15 mm Hg. Of the 12 eyes with pre- and postoperative static threshold perimetry, the mean deviation deteriorated in nine eyes (p = 0.003). The corrected pattern standard deviation changes were not statistically significant (p = 0.69). Complications (including two cases of late-onset endophthalmitis) were comparable with other studies reporting filtration surgery with adjunctive antimetabolites. We detected no untoward effects of applying the mitomycin at the end of the procedure rather than at the beginning. Conclusions:The combined procedure technique that we describe appears to be effective at restoring visual acuity and significantly reducing IOP. Nevertheless, many visual fields showed continued, diffuse glaucomatous progression in the year or two following surgery and the development of late endophthalmitis in two eyes is a concern.

Evaluation of optic disc measurements with the glaucoma-scope.

PurposeWe evaluated the Glaucoma-Scopes ability to acquire images of the optic disc, the reproducibility of its analysis, and the comparison between it and expert evaluation. MethodsOne hundred and sixty-eight patients with satisfactory standard fundus photography were referred for Glaucoma-Scope analysis. Characteristics of eyes in which Glaucoma-Scope analysis could not be obtained were evaluated. Eight glaucoma patients (15 eyes) were quantitatively evaluated: inter- and intraobserver reproducibility of the Glaucoma-Scope analyses were calculated utilizing weighted Kappa index of agreement and coefficient of variation. The Glaucoma-Scope cup-to-disc ratio was calculated from the gray scale analysis and compared to the ratio as evaluated by a glaucoma expert. ResultsGlaucoma-Scope analysis was not achieved in 14% of a total of 336 eyes of 168 patients. The conditions associated with the inability to obtain a satisfactory image were hyperpigmented fundi, pseudophakia, aphakia, corneal opacities, cataract, and contact lenses. The quantitative analysis of the 15 patients showed small inter- and intraobserver means of the coefficient of variation (0.136 ± 0.023 and 0.129 ± 0.016) and SD (0.063 ± 0.0056 and 0.064 ± 0.0077) and moderate-substantial intra- and interobserver agreement (weighted K = 0.427 ± 0.1 and 0.61 ± 0.14, respectively). Significant disagreement (weighted K = - 0.11, p = 0.0023) was found between Glaucoma-Scope (mean 0.52 ± 0.064) and experts evaluations (0.673) of the cup-to-disc ratio. ConclusionsThe inter- and intraobserver reliability and low variation of the Glaucoma-Scope readings indicates moderate to substantial reproducibility for detecting changes in optic discs topography under selected conditions. However, eyes with moderate cataract, aphakia, pseudophakia, mild corneal opacity, darkly pigmented fundi or myopia were inconsistently analyzable. In a small group of randomly selected eyes there was very low agreement between the glaucoma experts evaluation of the optic disc and that of the Glaucoma-Scope. These findings raise questions about the usefulness of the instrument as a diagnostic tool for glaucoma but show promise for detecting change when good images are possible.