ABSTRACT
BACKGROUND: There are few reports of histopathology of any form of optic neuropathy. This article provides histopathologic findings of an adult-onset, nonprogressive optic neuropathy that was diagnosed clinically as nonacute, nonarteritic anterior ischemic optic neuropathy (NAION) but which was found by a pathological study to be associated with diffuse calcium oxalosis that was confined in the involved orbit. METHODS: This is a case report that includes results of a neuro-ophthalmologic examination and histopathology of a complete autopsy, including en bloc removal of both orbits and the brain. The unaffected orbit/optic nerve served as a control. The affected orbit was serially sectioned into 2,550 increments each separated by 10 µm; the uninvolved orbit was sectioned into 150 equally spaced sections. The main outcome measures were derived from the autopsy, especially from the thin-section histopathologic study of both orbits that focused on blood vessels and the site of neural damage within the optic nerve. RESULTS: The neuro-ophthalmologic examination revealed a unilateral optic neuropathy with pallor of the left optic nerve head that had been documented just before death. The general autopsy showed acute bacterial endocarditis and a recent cerebral hematoma that caused death. Histopathology revealed sectoral loss of optic nerve axons in the left eye. Numerous arterial walls in the left orbit, including short posterior ciliary arteries and the central retinal artery, contained hundreds of crystals with anisotropic, colorful birefringence consistent with calcium oxalosis. Crystals were not found in the right, control orbit or elsewhere in the body. CONCLUSIONS: The patient developed an optic neuropathy late in life that was diagnosed by an experienced neuro-ophthalmologist as being most consistent with nonacute, nonarteritic anterior ischemic optic neuropathy. The autopsy identified sectoral loss of optic nerve fibers consistent with that diagnosis. However, the unexpected discovery of calcium oxalate crystals in blood vessels of the involved orbit, which curiously were not present elsewhere in the body, raises a question of their etiological role in this particular optic neuropathy. Whether the crystals were causal, epiphenomenal, or purely incidental to the optic neuropathy cannot be answered by our study.
ABSTRACT
PURPOSE: Trabeculectomy surgery is the most common operative procedure for the treatment of medically uncontrolled glaucoma. Variability exists in both the design and the position of the limbal wound as well as in outcomes, even in cases with similarly designed wounds. The purpose of this study is to describe the histologic features of the surgical site of human eyes received at a pathology laboratory that had undergone trabeculectomy surgery and then attempt to explore possible associations of these features with success or failure of surgery. METHODS: We examined 64 autopsy and enucleated eyes of 53 patients obtained at the Eye Pathology Laboratory, Wilmer Eye Institute, Baltimore, Md, between January 16, 1974, and November 15, 1999. Examined aspects included the position, dimensions, and depths of the trabeculectomy site; features at the internal opening; and the inclusion of trabecular meshwork in the internal resection. An attempt was also made to judge the success of the trabeculectomy by a comparison of preoperative and postoperative intraocular pressures. RESULTS: Of all the histopathologic features examined, there was a statistical difference between the success and failure groups in only the presence of a cleft and the location of the posterior incision. CONCLUSIONS: The main finding of this study is that there is a large degree of variability in the size, position, and pathologic features of trabeculectomy sites. Features that can be avoided with the initial surgical approach, particularly a posterior resection posterior to the scleral spur, may increase the chance of surgical failure.
