Transscleral diode laser cyclophotocoagulation on autopsy eyes with abnormally thinned sclera.

BACKGROUND AND OBJECTIVE: To determine, using autopsy eyes, whether diode laser energy adjustments are indicated in patients with thin sclera. MATERIALS AND METHODS: In the laboratory, the superior 180 degrees of sclera at the limbus was dissected to the level of barely visible anterior uvea and the opposite 180 degrees of sclera served as the control in three human cadaver eyes. A contact G-probe was placed at the limbus, and settings of a diode laser were increased in increments from 1.0 to 9.0 J at 4 burns per setting in each location. RESULTS: On gross examination, circular hypopigmented lesions were seen in the ciliary body (CB) beginning at 3.0 J in thin sclera and at 5.0 J in normal sclera. On light microscopic examination of thin scleral sections, CB damage began at 2.9 J and CB/ciliary body epithelium (CBE) damage occurred beginning at 3.5 J. In normal sclera, minimal CB/CBE changes occurred at 6.0 to 7.5 J. No scleral damage was visible in either the experimental or the control groups. CONCLUSION: Cycloablation energy adjustments are indicated on eyes with abnormally thin sclera to achieve similar histologic end points using the diode laser.

Effectiveness of apraclonidine and acetazolamide in preventing postoperative intraocular pressure spikes after extracapsular cataract extraction.

We studied the effectiveness of two prophylactic agents in controlling early postoperative intraocular pressure (IOP) increases after cataract surgery. Fifty-four nonglaucomatous patients received either topical 1% apraclonidine, one drop before and after surgery, or sustained-release acetazolamide, 500 mg, or no medication at the completion of planned extracapsular cataract extraction (ECCE). Mean baseline IOPs were similar among patients randomized to the apraclonidine, acetazolamide, and control groups: 15.29 mm Hg, 15.33 mm Hg, and 14.26 mm Hg, respectively. At 3 hours postoperatively, IOPs were significantly lower in the apraclonidine group (11.13 mm Hg, P = .035), nonsignificantly lower in the acetazolamide group (13.3 mm Hg, P = .17), and significantly increased in the control group (21.32 mm Hg, P = .003). One eye in the apraclonidine group and six in the control group had IOPs greater than 30 mm Hg. At 24 hours, the only statistically significant difference was in the control group, whose mean IOPs remained elevated (21.83 mm Hg, P = .0008). One eye in the apraclonidine group, two in the acetazolamide group, and five in the control group had IOPs greater than 30 mm Hg. We found a significant early IOP reduction with apraclonidine given topically preoperatively and at the completion of planned ECCE.

Histopathology of acute intraoperative suprachoroidal hemorrhage associated with transscleral intraocular lens fixation.

An 83-year-old hypertensive female had penetrating keratoplasty with insertion of a transsclerally fixated posterior chamber intraocular lens for pseudophakic corneal edema associated with a closed-loop, semiflexible anterior chamber intraocular lens. An acute intraoperative suprachoroidal hemorrhage developed five minutes after passage of the transscleral sutures. The eye became blind and painful and was enucleated three weeks later. Histopathologic examination showed an idiopathic suprachoroidal hemorrhage with no evidence of disruption of the ciliary body vasculature. Acute intraocular hemorrhage resulting from a needle pass through the highly vascularized ciliary body has been a greatly feared, though as yet unreported, complication of this procedure. Damage to the anterior uveal circulation was not implicated as a cause of the hemorrhage in this case.

MK-801 protects retinal neurons from hypoxia and the toxicity of glutamate and aspartate.

The protective effect of the anticonvulsant MK-801 and the antitussive dextromethorphan, which are both N-methyl-D-aspartate receptor antagonists, and kynurenic acid, a broad-spectrum excitotoxin antagonist, was tested in cultured rat retinal cells in an hypoxic environment. The protective effect of these antagonists also was tested in cultured retinal cells and in intact adult rat retinas exposed to the exogenous excitotoxins L-glutamic acid and N-methyl-D-aspartic acid. MK-801 and kynurenic acid protected retinal neurons from hypoxic damage and from the toxicity of exogenous L-glutamic acid and N-methyl-D-aspartic acid. Dextromethorphan, a less potent antagonist, did not protect the retinal neurons from hypoxic damage or the toxicity of exogenous L-glutamic acid, but did attenuate N-methyl-D-aspartate toxicity. These results provide evidence that the synaptic release of excitatory transmitters, most likely glutamate and aspartate, mediate the death of hypoxic retinal neurons. Compounds related to MK-801 may have possible therapeutic applications in the management of retinal ischemia.

CD68 antigen expression by human retinal pigment epithelial cells.

Although a primary role of the retinal pigment epithelium (RPE) is the phagocytosis of aged outer segment membranes, the RPE may also phagocytize particulates via several specific receptors that are characteristically present on mononuclear phagocytes of bone marrow origin. In recent immunophenotypic studies, CD68 monoclonal antibodies (mAb) have been shown to react selectively with a specific 110 kDa cytoplasmic glycoprotein present in mononuclear phagocytes from various sources. Designated as anti-macrophage antibodies that react with this macrophage-associated antigen, CD68 antibodies are now widely used for immunohistochemical identification of mononuclear phagocytes. Using a panel of CD68 mAb (KP1, EMB11, Ki-M6, Y1/82A, and Y2/131) we performed immunohistochemistry on three cytospin preparations of freshly isolated human RPE cells, three primary human RPE cultures, and 12 human RPE cell lines maintained in culture for up to 40 passages. Cytospin preparations of freshly isolated RPE cells demonstrated heavy reactivity in 5% of cells. Five- to 7-day-old primary RPE cultures exhibited uniform, heavy staining of all cells. Strong immunohistochemical reactivity persisted in all 12 cell lines at various passages up to and including passage 40. Stimulation of cultured RPE cells with interferon-gamma (100 U ml-1) for 24 and 48 hr did not produce observable differences in CD68 staining. RPE cells failed to stain when control mAb or mouse serum were substituted for the primary antibody. The constitutive expression of CD68 by neuroectodermally-derived RPE cells extends their immunophenotypic similarities with mesenchymally-derived mononuclear phagocytes and provides an additional antigenic marker to identify RPE cells in vitro.

Vitreoretinal traction and perimacular retinal folds in the eyes of deliberately traumatized children.

The pathophysiology of perimacular folds in eyes of deliberately traumatized children is disputed. The authors reviewed the clinical and forensic records and systemic and ocular findings at autopsy of three children with perimacular retinal folds who died after being violently shaken. Two of the children suffered direct head trauma in addition to being shaken; one patient was violently shaken without any physical or forensic evidence of direct head trauma. No direct ocular trauma was detected. In each case, the vitreous had partially separated from the retina but remained attached to the internal limiting membrane at the apices of the folds and the vitreous base, implicating traction in the pathogenesis of these folds. Although some intraocular findings in deliberately traumatized children may be explained by direct head injury, the possibility of both direct head trauma and shaking must be considered. Perimacular folds may develop without direct ocular or head trauma and may constitute evidence supporting violent shaking.

Keratoconus and Fuchs' corneal endothelial dystrophy in a patient and her family.

A 44-year-old patient with bilateral keratoconus and bilateral Fuchs' dystrophy underwent penetrating keratoplasty. Examination of the patient's family revealed keratoconus in the patient's son and central guttata and abnormal endothelial cells in the patient's mother and daughter. Histopathologic evaluation of the corneal button demonstrated a thinned central epithelium and folds and keratocytes in Bowman's layer consistent with keratoconus. Central guttata, subepithelial bullae, and a decreased number of endothelial cells, consistent with Fuchs' endothelial dystrophy, were also seen. This case demonstrates that two distinct familial corneal diseases can occur in the same patient. Although one cannot conclude inheritance patterns based on this limited evaluation, the findings in this family support previous observations that keratoconus can be familial, and that Fuchs' corneal dystrophy has a female predilection with an autosomal-dominant inheritance pattern.

Unusual mucopolysaccharide disorder with corneal and scleral involvement.

A 68-year-old man and a 66-year-old woman had diffuse corneal stromal deposits that stained with alcian blue and colloidal iron but did not react with periodic acid-Schiff stain and lipid stains. Similar deposits were found within postmortem sclera in one case, but not in other ocular or extraocular tissues. The abnormal material was sensitive to testicular hyaluronidase and chondroitinase. The material reacted with monoclonal antibody 9-A-2 after digestion by chondroitinase AC in one case and ABC in both cases, which is consistent with the identification of the glycosaminoglycans chondroitin 4-sulfate and dermatan sulfate. Electron microscopic examination of the cornea in both cases disclosed granular material in vacuoles dispersed extracellularly and, rarely, in keratocytes. Results of blood and skin fibroblast enzyme assays for clinically relevant mucopolysaccharidoses and mucolipidoses were normal in both patients, and there were no somatic abnormalities suggesting a storage disease.

Drusen and drusenoid macular lesions.

Yellow-colored lesions with a similar appearance at the level of the retinal pigment epithelium are frequently called drusen. Direct and indirect ophthalmoscopy, slit-lamp and contact lens examination, and fluorescein angiography allow differentiation among true drusen, retinal-pigment-epithelial detachments, and deposits secondary to retinal-pigment-epithelial degeneration. A combination of these lesions may be present in a single eye especially in patients with age-related macular degeneration. It is important to distinguish among these lesions because prognosis and treatment potential vary.

Complications after proton beam therapy for uveal malignant melanoma. A clinical and histopathologic study of five cases.

Proton beam therapy for uveal malignant melanoma has been advocated as effective therapy because of documented reduction in tumor size and few clinical complications. However, some eyes have been removed because of adverse effects. The authors report the clinical courses and pathologic findings of five eyes enucleated after proton beam irradiation. Neovascular glaucoma had developed in three eyes, two eyes had vitreous hemorrhage, and two had extraocular extension. The tumors in the radiation treatment field showed continued postirradiation growth clinically in four of the five eyes, and mitotic activity histologically in all five cases. Two and one half years after irradiation, and nearly 2 years after subsequent enucleation, one of those two patients had biopsy-proven liver metastases, and later died. Despite the considerable success rate of proton beam irradiation, the potential for clinical complications and subsequent tumor growth remains.

Scleromyxedema with corneal deposits.

Scleromyxedema (Arndt-Gottron syndrome) is a rare cutaneous disease in which hyaluronic acid is deposited in the dermis. The authors describe a patient with scleromyxedema and corneal deposits. A corneal biopsy demonstrated hyaluronic acid deposition in the corneal stroma and amyloid P component in Bowman's membrane. This is the first report of scleromyxedema involving the cornea. It is also the first report of amyloid P component deposition in the cornea occurring independent of corneal amyloid deposits.

Anomalies of retinal architecture in Aicardi syndrome.

Eyes obtained at autopsy from a female infant with Aicardi syndrome (chorioretinal lacunae, agenesis of the corpus callosum, and seizures) were studied by light and electron microscopy. The retinal insertion was displaced anteriorly over the ciliary body, the choroid was attenuated, and the retinal pigment epithelium showed hyperplasia and pigment migration throughout the sensory retina. Rosettes of photoreceptorlike cells and inversion of the photoreceptor layer were found. A hole within a lacuna showed total absence of the sensory retina. Optic disc epipapillary tissue consisted of glial and fibrous elements with a vascular core. The mechanism of photoreceptor folding is considered. The continuity of the external limiting membrane with the retinal pigment epithelium at sites of photoreceptor folding seen in our case suggests defective early development.

Helium ion charged-particle therapy for choroidal melanoma. Histopathologic findings in a successfully treated case.

A 47-year-old man with a large (20 X 20 X 12-mm) choroidal melanoma in his only eye was treated with helium ion radiation. The patient retained 6/7.5 visual acuity for 2 1/2 years before he was killed in an automobile accident. The eye was ruptured at the time of death; however, histopathologic examination of the eye revealed no residual tumor. The residual ocular mass was composed of eosinophilic amorphous material and macrophages. Necropsy failed to reveal any evidence of metastasis at the time of death. Helium ion charged-particle irradiation in this case was able to completely eradicate the tumor while preserving useful vision.

Malignant melanoma of the iris after 30 years.

We report a case of a spindle cell malignant melanoma of the iris that was excised locally in 1952, only to become clinically evident again 25 years later. The tumor exhibited unusually slow, compact growth, with local infiltration into the ciliary body and dispersion of tumor cells into the angle structures and onto the posterior cornea. No extraocular dissemination was evident. Histologically, the cells in the specimens taken in 1952, 1978, and 1981 had remarkably similar morphological findings. The patient has had no recurrences 12 months after enucleation.

Sunlight and human cataracts.

Studies of the cataractous lenses of humans in three different geographic locations indicate that where the ultraviolet components of sunlight are more intense, dark brown cataracts result at a higher frequency than in locations where they are weak. Individuals exposed to sunlight regularly by virtue of their outdoor occupations seemed to develop this dark brown type of cataract much more frequently than those who work indoors. The biochemical characteristics of all brunescent cataracts were found to be very similar, whether derived from individuals exposed to high or low levels of sunlight. These findings support the idea that exposure to sunlight specifically enhances brunescent cataract development in humans.