Adenoma of the pigmented ciliary epithelium: ultrastructural and immunohistochemical findings

We report the clinical and histological findings in a tumor of the pigmented ciliary epithelium. The tumor was detected because it had caused a unilateral cataract, and it was removed by local resection because a malignant melanoma could not be excluded. The diagnosis was established by light microscopy, and additional immunohistochemical and detailed ultrastructural studies were performed. The so-called foam cells which are considered typical of these adenomas appear to be mostly light microscopic artifacts and had no ultrastructural equivalent in the sections examined from our tumor. Our results also strongly support the hypothesis that no true glandular elements are formed and that, apart from the neoplastic tissue architecture, most of the pathological findings are related to melanosomes.

Bilateral necrotizing scleritis and blindness in the myelodysplastic syndrome presumably due to relapsing polychondritis

PURPOSE

The purpose of this study was to report a case of bilateral blindness, bilateral necrotizing scleritis, and bilateral deafness in a patient with myelodysplastic syndrome (MDS). In such a patient, the possibility of relapsing polychondritis (RPC) associated with MDS must be considered.

CASE REPORT/METHODS

A 66-year-old patient suffered from myelodysplastic syndrome (MDS). Shortly before his death, he became bilaterally blind and deaf. A biopsy was taken from the conjunctiva and the bone marrow, and both eyes were obtained after death for further investigation. Findings of the clinical and laboratory work-up for the patient's hematologic disorder as well as an examination of the eyes by light microscopy and immunohistochemistry are presented.

RESULTS

Ocular sections showed a diffuse necrotizing scleritis with moderate uveitis and no identifiable infectious agent. Neither was there any evidence of a leukemic infiltration. The deafness had been due to inner ear failure, and the patient died of a cardiac failure.

CONCLUSIONS

Non-infectious scleritis associated with inner ear deafness is a strong indication of relapsing polychondritis (RPC). Furthermore, RPC can be associated with MDS. Thus, in addition to leukemic infiltration and infection involving ocular structures, ophthalmologists and otolargyngologists should be aware of the association between MDS and RPC and the potential complications.

Effects of systemically applied allopurinol and prednisolone on experimental autoimmune uveitis

PURPOSE

To compare the effects of allopurinol to those of prednisolone on the oxidative tissue damage and inflammatory response in experimental autoimmune uveitis (EAU).

METHODS

Experiments were performed using 27 male Lewis rats. EAU was induced by means of crude retina extract, Freund's adjuvant and pertussis toxin. One group of animals served as controls and two groups were treated systemically, one with allopurinol and one with prednisolone. At the end of the experiments lipid peroxides (LPO), myeloperoxidase activity (MPO), and histological changes were determined in the retinal tissue. LPO were measured by two different methods [thiobarbituric acid reactive substances (TBARS) and malondialdehyde-like substances].

RESULTS

Allopurinol led to a significant reduction in LPO and MPO levels. The steroid treatment also resulted in a significant reduction in MPO activity but LPO were significantly reduced only when measured as TBARS. Histological changes were significantly reduced by allopurinol only.

DISCUSSION

Allopurinol is more effective than prednisolone in treating EAU. Its efficacy can be explained by the antioxidative/antiinflammatory and probably immunological action. The antiinflammatory effects of prednisolone are not sufficient to reduce the tissue damage. Allopurinol promises to be a useful alternative to steroids in the treatment of uveitis.

Long-term ultrastructural changes in human corneas after tattooing with non-metallic substances

AIM

To investigate the ultrastructural appearance and the deposition pattern of dye particles in long term non-metallic corneal tattooing.

METHODS

Two tattooed human corneas were obtained by keratoplasty. One corneal button was fixed in Karnovsky's solution and the other in Trumps' solution. Both corneas were divided and processed for conventional light (LM) and transmission electron microscopy (TEM). Five additional formalin fixed corneas with tattoos were retrieved from paraffin for TEM. The time between tattoo and removal of the corneal button/enucleation ranged from 7 to 61 years. All seven corneas were examined using a Jeol JCXA733 microprobe for wave length dispersive analysis in order to exclude any presence of metallic salts in the tattooed area.

RESULTS

Histologically, clumps of brown-blackish granules were present mainly in the mid stroma, but also in anterior and partially in the posterior half of the stroma. On TEM, numerous round and oval electron dense particles were seen in the cytoplasm of keratocytes arranged as clusters or large islands. The larger particles appeared black, while the smaller particles were grey. In well fixed tissue a unit membrane was observed around these clusters. No granules were detected in the extracellular matrix.

CONCLUSIONS

Keratocytes can actively ingest and retain tattooing particles of non-metallic dyes within their cell membrane for very long periods of time.

Immunohistochemical localization of Na+/Ca2+ exchanger in human retina and retinal pigment epithelium

BACKGROUND

Impaired calcium (Ca2+) metabolism has been implicated in the pathogenesis of various ocular diseases, suggesting that regulation of Ca2+ homeostasis in the retina is of major significance for normal function. There are known families of transport proteins that can catalyze net Ca2+ efflux across the plasma membrane, one of which is the Na+/Ca2+ exchanger. Using immunohistochemistry, we have investigated the human retina and retinal pigment epithelium (RPE) for the presence and distribution of the so-called cardiac-type Na+/Ca2+ exchanger.

METHODS

Paraffin sections of ten eyes enucleated for various disease processes were incubated according to the ABC method with a polyclonal antibody (pi) produced against the canine cardiac sarcolemmal Na+/Ca2+ exchanger. The reaction was visualized with aminoethylcarbazole.

RESULTS

There was a positive reaction with anti-Na+/Ca2+ exchanger in the retina and RPE in all eyes, but the labeling varied among the different specimens. In neural retina, staining was most intense in Mueller cells, in cells of the inner nuclear layer, and in cone inner segments. Immunoreactivity was less pronounced in ganglion cells, nerve fibers, the outer nuclear layer and in rod inner segments. Outer segments appeared mostly negative. In the RPE, positive staining was present but the intensity of staining varied both within and among the specimens. Reactive RPE cells revealed the most intense labeling.

CONCLUSION

Na+/Ca2+ exchanger of the cardiac type is present in human retina and RPE. The variation in immunoreactivity among the different specimens may reflect the different diseases of these eyes and their different metabolic states. A specific relation between certain diseases and malfunction of the Na+/Ca2+ exchanger could have a major impact on therapeutic regimens.

Prophylactic argon laser coagulation for rhegmatogenous retinal detachment in AIDS patients with cytomegalovirus retinitis

BACKGROUND

The incidence of cytomegalovirus (CMV) retinitis in patients with acquired immunodeficiency syndrome (AIDS) reaches 20-45%. Despite aggressive medical treatment, rhegmatogenous retinal detachments develop in up to 30% of the affected eyes. Surgical repair is often difficult due to multiple large and hardly visible retinal holes with vitreal traction. Pars plana vitrectomy with instillation of silicone oil is the procedure of choice, giving limited functional results with anatomical reattachment.

METHODS

We performed prophylactic laser coagulation in AIDS patients with medically treated CMV retinitis to prevent a progressive retinal detachment. Twenty-two quiescent CMV lesions in 22 eyes of 20 patients were treated with argon green laser coagulation. Each CMV lesion was completely surrounded with a double or triple row of laser spots (500-600 mumols; 0.2 s; gray-white lesions).

RESULTS

The duration of follow-up was 2-24 months. Histopathologic evaluation was possible in two eyes of one patient. Reactivated or smoldering CMV retinitis crossed the laser scars in 11 eyes, making additional laser coagulation necessary. In four eyes retinal holes in the CMV scar tissue led to retinal detachment, which stopped at the laser scar. In three eyes the detachment is still controlled by the laser scar. In one eye, the detachment stopped at the laser scar for 6.5 months and then slowly progressed across it. There were no complications associated with our laser treatment.

CONCLUSION

Prophylactic argon laser coagulation in quiescent CMV retinitis seems to reduce the rate of progressive retinal detachment with no need for vitrectomy and silicone oil tamponade.

Effect of aclacinomycin A on in vitro cultures of porcine lens epithelial cells

As a potential drug for the prevention of secondary cataract formation (SCF), we investigated the effect of Aclacinomycin A (ACM) on the growth of cultures of porcine lens epithelial cells in vitro. ACM is an anthracycline that has been used in the treatment of acute myeloid leukemia in the human for many years. It has been shown to be non-mutagenic and non-carcinogenic in in vitro and in animal models. Subconfluent cell cultures were exposed to different concentrations of ACM for 5 minutes. The drug effect was evaluated by cell counts after various lengths of culture time (between 1 and 10 weeks). No cells survived the treatment with 12 or 16 microg ml-1. Cultures treated with concentrations between 0.5 and 8 microg ml-1 showed a marked decrease in cell number when compared to controls. However, reproliferation occurred at concentration up to 8 microg ml-1 after 2-6 weeks. Intraocular application of ACM might be suitable in the prevention of SCF. However, with regard to reproliferation, long-term cultures (or long-term animal models, respectively) have to be used in further evaluating the appropriate dosage for this purpose.

Cholesterol granuloma of the orbit--pathogenesis and surgical management

BACKGROUND

Cholesterol granuloma of the orbit is a rare entity, and its pathogenesis is still poorly understood. We report on 6 cases including one patient who had been examined by X-ray prior to the tumor's clinical manifestation.

PATIENT DATA

All tumors were located in the superior temporal orbit. Histologically, they revealed the typical features of a cholesterol granuloma without any epithelial elements. They infiltrated the bone but left the soft tissues largely intact. Complete surgical removal of the granulomatous mass was attempted in each case, and particular attention was given to thorough abrasion of the bone. Only 2 patients reported a previous trauma. In one of them, retrospective evaluation of the X-ray scan taken a few hours after his accident revealed no definite changes in the orbital bone at the site of the future tumor. The only recurrence developed in a patient in whom the bony base of the tumor had not been drilled out completely.

CONCLUSIONS

The origin of orbital cholesterol granuloma remains unknown. According to our data and those available in the literature, trauma is not a precondition but may accelerate growth. Some non-epithelial malformation in the bone, with a predelection in the temporal upper quadrant, might be the origin. To prevent a recurrence it appears essential to totally erase the tumor from its bony bed.

Radiation response of porcine RPE cells in vitro

PURPOSE

To investigate the antiproliferative effect of ionizing radiation on retinal pigment epithelial (RPE) cells that are supposed to play a major role in the pathogenesis of proliferative vitreoretinopathy (PVR).

METHODS

RPE cells from pig eyes were irradiated with doses ranging from 4 to 16 Gy (1 Gray = 1 Joule/kilogram). Cells were counted at 1, 2, 3, and 4 weeks (Experiment 1) or 1, 2, 4, and 6 weeks (Experiment 2) after treatment. In Experiment 3, cells were trypsinized 24 h after radiation and seeded again. Colonies were counted 10 days later, and the surviving fraction was determined.

RESULTS

The numbers of cells and colonies were inversely correlated to the doses applied. In Experiment 2, cell numbers of radiated cultures remained stable during the time of follow-up, whereas, in Experiment 1, significant proliferation occurred in treated cultures as well as in controls. This may be due to the higher growing rate that was found in the cultures of Experiment 2, compared to those of Experiment 1, at the time of radiation. In Experiment 3, a D0 value of 0.72 Gy was found.

CONCLUSIONS

Proliferation of RPE cells can be suppressed by irradiation in a dose-dependent manner. Therefore, radiotherapy may be useful in the treatment of PVR. Its effect probably depends on the stage or activity of PVR at the time of radiation.

Immunolocalization of ubiquitin and related enzymes in human retina and retinal pigment epithelium

PURPOSE

To examine the localization of ubiquitin (Ub) and related enzymes in human retina with emphasis on the retinal pigment epithelium (RPE)-Bruch's membrane complex.

METHODS

Thirty human eyes enucleated for various disease processes were examined. Immunohistochemistry was performed on paraffin sections using antibodies against Ub, Ub-conjugating enzyme (E2), Ub carboxyl-terminal hydrolase (PGP 9.5), and, for comparison, arrestin (Arr). Immunoreactivity (IR) was tested using the avidin-biotin method.

RESULTS

Ub was present throughout retina but was particularly prominent in ganglion cells and RPE. Most intriguing was the presence of Ub IR in age-related, sub-RPE deposits such as drusen and basal laminar deposits (BLD). RPE immunolabeling was more intense in older tissue, but otherwise no pattern of Ub IR could be linked to specific diseases. E2 IR colocalized with Ub, with one exception; E2 IR was not found in drusen or BLD. PGP 9.5 IR was intense in nerve fibers, ganglion cells, and the inner nuclear and plexiform layers. RPE staining was faint and patchy; sub-RPE deposits were not labeled. Arr IR was present in photoreceptors but not within or beneath RPE cells.

CONCLUSION

The ubiquitination process is important in human retina and particularly in ganglion cells. Ub-related processes are also active in RPE and may be involved in the degradation and disposal of proteins from these cells. The presence of Ub in sub-RPE deposits--without related Ub-processing enzymes--raises the possibility that certain proteins become ubiquitinated within RPE but that further degradation of the Ub-protein complexes does not occur.

Immunoscintigraphy with anti-225.28S for ocular melanoma--a comparison with histology and immunohistochemistry

AIM

The purpose of this prospective study was to evaluate the value of immunoscintigraphy (ISG) with anti-225.28S in clinically suspected ocular melanoma.

METHODS

For this purpose standardized ISG was performed in 36 patients using both planar acquisition and emission computed tomography (ECT). Ocular melanoma was present in 31 patients. In 21 patients therapy was enucleation of the eye. These specimens were evaluated by histology and immunohistochemistry in 11 of 21 patients.

RESULTS

Regarding the clinical diagnosis, ISG was positive only in 15 of 31 patients with ocular melanoma, regarding histology in 11 of 21 and regarding immunohistochemistry in 5 of 6 patients with a positive immunoreaction 5 patients showed no immunoreactivity, their ISG was negative.

CONCLUSION

Thus a good correlation between ISG and immunohistochemistry was observed. However ISG using the cutaneous melanoma antibody 225.28S cannot be recommended for the diagnostic work-up of an ocular melanoma considering the poor immunoreactivity.

Toxicity and antiproliferative effect of aclacinomycin A on RPE cells in vitro

PURPOSE

Aclacinomycin A or aclarubicin is an anthracycline that, by contrast with daunomycin, lacks carcinogenicity and is less toxic to the retina. We investigated the toxicity and antiproliferative effect of aclacinomycin A on retinal pigment epithelial cells that are known to play a mayor role in the pathogenesis of proliferative vitreoretinopathy.

METHODS

In 3 experimental set-ups, RPE cells from pig eyes were incubated with aclacinomycin A at different concentrations (0.5-15 micrograms/ml) and for various lengths of time (1-10 min). Cells were counted on day 3 after exposure to evaluate toxicity, subcultured, and counted once more on day 15 to test for the antiproliferative effect. Data were analyzed using the Tukey's Studentized Range (HSD) Test. Furthermore, RPE cells were examined by light microscopy.

RESULTS

Cell numbers on day 3 after treatment were reduced significantly (p < or = 0.05) already at the lowest dosage tested (1 microgram/ml for 1 min). Higher doses, up to 15 micrograms/ml for 5 min, did not lower cell numbers below 20% of those of control cultures. Logarithms of cell numbers on day 15 were inversely correlated to drug concentration as well as to incubation time. Cells that had been treated with 5 micrograms/ml aclacinomycin A for 5 min were not able to start a new culture when subcultured 3 days after drug exposure.

CONCLUSIONS

Aclacinomycin A applied intraocularly during vitreoretinal surgery may be an alternative to daunomycin in the treatment of proliferative vitreoretinopathy.

Malignant tumor of the retinal pigment epithelium with extraocular extension in a phthisical eye

BACKGROUND

Malignant tumors of the retinal pigment epithelium (RPE) are exceedingly rare. We describe the histopathologic and immunohistochemical features of a RPE neoplasm that was found accidentally in a blind and painful phthisical eye.

METHODS

The enucleated eye was investigated by light microscopy, and tumor tissue was also studied by electron microscopy. Immunohistochemistry was performed using antibodies against HMB-45, S-100 protein, NSE, cytokeratins, vimentin, desmin, GFAP, the HNK-1 carbohydrate epitope and alpha-smooth muscle actin.

RESULTS

The tumor was located mainly in the vitreous cavity with practically complete destruction of the retina, but foci of choroidal infiltration and extraocular extension along vascular channels were identified. The mitotic rate was high, and large areas of necrosis were present. No features of differentiation were seen, apart from occasional desmosome-like junctions and deposition of basal lamina at the ultrastructural level. Adjacent to the tumor, reactive hyperplasia and metaplasia of RPE cells was prominent. By immunohistochemistry, tumor cells revealed intense immunoreactivity with anti-vimentin and weak staining with anti-S-100 protein. The hyperplastic RPE cells also reacted for cytokeratins 8, 18 and 19 and for alpha-smooth muscle actin. At more than 1 year post enucleation the patient is well and shows no signs of recurrence or metastatic disease.

CONCLUSION

We present the features of a malignant tumor of the RPE with unequivocal extraocular extension. These findings raise the possibility that RPE hyperplasia may transform into a malignant tumor.

Characteristic distribution of deposits in recurrent granular corneal dystrophy

Granular corneal dystrophy can recur after penetrating keratoplasty. In those cases as in the early primary manifestation of the disease, deposits are found predominantly in the superficial corneal layers. At a later stage, stromal deposits can also be seen. We describe an additional particular location of deposits and correlate clinical with histological findings in three corneas from two patients. Deposits were found mainly superficially within the graft and around the edge of the transplant along the scar between host and donor cornea. We suggest that the deposits are of epithelial origin, though their production by stromal cells cannot be excluded. Chemical interactions are discussed as an explanation for the characteristic distribution of the deposits.

Sympathetic ophthalmia: an immunohistochemistry study of four cases

We present histological and immunohistochemical data on four cases of sympathetic ophthalmia, a disease that is believed to occur predominantly after perforating injury to the eye. Only a few cases without previous perforation have been reported. Nevertheless, sympathetic ophthalmia should be taken into consideration if there is a bilateral intraocular inflammation, even without trauma, as in two of our cases (cases 1 and 2). An unusual case after uneventful intracapsular cataract extraction and a posttraumatic "classic" case are also presented (cases 3 and 4). We found a granulomatous infiltration of the uveal tract by lymphocytes, plasma cells, and epithelioid cells, particularly of the choroid. Dalen-Fuchs nodules were found in all cases, the second case also being associated with phacoanaphylaxis. Case 1 and 4 showed immunohistochemically a predominance of CD3-positive cells (T-lymphocytes), whereas in cases 2 and 3, many cells surprisingly stained positively for L26 (B-lymphocytes). In case 2 the immune response may have been altered by the additional phacoanaphylaxis. In all four cases, scattered epithelioid cells stained positively for CD 68. We conclude that in cases of bilateral uveitis, even without previous penetrating injury or after common intraocular surgery, sympathetic ophthalmia as a possible cause should be taken into consideration because an early diagnosis with subsequent enucleation of the exciting eye is of decisive influence on the course of the disease.

Immunoscintigraphy for ocular melanoma: a reliable diagnostic technique?

BACKGROUND

Immunoscintigraphy (IS) has recently been used as a diagnostic tool for ocular melanoma. We wanted to reevaluate published data in our own patients and to correlate immunoscintigraphic results with histologic findings and immunohistochemical characteristics of the tumour tissue.

METHODS

During a 4-year period, IS was performed on 35 patients (average age 64 years) with suspected ocular melanoma by i.v. injection of 225.28S, a monoclonal antibody against high-molecular-weight melanoma-associated antigen. Histology was available in 22 cases. Tumour tissue was evaluated for cell type, vascularization, necrosis, pigmentation, and lymphocytic infiltration, and immunohistochemistry was performed with 225.28S and antibodies against HMB-45, S-100 and vimentin. One hundred and two patients with metastasizing cutaneous melanoma served as controls. In these patients the identical immunoscintigraphic technique was applied.

RESULTS

IS yielded a positive result in about 50% of our patients with ocular melanoma, while in patients with cutaneous melanoma sensitivity was 89%. In five patients who turned out not to have melanoma, two false-positive results were obtained (one subretinal hemorrhage and one Wegener's granulomatosis). No correlation was found between any of the histological features or the immunoreactivity pattern and the immunoscintigraphic outcome. However, antigenic differences between ocular and cutaneous melanoma were evident.

CONCLUSION

We conclude that IS, using the antibody applied in this study, is of only limited value in patients with ocular melanoma. Our results suggest that antigenic differences, rather than histological characteristics or technical problems, are responsible for the low sensitivity in ocular melanoma compared to cutaneous melanoma.

Pigmented conjunctival epithelial dysplasia in an HIV positive African: detection of human papillomavirus type 16

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Anti-arrestin immunoreactivity in the human retina: difference between light- and dark-adaptation

Differences in arrestin (Arr) immunolocalization between light(LA)- and dark(DA)-adapted retinae have been described in various species. We have for the first time studied 5 LA and 5 DA human retinae from surgically enucleated eyes, each group comprising 1 exenteration specimen and globes with malignant melanoma or 2 degrees glaucoma. To examine the distribution of Arr, immunohistochemistry was performed on paraffin sections using three different antibodies to Arr: a48k, 3D1.2, and 5c6.47. Immunoreactivity (IR) was tested using the avidin-biotin method, and results were visualized with diaminobenzidine. With both a48k and 5c6.47, labeling was most intense in the photoreceptor layer. When comparing LA and DA retinae, IR of photoreceptor outer segments (OS) was clearly different with very little IR in OS of DA but distinct positivity in OS of LA retina. This was most obvious in melanoma eyes where retinal morphology was well-preserved while in glaucomatous eyes with retinal degeneration this pattern was less apparent. 3D1.2 did not react in any of the specimens. Although there was some variation within each group, we demonstrated a distinct difference in anti-Arr IR between LA and DA specimens. Thus Arr-IR might now be used as a promising tool to further study retinal diseases on human surgical specimens involving photoreceptor degeneration.

The effects of simultaneous occlusion of the posterior ciliary artery and vortex veins. A histopathologic study

OBJECTIVE

In previous research, experimental occlusion of the posterior ciliary arteries resulted in an infarction of the retinal pigment epithelium and outer retina. A simultaneous occlusion of one or two vortex veins (VVs) appeared to have an ameliorative effect on the retinal infarct based on previous clinical and angiographic observations. The objectives of this report were to evaluate the histopathologic changes of the ischemic retina and to examine the disruption and healing of the blood-retinal barrier under various combinations of ciliary artery and VV occlusions.

METHODS

Experimental posterior ciliary artery (PCA) occlusion with (n = 3) or without (n = 3) simultaneous VV occlusion was carried out in six rhesus monkey eyes. The eyes were enucleated over a course of 3 months. The histopathologic changes of the ischemic retina were examined by light and electron microscopy. In addition, the horseradish peroxidase tracer technique was used to study the blood-retinal barrier.

RESULTS

Ischemic changes following the occlusion of the PCA consisted of coagulation necrosis of the retinal pigment epithelium and of the outer retinal layers and were less pronounced in eyes with simultaneous VV occlusion. At 6 hours after the insult, the blood-retinal barrier was broken and horseradish peroxidase leaked into the subretinal space (PCA occlusion with one VV occlusion). Three months later, the blood-retinal barrier had re-formed, even in the eyes with severe ischemic injury.

CONCLUSIONS

The histopathologic changes suggest that the ameliorative effect of simultaneous VV occlusion on the effects of PCA occlusion might be due to reduced perfusion in the choroidal circulation.

Tau-2 immunoreactivity of corpora amylacea in the human retina and optic nerve

PURPOSE

To characterize the constituents of corpora amylacea in the human retina and optic nerve.

METHODS

Immunohistochemistry was performed on sections of retina, optic nerve, and brain tissue using antibodies against tau 1, tau-2, and amyloid precursor protein.

RESULTS

Consistent anti-tau-2 immunoreactivity was noted in the corpora amylacea in the retina, optic nerve, and brain tissue, albeit with variations in pattern and intensity of staining. No immunoreactivity was observed with antibodies anti-tau 1 and anti-amyloid precursor protein.

CONCLUSION

Our findings suggest the accumulation of possibly abnormal tau-2 within the corpora amylacea, which may be either astrocytic or axonal in origin.

Dominantly inherited cystoid macular edema. A histopathologic study

BACKGROUND

Dominantly inherited cystoid macular edema was described as a clinically distinct form of macular dystrophy with an onset at approximately age 30 years with slow progression over the ensuing decades. This is the first report of the light and electron microscopic findings in two donor eyes of one of the patients with this clinical entity.

METHODS

Both eyes were obtained after death and fixed within 24 hours in a buffered 4% formaldehyde-1% glutaraldehyde solution. For light microscopy, tissue was embedded in paraffin and stained with hematoxylin-eosin, periodic acid-Schiff, colloidal iron for mucopolysaccharides, and an antibody to glial fibrillar acidic protein. For ultrastructural investigation, several blocks of choroidal/retinal tissues from the posterior pole, including both maculae, were embedded in epoxy resin and processed for transmission electron microscopy.

RESULTS

Major findings included large retinal cysts in the macula, atrophy and marked disorganization of the inner nuclear layer, advanced degeneration of Müller cells with nodular aggregates of basement membrane-like material, and a preretinal membrane. The retinal vasculature did not show excessive endothelial alterations but was surrounded by deposits of multilayered basement membrane in the perivascular space.

CONCLUSION

The authors believe that the pathologic features of dominantly inherited cystoid macular edema are different from those of macular edema caused by other disease processes. The predominant pathologic changes affected mainly the inner nuclear layer. The possibility of a primary disease of the Müller cell is suggested.