Karin U. Loeffler

High-Resolution Spectral Domain-OCT Imaging in Geographic Atrophy Associated with Age-Related Macular Degeneration

PURPOSE To describe morphologic variations in outer retinal layers in eyes with atrophic age-related macular degeneration (AMD) using high-resolution, spectral-domain optical coherence tomography (SD-OCT). METHODS SD-OCT scans were obtained with a combined confocal scanning laser ophthalmoscope (cSLO) and SD-OCT for simultaneous tomographic and topographic in vivo imaging. A total of 81 eyes of 56 patients (mean age, 77.8 +/- 7.4 years) with geographic atrophy (GA) were examined. Morphologic alterations were analyzed and classified in the perilesional zone, at the junction between GA and nonatrophic retina, and in the atrophic area itself. RESULTS In the perilesional zone, distinct morphologic alterations included elevations of the outer retinal layers, thickening, and spikes of the outer hyperreflective band as well as clumps at different neurosensory retinal levels. At the junction, highly variable transitions of the outer retinal layers were present with different degrees of loss of the normal hyperreflective bands. Within the actual GA, hyperreflective clumps at different retinal levels, segmented plaques of the outer band and elevations with variable reflectivity were visualized. CONCLUSIONS SD-OCT imaging in eyes with GA revealed a wide spectrum of morphologic alterations, both in the surrounding retinal tissue and in the atrophic area. These alterations may reflect different disease stages or, alternatively, heterogeneity on a cellular and molecular level. Longitudinal studies using in vivo SD-OCT imaging may allow evaluation of the relevance of these phenotypic changes as potential predictive markers for the progression of disease (i.e., enlargement rates of GA over time) and may be used for monitoring of future therapeutic interventions.

Morphological and immunohistochemical changes after corneal cross-linking.

Purpose: To present light and electron microscopic as well as immunohistochemical findings after corneal cross-linking (CXL). Methods: Six keratoconus corneas after CXL, 12 keratoconus corneas without CXL, and 7 normal corneas were examined by light microscopy, indirect immunohistochemistry using antibodies against proapoptotic BAX, antiapoptotic survivin, and BCL-2, and anti–smooth muscle actin and, in part, by transmission electron microscopy. Direct immunofluorescence with 4′6-diamidino-2-phenylindole was performed to analyze keratocytes/area in the anterior, middle, posterior, peripheral, and central corneal stroma. Results: The period between CXL and keratoplasty ranged from 5 to 30 months. All keratoconus corneas showed the typical histological changes. Increased proapoptotic BAX expression and/or antiapoptotic survivin expression were noticed in keratocytes and endothelium in 2 keratoconus specimens after CXL. Smooth muscle actin was only observed in subepithelial scar tissue of 2 keratoconus corneas without CXL. Keratoconus corneas after CXL revealed a significant reduction in keratocyte counts in the entire cornea (P = 0.003) compared with keratoconus corneas without CXL and normal corneas. This difference was because of a loss of keratocytes in the anterior (P = 0.014) and middle (P = 0.024) corneal stroma. Keratocytes in CXL corneas were reduced in the center (P = 0.028) and the periphery (P = 0.047). Conclusions: CXL in human keratoconus can cause considerable morphologic corneal changes up to 30 months postoperatively. Especially noteworthy is a long-lasting, maybe permanent, keratocyte loss in the anterior and middle corneal stroma involving the central and peripheral cornea. As long-term corneal damage after CXL is of genuine concern, particular care should be taken to perform this procedure only in accordance with investigational protocols.

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.

Keratoepithelin in secondary corneal amyloidosis

BackgroundAmyloid is found in several corneal dystrophies, including distinct lattice corneal dystrophies (LCD) and Avellino corneal dystrophy. Recently, point mutations in the transforming growth factor-beta-induced gene (TGFBI) encoding for keratoepithelin (KE) have been demonstrated in these corneal disease entities. We intended to investigate if KE was also a component of the rarely seen secondary corneal amyloid deposits.MethodsImmunohistochemical staining with a polyclonal antibody against KE was performed on formalin-fixed paraffin-embedded tissue of five corneal buttons with secondary amyloid obtained after keratoplasty. Secondary amyloidosis was due to Fuchs´ endothelial dystrophy (FED) with bullous keratopathy and/or recurrent erosions in all cases. The diagnosis had been established by light microscopy using Congo red staining. Two cases of LCD type I served as positive controls and three corneas with FED and one with keratoconus without amyloid served as negative controls.ResultsAll corneas with secondary amyloidosis as well as LCD type I revealed positive staining in the respective amyloid deposits. KE was localized in the subepithelial pannus and in the anterior stroma in the corneas with secondary amyloidosis. In the specimens with LCD type I it was distributed in the amyloid deposits located in the anterior and mid-stroma. Staining for KE showed a granular appearance in all cases. The intensity of staining was variable among the specimens.ConclusionsKE is found not only in primary amyloid deposits of hereditary corneal dystrophies, but also in secondary amyloidosis of the cornea of diverse ethiologies.

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

Abstract• 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 α-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 α-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.

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

Abstract · 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 μm; 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.

Effects of systemically applied allopurinol and prednisolone on experimental autoimmune uveitis.

Abstract · 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.

Short-Time Application of Latanoprost Does Not Stimulate Melanogenesis in Bovine Ocular Melanin-Containing Cells in vitro

Topical use of latanoprost for glaucoma can lead to an increase in iris and eye lash pigmentation but the precise mechanism is unclear. To study the possible effect of this drug on ocular melanogenesis, we used cultures of bovine iris melanocytes, iris pigment epithelial cells, retinal pigment epithelial cells, and choroidal melanocytes. Latanoprost (at concentrations of 10–8 and 10–6 mol) was applied for 3 days, and cell numbers as well as melanin content were measured prior to and 10 days after exposure and compared to untreated controls. In none of the cell types examined a significant increase in melanin content or an increase in cell proliferation was observed. Additional treatment with the tyrosinase inhibitor α-methyl-p-tyrosine showed no significant effect either. Our results support the concept of a rather complex mechanism underlying the increased iris pigmentation after treatment with latanoprost.

Sebaceous gland carcinoma of the eyelid masquerading as a cutaneous horn in Li–Fraumeni syndrome

A Caucasian man in his 50s was referred to our department with a diagnosis of cutaneous horn. He presented with an exophytic lesion of the right upper eyelid progressively enlarging over the last 6 months with bleeding on some occasions. His past medical and ocular history were unremarkable. His family history (figure 1), however, revealed cancer in at least three generations. One daughter had been diagnosed with early onset colon cancer, and the other with a malignant parotid neoplasm and breast cancer as a teenager. One brother had an unknown cancer of the face, and the other died shortly after birth of unknown cause. His mother was diagnosed with either a sarcoma or a tracheal carcinoma in her 20s. His aunt had a genitourinary malignancy. Slit lamp examination disclosed a conical horn of the right upper eyelid margin. The surface of the lesion appeared dark with a crusty, hyperkeratotic and ulcerative facade. On everting the lid, a yellowish nodular base was observed (figure 2A). Further clinical examination of both eyes was normal and visual acuity was 20/20 OU. A wedge resection was performed, and the lesion was submitted for histopathologic evaluation (figure 2B). The patient died 5 years later due to colon cancer. Figure 1 Family history of the Li–Fraumeni patient. Shaded symbols indicate cancer; cross-hatch indicates deceased members; tumour type is indicated. The Li–Fraumeni syndrome patient (III: 2) is described in this report. Figure 2 (A) Inspection on everting the eyelid showing a …

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.