ABSTRACT
BACKGROUND: The accumulation of autofluorescent bodies in retinal pigment epithelium (RPE) cells has an impact on the pathogenesis of retinal diseases, including age-related macular degeneration. While current in vivo fluorescence microscopy allows a lateral resolution of fluorophores in a micrometer range, with ex vivo microscopy a lateral resolution down to 200 nm is possible. For the first time, we used structured illumination microscopy for ex vivo high-resolution fluorescence microscopy of RPE cells. METHODS: Histological sections were prepared from a 68-year-old patient. With epifluorescence microscopy, fluorescent RPE cells were detectable. Structured illumination uses inhomogeneous illumination for resolution of previously nonresolvable structures, similar to the Moiré effect. Images were taken from RPE cells at different excitation wavelengths (488, 568, and 647 nm) and were reconstructed with special software. The different excitation patterns of the fluorescent granules in the RPE cells were colour-coded and analysed. RESULTS: With structured illumination microscopy, autofluorescence signals of RPE cells were detectable, and a lateral resolution of 110 nm could be achieved. Using varying wavelengths, different pigments were excitable. Lipofuscin gave the highest signals, at 488 and 568 nm. The improved resolution showed inhomogeneous intragranular fluorophore patterns. CONCLUSION: Structured illumination microscopy enabled us to generate images of fluorescent structures in RPE cells ex vivo with a lateral resolution of 110 nm. With the use of different excitation wavelengths, intracellular fluorescence patterns in single cell compartments are visible and allow further differentiation.
Subject(s)
Dermoscopy/methods , Image Processing, Computer-Assisted/methods , Microscopy, Fluorescence/methods , Pigment Epithelium of Eye/pathology , Humans , Lipofuscin/metabolism , Male , Melanins/metabolism , Middle Aged , Moire Topography/methods , Sensitivity and Specificity , SoftwareABSTRACT
PURPOSE: This study aimed to investigate the effect of bevacizumab on pigment epithelial detachment (PED) in occult choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD) and to determine predictive factors. METHODS: 73 eyes of patients with AMD and PED due to CNV with subretinal and/or intraretinal fluid were assessed. Patients were treated with 1.25 mg of intravitreal bevacizumab. RESULTS: After 30.6 weeks, the mean visual acuity (VA) increased from 0.53 to 0.49 logMAR (p=0.170). The mean PED height decreased from 354.4 µm to 277.4 µm (p=0.004). Although 53.4% of the eyes showed a reduction in PED, this did not correlate with a significant change in VA. Predictive factors were a high baseline PED and VA <0.32. CONCLUSION: Half of the patients showed PED flattening. Especially in patients with distinctive PED, a response to intravitreal bevacizumab may be expected. This therapy can stabilize VA, but PED flattening does not essentially correlate with an increase in VA.
Subject(s)
Antibodies, Monoclonal/administration & dosage , Choroidal Neovascularization/drug therapy , Choroidal Neovascularization/etiology , Macular Degeneration/complications , Macular Degeneration/drug therapy , Retinal Detachment/complications , Retinal Detachment/drug therapy , Retinal Pigment Epithelium/drug effects , Aged , Angiogenesis Inhibitors/administration & dosage , Antibodies, Monoclonal, Humanized , Bevacizumab , Female , Humans , Male , Treatment OutcomeABSTRACT
BACKGROUND: Cysts of the iris are uncommon and most of them occur secondarily after surgery or penetrating injury. The minority of the iris cysts is primary without a reasonable cause. They are classified into the more common pigment epithelial cysts and the rare cysts of iris stroma ("intrastromal cysts"). These intrastromal iris cysts are generally diagnosed in children and often cause symptoms such as a decrease of visual acuity because of ingrowth into the optical axis. A diagnosis of stromal cysts in adults is very rare. Most of these patients remain without any symptoms and do not need treatment. The cellular origin is so far unknown. Mesoderm, neuroectoderm and surface ectoderm have been discussed in this context. CASE REPORTS: Two patients with primary intrastromal iris cysts are presented, a 5-year-old boy and a 65-year-old woman. In both cases, the cyst affected the optical axis and was removed by sector iridectomy. In histological and electron-microscopic examinations both cysts presented a typical epithelial structure. Immunohistochemical examination revealed positivity for epithelial markers and negativity for mesenchymal and neuroectodermal markers. CONCLUSION: Primary intrastromal iris cysts can occur in advanced age and may cause symptoms due to progressive growth. The cellular origin of primary intrastromal iris cysts is controversially discussed in the literature. On electron microscopy and immunohistochemistry, the iris cysts presented here showed characteristic features of surface ectodermal origin.
