Christoph W. Spraul

Histologic and Morphometric Analysis of the Choroid, Bruch's Membrane, and Retinal Pigment Epithelium in Postmortem Eyes With Age-Related Macular Degeneration and Histologic Examination of Surgically Excised Choroidal Neovascular Membranes

OBJECTIVE Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in industrialized countries. Different risk factors have been associated with AMD. We performed a histopathologic and morphometric study to compare eyes with different stages of AMD to age-matched eyes. This study aimed to investigate the correlation among morphometric characteristics of choroidal vessels, the retinal pigment epithelium, and Bruchs membrane, to study the association between these characteristics and the presence and type of AMD, and to identify morphologic risk factors for exudative AMD. Furthermore, we histologically analyzed surgically removed choroidal neovascular membranes secondary to underlying diseases other than AMD to discern whether the cellular and extracellular components of the membranes of eyes with AMD are similar to those with diseases other than AMD. METHODS We analyzed 51 eye bank eyes (Georgia Eye Bank, Atlanta, GA) from 40 donors with different stages of AMD and compared them with 40 age-matched controls. The eyes were processed for light microscopy. The degree of calcification of Bruchs membrane, fragmentation of Bruchs membrane, number and types of drusen, basal laminar deposit, and seven morphometric variables of the choroid were assessed in the macular and extramacular regions. Surgically excised subfoveal membranes were processed and evaluated by light and transmission electron microscopy. RESULTS There were no statistically significant differences observed between eyes with neovascular and non-neovascular AMD. The single most important difference between eyes with and without AMD was the amount of basal laminar deposit (P < 0.001). Eyes with AMD displayed fewer large choroidal vessels in the submacular choroid than eyes without AMD (mean density values of all choroidal vessels [arteries and veins] were 3.5 +/- 1.5 mm(-1) and 5.7 +/- 1.6 mm(-1), P < 0.001, respectively). The submacular choriocapillaris density was higher in eyes with AMD (mean density, 0.62 +/- 0.06) than in eyes without AMD (mean density, 0.51 +/- 0.08 [P < 0.001]). The diameter of the larger choroidal vessels in the peripheral choroid was higher in eyes with AMD (mean diameter, 30 +/- 8 microm) than in eyes without AMD (mean diameter, 21.4 +/- 6.2 microm [P < 0.001]). The peripheral choriocapillaris density displayed the same pattern as the macular region in eyes with and without AMD. There was a statistically significant difference observed in the degree of calcification and fragmentation of Bruchs membrane in eyes with exudative AMD (mean degree of calcification, 1.6; median number of breaks in Bruchs membrane, five) as compared with controls (mean degree of calcification, 0.8; median number of breaks in Bruchs membrane, zero). The difference for these two variables between eyes with nonexudative AMD (mean degree of calcification, 0.8; median number of breaks in Bruchs membrane, one) and controls (mean degree of calcification, 0.8; median number of breaks in Bruchs membrane, zero) failed to reach statistical significance. Eyes with AMD displayed significantly more soft, diffuse, and large drusen, as well as basal laminar deposit, in the macular area than controls. CONCLUSION Combining our data with data from the literature, we conclude that AMD can be interpreted as a dynamic process with early proliferation and subsequent atrophy of capillaries of the choriocapillaris. Calcification and fragmentation of Bruchs membrane; soft, diffuse, and large drusen; and basal laminar deposit, but not hard drusen, strongly correlate with the histologic presence of AMD. The degree of calcification and fragmentation of Bruchs membrane is prominent in eyes with exudative AMD. The formation of choroidal neovascular membranes represents a stereotypic, nonspecific wound repair response independent of the underlying disease.

Morphometric changes of the choriocapillaris and the choroidal vasculature in eyes with advanced glaucomatous changes.

PURPOSE In addition to an elevated intraocular pressure a compromise of the ocular blood supply have been implicated in the pathogenesis of primary open-angle glaucoma. The purpose of this study was to quantify morphologic changes in the choroid including choriocapillaris thickness and density and diameter of large choroidal vessels in post mortem eyes with advanced primary open-angle glaucoma. METHODS We analyzed 20 eye bank eyes (provided from the Georgia Eye Bank in Atlanta) with end stage primary open-angle glaucoma and compared them with 20 age-matched control eye bank eyes. The eyes were processed for light microscopy and following variables were measured with a digital filar micrometer: density and diameter of large choroidal vessels in the macular and equatorial choroid; thickness of the choroid in the macular and equatorial region; density and thickness of choriocapillaris in the macular, peripapillary, and equatorial choroid; and peripapillary capillary-free area nasal and temporal to the optic disk. RESULTS Eyes with glaucoma displayed a lower density of the capillaries of the choriocapillaris as compared to control eyes in the macular, temporal peripapillary, and equatorial choroid with 0.50-0.55 (p=0.018), 0.46-0.51 (p=0.016), and 0.50-0.55 (p=0.038), respectively. There was no significant difference for the choriocapillaris density in the nasal peripapillary choroid, the thickness of the capillaries of the choriocapillaris in all assessed locations, and the nasal and temporal peripapillary capillary-free zone of the choriocapillaris between eyes with glaucomatous damage and controls. Assessment of large choroidal vessels in the macular choroid showed that eyes with glaucoma had a decreased density of veins (11.7-38.9 mm(-2); p<0.001) and arteries (7.7-12.4 mm(-2); p=0.005) and arteries with a higher diameter (45.6-28.2 microm; p<0.001) as compared to control eyes. The large vessels in the equatorial choroid displayed no significant difference in diameter but a lower density (21.2-44.1 mm(-2); p=0.017) in eyes with glaucomatous damage as compared to controls. CONCLUSION Eyes with advanced glaucomatous damage after long standing primary open-angle glaucoma exhibit several changes including decreased density of capillaries of the choriocapillaris and decreased density of large choroidal vessels. We cannot conclude from our study whether the observed vascular changes in the choroid are primary pathogenic factors or secondary phenomena.

Imaging quality of intraocular lenses.

PURPOSE: To compare the imaging quality of several commercially available intraocular lenses (IOLs) using the modulation transfer function (MTF) method according to the requirements of the International Standard European Industrial Norm/International Organization for Standardization 11979. SETTING: Universitat für Technik der Informationsverarbeitung, Universität Karlsruhe, Karlsruhe and Universitäts Augenklinik, Ulm, Ulm, Germany. METHODS: Two refractive powers (+13 diopter [D] and +26 D) of each IOL type were tested. The imaging quality of all tested IOLs was measured before the injection test and in 5‐minute intervals after the injection for 40 minutes. The measurement data were analyzed according to 2 quality criteria, Strehl ratio and the ISO condition. For analysis of the type of optical design, SEM images of the central cross section were taken of each IOL. Basic terms in optics such as MTF, resolution, and optical aberration are introduced, and their relevance for ophthalmology is discussed in detail. This paper represents an extensive study comparing the imaging quality of various IOLs including the comparison of measurements before and after injection through a cartridge as used for state‐of‐the‐art implantation techniques. All measurements were performed using an MTF measurement system using a 546 nm optimized laser source and an effective aperture of 3.0 mm on the IOL according to ISO standard. An ISO standard eye model using an artificial cornea (spherical design) and a watery solution to simulate in vivo conditions was used. RESULTS: All IOLs apart from 1 +26 D lens complied with ISO standard requirements. However, the imaging quality varied up to 49% depending on the optical design and the manufacturing quality. CONCLUSION: When the methods and materials recommended by the manufacturer for IOL injection through a cartridge were used, no long‐term effect on the imaging quality of the IOLs was observed. However, the basic imaging quality of different designs and different manufacturers varied significantly (up to 50% at +26 D) IOLs and should be considered when choosing an IOL.

Kimura disease of the orbit and ocular adnexa.

Kimura disease (KD) is a distinct clinicopathologic entity that has been the subject of considerable confusion and debate. Although common in Asia, KD rarely occurs in non-Asian patients. Kimura disease shares both clinical and histopathologic features with angiolymphoid hyperplasia with eosinophilia (ALHE). Because of this overlap and the rarity of KD in Europe and the United States, KD and ALHE have been used synonymously in the Western medical literature, as they were thought to represent variations of the same disease. Some pathologic reports have called for distinguishing KD and ALHE as two separate entities, based on their histologic features. Kimura disease occurs most commonly in the head and neck region and has been described in the orbit, eyelids, and lacrimal gland more frequently than ALHE. Because both diseases can cause proptosis, lid swelling, ocular dysmotility, or a palpable mass, they should be considered in the differential diagnosis of orbital lesions occurring in adults. We report two cases of KD involving the orbit and ocular adnexa, and review additional cases reported in the literature. The ophthalmic literature does not clearly reflect the current understanding that KD and ALHE are best considered two separate clinicopathologic entities.

Reproducibility of measurements with a new slit lamp-mounted ocular blood flow tonograph

Abstract · Purpose: To assess the reliability of measurements of intraocular pressure (IOP), pulse amplitude (PA), and pulsatile ocular blood flow (POBF) and the validity of measurements of IOP with a new ocular blood flow tonograph. · Methods: Intraocular pressure pulse was assessed with pneumatic tonometry. In this study, we used the OBF Labs ocular blood flow tonograph with two different pneumatic probes, a modified Langham probe and a newly developed probe. One ophthalmologist compared two machines, first with the modified Langham probe and secondly with the newly developed probe (40 volunteers). Additionally, two ophthalmologists performed measurements on different days and in different sequence (34 volunteers). Furthermore, results of IOP measurements performed with this tonograph were compared to those of Goldmann applanation tonometry (213 volunteers). · Results: Using the modified Langham probe, POBF and PA were associated with the machine used for the test. However, using the newly developed pobe, no relevant or statistically significant differences were found for any variables, and reliability coefficients were between 0.70 and 0.90. Linear regression analysis of the Goldmann applanation tonometer on the measurements of IOP with the tonograph showed a regression coefficient of 0.765. · Conclusions: Results of measurements performed with this ocular blood flow tonograph and the newly developed probe are expected to be reliable and comparable.

Effect of Growth Factors on Bovine Retinal Pigment Epithelial Cell Migration and Proliferation

Background: To examine the effects of platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), acidic fibroblast growth factor (aFGF), insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF), and transforming growth factor beta 2 (TGFβ2) on bovine retinal pigment epithelial (RPE) cell migration and proliferation. Materials and Methods: Cultured bovine RPE cells were treated with 10 ng/ml PDGF, bFGF, aFGF, IGF-1, EGF, or TGFβ2. RPE cell migration studies were performed in multiwell plates confluently covered with RPE cells. After inhibition of proliferation and denudation of half of each well, cells were incubated with various growth factors. Migration was measured as the number of cells that had entered the denuded area after 20 h. RPE cell proliferation was determined by [3H]thymidine incorporation after growth factor stimulation for 24 h. Results: RPE cell migration was significantly enhanced after incubation with PDGF (stimulation of 213% compared to the negative control, p = 0.002), bFGF (206%, p = 0.003), aFGF (175%, p = 0.003), IGF-1 (150%, p = 0.003), and EGF (144%, p = 0.003). RPE cell proliferation was stimulated by bFGF (322% compared to the negative control, p < 0.005), PDGF (119%, p < 0.005), aFGF (121%, p < 0.005), and EGF (94%, p < 0.005). IGF-1 showed no significant effect on RPE cell proliferation; TGFβ2 displayed no effect on RPE cell migration nor on proliferation. Conclusions: The peptide growth factors PDGF, bFGF, aFGF, IGF-1, and EGF play an important role in initiating RPE cell migration. Basic FGF, PDGF, aFGF, and EGF stimulate RPE cell DNA synthesis.

Changes of retinal capillary blood flow in age-related maculopathy

Abstract  Background: To investigate retinal capillary blood flow characteristics in patients with age-related maculopathy (ARM). Methods: Retinal capillary blood volume (VOL), blood flow (FLOW), and velocity (VEL) were measured in four macular sectors (I, II, III, IV) and in two areas beyond the temporal superior and inferior major vessel arcades (V and VI) in: 10 eyes with early ARM (drusen ≥63 µm and/or atrophy of the retinal pigment epithelium, RPE, <175 µm and/or proliferation of RPE), 13 with late ARM (exudative), 10 with late ARM (fibrotic), 14 normal eyes of 14 children of patients with ARM, and in 4 age- and sex-matched control groups using the Heidelberg retinal flowmeter (HRF). Statistical analysis was performed with the exact Wilcoxon test using an additional adjustment procedure by Bonferroni-Holm. Results: As compared to the control group, there was no significant change of VOL, FLOW, and VEL in patients with early ARM. In patients with late ARM (exudative), there was a significant higher FLOW in sectors I, II, and IV and a higher VOL and VEL in sectors III and IV. The group with late ARM (fibrotic) showed a reduction of VOL and FLOW in sectors I–IV and of VEL in sectors II and IV. In children of ARM patients, VOL, FLOW, and VEL of sectors I–VI did not differ from the control group. Conclusion: HRF measurements in patients with ARM indicate an increased macular retinal capillary blood flow in patients with the exudative form of late ARM and a decreased macular perfusion in those with the fibrotic form.

Retinal Pigment Epithelial Changes Associated with Systemic Corticosteroid Treatment: Report of Cases and Review of the Literature

Purpose: The aim of our study was to describe two different manifestations of retinal pigment epithelial changes associated with systemic corticosteroid treatment. Methods: We report 4 patients who developed maculopathy during treatment with systemic corticosteroids. Additionally, the literature was reviewed for similar cases. Results: Two patients showed diffuse retinal pigment epitheliopathy. Two patients developed central serous chorioretinopathy with localized changes in the retinal pigment epithelium. A review of the literature revealed 51 patients with similar changes during treatment with corticosteroids. Conclusion: These 4 patients provide further evidence that systemic treatment with corticosteroids may cause central serous chorioretinopathy or diffuse retinal pigment epitheliopathy. Ophthalmologic examination is recommended on a regular basis for patients treated with systemic corticosteroids.

Thalidomide and Prednisolone Inhibit Growth Factor-Induced Human Retinal Pigment Epithelium Cell Proliferation in vitro

Thalidomide and prednisolone were recently introduced as treatment modalities in age-related macular degeneration (AMD). Growth factor-induced activation of retinal pigment epithelial (RPE) cells is a crucial event in this disease. The purpose was to examine the effect of thalidomide and prednisolone on growth factor-preactivated RPE cells. Human RPE cells were stimulated with 10 ng/ml platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), or vascular endothelial growth factor (VEGF) for 24 h. Afterwards, thalidomide (50 µg/ml) or prednisolone (100 ng/ml) were added for 24 h. RPE cell proliferation was determined by [3H]-thymidine incorporation. PDGF and bFGF significantly stimulated human RPE cell proliferation (p < 0.005), the value for VEGF stimulation was not significant (p = 0.3). The effect of the growth factors was diminished after addition of thalidomide and prednisolone (p < 0.005). The current study shows that the inhibitory properties of thalidomide and prednisolone remain even after growth factor activation of the cells.

Analysis of 24,444 surgical specimens accessioned over 55 years in an ophthalmic pathology laboratory

Purpose: To summarize the pathologic diagnoses of a large number of surgically-obtained specimens over an extended time period in a single ophthalmic pathology laboratory. Methods: We analyzed the records of 24,444 surgically obtained specimens accessioned in the L.F. Montgomery Ophthalmic Pathology Laboratory, Emory University, Atlanta, GA between May 1941 and December 1995. Age, sex, topography,clinical procedure, and histologic diagnosis were entered into a database using the modified SNOMED coding system. The diagnosis of the surgically enucleated eyes were analyzed with respect to years of enucleation. Results: The most common topographic area associated with a histologic diagnosis was the cornea (39.3%), followed by lens (16.0%), vitreous (12.0%),uvea (9.8%), eyelids (8.0%), conjunctiva(7.7%), retina (7.7%), and orbit(2.1%). The relative proportion of vitreous specimens has continuously increased and became the most common surgical specimen in 1995. The most common underlying disease of surgically enucleated eyes is trauma (40.9%), followed by ocular neoplasia (24.2%), ‘surgical‘ diseases of the cornea,lens and retina including glaucoma (17.3%), vascular diseases(6.7%), and inflammatory conditions (6.7%). The relative frequency of trauma and ocular inflammation as a cause of enucleation decreased significantly (p < 0.05) over the time of the study period while the relative proportion of ocular neoplastic processes increased (p < 0.0001).Conclusions: The availability of new surgical techniques has caused a change in the relative frequencies of different ocular specimens submitted for histologic examination.