Stephan Kaminski

Treatment of Ocular Toxocariasis with Albendazole

The purpose of this study was to evaluate the efficacy of combined albendazole and steroid treatment for uveitis caused by Toxocara canis in immunocompetent patients. Five patients (7 eyes) with ocular larva migrans syndrome (OLM) were used in this study. Toxocariasis was suspected based on clinical manifestations and confirmed by anti-toxocara IgG and Western blot analysis. Systemic albendazole (adults: 800 mg b.i.d.; children: 400 mg b.i.d.) was given in conjunction with steroids. Visual acuity before and after therapy, inflammatory response, side effects and toxicity were evaluated. Treatment resulted in an improved visual acuity in all patients. Mean initial Snellen visual acuity was 20/40, and mean final acuity was 20/20. There were no recurrences of uveitis throughout the observation period (average: 13.8 months; range: 3 days to 24 months). These findings suggest that albendazole, in combination with systemic steroids, is a useful regimen to treat ocular larva migrans syndrome.

Rapid Communication The Mydriatic Effect of Tropicamide and its Diagnostic Use in Alzheimer's Disease

The mydriatic effect of topically administered tropicamide was investigated as a possible diagnostic indicator for Alzheimers disease. Although an initial series seemed to show a correlation between hypersensitivity to tropicamide and intellectual impairment, subsequent testing showed a greater inter- and intra-individual variation than that between the normal group and the group of patients with intellectual impairment. This procedure seems, therefore, to lack sufficient specificity to be useful for such a diagnostic purpose.

Effect of tenascin and fibronectin on the migration of human corneal fibroblasts

Purpose: To investigate the effect of fibronectin and tenascin on the migration of corneal fibroblasts. Setting: Department of Ophthalmology, University of Vienna, Medical School, Vienna, Austria. Methods: Using human corneal fibroblasts, a monolayer migration assay was performed to measure corneal fibroblast movement. The migration on collagen I, fibronectin, and tenascin with and without transforming growth factor (TGF)‐&agr;/fibroblast growth factor (FGF)‐2 stimulation and the effect of soluble tenascin and fibronectin on corneal fibroblast migration on collagen‐I‐coated wells were investigated. Results: The cytokines TGF‐&agr; and FGF‐2 stimulated migrational activity of corneal stromal cells in a dose‐dependent manner, reaching the maximum effect at 100 ng/mL and 10 ng/mL, respectively. The migration of corneal fibroblasts on fibronectin was significantly higher (P < .05) than the migration on collagen I. Transforming growth factor‐&agr; and FGF‐2 increased radial cell displacement independent of the provided matrix composition. Tenascin had a negative effect on corneal fibroblast adhesion/migration in this in vitro model. Conclusion: Fibronectin and tenascin influenced corneal fibroblast migration and adhesion, respectively, and may play a role in stromal cell movement during wound healing. The cytokines TGF‐&agr; and FGF‐2 had an additive effect on corneal fibroblast migration on a fibronectin matrix.

Immunohistochemical detection of estrogen and progesterone receptor in human cornea

OBJECTIVE For treatment of postmenopausal keratoconjunctivitis sicca hormone therapy is favored by some clinicians. The likely morphological basis assessing the hormone receptor status in the human cornea has not been performed. Immunohistochemical staining methods provide the opportunity to evaluate the hormone receptor content within the histologic compartments of the cornea. The aim of our study was to assess and localize immunohistochemical hormone receptor staining in the human cornea. METHODS Formalin-fixed and paraffin-embedded specimens of three pre- and three postmenopausal women were assessed for localization of estrogen receptor (ER) and progesterone receptor (PR) expression with established immunohistochemical hormone receptor staining methods. RESULTS No nuclear staining reaction was found in the epi- and endothelial layers of the corneas. The stroma of the corneas showed no immunohistochemical staining reaction in all cases. We found cytoplasmatic PR staining of the endothelial layer in two cases. CONCLUSIONS We found no morphological basis in the human cornea for the use of topical steroid hormone treatment in postmenopausal keratoconjunctivitis sicca. Hormone receptor expression in the conjunctiva or in the lacrimal gland may have an impact in some patients showing relief of symptoms in postmenopausal dry eye syndrome.

Impact of Growth Factors on Morphometric Corneal Endothelial Cell Parameters and Cell Density in Culture-preserved Human Corneas

Purpose Donor corneas can be preserved for ≤4 weeks in organ culture (31°C) by using modified minimal essential medium (MEM). About one fifth of them have to be discarded, however, as disintegration of the endothelial cell monolayer— enhanced polymegethism, cell loss—occurs. The objective of this study was to investigate whether addition of insulin, dextran, and epidermal growth factor (EGF) makes corneal endothelial cells more viable, stable, and homogeneous. Methods Sixteen paired human donor corneas were cocultured in media supplemented with EGF and insulin-like growth factor (IGF) or in conventional modified MEM for 4 weeks. Endothelial parameters were evaluated at the outset and at days 7, 14, 21, and 28 of culture by using an automated digital image-analysis system. Results No significant differences were observed in the first 2 weeks of culture. Beginning with day 14, however, stabilization of endothelial cell patterns was evident for corneas cultured in supplemented culture media. Conclusion Our data indicate that the addition of growth factors to culture media might increase the percentage of corneas available for transplantation and would also allow a significantly longer period of preservation.

Biocompatibility of a nonpenetrating synthetic cornea in vascularized rabbit corneas

Purpose: This study was designed to assess feasibility and biocompatibility of a lamellar, nonperforating supraDescemetic Synthetic Cornea (sDSC) implanted in rabbit eyes after a corneal injury. Methods: Corneal vascularization and scarring was induced in the right eye of 15 rabbits by application of 1-heptanol and complete surgical removal of the limbus. An sDSC (7-mm diameter, 450-μm-thick optical zone, 100-μm-thick outer flange) was implanted after 45 ± 5 days. The keratoprostheses were implanted with their central optic part positioned on a completely exposed Descemets membrane (DM) while the outer flange was located in deep stroma. Three different materials were tested: hydrophobic PMMA (n = 5) and hydrophilic HEMA-MMA (n = 5) and HEMA-NVP (n = 5) with a water content of 34% and 75%, respectively. The corneal surface was covered with a conjunctiva-Tenon flap. Central flap trephination was performed after 63 ± 7 days. DM vascularization and scarring was assessed and graded after flap opening and weekly thereafter. Results: In all 15 consecutive cases implantation could be completed successfully without perforation of DM. Repair of the conjunctival flap had to be performed in five rabbits. Four months postoperatively, the flaps were opened. Four of five corneas (80%) with a PMMA implant and three of five (60%) with a HEMA-NVP75 implant had retained their original transparency. The others had developed significant neovascularization in the Descemet-sDSC optic interface. All corneas (100%) that received an sDSC made of HEMA-MMA34 displayed a completely clear DM without any vessels or scarring. DM was found firmly attached to the posterior surface of the optic. Conclusion: Implantation of a nonperforating synthetic cornea on top of an exposed DM is feasible. HEMA-MMA34 showed the most promising results. Because opening of the anterior chamber is not required, a lamellar supraDescemetic Synthetic Cornea would theoretically reduce some of the risks attributed to penetrating keratoprostheses.

Ten-year follow-up of epikeratophakia for the correction of high myopia

OBJECTIVE To determine the long-term functional results of epikeratophakia for myopic patients. DESIGN Retrospective, noncomparative, interventional case series. PARTICIPANTS Twenty-two patients (32 eyes; average age, 43+/-6 years) who underwent epikeratophakia surgery for high myopia. Mean preoperative myopia was -18.74+/-9.16 diopters (D; range, -7 D to -49 D). Follow-up was 12+/-2 years. MAIN OUTCOME MEASURES Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), change in mean keratometry, visual acuity under glare conditions, BCVA versus potential acuity meter reading, and patient satisfaction with the visual outcome. RESULTS Mean preoperative UCVA increased from 20/800+/-20/400 (range, counting fingers-20/400) to 20/80+/-20/200 (range, 20/250-20/32) in 24 eyes. Mean preoperative BCVA of 20/32+/-20/64 increased only in five eyes, whereas six eyes had no change and 18 eyes had a more than one line loss of Snellen BCVA. Mean preoperative keratometry reading decreased from 43.67+/-0.90 D (range, 41.0-46.25 D) to 37.40+/-2.92 D (range, 29.43-47.68 D). In the presence of glare, mean BCVA decreased to 20/100+/-20/100 (range, counting fingers-20/32). Potential acuity meter (PAM) readings were significantly (P<0.05) higher than BCVA. Mean PAM reading was 20/25+/-20/100 (range, 20/100-20/16). Seven patients (11 eyes) were extremely satisfied with the operative result more than 10 years after the operation, whereas four patients (four eyes) were not satisfied at all. CONCLUSIONS Epikeratophakia for the correction of myopia improved UCVA significantly, but BCVA decreased. The removal of the lenticules in patients who were not satisfied with their visual acuity was uncomplicated, and acceptable vision could be achieved with either contact lenses or intraocular lens implantation.

Three dimensional polarization sensitive optical coherence tomography of normal and pathologic human cornea

Polarization sensitive optical coherence tomography (PS-OCT) is a functional extension of optical coherence tomography (OCT). We used phase resolved PS-OCT to measure and image three dimensional birefringent properties of pathologic and non pathologic human corneas and compare the results. Knowing the retardation and optic axis distribution might be useful information for early detection of different corneal diseases.

Influence of laser in situ keratomileusis and laser epithelial keratectomy on patients' reading performance

PURPOSE: To evaluate the influence of laser in situ keratomileusis (LASIK) and laser‐assisted subepithelial keratectomy (LASEK) on reading performance regarding reading acuity, reading speed based on print size, maximum reading speed, and critical print size. SETTING: Department of Ophthalmology, University of Vienna, Vienna, and Auge‐und‐Laser, Medicent Baden, Austria. METHODS: Fifty‐two eyes of 34 patients (26 eyes per group) were studied. Best corrected LogMAR visual acuity (Early Treatment Diabetic Retinopathy Study charts), reading acuity, and reading speed were tested monocularly before LASIK or LASEK and 3 weeks after surgery. Reading acuity (LogRAD) and reading speed were determined with the standardized Radner reading charts. RESULTS: Preoperatively, the distance visual acuity and reading acuity were comparable between the LASIK and LASEK patients. Reading speed measurements also showed no statistical difference. Three weeks after refractive surgery, no statistically significant differences in the preoperative measures and between the 2 surgical procedures could be found in any tested parameters. The mean distance visual acuity was LogMAR −0.02 ± 0.06 (SD) (LASIK) and LogMAR −0.05 ± 0.07 (LASEK). The mean reading acuity was LogRAD 0.00 ± 0.12 (97.7% of LogMAR) (LASIK) and LogRAD 0.04 ± 0.16 (93.7% of LogMAR) (LASEK). The mean maximum reading speed was 235 ± 35 words per minute (LASIK) and 240 ± 37 words per minute (LASEK), and the mean critical print size was at LogRAD 0.48 ± 0.19 (LASIK) and 0.49 ± 0.17 (LASEK). CONCLUSIONS: In a standardized reading test setting, no significant effects of LASIK and LASEK on individual reading performance could be evaluated. This indicates that patients can expect to retain their normal visual function after refractive surgery with these 2 procedures under full light conditions.

Laser shaping of corneal transplants in vitro: area ablation with small overlapping laser spots produced by a pulsed scanning laser beam using an optimizing ablation algorithm

Area laser lathing and trephination of donor corneas is used to produce different types of grafts for human transplantation. 193 nm (ArF excimer) laser radiation is used, since this is known to give a non-thermal laser-tissue interaction with a minimal zone of tissue damage. To guarantee the highest degree of flexibility concerning the overall shape of the grafts as well as their thickness profiles, we use a small (compared with the area to be ablated) scanning laser spot. For area lathing of the tissue we have developed a new ablation algorithm (optimized scanning laser ablation, OSLA) that can be applied to lathe and perforate any tissue--with concave (as in this application), convex or plane surface geometry--where surface precision and smoothness are key issues. Using OSLA with the Excimer Laser Corneal Shaping System (a tool for in vitro fabrication of all kinds of corneal transplants like donor buttons for keratoplasty, lamellar grafts for epikeratoplasty and refractive lenticules) enabled us to produce all types of corneal grafts with very high precision. This is considered to be a major improvement towards the production of refractive lenticules.