[Results of low-vision rehabilitation in vision impaired patients]. / Ergebnisse der optischen Rehabilitation mit vergrössernden Sehhilfen bei Patienten mit irreversibel visuslimitierenden Erkrankungen.

PURPOSE: Diseases of the retina, the optic nerve and the cornea may lead to a non-treatable loss of central vision. We report on low vision rehabilitation in 100 vision impaired patients. METHODS: Low vision rehabilitation was performed in 100 consecutive patients (61 % AMD, 23 % diabetic retinopathy, 16 % other diseases). Most of the patients were between 70 and 90 years old (78 %). In 62 cases we fitted optic systems for visual rehabilitation of the far distance (Galilei systems 54; Kepler systems 8), in additional 54 of them we fitted optic systems for the reading distance (additional lens 40; others 14; e. g. magnifier, television reader) and in 38 patients we fitted optic systems for visual rehabilitation only of the reading distance (magnifier 21, reading glasses with higher refraction and additional prism system 17). RESULTS: In 62 patients with low vision fitted with a system for the far distance we reached an increase of the visual acuity of more than one line in 95 %. In all 92 patients fitted with a system for the reading distance the reading of newspaper letters was possible. In 8 patients we could not fit a low vision systems due to handling difficulties. CONCLUSIONS: We could reach a satisfactory improvement of visual acuity in more than 90 % of the patients fitted for the far and the reading distance. Especially in elderly, vision impaired patients significant improvements in overall quality of life and specific areas of daily living are possible.

[Quantitative assessment of topographical parameters to differentiate keratoconus from pellucid marginal corneal degeneration and ]. / Quantitative Evaluierung topographischer Parameter zur Differenzierung von Keratokonus und pelluzidaler marginaler Hornhautdegeneration.

INTRODUCTION: The purpose is to compare videokeratometric data (Fourier series harmonic analysis and wave-front analysis) in eyes with ectatic corneal disease (keratoconus; pellucid marginal corneal degeneration [PMCD]) and to determine parameters for early diagnosis and distinction of keratoconus and PMCD. PATIENTS AND METHODS: 13 eyes with PMCD, 32 eyes with keratoconus and 18 healthy eyes were included. Computerized videokeratographic methods were assessed, using Fourier series harmonic analysis, Zernike coefficients and eccentricity. RESULTS: Irregular astigmatism (Fourier series harmonic analysis: decentration and/or irregularity) and the aberration coefficient were out of the normal range in all pathologic eyes. Both the nasal and the temporal eccentricities were greater than 0.63 in all PMCD patients, whereas either the superior or the inferior eccentricity was negative in all patients. In keraotoconic eyes, all quadrant eccentricities were positive and greater than 0.4. CONCLUSIONS: Irregular astigmatism and the aberration coefficient are useful parameters in detecting ectatic corneal disease using a computerized videokeratoscope. The calculation of the spherical equivalent (Fourier series harmonic analysis: no decrease of spherical equivalent in PMCD subjects) and of quadrant eccentricities are useful tools in distinguishing PMCD and keratoconus.

Contact lenses and special back surface design after penetrating keratoplasty to improve contact lens fit and visual outcome.

AIMS: To describe the fitting of patients with high or irregular astigmatism following penetrating keratoplasty with contact lenses and to answer the question whether or not contact lenses with special back surface design can improve visual acuity in complex cases after penetrating keratoplasty. METHODS: 28 eyes were included. They were fitted with contact lenses with a special back surface that was designed for optical rehabilitation after penetrating keratoplasty. Four different types of these lenses (tricurve, keratoconus, reverse, oblong) were used selectively depending on abnormal eccentricity determined by videokeratoscope. The patients were followed up for an average period of 15.5 months. Lens tolerance and corrected visual acuity were evaluated and compared with that corrected with spectacles. RESULTS: The visual acuity was significantly improved in nearly all eyes with an average increase of 3.6 lines (maximal nine lines) accompanied by good contact lens tolerance and satisfactory contact lens fit. No noticeable complications were observed. CONCLUSION: Contact lenses with special back surface design can improve visual results and lens tolerance, and minimise problems in contact lens fitting. This is in favour of contact lenses as an alternative to surgical procedures for correction of high or irregular astigmatism after penetrating keratoplasty. This procedure is recommended especially in cases of patients who decline further operative interventions.