Corneal morphology and sensitivity in lattice dystrophy type II (familial amyloidosis, Finnish type).

PURPOSE: To describe the corneal abnormalities and to measure different modalities of corneal sensitivity in corneal lattice dystrophy type II (familial amyloidosis, Finnish type, also known as gelsolin-related amyloidosis and originally as Meretoja syndrome). METHODS: Twenty eyes of 20 patients were examined by in vivo confocal microscopy and noncontact gas esthesiometry. RESULTS: Pleomorphism of, and dense deposits between or posterior to, the basal epithelial cells were frequently observed, as well as a reduction of long nerve fiber bundles in the subbasal nerve plexus. The anterior stroma was altered in most cases, with fibrosis and abnormal extracellular matrix. In 15 corneas, thick anterior and midstromal filaments, corresponding to lattice lines, and in 11 corneas, thin undulated structures were observed. The average mechanical sensitivity threshold of 12 subjects was increased, and in the remaining 8 subjects there was no response, even to the highest intensity of stimuli used. Three patients did not respond to CO(2), 11 to heat, and 2 to cold, but those patients who responded had normal thresholds. Patients with more long nerve fiber bundles per confocal microscopic image had better mechanical and cold sensitivity than patients with fewer nerve fiber bundles. CONCLUSIONS: Lattice lines seem to be related to amyloid material and not to corneal nerves. However, the subbasal nerve density appears reduced, which results mainly in a decrease in mechanical and, to a lesser extent, thermal sensitivity. The location of stromal filaments and undulated structures changes with increasing age.

Photorefractive keratectomy in ophthalmic residents.

PURPOSE: To find out how ophthalmologists themselves experience the correction of myopia after photorefractive keratectomy. Visuomotor functions were of special interest. METHODS: Four ophthalmology residents and one medical engineer underwent photorefractive keratectomy for myopia. Objective measurements including refraction, corneal topography, perimetry, contrast sensitivity, pattern visual evoked potentials, in vivo confocal microscopy, and a car driving simulator test were performed preoperatively, postoperatively, and at 6 months. Subjective evaluation was reported. RESULTS: Performing ophthalmological examinations and microsurgery without spectacles was easier postoperatively and was appreciated by the four ophthalmology residents. Minimal haze formation, good accuracy, and normal performance in the car driving simulator were also observed. Visual fields, contrast sensitivity, and pattern visual evoked potentials did not show changes. Negative observations included postoperative pain for 2 to 4 days, dry eye symptoms, a period of anisometropia between operations, and hypersensitivity of the lids. CONCLUSIONS: The four ophthalmic residents were satisfied with the outcome of their refractive surgery. Low to moderate myopic correction did not affect the objective measurements of high and low contrast sensitivity, pattern visual evoked potentials, or simulated car driving in dark illumination.