Morphological evaluation of Schnyder's central crystalline dystrophy by confocal microscopy before and after phototherapeutic keratectomy.

A 29-year-old man with Schnyder's central crystalline dystrophy was treated with phototherapeutic keratectomy (PTK) in his right eye. Ocular examination revealed abnormal deposits of cholesterol and lipid within the corneal stroma (appearing as crystalline spindle-shaped deposits), high myopia, phakic anterior chamber intraocular lens implantation, and myopic macular degeneration in both eyes. Phototherapeutic keratectomy ablation to a central zone of 7.0 mm and a depth of 96 microm was performed with an Aesculap Meditec MEL-70 excimer laser. Confocal microscopy performed before PTK showed multiple deposits of large, brightly reflective crystalline material extending from the anterior to the mid stroma. The Z-scan curves revealed that the highest density of crystalline deposits was located within the first 140 microm of corneal depth. Six months after PTK, confocal microscopy showed a markedly decreased density of corneal crystalline deposits in the anterior stroma.

In vivo confocal microscopy of patients with amiodarone-induced keratopathy.

PURPOSE: To describe the corneal findings in patients with amiodarone-induced keratopathy by means of in vivo confocal microscopy. METHODS: Twenty-two eyes of 11 patients (eight men and three women) receiving amiodarone therapy and 20 eyes of 10 healthy sex-and age-matched control subjects were selected for confocal microscopic examination. The patients were examined by use of a scanning slit corneal confocal microscope (Confoscan 2.0). Five complete scans of the entire cornea were performed for each eye with a total examination time of less than 5 minutes. RESULTS: All patients receiving amiodarone showed the presence of high reflective, bright intracellular inclusions in the epithelial layers. These findings were more evident within the basal cell layers. In the eyes with advanced keratopathy (stages 2 and 3), bright microdots were detectable within the anterior and posterior stroma and on the endothelial cell layer. In the anterior stroma, the keratocyte density in the treated group was reduced compared with values of the control group (p < 0.001), and a markedly irregular aspect of the stromal nerve fibers was found. The main characteristic of this nerve irregularity was represented by the clew-shaped appearance of the nerve trunks. CONCLUSION: Detailed examination of corneal structure by confocal microscopy shows that amiodarone keratopathy in long-term treated patients presents some findings that are consistent with higher toxicity than was expected and that involve the deep corneal layers.

Effect of photorefractive keratectomy for myopia on measurement of retinal nerve fiber layer thickness using optical coherence tomography.

PURPOSE: To evaluate the effect of excimer laser photorefractive keratectomy (PRK) on nerve fiber layer thickness measurements by optical coherence tomography in myopic eyes. METHODS: Twenty-two patients who had PRK for myopia underwent nerve fiber layer measurement by optical coherence tomography in both eyes before and 6 months after surgery in the first operated eye and before surgery in the fellow (control) eye, 6 months after the first PRK. Optical coherence tomography was performed with a Humphrey Optical Coherence Tomography Scanner. Each eye was scanned at the nerve head program radius of 1.5. For each of the optical coherence tomography parameters (average for each quadrant, superior, inferior, temporal, nasal; average for each clock hour; average over the entire cylindrical section), descriptive statistics were calculated. The difference between the observed change from the first to the second examination was calculated between the treated and the control eye. Individual mean differences were tested with Student's t-test. Hotelling's T-squared generalized means test was used to determine whether the set of mean differences was equal to zero. RESULTS: The average preoperative refractive error was -3.90+/-1.50 D in treated eyes and -3.89+/-1.50 D in control eyes (P = .81, Student's t-test). Mean achieved refractive correction was 3.70+/-1.70 D, corresponding to 48.1+/-22.1 microm of corneal ablation. No statistically significant difference was found in any measurement in the treated eye compared with the untreated control eye. CONCLUSIONS: At 6 months postoperatively, photorefractive keratectomy for moderate myopia that resulted in clear corneas did not affect nerve fiber layer thickness measurements, as obtained by optical coherence tomography.