[The use of confocal corneal microscopy in the Cogan microcystic dystrophy diagnosis and follow-up of the ultrastructural changes after phototherapeutic keratectomy].

Unlabelled: Confocal microscopy represents modern, non-invasive, semi-contact examination method making possible to visualize separate corneal layers (from the endothel to the epithel) in high resolution. Phototherapeutic keratectomy (PTK) is a method using argon-fluoride laser with 193 nm wavelength to treat corneal surface diseases.

Aim: To evaluate the use of confocal microscopy for epithelial basal membrane dystrophy diagnosis (Cogan microcystic dystrophy) and following corneal ultra-structural changes in vivo after PTK.

Material And Methods: The group consisted of 14 eyes of 9 patients (6 men and 3 women) of average age 45.8 +/- 14.4 years who underwent in the department in last two years phototherapeutic keratectomy for recurrent erosion in Cogan microcystic corneal dystrophy. For the diagnosis of this disease, the confocal corneal microscope (Confoscan 4, Nidek, probe x 40) was used. Computer controlled laser photoablation was in all patients performed; the average depth was 14.8 +/- 3.3 microm (Technolas 217, Bausch & Lomb). The follow-up visits were scheduled always day 5 and 12, and month 1, 3, 6, and 12 after the PTK. The reactive processes in all corneal layers, the subepithelial inervation restoration velocity and recurrence of the primary disease detectable by means of the confocal corneal microscope were followed-up.

Results: Cogan microcystic dystrophy was diagnosed in all followed-up patients by means of confocal microscope according to the findings of the area thickening and corneal epithelium basal membrane irregularities. These patients were indicated to the PTK. After the treatment, the healing of the epithelial layer was finished as early as the fifth day. The subepithelial nervous plexus average regeneration period was 6.2 +/- 2.8 months. In all patients, the edema of the anterior stroma was found at the day 5. The beginning of the re-popularization of the anterior stroma by keratocytes from deeper layers we diagnosed, on average, at the day 11.5 +/- 1.9 after the treatment and the following reduction after 5.1 +/- 1.4 months. In the posterior stroma and in the endothel, no changes were found. During the follow-up period, in none of the followed-up patients, the recurrence of the primary disease was found.

Conclusion: The confocal microscopy may be recommended for superficial corneal dystrophies quality and accurate diagnosis and to follow up changes after phototherapeutic keratectomy as suitable treatment method of these diseases.