Phototherapeutic keratectomy for Schnyder's crystalline corneal dystrophy.

PURPOSE: To describe the treatment of Schnyder's crystalline dystrophy (SCD) with excimer laser phototherapeutic keratectomy (PTK).

METHODS: Chart review of three patients (four eyes) with SCD treated with PTK between March 1992 and December 1998. Pre- and posttreatment visual acuity, subjective glare, photophobia, manifest refraction, ultrasound pachymetry, hyperopic shift, and biomicroscopic findings were studied. Brightness acuity testing (BAT) was evaluated in two eyes.

RESULTS: Four eyes were treated during the study period. The average best corrected visual acuity (BCVA) improved from 20/175 to 20/40 under bright conditions. All patients reported subjective improvement in glare and photophobia. No visually significant recurrence was observed during the follow-up period which ranged from seven months to three years. The mean spherical equivalent refractive shift was +3.28 diopter (D). One patient developed irregular astigmatism from an eccentric ablation. No vision threatening complications were observed.

CONCLUSION: PTK can be effective at improving visual symptoms in patients with SCD. It can be a useful therapeutic alternative to lamellar or penetrating keratoplasty in these patients.