Clinical Results of Penetrating Keratoplasty in Keratoconus

We conducted a retrospective study of 45 penetrating keratoplasties (39 patients) for keratoconus from March 1986 to February 1991 at St. Mary's Hospital, Catholic University Medical College. The follow-up period was at least over 1 year. The penetrating keratoplasties were performed most commonly in the interval between 1 and 5 years after the diagnosis of keratoconus (25 patients; 64.1%). The hard contact lenses were the most commonly used for visual correction before penetrating keratoplasty. Corneal scar was the most common indication for keratoplasty (35 eyes: 77.8%). The most common postoperative complication was loose suture (14 eyes; 31.1%). Overall, 43 out of the 45 corneal transplants (95.6%) remained clear and these eyes attained best-corrected visual acuity of 0.5 or better.

Influence of VDT Work on Accommodative Function

In order to observe the influence of visual display terminal (VDT) work on accommodative function, we measured accommodative power, accommodative constriction time and accommodative response / accommodative stimulus ratio (Ar / As) by infrared optometer on 15 normal subjects who were not exposed to VDT work before. VDT task was programed to search a specified Korean alphabet letter among randomized letters for 90 minutes. After VDT task, accommodative constriction time was prolonged, near point extended and accommodative power decreased in all subjects (p<0.05, by paired t-test). After resting for 30 minutes, constriction time, near point and accommodative power had a tendency to return to the previous normal value. Accommodative response / accommodative stimulus ratio (Ar / As) was decreased according to the duration of VDT work but no statistical difference was found between before and after VDT work. From this study, it is suggested that the function of accommodation seems to be affected by VDT work.