Related Experiment Videos
Treatment of hyperopia with contact Ho:YAG laser thermal keratoplasty
C A Eggink1, Y Bardak, M H Cuypers
1Institute of Ophthalmology, University Hospital Nijmegen, The Netherlands.
Purpose:
To evaluate the effectiveness, safety, and stability of contact Ho:YAG laser thermal keratoplasty for low to moderate hyperopia.
Methods:
Fifty-five hyperopic eyes of 39 patients were treated with a Technomed contact Ho:YAG laser; 23 eyes were treated a second time. Treatment parameters were 1 octagonal ring of 8 spots with a treatment diameter of 6 mm, 7 mm, or 8 mm. Efficacy of the Ho:YAG laser treatment was evaluated after 6 months, comparing 3 treatment zone diameters. Stability and efficacy after 12 months was evaluated comparing 7-mm and 8-mm treatment zone diameters.
Results:
Mean reduction of spherical equivalent refraction after 6 months was not statistically significantly different between the 6-mm or 7-mm diameter zones: 1.42 (+/- 1.30) D versus 2.22 (+/- 0.44) D. An 8-mm diameter treatment zone was significantly less effective, 1.12 (+/- 0.47) D. Longer follow-up did not show stability: mean reduction of spherical equivalent manifest refraction was 1.58 (+/- 0.45) D for the 7-mm diameter treatment zone and 0.82 (+/- 0.61) D for the 8-mm diameter treatment zone after approximately 12 months. Retreatment had a limited additive effect. No clinically significant loss of spectacle-corrected visual acuity was reported. No eyes lost more than 1 line of visual acuity.
Conclusion:
Contact Ho:YAG laser thermal keratoplasty corrected hyperopia up to 2.50 D, but predictability was poor and a regression of initial effect occurred. Instability of refraction persisted to 1 year after surgery.