Intraoperative correction of induced astigmatism after spherical correction of hyperopia with conductive keratoplasty.
OBJECTIVE
To evaluate the treatment of surgically induced astigmatism intraoperatively during conductive keratoplasty (CK) for correcting hyperopia.


METHODS
Conductive keratoplasty uses radiofrequency energy applied to the peripheral corneal stroma to shrink the collagen and alter the central cornea to correct hyperopia. Nineteen consecutive patients (27 eyes) who underwent CK for hyperopia and were treated intraoperatively for induced astigmatism were examined. By using automated keratometric readings taken during the procedure, additional spots were applied at the minus cylinder or flat axis at the 7-mm zone until the intraoperative astigmatism was 2 diopters (D) or less.


RESULTS
The intraoperative treatment reduced the astigmatism by an average of 2.30 +/- 1.32 D (P=0.00001). The mean induced astigmatism was 3.33 +/- 0.14 D for eyes that received eight spots, 4.12 +/- 1.13 D for eyes that received 16 spots, 4.43 +/- 0.82 D for eyes that received 24 spots, and 4.60 +/- 1.08 D for eyes that received 32 spots. Additional spots reduced astigmatism in most patients to less than 2 D.


CONCLUSIONS
Intraoperative treatment of astigmatism through the addition of more spots at the minus cylinder or flat axis reduced the degree of induced astigmatism. Surgically induced astigmatism was observed more frequently in patients who received 32 treatment spots and 6-mm treatment zone application.
Haji
Shamim A
SA
Department of Ophthalmology, Mount Sinai School of Medicine, New York, NY 10029, USA.
Ramonas
Krista
K
Potapova
Natalia
N
Wang
George
G
Asbell
Penny A
PA
D001251:Astigmatism / Q000209:etiology / Q000601:surgery*; D003315:Cornea / Q000601:surgery*; D019781:Corneal Topography; D004564:Electrocoagulation / Q000379:methods*; D006801:Humans; D006956:Hyperopia / Q000601:surgery*; D007430:Intraoperative Care; D007431:Intraoperative Complications; D012189:Retrospective Studies; D014792:Visual Acuity