Inadvertent corneal burn by using indirect wide-field contact lenses and different laser beam delivery systems during experimental fundus photocoagulation.
OBJECTIVE
At fundus photocoagulation by using a wide-field indirect contact lens, the laser radiant exposure may be increased at the anterior segment of the eye. We examined the likelihood of producing inadvertent corneal burn by using parfocal and sharped edge defocus laser delivery systems with various indirect contact lenses.


METHODS
The two laser delivery systems were used with four lenses of different viewing angles during fundus photocoagulation in a total 44 eyes of rabbits.


RESULTS
By using the lenses, the parfocal system increased corneal radiant exposure more than did the sharped edge defocus system. By using the Widefield PRP 165 lens of the widest viewing angle, there was no difference between the two systems in the corneal burns produced.


CONCLUSIONS
Some indirect contact lenses used in combination with the parfocal system caused inadvertent corneal burns more readily than did the same lenses in combination with the sharped edge defocus system.
Department of Ophthalmology, Osaka City University Medical School, Osaka, Japan.
K
K
Shiraki
M
M
Moriwaki
T
T
Kohno
N
N
Yanagihara
T
T
Miki
D000818:Animals; D002056:Burns / Q000209:etiology*; D003261:Contact Lenses / Q000009:adverse effects*; D065306:Corneal Injuries; D017075:Laser Coagulation / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D008028:Light Coagulation / Q000009:adverse effects / Q000379:methods; D011817:Rabbits; D012160:Retina / Q000601:surgery*