Visual function before and after photorefractive keratectomy for myopia.
BACKGROUND
To date, Snellen visual acuity and postoperative refraction have been used to evaluate the results of photorefractive keratectomy. However, other parameters, such as contrast sensitivity function and glare, may be affected by refractive surgery and lead to unsatisfactory visual performance. This prospective study is aimed at evaluating the effect of photorefractive keratectomy on contrast sensitivity function and glare.


METHODS
Static contrast sensitivity function, dynamic contrast sensitivity function, and glare sensitivity were evaluated in 22 myopic eyes before as well as 1, 3, and 6 months after photorefractive keratectomy. The eyes tested were divided into three groups, according to the amount of myopia: group I, from -4.00 to -8.00 diopters (D); group II, from -8.25 to -11.00 D; group III, from -11.25 to -20.00 D.


RESULTS
Both static and dynamic contrast sensitivity function at the intermediate spatial frequencies were altered at 1 month after photorefractive keratectomy, with a trend toward recovery at 3 and 6 months postoperatively. Glare sensitivity was not significantly affected by surgery.


CONCLUSIONS
Contrast sensitivity function and glare testing may show abnormalities in the presence of optimal visual and refractive results. These tests may result especially important for the evaluation of new refractive surgical procedures.
Ambrosio
G
G
Università degli Studi di Napoli--Federico II, Facoltà di Medicina e Chirurgia, Istituto di Oftalmologia, Italy.
Cennamo
G
G
De Marco
R
R
Loffredo
L
L
Rosa
N
N
Sebastiani
A
A
D000293:Adolescent; D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology; D003315:Cornea / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D053685:Laser Therapy; D008027:Light; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology* / Q000601:surgery*; D011446:Prospective Studies; D012542:Scattering, Radiation; D014786:Vision Disorders / Q000503:physiopathology; D014785:Vision, Ocular / Q000502:physiology*; D014792:Visual Acuity