Purpose:The goal of this
study was to compare differences in the mean heterophoria and fusional
amplitudes before and after photorefractive keratectomy (PRK) for myopia.
Methods:In a prospective
controlled study, myopic patients were treated with aspheric and
wavefront-guided (personalized) PRK. The manifest refraction, visual acuity,
fusional amplitudes and heterophoria were evaluated preoperatively and at three
and six months postoperatively. Fusional amplitudes were measured at far (six
meters) and near (40 centimeters) by rotary prism and heterophoria was
evaluated at nearby Maddox wing.
Results: A total of 48 cases
(96 eyes, 68.75% female) were treated, with a mean age of 26.70±4.89 years (18-34
years). In the fusional reserves, comparisons between preoperative and six
months postoperative means showed that far and near convergence reserves (or
base out recovery points)and near divergence
(or base in recovery point) were decreased significantly (p-values were 0.013,
0.002 and 0.008, respectively). In heterophoria
measurements, contrary to the rest of the deviations, exophoria was increased,
but not significantly (p=0.063).
Conclusion: Findings of this
study imply that far and near convergence amplitude (or base out reserves) were
decreased significantly after keratorefractive surgery (KRS). The other
fusional reserves were similarly decreased at three months postoperatively and
returned to the preoperative values at six months.
Etezad Razavi M, Zarei-Ghanavati S, Gharaee H, Eslampour A, Abrishami M. Heterophoria and Fusional Reserves Changes after Photorefractive Keratectomy for Myopia. Iranian Journal of Ophthalmology. 2014; 26 (2) :87-91 URL: http://irjo.org/article-1-920-en.html