Abstract
Purpose::
To quantitatively evaluate the influence of unilateral small incision cataract surgery on eye position and binocular visual function.
Methods::
In this case series, 68 eyes of 68 consecutive patients with unilateral age-related cataract underwent phacoemulsification (PEA) and intraocular lens (IOL) implantation. No patient had ocular disease in fellow eye. The surgery was performed with topical anesthesia, superior sutureless scleral incision, PEA, and implantation of foldable acrylic IOL. Visual acuity, eye position, and stereoscopic acuity were measured preoperatively and 1 week postoperatively. Eye position and stereoscopic acuity was measured by alternating prism cover test and by Titmus Stereo Test, respectively. A period of subjective visual disturbance was estimated preoperatively.
Results::
The mean preoperative deviation of exophoria/tropia at near was 12.3 ± 4.0 prism diopters (PD). It decreased to 10.8 ± 3.1 PD postoperatively (Paired-t, p<0.0001). The mean preoperative deviation at distance was 1.9 ± 2.9 PD, which decreased to 1.1 ± 1.9 PD postoperatively (Paired-t, p=0.0011). Stereoscopic acuity was significantly improved by surgery (Wilcoxon signed-rank, p<0.0001). The preoperative visual acuity of the affected eye showed a significant correlation with the preoperative deviation both at near and at distance (Pearson correlation coefficient, r = 0.293, p = 0.016, at near / r = 0.454, p<0.0001, at distance). There was no significant correlation between the period of subjective visual disturbance and the change in eye position (r = -0.136, p = 0.52).
Conclusions::
In patients with unilateral cataract, the eye position and binocular visual function are considerably compromised before surgery, which are significantly improved by cataract surgery.
Keywords: small incision cataract surgery • binocular vision/stereopsis • strabismus