Posters

Pinhole test better predicts the postoperative visual acuity than potential acuity meter

Poster Details

First Author: A.Grzybowski POLAND

Co Author(s):    M. Gaca-Wysocka   J. Oleaniewicz                 

Abstract Details

Purpose:

To evaluate post-surgical visual acuity the Potential Acuity Meter (PAM) and the Pinhole Test (PHT) can be used. The PAM uses imaging of interference fringes to the retina based on the theory of double-slit interference of light. On the other hand, the PHT is based on retinal transmission of central rays of light that do not require refraction, increasing the eye�â�€�™s depth of focus and decreasing the light scattering effect of lenticular opacities. We aimed our study to compare the accuracy of the PAM and the simple modification of the PHT in predicting visual acuity after cataract surgery.

Setting:

Dept. of Ophthalmology, ul. Szwajcarska 3, 61-285 Poznan, Poland

Methods:

We used Heine retinometer. During the PHT the patient was given a pinhole ocular with 1 mm aperture on the eye with the cataract. The ETDRS charts were presented at distance of 1.5 m from the patient. As the patient correctly recognized bigger letters, smaller optotypes were presented. A complete examination was performed before operation and 6 weeks after cataract surgery. This prospective case series included 33 patients with mild to moderate cataract. Inclusion criteria were patients undergoing phacoemulsification with intraocular lens implantation and no coexisting ocular disease and with VA better than 0.1.

Results:

The difference in logMAR forecasted after six weeks from surgery by the means of PHT versus the baseline measurement was statistically significant (p < 0,001), whereas that forecasted through retinoscopy was statistically insignificant (p = 0,089). The effect size measured, Cohen�â�€�™s D, amounted to: D = 2,776 for PHT; and D = 0,478 for retinoscopy. The Lin�â�€�™s concordance correlation coefficient between VA after surgery and according to PHT was moderate, �Ï�c = 0,310; between VA after surgery and according to retinoscopy was fair, �Ï�c = 0,161; between retinoscopy versus the PHT was very poor, �Ï�c = 0,080.

Conclusions:

In our study the Pinhole Test gave more accurate results than the Potential Acuity Meter. The Potential Acuity Meter more frequently underestimated the visual outcome and was more sensitive to cataract hardness. Moreover, the Pinhole Test is easy to perform and based on simple and inexpensive tools, like pinhole occluder and ETDRS charts.

Financial Disclosure:

NONE