Acute symptomatic posterior vitreous detachments do not adversely affect contrast sensitivity

Abstract

Purpose : Vitreous floaters and posterior vitreous detachments (PVD) are common. With the growing interest in performing vitrectomy for symptomatic patients, there is a need to objectively identify who will benefit from invasive management. Some studies have suggested that contrast sensitivity (CS) in eyes with PVD is reduced and may account for disturbances in activities of daily living. This study aims to evaluate patients with unilateral acute symptomatic PVD to determine if there is evidence of reduced CS during the highly symptomatic phase of a PVD.

Methods : This is a case control study with paired statistics comparing two eyes of the same patient. All patients underwent a complete ophthalmologic examination. Inclusion was based on the presence of a clinical PVD in one eye, evidenced by a Weiss ring or a visibly detached posterior hyaloid on dilated ophthalmoscopy. The presence of any concurrent ocular pathology or bilateral PVD excluded the patient. Contact B-scan ultrasonography and optical coherence tomography were used to verify the presence and absence of a PVD in the involved and fellow eyes, respectively. Best corrected visual acuity (BCVA) was obtained by subjective refraction. CS test was performed under standard conditions using Freiburg Contrast and Acuity Test (FrACT) and Pelli-Robson for peak and low spatial frequencies, respectively.

Results : Twenty consecutive patients with a mean age of 63 ± 4.46 years were included. The median BCVA was 20/20 in both eyes (p=0.46). The mean refraction was -1.07D ± 2.90 and -1.15D ± 2.67 (p=0.815) in the involved and fellow control eyes, respectively. Eyes with PVD had a higher mean CS on the low spatial frequency CST, the fellow control eyes had a higher mean CS on the peak spatial frequency CST. The mean CS was 2.71 ± 0.99 %W and 1.71 ± 0.14 logCS in the involved , and 2.68 ± 0.93 %W; 1.67 ± 0.10 logCS in the fellow control eye using the FrACT (%W) and Pelli-Robson (logCS) tests. The mean difference in CS between paired eyes (0.03 %W and 0.04 logCS) was not statistically significant (p=0.815; 0.387).

Conclusions : Contrast sensitivity is not affected by the presence of a structurally confirmed acute symptomatic PVD. This suggests that CS is not a useful objective marker to determine the impact of a symptomatic floater on quality of vision. It is therefore unsuitable to use CS tests to evaluate visual improvement after surgery for symptomatic PVDs.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.