Name

Mesure de l'acuité visuelle dans deux conditions de polarité différentes : lettres noires sur fond blanc et lettres blanches sur fond noir

To compare the visual acuity while reading a text under different contrast conditions: black letters on white background (BoW condition) versus white letters on black background (WoB condition).

We conducted a prospective observational study, which included 53 patients who consulted an ophthalmologist during November 2018. Visual acuity of the eye while reading a text with BoW or WoB contrast polarity was obtained objectively with a Monoyer Test after optical correction.

Visual acuity was measured in logmar.

Our primary endpoint was the difference of visual acuity between both tests in logmar.

We had 53 patients (50% women) with a mean age of 61 years (SD 15). Among the 106 eyes, 53 were phakic (50%), and 53 pseudophakic with mono-focal implant (50%), 12 (11%) had atrophic DMLA, 24 (22%) were treated for glaucoma, 6 (5%) have been treated with refractive surgery. The intra ocular pressure was 15 mmHg (SD 5). The analysis shows a difference of - 0.005 logmar p (<0.001) with the WoB condition in 27% of the eyes analyzed.

We showed an increase in visual acuity while reading white letters on a black background. However, the difference remains small. The small percentage of patients with ocular pathology leads to selection bias. A second study on patients with low visual acuity should be performed.

Visual acuity seems better on a WoB condition with a statistically significant difference.

However, this difference seems to have little impact on clinical practice.

It seems interesting to evaluate this difference in visual acuity in patients with low vision.