Abstract
Purpose :
Stereotesting booklets vary in their mode of interocular separation, range of disparities, inter-element separation, target size, and whether or not they contain monocular depth cues. This study compared the effects of simulated anisometropia and asymmetric cataract on stereothresholds measured with TNO, Random-Dot, Randot3, and Titmus Stereofly stereotests.
Methods :
Stereothresholds of healthy participants aged 18-40 years were measured two consecutive times using four stereotesting booklets, under three conditions; baseline, +2.00DS monocular blur (simulatng anisometropia), and monocular neutral density (ND) filter (simulating asymmetric cataract), in random order. Mann-Whitney U tests compared between the conditions.
Results :
The mean stereothresholds of thirty-one participants (90% female, mean age: 21.03±1.50 years) were significantly higher (all p<0.001) when measured with the TNO stereotest for all testing conditions (normal: 67”, blur: 382”, ND: 398”). Stereothresholds with the Randot3 (normal: 15”, blur: 70”, ND: 183”) were significantly lower than the Random-Dot (normal: 26”, blur: 171”, ND: 84”) and Fly (normal: 29”, blur: 72”, ND: 145”) for the normal condition, and the Random-Dot and TNO for the ND condition. Randot3 and TNO were significantly affected by monocular blur. Random-Dot and TNO were significantly affected by the monocular ND filter.
Conclusions :
Higher stereothresholds measured with the TNO may be due to binocular asymmetries imposed by the anaglyphic inter-ocular separation. Lower stereothresholds measured with the Randot3 may be a floor effect, as this booklet measures the lowest stereothresholds. The TNO was most impacted by induced binocular vision disorders and is recommended for clinical use.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.