Abstract
Introduction: When exploring horizontal version movements, the pathways integrating Slow Eye Movements (SEMs) are analyzed, and when exploring pupil behavior, the pupillary pathway is analyzed. In healthy patients, the horizontal version trajectory is concomitant and the difference in size between both pupils is usually not significant, however, in Congenital Esotropia (CE), differences can be significant.
Objective: Identify if the type of horizontal incomitance is related to the degree of anisocoria in CE.
Materials and Methods: A prospective, cross-sectional, and experimental study was conducted on patients diagnosed with CE from Querétaro, Mexico. Infrared Video-oculography was performed under scotopic conditions (0.3 lux). Signs of congenital stigma such as Dissociated Vertical Deviation (DVD) and Latent Nystagmus (NL) were sought; likewise, the type of Horizontal Incomitance (IH) was classified according to motor behavior. Pupil area was measured using Voxel-based morphometry (VBM) and anisocoria was classified. The results were statistically analyzed.
Results: 53 patients aged 5 to 14 years were recruited: 22 boys and 31 girls. 21 patients presented with DVD and 25 with NL. All patients showed abduction limitations to varying degrees. IH had an incidence of 0.698, NL 0.471, DVD 0.396, Passive Horizontal Incomitance (PHI) 0.377, Active Horizontal Incomitance (AHI) 0.320, and No Horizontal Incomitance (NHI) 0.301.
Discussion: Both anisocoria and incomitance occur in CE. It is the first time the type of horizontal incomitance has been related to the degree of anisocoria. The analysis suggests a relationship between anisocoria and the type of incomitance, establishing differences between forms with and without Ciancia of CE. This contributes to decision-making and guides diagnosis, as well as prognosis.