Evaluating relative accommodations in general binocular dysfunctions

Abstract

Purpose. To examine the relationship between relative accommodation and general binocular disorders and to establish their importance in the diagnosis of these anomalies. Methods. We analyzed data of negative relative accommodation (NRA) and positive relative accommodation (PRA) in 69 patients with nonstrabismic binocular anomalies. Results. Statistical analysis showed that low values of NRA and PRA were not associated with any particular disorder. High values of PRA (>3.50 D) were related to the disorders associated with accommodative excess, whereas high values of NRA (>2.50 D) were not related to accommodative excess. Statistical differences suggested that a high value of PRA could distinguish between anomalies. Sensitivity analysis revealed that high PRA was the most sensitive sign in patients with convergence insufficiency combined with accommodative excess (0.89) and one of the most sensitive signs for subjects with accommodative excess (0.72) and for those with convergence excess combined with accommodative excess (0.70). Conclusions. Anomalous results of NRA were not clearly associated with any dysfunction. High values of PRA were related to disorders associated with accommodative excess, so the sign of a high value of PRA should be considered as one of the diagnostic signs of these anomalies.