Creating consistency in the diagnosis of convergence insufficiency: screening methods

Purpose: To determine the sensitivity of various clinical tests in the diagnosis of convergence insufficiency.

Methods: A total of 254 patients were recruited with complaints consistent with convergence problems but no prior history of strabismus surgery, eye exercises, prism use, recent concussion, or other ocular or neurological diseases. Each patient completed the convergence insufficiency symptom survey (CISS), and the following data were collected: ocular alignment at distance and near, convergence and divergence fusional amplitudes at distance and near, near-point of convergence (NPC) using an accommodative target and red lens, and assessment of quality of convergence movement (QoCM) and quality of fusional movements (QoFM). The sensitivity of each clinical test was calculated.

Results: Measurement of NPC using red lens and subjective assessment of the QoCM and QoFM were the most sensitive diagnostic tools for near symptoms consistent with convergence insufficiency: 93.3%, 98.4%, and 94.5% respectively. CISS score, convergence fusional amplitude at near, and exophoria at near had lower sensitivities: 62.9%, 46.0%, and 72.0%, respectively. Although the majority of our patients had a heterophoria or heterotropia at distance (96.8%) and/or near (98.8%), most presented with only small phorias. Furthermore, of those who had a deviation at near, only 22% had the near exophoria exceeding the distance exophoria by 10^Δ.

Conclusions: In our study cohort, NPC with red lens and subjective assessment of QoCM and QoFM proved to be the most sensitive screening tools for near symptoms consistent with convergence insufficiency.