Faculty Bibliography

A 73-year-old woman with 3 years of monocular visual distortion and progressive binocular diplopia. She was found to have a comitant left hypertropia due to an epiretinal membrane causing inferior foveal drag. Displacement of the fovea from an epiretinal membrane is a likely under-recognized cause ocular cause of a comitant binocular diplopia.

OBJECTIVE:The Mobile Universal Lexicon Evaluation System (MULES) is a test of rapid picture naming that captures extensive brain networks, including cognitive, language and afferent/efferent visual pathways. MULES performance is slower in concussion and multiple sclerosis, conditions in which vision dysfunction is common. Visual aspects captured by the MULES may be impaired in Parkinson's disease (PD) including color discrimination, object recognition, visual processing speed, and convergence. The purpose of this study was to compare MULES time scores for a cohort of PD patients with those for a control group of participants of similar age. We also sought to examine learning effects for the MULES by comparing scores for two consecutive trials within the patient and control groups. METHODS:MULES consists of 54 colored pictures (fruits, animals, random objects). The test was administered in a cohort of PD patients and in a group of similar aged controls. Wilcoxon rank-sum tests were used to determine statistical significance for differences in MULES time scores between PD patients and controls. Spearman rank-correlation coefficients were calculated to examine the relation between MULES time scores and PD motor symptom severity (UPDRS). Learning effects were assessed using Wilcoxon rank-sum tests. RESULTS: = 0.37, P = .02). Learning effects were greater among patients with PD (median improvement of 14.8 s between two MULES trials) compared to controls (median 7.4 s, P = .004). CONCLUSION/CONCLUSIONS:The MULES is a complex test of rapid picture naming that captures numerous brain pathways including an extensive visual network. MULES performance is slower in patients with PD and our study suggests an association with the degree of motor impairment. Future studies will determine the relation of MULES time scores to other modalities that test visual function and structure in PD.

Accurate detection and interpretation of eye movement abnormalities often guides differential diagnosis, discussions on prognosis and disease mechanisms, and directed treatment of disabling visual symptoms and signs. A comprehensive clinical eye movement examination is high yield from a diagnostic standpoint; however, skillful recording and quantification of eye movements can increase detection of subclinical deficits, confirm clinical suspicions, guide therapeutics, and generate expansive research opportunities. This review encompasses an overview of the clinical eye movement examination, provides examples of practical diagnostic contributions from quantitative recordings of eye movements, and comments on recording equipment and related challenges.

Keynote at the 20th European Conference on Eye Movement Research (ECEM) in Alicante, 20.8.2019. Video stream: https://vimeo.com/357889739.