Jasmine Kalyani, S.Saravanan, Jason Ambrose, Ravi, Shankaranarayanan
Background: Eye is a biologic camera gifted to us and ocular movement is a very easy task but provides useful information regarding the diagnosis of parkinsonian disorders. Some interpretation of the abnormalities are highly characteristic of a specific disease i.e., progressive supranuclear palsy, oculogyric crisis in post encephalitic Parkinson’s but many are nonspecific .symptoms of parkinsonism regarding the eye are nonspecific. Retina contains dopamine, hence the ocular symptoms like astenopia are common in PD. This study has been done with a purpose of providing an overview of eye movement abnormalities in Parkinsonism.
Materials and methods: 100 patients attending neurology OPD diagnosed as Parkinson’s disease and Parkinson plus syndromes. Demographic details, detailed history, ocular signs and symptoms, ocular deviation, visual acuity, diagnosis, and management aspects were extracted from the medical records. Visual acuity by Snellen values. Ocular deviation was measured by prism cover test, and ocular motility was carried out to evaluate the gaze limitation. A diagnosis of CI was made if Near Point of Convergence (NPC) value was larger than 10 cm. Saccade and pursuit scores evaluated using the Northeastern State University College of Optometry method was used to determine if they were lower than the age expected norms. Color vision was assessed using Ishihara pseudo isochromatic plates. Reading speed was measured in Words Per Minute (wpm) based on reading a simple paragraph in an English magazine for a minute. Developmental Eye Movement (DEM) rate was calculated based on the time taken for the vertical and horizontal tasks on the DEM test. Protocol of eye movement examination was followed
Conclusions: Parkinsonian group of disorders are a unique group that in most of the cases eye movement gets affected and we get a valuable clue for the diagnosis. The most frequently affected include saccades, smooth pursuit and fixation. Asthenopia-Decreased vision associated with reading difficulty was common in PD patients. In terms of gaze restriction, vertical gaze involvement) was more than horizontal involvement Convergence Insufficiency (CI) was the most common binocular vision dysfunction ,followed by CI with oculomotor dysfunction and vertical gaze palsy. Ground prisms were recommended for few patients and home vision therapy for few patients as corrective measures.