Basic and translational neuro-ophthalmology of visually guided saccades: disorders of velocity

Abstract

Introduction: Saccades are rapid, yoked eye movements in an effort to direct a target over fovea. The complex circuitry of saccadic eye movements has been exhaustively described. As a result clinicians can elegantly localize the pathology if it falls on the neuraxis responsible for saccades. Traditionally saccades are studied with their quantitative characteristics such as amplitude, velocity, duration, direction, latency and accuracy. Areas covered: Amongst all subtypes, the physiology of the visually guided saccades is most extensively studied. Here we will review the basic and pertinent neuro-anatomy and physiology of visually guided saccade and then discuss common or classic disorders affecting the velocity of visually guided saccades. We will then discuss the basic mechanism for saccade slowing in these disorders. Expert commentary: Prompt appreciation of disorders of saccade velocity is critical to reach appropriate diagnosis. Disorders of midbrain, cerebellum, or basal ganglia can lead to prolonged transition time during gaze shift and decreased saccade velocity.

Response times for reflexive saccades correlate with cognition in parkinson's disease, not disease severity or duration

“…As the final common pathway for both reflexive and voluntary saccades, the SC is involved in initiation and inhibition of saccades and activity of the SC is negatively related to saccade latency. The stronger the activity, the faster eyes move to the target, thus the shorter the latency will be (12,24,25). Excessive inhibition of the SC may have resulted in the abnormal reflexive saccades in the PD group in our study.…”

Manifestasi Neurooftalmologi pada Penyakit Parkinson dan Gangguan Gerak Lainnya

“…Degenerasi saraf pada PD adalah di ganglia basalis dengan beberapa gejala klinis khas seperti bradikinesia, tremor, postur tubuh tidak stabil, hipomimia (wajah seperti memakai topeng), peningkatan tonus otot, sehingga terjadi kekakuan gerak persendian (rigiditas). 5 Keluhan okular pada pasien PD dapat berupa Gambar 1. Algoritma penyakit gangguan gerak yang berhubungan dengan gangguan gerak bola mata.…”