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Movement detection threshold and ocular hypertension
1Department of Ophthalmology, University Hospital of Wales, Cardiff, UK. eaansari@aol.com
Purpose:
To determine whether patients with ocular hypertension (OH) have elevated oscillatory movement displacement thresholds (OMDT) indicative of early neural damage.
Methods:
Evidence of early neural loss was sought using OMDT. The OMDT of 29 normotensive individuals were compared with those obtained from 44 untreated age-matched OH eyes (20 male, 24 female).
Results:
A mean OMDT at 15 sec arc at 40 years of age was obtained in normotensive individuals, the age trend increasing by about 4 sec arc per decade. About one-third of all ocular hypertensives (13 cases; 6 male, 7 female), who were dismissed without treatment, exhibited abnormal OMDT. An equal proportion of abnormal thresholds were observed in individuals in each decade, although the age trend diverges from that established for normotensives with increasing age. Mean OMDT for ocular hypertensives (37.1 sec arc) were significantly different (t = 2.7, p < 0.007) from the mean obtained from normotensives (22.2 sec arc).
Conclusion:
The results emphasise the need for more rigorous differentiation of OH using psychophysical techniques indicating early neural damage.