Comparative analysis of various Automated Perimeters.

Ranjit Prabhu, D (2006) Comparative analysis of various Automated Perimeters. Masters thesis, Madras Medical College, Chennai.


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INTRODUCTION: The visual field is that portion of space in which objects are simultaneously visible to the steadily fixating eye. It is somewhat more than one half of a hollow sphere situated before & around each eye of the observer. Visual field: “An island hill of vision surrounded by a sea of blindness: Traquair” Advocated by Bjerrum, Ronne, Sinclair, Walker, Traquair, Harrington, Goldmann, Friedman, Humphry, Allen robin & Mark Liberman. The hill island is oval, with a regular coastline rising abruptly from the sea, in precipitous cliffs. These cliffs are surrounded by a sloping plateau that rises toward an eccentrically placed summit, which in turn slopes steeply upward to a needle like peak. Beside the summit, is a pit or well that extends downward to the level of the sea. This is the blind spot. The limits within which an object of a certain size can be seen by the normal observer can be surveyed on the hill as a contour line and plotted on a map or chart. These are the isopters of the normal field. A thorough and complete medical history, visual acuity, a careful physical examination including confrontation perimetry are needed before a perimetry is done. The instruments & techniques available to measure the visual fields vary from the very simple to the extremely complex. No one method is the best for all patients under all circumstances. The modern perimetrists must have the working knowledge of many methods to choose the most appropriate test for each patient. In the established glaucoma cases the global indices is arrived at doing visual field plotting with all 3 perimeters are comparable. In early glaucoma cases the defects are better recognized by using FDT. Since the sample size is small correlation was not calculated. It could be taken that considering early detection of fields and portability of the machine, FDT could be recommended for glaucoma screening programmes. CONCLUSION: 1. Visual field plotting by Octopus TOP takes lesser time. 2. In established glaucoma patients the global indices of 3 perimeters are comparable. 3. FDT can be used for screening purpose to detect early glaucoma changes.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Automated Perimeters; Comparative analysis
Subjects: MEDICAL > Ophthalmology
Depositing User: Subramani R
Date Deposited: 04 Jul 2017 00:53
Last Modified: 01 Aug 2017 09:08

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