Global Ophthalmology and Glaucoma Conference

Glaucoma is the 2nd most common cause of blindness worldwide. It is the most common irreversible cause of vision loss. Definition of glaucoma has changed over a period of time. In 1960, glaucoma is a condition characterized by raised IOP, optic nerve head changes and visual field defects. In 1980, it is an optic neuropathy characterized by ONH changes, visual fields with IOP as a risk factor. In 2004, glaucoma is recognized and defined by changes in the optic nerve head and RNFL as a result of a characteristic acquired loss of retinal ganglion cells. Diagnostic tools such as Anterior segment evaluation, Gonioscopy,

Ophthalmoscopic examination, IOP, Stereoscopic ONH photograph, NFL photography, Fields, Imaging techniques are used. There are various disadvantages of each technique. C/D ratio is not reliable (tremendous variability in the size of normal disc), Photography has relatively high inter-observer and intra-observer variability: Subjective psychophysical test; Automated perimetry. It demands high degree of performance by patient. VF damage was a relatively late phenomenon, and has 30- 45% death rate of RGC to produce a demonstrable field defect. It is not sufficient to diagnose “Pre perimetric glaucoma”. So a technology that assesses the health, structure and thickness of RNFL is clearly the most appropriate choice to diagnose and follow glaucoma. In this presentation, I will be discussing the principle, techniques, interpretation, advantages and disadvantages of each imaging technique and also will compare each of them.