“Glaucoma an optic neuropathy is a caused by progressive retinal ganglion cell(RGC) loss associated with characteristic structural changes in the optic nerve and retinal nervefiber layer (RNFL).Glaucoma induced damage causes the retinal ganglion cells loss that canresult in functional loss and decrease in vision of patient . Measurement of intraocular pressureby Tonometery, characteristics of the optic nerve head changes and associated visual fieldloss are used for diagnosis of Glaucoma. Objectives: To determine the diagnostic accuracy ofOptical Coherence Tomography in detection of glaucoma taking perimetry as gold standard.Study Design: Cross sectional (validation). Period: Six months from 17-02-2014 to 16-08-2014.Material and Method: Regarding the Inclusion Criteria patients of glaucoma suspects that meetthe criteria mentioned in operational definition of either gender with age range between 35- 60years were included while patients having refractive errors, hazy media, pupil size less than4mm after dilation were not included in this study. Also patients with history diabetes mellitus,refractive or retinal surgery were also excluded. All the data was entered and analyzed by usingSPSS V-16. Results: A total of 100 patients were included in this study during the study period.Majority of the patients were between 35-45 years of age and minimum patients were 56-60 years old. Mean age of the patients was 47.10±8.02 years. Males and females were 50(50%). At OCT glaucoma was present in 71 patients while at perimetry glaucoma was presentin 69 patients .Sensitivity, specificity and diagnostic accuracy of OCT was 92.7%, 77.4%, 88.0%,respectively .Positive predictive value and negative predictive value of OCT was 90.1% and82.7%, respectively. Discussion: Regarding the pathogenesis of Glaucoma induced damageis due to result of retinal ganglion cell (RGC) death with progressive loss of axons located inthe retinal nerve fiber layer (RNFL). Many clinical studies showed that optic nerve head (ONH)damage and thinning of the RNFL occur earlier than the appearance of Glaucoma inducedvisual field defects; Conclusion: In conclusion, glaucoma suspects undergoing the OCT canbe assessed for the presence of glaucoma based purely on the results of the OCT.
Microvascular Density Is Associated With Retinal Ganglion Cell Axonal Volume in the Laminar Compartments of the Human Optic Nerve Head
