1Postgraduate in MD Physiology (2012–15 batch), Upgraded Department of Physiology; Osmania Medical College, Hyderabad, Telangana, India
2Prof, Upgraded, Department of Physiology; Osmania Medical College, Hyderabad, Telangana, India
3Prof& HOD, Upgraded, Department of Physiology; Osmania Medical College, Hyderabad, Telangana, India
Online published on 11 February, 2016.
The aim of the study is to evaluate the retinal function, especially ganglion cell functional changes in macula in individuals with high myopia using Pattern Electroretinogram(PERG).
Recording axial length &PERG in 128 eyes of 64 individuals (4 groups)with myopia.
-Comparing PERG wave amplitudes among individuals with low & high myopia
-Comparing PERG wave latencies & correlating axial length changes with PERG waveforms
Total of 64 subjects were included in the study of 18–30 years age group of both sexes. The subjects were divided into 4 groups according to refractive error as
Group-1(controls): 0 D to-0.75D
Group-2: -1.00 to-3.00D
Group-3: -3.25 to-6.00D
Group-4: -6.25 to-10.00D
Statistical analysis was done using window stat software version 9.2 applying ANOVA test& unpaired t-test. Axial lengths of both the eyes of 64 subjects were recorded using A scan ultrasonography.
Amplitudes & latencies of P50 & N95 waves of PERG were recorded using RETIMAX CSO EQUIPMENT following ISCEV GUIDELINES for PERG 2012 update.
P50 & N95 wave amplitudes were lower in high myopes than low myopes(group2, 3, 4 compared to group 1)(p<0.001)
-P50 wave latencies were prolonged in individuals in group2, 3, 4 compared to group1(p<0.001)
-N95 wave latencies were prolonged in group 3, 4 compared to group 1(control group)
Decreased P50 amplitude indicates a macular functional disorder in subjects with high myopia & decreased N95 amplitude shows ganglion cell dysfunction. Thus the PERG findings show that macular &ganglion cell disorder contributes to decreased visual performance in myopia.
Myopia, Electroretinogram, Pattern Electroretinogram, Macula, Ganglion cell function
