The study of the application value of graph retinal electrogram in macular disease

Objective To establish the medical reference range of pattern electroretinogram (PERG) measurement parameters in our laboratory. To evaluate the changes of macular function in patients with macular diseases by PERG. Methods The clinical data of 21 cases (29 eyes) with maculopathy who have visited Guang zhou Aier Eye Hospital and 68 cases (68 eyes) with normal eyes and no other ocular diseases were collected from January 2013 to March 2014 for our prospective controlled study. All normal subjects were included in the control group. The control group was divided into two subgroups according to age and naked vision. The naked vision ≥1 and 45 years of age or older subjects were divided into ≥45 years old group; the naked vision ≥0.8 and younger than 45 years subjects were divided into <45 years old group. All patients with maculopathy were treated as macular disease group. Patients with maculopathy were divided into two subgroups according to age and best corrected visual acuity. Among them, the best corrected visual ≥0.1 and younger than 45 years patients were divided into <45 years old group; the best corrected visual ≥0.1 and 45 years of age or older subjects were divided into ≥45 years old group. Normal subjects in the control group and the patients with maculopathy were detected with the same PERG. The PERG measurement parameters of peak latency of N35 wave, P50 wave and N95 wave and the peak amplitude of P50 wave and N95 wave were recorded for all subjects. The 2.5%~97.5% percentile of each measurement parameters of 2 age groups in the control group were used as the medical reference range of PERG in our laboratory. Abnormal rate of PERG measurement parameters in patients with maculopathy were calculated. PERG measurement parameters of normal subjects in the control group and patients in the macular disease group were described by median and 2.5%~97.5% percentile. PERG measurement parameters between control group and macular disease group in corresponding age group were compared using Mann-Whitney test. Results The PERG measurement parameters in our laboratory are following. For ≥45 years old people, peak latency of N35 wave, P50 wave and N95 wave were 29.00~32.50 ms, 50.00~58.40 ms and 93.50~112.90 ms respectively, and the peak amplitude of P50 wave and N95 wave were 1.14~3.30 μV and 3.41~9.61 μV; for 0.05). Comparing the peak amplitude of P50 wave and N95 of macular disease group with the control group, the peak amplitude of P50 wave and N95 of macular disease group in each age were lower than the normal group, the differences were statistically significant [ 45 years old group (Z=8.17, 5.88; P<0.05)]. Conclusion PERG can objectively reflect the changes of macular function in patients with maculopathy, which is simple, fast and safe, especially suitable for the elderly and children. Key words: Macular; Pattern electroretinogram; Electrophysiology