Objective To evaluate the variability of four parameters of multi-focal electroretinogram (mERG) a-wave amplitude, b-wave amplitude, awave latent period, b-wave latent period. Methods Sixty normal eyes of 46 volunteers were divided into 3 groups of different ages. RETIscan 3-12 system was used to carry out mERG examination. The stimulus matrix of 61 hexagonal elements spanning the central 24deg;of the visual field. These hexons were scaled with eccentricity and divide d into 5 rings. First-order kernel was selected. Results The variability of four parameters of mERG was great. The variability of b-wave latent period was the smallest, its coefficient of variatian was 4.52%～15.62%；that of a-wave latent period held the second place:10.29%~48.67%；that of b-wave amplitude was greater:25.92%~76.11%；that of a-wave amplitude was the greatest:43.82%~88.23%. The results of three groups showed that b-wave amplitude of ring 1 had the smallest variability. Conclusions The variability of latent period is smaller than that of amplitude; the variability of b-wave was smaller than that of a-wave. The longer the centrifugal distance, the lower the amplitude density of a-wave and b-wave. Physiological and anatomical factors might be important for the variability of parameters of multi-focal electroretinogram. (Chin J Ocul Fundus Dis, 2001,17:277-279)
ObjectiveTo evaluate the efficacy of 30% and 50% dose photodynamic therapy (PDT) for acute central serous chorioretinopathy (CSC). MethodsA retrospective cohort study. Ninety-two eyes of 88 patients with CSC, diagnosed by best corrected visual acuity (BCVA) of logarithm of the minimum angle of resolution (logMAR), indirect ophthalmoscope, fundus colorized photography, fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA)and optical coherence tomography (SD-OCT) treated with 30% and 50% doses of verteporfin respectively between March 2007 and August 2013, were enrolled. The eyes were divided into 50% dose group (49 eyes) and 30% dose group (43 eyes). The differences of age (t=-1.45), gender (χ2=0.011), eyes (χ2=2.140), mean logMAR BCVA (t=-0.40), mean central retinal thickness (CRT) and the maximum thickness of serous retinal detachment (SRD) between two groups were not significant (P > 0.05). The difference of spot size between two groups was significant (t=-2.84, P < 0.05). The follow-up time was ranged from 6 to 68 months, with a mean of (17.16 ±11.30) months. The difference of follow-up between two groups was significant (P > 0.05). The BCVA, cure rate, recurrence rate and the changes of CRT and maximum SRT were observed by SD-OCT. ResultsThe subretinal fluid (SRF) of 31 eyes (72.09%) in the 30% dose group and that of 47 eyes (95.92%) in the 50% dose PDT group was absorbed completely respectively. The cure rates in the 30% dose PDT group was significantly less than that in the 50% dose group (χ2=10.077, P=0.020). There was a significant negative association between the cure rate and spot size by Logistic regression (odds ratio > 1, P=0.040). The difference of changes in the BCVA of logMAR in 50% dose group was better than that in 30% dose group after more than 12 months after PDT (P=0.036). On 3, 6, 12 and more than 12 months after PDT, the difference in CRT in 50% dose group and 30% dose group were not statistically significant (P=0.068, 0.060, 0.082, 0.067). The difference in maximum thickness of SRD was not statically significant (P > 0.05). SRF was appeared in 8 eyes (25.81%) of 31 eyes in the 30% dose group, while SRF was appeared in 1 eye (2.13%) of 47 eyes in the 50% dose group. The recurrence rate of 30% dose group was much higher than that of 50% dose group (P < 0.05). ConclusionsFor acute CSC treated by PDT, the curative effect of 50% dose group is better than the 30% dose group.