Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
Invest Ophthalmol Vis Sci. 2012 Feb 13;53(2):659-63. doi: 10.1167/iovs.11-8525. Print 2012 Feb.
To investigate progressive changes of retinal ganglion cell (RGC) function in glaucoma suspects before and after IOP-lowering treatment.
The authors retrospectively analyzed pattern electroretinograms (PERG) recorded twice a year in 32 glaucoma suspects over at least 6 years. Fifteen patients (28 eyes in the study group) received IOP-lowering treatment at intermediate points during the follow-up, thereby generating a break point between the untreated period and the treated period. Seventeen patients (31 eyes in the control group) were not treated; a break point in the follow-up period was randomly assigned. To assess the effect of treatment, linear regression slopes of PERG amplitude were calculated for periods before and after the break point, and compared both within and between groups. Linear mixed models applied to raw PERG amplitudes recorded over the entire follow-up period were also calculated.
Before the break point, slopes had a similar negative trend in both groups, whereas after the break point the slope became shallower in the treated group (P = 0.002). The linear mixed model revealed an interaction between groups, period relative to break point, and segment duration (P = 0.001). Both analyses agreed that after the break point, the rate of PERG amplitude decline slowed in treated eyes by 0.013-0.019 μV/year compared with the untreated eyes. Mean IOPs measured before and after break point were similar in control eyes (14.8 ± 3.20 vs. 14.8 ± 3.14 mm Hg) but different in treated eyes (16.84 ± 3.96 vs. 14.8 ± 3.24 mm Hg; P < 0.001).
Progressive loss of RGC function in early glaucoma may be alleviated after IOP lowering, as measured by PERG.
研究降眼压治疗前后青光眼疑似患者的视网膜神经节细胞（RGC）功能的进行性变化。
作者对至少 6 年内每年两次记录的 32 例青光眼疑似患者的图形视网膜电图（PERG）进行了回顾性分析。15 例患者（研究组 28 只眼）在随访期间的中间点接受了降眼压治疗，从而在未治疗期和治疗期之间产生了一个断点。17 例患者（对照组 31 只眼）未接受治疗；在随访期间随机分配了一个断点。为了评估治疗效果，在断点前后分别计算 PERG 幅度的线性回归斜率，并在组内和组间进行比较。还对整个随访期间记录的原始 PERG 幅度应用线性混合模型进行了计算。
在断点之前，两组的斜率都有类似的负向趋势，而在断点之后，治疗组的斜率变浅（P = 0.002）。线性混合模型显示组间、相对于断点的时间段和节段持续时间之间存在交互作用（P = 0.001）。这两种分析都表明，在断点之后，与未治疗的眼睛相比，治疗的眼睛的 PERG 幅度下降速度减慢了 0.013-0.019μV/年。对照组眼睛在断点前后测量的平均眼压相似（14.8 ± 3.20 与 14.8 ± 3.14mmHg），但治疗组眼睛的眼压不同（16.84 ± 3.96 与 14.8 ± 3.24mmHg；P < 0.001）。
PERG 测量表明，早期青光眼的 RGC 功能进行性丧失可能在降眼压后得到缓解。
