未累及黄斑区的缺血型视网膜分支静脉阻塞眼底激光治疗前后对比敏感度的变化

Analysis of contrast sensitivity before and after fundus laser treatment for ischemic branch retinal vein occlusion without involving macular region

摘要:

目的观察未累及黄斑区的缺血型视网膜分支静脉阻塞（BRVO）患者眼底激光治疗前后对比敏感度（CS）的变化情况。方法收集38 眼未累及黄斑区的缺血型BRVO患者进行眼底激光治疗，并观察3 个月，分别测试激光治疗前及治疗后1 和3 个月的矫正视力及空间频率为1.5、3、6、12、18 周/ 度（c/d）处的CS。CS两组间的比较采用两独立样本检验，CS 及矫正视力的多组间比较采用单因素方差分析，组间多重比较方差齐性时采用LSD检验，方差不齐性时采用Dunnett’s T3 检验。结果所有患者激光治疗后3 个月通过眼底荧光血管造影（FFA）检查证实显效的20 眼（52.63%），有效13 眼（34.21%），无效的5 眼（13.16%），总共治疗有效33 眼（86.84%）。所有患者激光治疗前及激光治疗后1 和3 个月与对照组比较，差异有统计学意义（P <0.05），各空间频率下的CS 降低。激光治疗后1 个月与激光治疗前比较，差异有统计学意义（P <0.05），各空间频率CS降低。激光治疗后3 个月与激光治疗前及激光治疗后1 个月在12c/d、18c/d空间频率下比较，差异有统计学意义（P <0.05）。激光治疗后CS 降低值在患者性别及年龄分组比较，差异无统计学意义（P >0.05）。将BRVO 按阻塞部位、范围及非灌注区面积分组比较激光治疗后CS 降低值，差异有统计学意义（P <0.05），显示阻塞部位在颞侧及阻塞范围较大、非灌注区面积较大的患者在激光治疗后在高频区（12c/d、18c/d）CS 降低较多。随访3 个月，BRVO 患者激光治疗后与未进行激光治疗的患者比较，差异有统计学意义（P <0.05），各空间频率下的CS 降低，特别是12c/d、18c/d空间频率下CS 降低明显。结论眼底激光治疗是治疗缺血型BRVO 的有效方法，但是激光治疗对于患者视网膜功能也是一种损伤，可造成未累及黄斑区的缺血型BRVO 患者CS 下降，尤其是高频区CS。

Abstract:

Objective To observe the change of contrast sensitivity (CS) before and after fundus laser treatment for ischemic branch retinal vein occlusion (BRVO) without involving the macular region. Methods Thirty-eight eyes with ischemic BRVO without involving the macular region received fundus laser treatment and were observed for 3 months. The CS with the spatial frequency of 1.5, 3, 6, 12 and 18 weeks/degree (c/d) and the corrected visual acuity were tested before and 1 and 3 months after laser treatment. The CS in the two groups was compared with two independent samples -test. The CS and the corrected vision were compared among multiple groups using the analysis of variance (ANOVA), and compared between two groups using LSD test in case of homogeneity of variance but using Dunnett's T3 test in case of nonhomogeneity of variance. Results Confirmed by FFA 3 months after treatment, laser treatment was markedly effective for 20 of 38 eyes (52.63%), effective for 13 eyes (34.21%), and ineffective for 5 eyes (13.16%) ; the total effective rate was 86.84% (33/38). Before treatment and 1 and 3 months after laser treatment, the CS at each spatial frequency decreased in all patients compared with the control group with statistical differences (P < 0.05). The CS at each spatial frequency decreased 1 month after laser treatment compared with that before treatment, the differences were statistically significant (P < 0.05). The CS at the spatial frequency of 12 c/d and 18 c/d decreased 3 months after laser treatment compared with that before treatment and 1 month after laser treatment with statistical differences (P < 0.05). After laser treatment, there were no significant differences in the CS reduction among different gender or age groups. Grouping BRVO according to obstruction location, range and non-perfusion area, the CS reduced, the reduction was more obvious at high frequency (12c/d and 18c/d) in the patients with obstruction on the temporal side, a larger blocking range or a larger non-perfusion area, the differences were statistically significant (P < 0.05). After follow-up for 3 months, the CS at each spatial frequency reduced in the BRVO patients with laser treatment compared to those without laser treatment, particularly at high frequency (12c/d and 18c/d), the differences were statistically significant (P < 0.05). Conclusions Fundus laser treatment is an effective method for ischemic type BRVO. However, laser treatment is also a damage to retinal function of the patients, and can cause CS decrease in the ischemic BRVO patients without macular involvement, especially the CS in high frequency region.