光学相干断层扫描在判断垂体瘤患者术后视功能预后中的应用

Predicting visual function after treatment of pituitary adenomas with optical coherence tomography

目的应用光学相干断层扫描（OCT）测量视网膜神经纤维层（RNFL）厚度，探讨其在判断垂体瘤患者术后视功能预后的作用。方法选取2007年1月至2008年12月经蝶窦垂体腺瘤切除术病理检查、MRI确诊的垂体瘤伴视交叉压迫患者16例（32眼），其中男性7例，女性9例，年龄23—67岁，平均（44．4±14．71岁。在术前、术后1周、术后3个月，分别采用标准对数视力表、Stratus OCT Ⅲ和Humphrey视野分析仪．检测患者的矫正视力、平均RNFL厚度、4个象限的RNFL厚度和视野指数平均缺损（MD）。根据术前视野缺损情况及随访变化，将研究对象分为3组：A组即术前有视野缺损，术后视野缺损无改善或加重；B组即术前有视野缺损，术后视野缺损改善；C组为术前及术后均无视野缺损。对所得数据进行相关统计学分析。结果16例（32眼）患者中，A组10眼，B组11眼，C组11眼。术前有视野缺损者，平均RNFL越厚，视野缺损改善的比例越大（OR=1．189，P=0．020）；下方RNFL厚度对视野缺损改善有显著影响fOR=6．093，P=0．000），而术前MD对术后视野缺损改善无显著影响（OR=0．955，P=0．509）。术后1周及术后3个月，B组的视力均较术前提高（t=3．893，P=0．003；t=4．310，P=0．002），而A组和C组视力较术前差异均无统计学意义。术后3个月，A组平均RNFL厚度及颞侧RNFL厚度均较术前变薄（t=-2．378，P=0．041；（t=-2．630，P=0．025），而上方、下方及鼻侧RNFL厚度较术前差异均无统计学意义：B组的平均RNFL厚度、鼻侧及颞侧RNn．厚度均较术前增厚（t=2．438，P=0．035；t=2．630；Pl-0．025；t=4．457，P=0．001）；C组平均RNFL厚度及4个象限RNFL厚度手术前后差异均无统计学意义。结论运用OCT检测垂体瘤患者的平均RNFL厚度及下方RNFL厚度，可作为判断患者术后短期视功能预后的较敏感指标：手术前后RNFL厚度的变化与视野缺损的变化具有较好的一致性。

Objective To assess if optical coherence tomography （OCT） can provide objective measurements of the thickness of the retinal nerve fiber layer （RNFL） in patients with pituitary adenomas, offering a dependable prediction of visual function. Methods Thirty-two eyes of 16 consecutive patients who visited our hospital between January 2007 and December 2008 and were diagnosed with pituitary adenomas compressing the chiasma as determined by magnetic resonance imaging （MRI） were included in the study. All patients underwent transsphenoidal resection of pathologically proven pituitary adenomas by the same surgeon. The patient group consisted of 7 males and 9 females, and the mean age of the patients was （44.4±14.7）years （range 23-67 years）. Visual acuity, automated visual fields （VF） and OCT （fast-RNFL program） were assessed before treatment, and 1 week and 3 months after treatment. RNFL thickness was measured with the Stratus OCT m and mean deviation （MD） visual field （VF） with the automated Humphrey Field Analyzer （both from Carl Zeiss Meditec, Dublin, CA）. Eyes were divided into 3 groups based on the initial VF defect and its evolution. The presence of an initial VF defect in group A either without improvement or had worsened 3 months after treatment, the presence of an initial VF defect in group B with improvement 3 months after treatment, and group C without VF defect either initially or after treatment. Covariance analysis was applied to analyze the data for the mean RNFL measurements and the initial VF defect in the groups. A logistic regression model was used to evaluate the prognostic value of the initial VF defect and the RNFL thickness on the final visual outcome. A paired samples t-test was used to compare preoperative visual acuity and mean RNFL thickness with postoperative visual acuity and thickness. Results For all patients （32 eyes）, there are 10 eyes in group A, 11 eyes in group B and 11 eyes in group C. In the eyes with a VF defect before treatment, a greater mean RNFL thickness increased the probability of improvement from the initial VF defect （OR=1.189, P=0.020）. Inferior RNFL was a very strong prognostic factor （OR=6.093, P=0.000）, but the effect of the initial VF defect did not reach significance （OR=0.955, P=0.509）. At 1 week and 3 months, respectively, after group B was treated, visual acuity improved （t=3.894, 4.310; P=0.003, 0.002）. At 3 months after treatment, both the mean RNFL and temporal RNFL were thinner （t=-2.378, -2.630; P=0.041, 0.025） in group A, and the mean RNFL, the nasal RNFL and temporal RNFL were thicker （t= 2.438, 2.630, 4.457; P=0.035, 0.025, 0.001） in group B. In group C there was no significant difference between preoperative and postoperative RNFL thickness. Conclusion Mean RNFL thickness and inferior RNFL thickness measured by OCT are prognostic factors influencing the short-term prognosis of pituitary adenomas compressing the chiasma. The change between pre-and postoperative RNFL thickness seems to be consistent with the VF defect.