Optical Coherence Tomography Is Applied Research In The Pituitary

PartⅠOptical coherence tomography applied for measurement of retinal nerve fiber layer thickness in normal eyes.Objective:To evaluate RNFL thickness(quadrant type and mean) in the normal human eye as measured by optical coherence tomography(OCT) and determine the effects of age,gender,and eye on the RNFL.Methods:89 normal subjects(169 eyes) were included in this study. Peripapillary fast RNFL scans performed by OCT with a nominal diameter of 3.46mm centered on the optic disc were performed on each eye.The differences in RNFL thickness were analyzed with age,gender and either eye.Results:The mean RNFL thickness of the entire population was (89.62±11.68)μm, (140.58±12.30)μm, (87.04±12.06)μm, (141.38±13.20)μm and (113.20±10.44)μm (temporal,superior,nasal,inferior and the mean of the whole layer,respectively).We found a decrease in RNFL thickness with aging except nasal quadrant,and there were no significant differences between RNFL thickness of various quadrant and mean (P=0.154～0.829),gender and right or left eye(P=0.396～0.976).Conclusion:Normal RNFL thickness can be measured accurately by OCT. The elder of persons, the thinner of RNFL thickness. RNFL thickness was not related to gender and right or left eye. PartⅡOptical coherence tomography in measuring retinal nerve fiber layer thickness in pituitary tumorObjective:To evaluate the significance of the retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) in the diagnosis and prognosis of visual function of pituitary tumor.Methods:Thirty-nine pituitary tumor patients(39 eyes) of our hospital were included in the study from January, 2006 to June, 2008. All the patients were examined with both OCT and Standard Automated Perimetry(SAP). Seventy-six normal subjects(76 eyes) were also included in the study, and the thickness of RNFL was examined with OCT. Comparisons were made with regard to the RNFL thickness of quadrants and in means between normal and pituitary tumor group.The correlation between mean RNFL thickness and mean defect of visual field was also analyzed.Results:There was significant difference of RNFL thickness in various quadrants and in means between normal and pituitary tumor group (P<0.000).The mean RNFL thickness was positively correlated with mean defect of visual field (R=0.41,p<0.000).Conclusion: The objective thinning of retinal nerve fiber layer documented by OCT on the pituitary tumor patients is consistent with the visual field defects examined by Humphrey Perimetry. RNFL thickness measured by OCT provides a new method for the diagnosis of pituitary tumor. Part III Predicting visual function after treatment of pituitary adenomas with optical coherence tomographyObjective:To assess if optical coherence tomography (OCT), by providing an objective measures of the retinal nerve fiber layer (RNFL) thickness in patients with pituitary adenomas ,offers a dependable prediction of visual function.Methods:This was a prospective case series. Thirty-two eyes of 16 consecutive patients from our hospital suffering from pituitary adenomas compressing chiasma as determined by magnetic resonance imaging (MRI) were included between January, 2007 and December,2008.All patients underwent transsphenoidal resection of pathologically proven pituitary adenomas by the same surgeon. Automated visual fields (VF) and OCT (fast-RNFL program) were performed before treatment, and one week and three months after treatment. RNFL thickness was measured with the Stratus OCTⅢand mean deviation(MD) with the automated VF(Humphrey Field Analyzer, both from Carl Zeiss Meditec, Dublin, CA). The SPSS 13.0 software was applied to analyze data. Eyes were divided into three groups based on the initial VF defect and its evolution. Independent-samples t test was applied to analyze the date about age among the groups. Covariance analysis was applied to analyze the date about the means of RNFL measurements and of the initial VF defect among the groups (taking into account the dependence of the age of patients and the measures performed on both eyes of the same subject).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 (taking into account the age).P<0.05 represents statistically significant difference.Results:Among all patients (32 eyes), there are 10 eyes in group 1(presence of an initial VF defect, which either unimproved or worsened three months after treatment), 11 eyes in group 2(presence of an initial VF defect, which improved three months after treatment) and 11 eyes in groups ( no VF defect either initially or after treatment).The age was significantly older in group 1 compared with group 2 and group 3.Among 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).Conclusions:Mean RNFL thickness and inferior RNFL thickness measured by OCT were prognostic factors influencing the short-term prognosis of pituitary adenomas compressing chiasma. Further studies may establish its mechanism of action.