Abstract
Abstract: :
Purpose:To quantify anatomic parameters of normal anterior segment by real-time Optical Coherence Tomography at 1310 nm and compare with standard techniques. Methods:Temporal angle opening (AOD500), angle grading and central measurements of corneal thickness (CCTOCT) and anterior chamber depth (CACDOCT) by OCT were compared with gonioscopy (BSG), central ultrasonic pachymetry (CCTPACH ) and A-scan-biometry on 23 normal volunteers (age range, 21-60 ). Results:There was a significant positive association of both BSG and OCT grading of the angle to AOD500 (P<0.001). OCT grading results demonstrated less variation than BSG gradings. OCT and BSG gradings were significantly correlated [Kendall's Tau-B = 0.66 (SE=0.14; P<0.0001)], but showed some discrepancies [exact agreement = 32/42 (76.2%)]. CCTOCT yielded a significantly thinner average than CCTPACH [mean difference of 40.8 um (S.D, 28.0); P<0.0001]. Likewise, CACDOCT resulted in a significantly smaller average than by ultrasound [mean difference of 0.489 um (SD, 0.237); P<0.0001]. CACDOCT was negatively correlated with lens thickness (r=-0.53) and positively correlated with axial length (r=+0.46). Significant negative associations with age were found for AOD500 and CACDOCT, whereas lens thickness (LT) increased with age. Significant negative associations of refractive error (spherical equivalent, SE) were found for average K-readings and axial length (AL), whereas LT decreased with increasing SE. Conclusion:OCT angle measurements are highly positively correlated with most standard techniques. The clinical and research utility of OCT measurements for all the anterior segment parameters is demonstrated by the above findings. Future use will be enhanced by adaptations that will permit slit-lamp OCT access. Support: NIH Grant EY13105, P30EY11373, T32EY07157, RPB
Keywords: 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 359 clinical research methodology • 318 anterior segment