Abstract
Purpose: :
To use optical coherence tomography (OCT) to guide the design and fit of an ocular surface prosthetic device.
Methods: :
A prototype time domain 1310nm wavelength anterior segment OCT scanner (Optovue, Inc., Freemont, CA) was used to image the anterior segment of patients undergoing fitting of an ocular surface prosthetic device. A prosthetic device of 18.5-20mm diameter was fitted according to the standard, resource intensive, iterative approach to fitting using trial devices and custom modification of device contours based on clinical findings. OCT scans using a combination of radial and circular scans in primary and deviated gaze were obtained of each eye before and then wearing a fitted prosthetic device. Slit lamp photographs were taken to document device orientation and clinical features of fit. OCT image processing software was developed to generate elevation profiles and ultra-wide montages that were analyzed to obtain measurements of corneal vault, sagittal depth of sclera at 17mm from corneal center, and scleral curvature. OCT-measured parameters were compared with the device contours for each eye fitted.
Results: :
Six eyes in 5 patients were studied. One eye was fitted with a device having a rotationally symmetric haptic; the others required customized asymmetric haptic shapes. The circumferential scleral distribution as measured by OCT was highly correlated with the height distribution of the device haptic bearing zone for all fitted devices (Pearson’s correlation coefficients r > 0.9) with the exception of the one with greatest asymmetry (r = 0.49). Visual assessment of the fitted devices on OCT scans reveals correspondence with slit lamp image characteristics of satisfactory haptic fit over the limbus and sclera.
Conclusions: :
OCT imaging of the ocular surface provides profiles and indices useful for the custom design and fit of ocular surface prosthetic devices of 18.5-20 mm diameter, serving the ultimate goals of improved efficiency and quality of fit.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical • anterior segment