Pilot Study for OCT Guided Design and Fit of a Prosthetic Device for Treatment of Corneal Disease

Abstract

Purpose. To assess optical coherence tomography (OCT) for guiding design and fit of a prosthetic device for corneal disease. Methods. A prototype time domain OCT scanner was used to image the anterior segment of patients fitted with large diameter (18.5–20 mm) prosthetic devices for corneal disease. OCT images were processed and analyzed to characterize corneal diameter, corneal sagittal height, scleral sagittal height, scleral toricity, and alignment of device. Within-subject variance of OCT-measured parameters was evaluated. OCT-measured parameters were compared with device parameters for each eye fitted. OCT image correspondence with ocular alignment and clinical fit was assessed. Results. Six eyes in 5 patients were studied. OCT measurement of corneal diameter (coefficient of variation, CV = 0.76%), cornea sagittal height (CV = 2.06%), and scleral sagittal height (CV = 3.39%) is highly repeatable within each subject. OCT image-derived measurements reveal strong correlation between corneal sagittal height and device corneal height (r = 0.975) and modest correlation between scleral and on-eye device toricity (r = 0.581). Qualitative assessment of a fitted device on OCT montages reveals correspondence with slit lamp images and clinical assessment of fit. Conclusions. OCT imaging of the anterior segment is suitable for custom design and fit of large diameter (18.5–20 mm) prosthetic devices used in the treatment of corneal disease.

BCLA CLEAR - Scleral lenses

“…Ocular surface height data obtained using an OCT over a 16 mm chord has been utilised to design customised scleral lenses for complex ocular shapes when an optimal fit could not be achieved with spherical diagnostic lenses [146]. Scleral height data along the horizontal and vertical meridians has also been used to estimate the required landing zone toricity, however there was only a modest association between the OCT derived scleral toricity and the toricity of the optimal fitting scleral lens [147].…”

Analyse von corneo-skleralen und biometrischen Messwerten als Prädiktoren für Sklerallinsenparameter: eine systematische Übersicht

“…26 They showed that scleral asymmetry at chord 15.00 mm or beyond is significant, suggesting adding peripheral toricity to large scleral lenses to achieve an optimal alignment with the underlying tissue and provide more comfort. Le et al also evaluated the correlation between scleral toricity and the scleral lens landing zone toricity using the AS-OCT. 19 Although they found a modest correlation and the sample size was small (including six eyes), the authors concluded that the AS-OCT data might help determine scleral lens fitting.…”

“…These outcomes are in agreement with those of a pilot study that assessed the use of the AS-OCT for designing and fitting scleral lenses finding a strong correlation between the corneal sagittal height and that of the scleral lens. 19 Other reports have suggested the use of corneal sagittal height provided by the corneal topographer to estimate the initial diagnostic scleral lens sagittal height. 20, 21 To the corneal sagittal height calculated by the topographer at chord 10.00 mm (Figure 1), it is necessary to add 200 μm height for every additional 0.50 mm chord.…”

Stevens-Johnson Syndrome and Corneal Ectasia: Management and a Case for Association

“…They are filled with sterile saline at the time of application, worn on a daily-wear basis, and removed for sleep (Figure 1). 10,11 PROSE treatment is also used in the management of corneal ectasia (ECT), 11,12 a degenerative disorder that manifests as progressive corneal thinning and steepening. The resultant irregular astigmatism, myopia, and irregular corneal surface can lead to impaired vision and can require surgical intervention.…”