Intraoperative optical coherence tomography-guided donor corneal tissue assessment and preparation

Abstract

Purpose: To evaluate the role of intraoperative optical coherence tomography (i-OCT) in donor grading, selection, and preparation during different types of keratoplasty. Methods: Seventy-one consecutive donor corneas collected over 6 months, after clinical grading, were observed by an experienced corneal surgeon under an i-OCT equipped microscope. The donor preparation (manual/automated) for different types of keratoplasty procedures was also undertaken under i-OCT. Results: The mean central corneal thickness of optical and nonoptical grade tissues was 533 ± 19 and 662 ± 52 mm, respectively. The i-OCT-based grading matched with clinical grading in 98.5% cases. Irregular thickness, anterior stromal hyperreflectivity, and previous scars were appreciated in 1.4, 1.4, and 7.04% donors, respectively. During Descemet stripping automated endothelial keratoplasty, i-OCT facilitated selection of appropriate microkeratome head for automated donor preparation in all cases, besides allowing manual dissection of partially dissected lenticule, identification of site of inadvertent perforation, and eccentric trephination in one case each. During Descemet membrane endothelial keratoplasty, i-OCT-based assessment of preexisting scar (five cases) guided careful tissue selection (2/5) and preparation. During predescemetic endothelial keratoplasty, precise needle advancement allowed successful type-1 bubble formation in all cases. All manually punched donors demonstrated an extra endothelial ledge, while those with automated preparation showed tapering donor margins. Conclusion: i-OCT might serve as a useful imaging tool for objective assessment of donor characteristics. The modality may complement clinical evaluation for donor grading, selection, and preparation.

Intraoperative OCT for Lamellar Corneal Surgery: A User Guide

“…During graft preparation, either one or two consecutive passes of a microkeratome blade allow for the creation of a very thin lenticule in a procedure known as UltraThin-DSAEK (UT-DSAEK), which has become the standard modern approach to DSAEK [40,45,46]. In cases in which this preparation is carried out in the operating room rather than at the eye bank, iOCT allows the surgeon to easily check the residual stromal thickness, the smoothness of the cut, and the regularity of the UT-DSAEK lenticule [47][48][49][50][51] (Figure 3).…”

“…Finally, iOCT can also help in the preparation of the graft as well as in teaching novice surgeons. In fact, iOCT has been used to quantitatively assess the quality of donor corneas and pre-stripped grafts and to monitor each step of the stripping procedure [47,48]. Likewise, wet labs equipped with microscope-integrated iOCT allow expert surgeons to monitor the progression of their pupils and correct them accordingly [77].…”

Properties of Dual-Crosslinked Collagen-Based Membranes as Corneal Repair Material

“…Anterior segment optical coherence tomography (OCT), one of the most useful instruments in ophthalmic imaging, was used to measure corneal shape, corneal morphology, corneal thickness, and corneal curvature. [28,29]. On day 7 after surgery, the anterior Anterior segment optical coherence tomography (OCT), one of the most useful instruments in ophthalmic imaging, was used to measure corneal shape, corneal morphology, corneal thickness, and corneal curvature [28,29].…”

“…[28,29]. On day 7 after surgery, the anterior Anterior segment optical coherence tomography (OCT), one of the most useful instruments in ophthalmic imaging, was used to measure corneal shape, corneal morphology, corneal thickness, and corneal curvature [28,29]. On day 7 after surgery, the anterior segment OCT showed that the Col-EDC-PRA adhered to the residual corneal stromal bed, with a clearly visible interface and higher density compared to the cornea.…”