Abstract
Purpose :
A full air fill and sufficiently high intraocular pressure (IOP) are crucial to ensure optimal graft adhesion during endothelial keratoplasty. While air fill and IOP can be approximated on the operating table, it is difficult to quantify if the air fill will provide an adequate IOP. The purpose of this study is to evaluate how the air fill in the anterior chamber anterior chamber (AC) correlates with IOP, AC depth, and the iris configuration.
Methods :
Cadaveric human eyes were mounted on a microscope with intraoperative optical coherence tomography (OCT). Inclusion criteria for the eyes included pseudophakia and harvest time within 48-72 hours. Three categories were used: baseline, an air fill that just spanned limbus to limbus (“limbus to limbus”), and an air fill that maximally filled the entire AC (“max fill”). IOP was measured by taking the average of 3 Tono-pen (Reichert, Buffalo, New York) measurements. OCT images were obtained in the operating room and analyzed using ImageJ software. ImageJ was used to measure the distance from the posterior cornea to the anterior iris to determine AC depth, and to measure the angle between the iris and the cornea to determine iris configuration.
Results :
Preliminary data has shown that at baseline the IOP was 14.33, AC depth was 3.067, and an irido-corneal angle of 37.33°. Limbus to limbus fill had an IOP of 14.33, an AC depth of 2.968, and an irido-corneal angle of 36.25°. Max fill had an IOP of 17.33, an AC depth of 3.37, and an irido-corneal angle of 44.09°. Finalized data will be based on a total of 10 eyes to power this study, assuming an 80% power, a p-value of <0.05, an R-squared of 0.50, and a single variable model.
Conclusions :
Early data has indicated a correlation of IOP with AC depth as perceived on intraoperative OCT. In addition, while an air bubble may appear to fill the AC, as demonstrated by the “limbus to limbus” category, it’s IOP may not be sufficiently high to optimize graft adherence. Finally, a concave iris contour on OCT may be a reliable surrogate to suggest an adequate anterior chamber fill.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.