Intraoperative optical coherence tomography in anterior segment surgeries

Abstract

Intraoperative optical coherence tomography (iOCT) is a noninvasive imaging modality that provides a real-time dynamic feedback of the various surgical steps. Comprehensive literature search was performed in MEDLINE using “intraoperative optical coherence tomography” and “iOCT” as keywords. The use of iOCT as an aid to decision-making has been successfully reported in cases undergoing keratoplasty, implantable Collamer lens (ICL) implantation as well as cataract surgery. iOCT helps to assess the graft-host relationship in penetrating keratoplasty. It helps confirm the presence of a big bubble, detect subclinical big bubbles and guide layer by layer stromal dissection in cases of deep anterior lamellar keratoplasty. It acts as a guide during crucial surgical steps in endothelial keratoplasty, right from scoring of the Descemet membrane to ensuring graft apposition at the end of surgery. The morphological features of the corneal incision in phacoemulsification may be assessed. iOCT is a useful tool in assessing the status of the posterior capsule and may help identify preexisting posterior capsular defects during cataract surgery in various clinical scenarios such as posterior polar cataract, traumatic cataract, and vitrectomized eyes. It allows on-table assessment of the ICL vault and potentially facilitates exchange of ICL in the same sitting in extremes of vault. Ocular surface disorders such as ocular surface squamous neoplasia, pterygium, and dermoid may find an application for iOCT, wherein an iOCT-guided stromal dissection will ensure adequate depth of dissection. Further technological advancements may allow for automatic centration and tracking and address the present limitation of instrument-induced shadowing.

Intraoperative OCT for Monitoring Corneal Pachymetry during Corneal Collagen Cross-Linking for Keratoconus

“…Intraoperative OCT has also been used as a useful extension of the normal surgical microscope during anterior segment procedures for finding the plane of corneal dissection during anterior lamellar surgery, for assessment of graft-host relationship in penetrating keratoplasty, as a guide during the crucial aspects of posterior lamellar surgery, cataract surgery, and glaucoma procedures like canaloplasty or trabectome surgery [17][18][19][20][21][22].…”

Anatomical and Topographical Relations between the Posterior Lens Capsule and the Intraocular Lens in Pseudoexfoliation Syndrome

“…Современные методы визуализации в офтальмологии (оптическая когерентная томография, шеймпфлюг-изо-бражение) позволяют прецизионно исследовать данную область [3][4][5][6]. Послеоперационная трансформация КМХ является объектом многочисленных ОКТ-исследований, оценивающих темпы, особенности и обстоятельства данного процесса [7][8][9][10][11].…”

Intraoperative OCT in Lamellar Corneal Transplants (DALK, DSAEK, DMEK)

“…When preparing the donor button in the DSAEK transplant, after passing the microkeratome, the residual thickness of the donor can be evaluated with the help of transoperative OCT to guide the surgeon in selecting the ideal blade size for a second cut with the microkeratome [16], in case a thinner donor button is required. Even in cases where the microkeratome is passed once, transoperative OCT evaluates the thickness of the donor cornea and helps to select the ideal size of the blade.…”

“…In cases with opaque or edematous corneas, the visualization of the Descemet is difficult, and transurgical OCT can help with its visualization and descemetorhexis. The remaining Descemet membrane can be identified in the case of fibrous or scarred corneas [16]. In this case, transurgical OCT also helps to monitor the insertion and unfolding of the graft, since it can inadvertently have an inverse configuration and result in a failed surgery.…”

“…The use of OCT has proved to be useful in detecting any residual space in the interphase at the end of DSAEK surgery. In 2010, Knecht published the first use of transurgical OCT in DSAEK and demonstrated serially the decrease of fluid in the interphase [16], doing manual measurements of the interphase's area of greatest amplitude (between the graft and the recipient).…”