Visualization from microscope-integrated swept-source OCT in vitreoretinal surgery for diabetic tractional retinal detachment

Abstract

Purpose : Two dimensional (2D) intraoperative spectral-domain OCT has been used to identify surgical planes during membrane delamination in diabetic tractional retinal detachment (DTRD) surgery. We evaluated the potential utility of live volumetric (4D) intraoperative swept-source microscope-integrated OCT (SS-MIOCT) in DTRD surgery.

Methods : In this retrospective study, cases with DTRD were imaged under IRB approved prospective protocol using SS-MIOCT capable of producing live volumetric (4D) imaging during surgical maneuvers. In near real time, images were displayed in stereo heads-up display with surgeon-controlled volume rotation via a joystick facilitating intraoperative image analysis and surgeon feedback. Postoperative review included scoring image quality, identifying DTRD-related pathologies and tracking surgical maneuvers. Image quality was scored as “good” if the detached retina could be distinguished from overlying fibrovascular membrane in 2D and 4D images.

Results : Good quality 4D visualization from SS-MIOCT was obtained in 12/16 eyes (75%). Identification of DTRD-related pathologies was feasible in 9 eyes. These included: retinoschisis (Fig. 1), intraretinal versus subretinal fluid, focally versus broadly adherent membranes, intraretinal cysts before and after membrane peeling and laser treatment scars that showed adhesions bridging choroid to detached retina. In review, one could view interaction between instruments and fibrovascular membranes and confirm separation of membranes from retinal tissues during delamination (Fig. 2). In 2 cases, delamination required viscodissection, achieved by creating a hole in the fibrovascular membrane and injecting viscoelastic. In one of these cases, SS-MIOCT differentiated between an initial partial thickness hole created in the membrane versus a full thickness hole, facilitating successful viscodissection. A limitation of SS-MIOCT was the depth of field and challenge to rapidly shift the focus. This resulted in poor quality images in 4/16 eyes (25%) due to high DTRD elevation.

Conclusions : SS-MIOCT can provide important guidance during complex vitreoretinal surgery for DTRD. Further advances are needed for wider application of this technology.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Fig. 1: Retinoschisis.

 

Fig. 2: Membrane delamination. A) En face view. B) B-scan. C) and D) Volume rotation with 3D image from 2 different angles. (*): Fibrovascular membrane.