What Is the Impact of Intraoperative Microscope-Integrated OCT in Ophthalmic Surgery? Relevant Applications and Outcomes. A Systematic Review

Abstract

Background: Optical coherence tomography (OCT) has recently been introduced in the operating theatre. The aim of this review is to present the actual role of microscope-integrated optical coherence tomography (MI-OCT) in ophthalmology.

Method: A total of 314 studies were identified, following a literature search adhering to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. After full-text evaluation, 81 studies discussing MI-OCT applications in ophthalmology were included.

Results: At present, three microscope-integrated optical coherence tomography systems are commercially available. MI-OCT can help anterior and posterior segment surgeons in the decision-making process, providing direct visualization of anatomic planes before and after surgical manoeuvres, assisting in complex cases, and detecting or confirming intraoperative complications. Applications range from corneal transplant to macular surgery, including cataract surgery, glaucoma surgery, paediatric examination, proliferative diabetic retinopathy surgery, and retinal detachment surgery.

Conclusion: The use of MI-OCT in ophthalmic surgery is becoming increasingly prevalent and has been applied in almost all procedures. However, there are still limitations to be overcome and the technology involved remains difficult to access and use.

Keywords: cataract surgery; corneal surgery; glaucoma surgery; intraoperative OCT; macular surgery; microscope-integrated OCT; paediatric examination; proliferative diabetic retinopathy surgery; retinal detachment surgery; strabismus surgery.

Figure 1

Commercial MI-OCT systems. (A) Haag—Streit Surgical iOCT system, (B) Zeiss RESCAN 700 system, and (C) Leica EnFocus system.

Figure 2

Preferred reporting items for systematic reviews and meta-analyses (PRISMA) flowchart.

Figure 3

Microscope-integrated optical coherence tomography (MI-OCT) assisted Descemet’s membrane endothelial keratoplasty (DMEK). (A) The left column shows en-face view. The right column shows the accompanying MI-OCT image. Top row: Peripheral Descemet’s membrane remnants prior to graft insertion (arrow). Bottom row: Attached graft overlapping Descemet’s membrane remnants (arrow). (B) Top row: Inverted graft after insertion. Bottom row: Corrected graft orientation. (C) From the top to bottom, rows represent consecutive time points. Progressive graft apposition during gas infusion (fluid interface indicated by white arrows; complete graft apposition indicated by yellow arrows).

Figure 4

MI-OCT assisted Cataract surgery: The left column shows en-face view. The right column shows the accompanying MI-OCT image. (A) Manual keratome corneal incision (red arrows). (B) femtosecond laser-assisted corneal incision (yellow arrows). (C) Depth and width of trench before dividing the nucleus (red arrows). (D) Image after nucleus division (posterior capsule, yellow arrow), epinuclear plate (yellow bracket). (E) Pseudo-posterior polar cataract: a gap between lens and posterior capsule (red arrows). (F) True posterior polar cataract: no gap between lens and posterior capsule (yellow arrows). Reproduced with the permission from reference [58].

Figure 5

MI-OCT assisted Macular Hole surgery. (A) En-face view. (B) MI-OCT images confirm inverted ILM flap positioning after fluid-air exchange. Reproduced with the permission from reference [83].

Figure 6

MI-OCT assisted Retinal detachment surgery. (A) En-face view. (B) MI-OCT shows a subretinal membrane consistent with proliferative vitreoretinopathy (arrowhead). Reproduced with the permission from reference [87].