Intraoperative OCT can affect decisions during VMT surgery

This study’s results indicate that intrasurgical imaging with intraoperative optical coherence tomography (iOCT) during vitreomacular traction (VMT) surgery can help identify subclinical changes such as full-thickness macular hole (FTMH) and residual epiretinal membrane (ERM), possibly impacting surgical decision making.

The authors describe their use of iOCT to assess microarchitectural changes during pars plana vitrectomy surgery (PPV) for VMT.

Subjects included 12 consecutive patients who underwent either 23- or 25- gauge standard 3-port PPV for VMT with concurrent iOCT imaging. The internal limiting membrane was stained with indocyanine green and peeled in cases of ERM. 

All eyes showed complete clearance of tractional forces prior to completion of the surgical procedure. Overall, iOCT impacted the surgical plan in five of 12 eyes. Two eyes with pre-incision iOCT revealed conversion of the VMT to a subclinical FTMH, and two eyes with iOCT imaging after hyaloid elevation showed that FTMH caused the surgeon to alter surgical planning to include ILM peeling, long-term gas tamponande and postoperative face-down positioning. All four of these eyes achieved successful closure of the FTMH during the postoperative period. In the seven eyes with underlying ERM that underwent peeling, one showed a residual ERM on iOCT requiring additional peeling.

The authors also performed a quantitative analysis with iOCT in nine eyes with pre-incision and posthyaloid scans of sufficient quality. Their analysis showed a decrease in central foveal thickness from a preincision mean of 792 μm to posthyaloid elevation mean of 694 μm. All nine eyes showed subfoveal expansion of hyporeflectivity, e.g., increased retinal pigment epithelium to ellipsoid zone distance.

They conclude that the combined used of iOCT and contrast dyes may have value in enhancing visualization of anatomical structures.