Composite spectral domain optical coherence tomography images of diabetic tractional retinal detachment

WIDE-FIELD SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF DIABETIC TRACTIONAL RETINAL DETACHMENTS BEFORE AND AFTER SURGICAL REPAIR

PURPOSE

Wide-field (WF) swept-source (SS) optical coherence tomography angiography (SS-OCTA) was used to image diabetic tractional retinal detachments (TRDs) before and after pars plana vitrectomy. The clinical utility of SS-OCTA was assessed.

METHODS

Patients with diabetic TRDs were imaged prospectively with SS-OCTA. Ultrawide-field imaging was obtained when possible. Postoperative WF SS-OCTA imaging was performed.

RESULTS

From January 2018 through December 2019, 31 eyes of 21 patients with diabetic TRDs were imaged. Wide-field SS-OCTA en-face images captured all areas of TRD and fibrovascular proliferation within the posterior pole that were visualized on ultrawide-field imaging. Optical coherence tomography angiography B-scans revealed the vascularity of preretinal membranes and identified areas of vitreoretinal traction and posterior vitreous detachment. Ten eyes underwent pars plana vitrectomy. Postoperative SS-OCTA imaging demonstrated removal of fibrovascular membranes, relief of traction, and resolution of TRDs. Retinal ischemia before and after surgical repair appeared similar.

CONCLUSION

All clinically relevant features of diabetic TRDs were identified at baseline and assessed longitudinally after pars plana vitrectomy using WF SS-OCTA, which showed resolution of vitreoretinal traction and no apparent change in the status of retinal perfusion after surgery. If the media are clear and fixation is adequate, WF SS-OCTA is likely the only imaging modality needed for the diagnosis and longitudinal evaluation of diabetic TRDs.

Relative retinal flow velocity detection using optical coherence tomography angiography imaging

Optical coherence tomography angiography (OCTA) imaging is a valuable tool for the visualization of retinal vasculature at an unprecedented level of details. However, due to relatively long time-interval between repeated scans in the conventional OCTA scanning protocol, the OCTA flow signal suffers from low dynamic range and loss of velocity-intensity correlation. The ability to distinguish fast and slow flow in the retina may provide a powerful tool for the assessment of early-stage retinal diseases such as vein occlusion. Here, we report a method to detect relative flow velocity in human retina using a 67.5 kHz spectral-domain OCTA device. By adapting the selection of A-scan time-intervals within a single OCTA acquisition and combining the resulting OCTA images, we expand the detectable velocity range. After a quantitative validation of this method performing microchannel flow experiments with varying flow velocities, we demonstrate this approach on human eyes using CIRRUS HD-OCT 5000 with AngioPlex (ZEISS, Dublin, CA) through a prototype scanning pattern.

Persistent subretinal fluid following diabetic tractional retinal detachment repair: risk factors, natural history, and management outcomes

PURPOSE

To study the natural history, anatomical and functional outcomes of persistent subretinal fluid (SRF) after pars plana vitrectomy (PPV) for diabetic tractional retinal detachment (TRD) and combined traction-rhegmatogenous retinal detachment (TRRD).

METHODS

Retrospective interventional case series of 43 patients (46 eyes) with persistent SRF following PPV for diabetic TRD or combined TRRD from January 2010 to December 2017 at single tertiary institution. Primary outcomes included best corrected visual acuity (BCVA) and central foveal thickness (CFT).

RESULTS

Thirty-one eyes (67.4%) had macula-off TRD, 5 (10.9%) had fovea-threatening TRD and 10 (21.7%) had combined TRRD. The mean (± SD) duration of decreased vision was 48.0 ± 58.2 weeks. The mean follow-up duration was 21 ± 13.2 months. Residual macular SRF was detected by optical coherence tomography in all eyes at 3 months and in 10 eyes (23.8%) at 12 months after surgery. Only 3 eyes (6.5%) had persistent SRF at final follow up. The mean time to resolution was 10.6 ± 4.1 months [range 6.0-23.0]. Thirteen eyes received additional intervention to address SRF. The mean CFT gradually improved until final follow-up (P-value < 0.001). The mean BCVA improved from 1.62 ± 0.88 LogMAR at presentation to 1.05 ± 0.76 LogMAR at final follow up. No statistically significant difference in final BCVA was found between eyes that had intervention and eyes that were observed (P value = 0.762).

CONCLUSION

Persistent SRF after diabetic vitrectomy resolves slowly over time with gradual improvement in visual acuity. Additional drainage of persistent SRF may not be necessary.

Spectral domain ocular coherence tomography findings pre- and post vitrectomy with fibrovascular membrane delamination for proliferative diabetic retinopathy

PurposeTo describe the intraretinal microstructure using serial spectral domain optical coherence tomography (SD-OCT) preceding and following pars plana vitrectomy and delamination of fibrovascular membranes in patients with proliferative diabetic retinopathy (PDR).MethodsThis retrospective, interventional case series includes 28 eyes. Outcome measures included LogMAR distance best-corrected visual acuity (BCVA), SD-OCT integrity of photoreceptor inner and outer segments junction (IS/OS), and integrity of external limiting membrane (ELM).ResultsPre-operative central macular thickness (CMT) was significantly correlated with the final post-operative LogMAR BCVA (Pearson's coefficient r=0.89; P=0.001). The eyes were categorised into three groups based on post-operative IS/OS integrity (group 0: IS/OS intact; group 1: IS/OS irregular but not completely disrupted; group 2: IS/OS completely disrupted). Mean BCVA improved significantly in group 0 (n=9) from 1.13±0.75 preoperatively to 0.34±0.21 (Student's t-test: P=0.06), in group 1 (n=10) the BCVA improved from 0.88±0.56 to 0.58±0.31 (Student's t-test: P=0.053) and in group 2 (n=9) the BCVA improved from 1.64±0.53 to 1.53±0.75 (Student's t-test: P=0.652).IS/OS integrity and ELM integrity at 3 months post operatively, were significantly and positively correlated with final BCVA (Pearson's coefficient: r=0.83, P<0.001 and r=0.72, P<0.001, respectively).ConclusionsPre-operative CMT and post-operative disruption of the IS/OS and ELM are useful prognostic indicators in fibrovascular delamination surgery for patients with PDR.