Intrasession Repeatability of OCT Angiography Parameters in Neurodegenerative Disease

Purpose

To assess the intrasession repeatability of macular OCT angiography (OCTA) parameters in Alzheimer's disease (AD), mild cognitive impairment (MCI), Parkinson's disease (PD), and normal cognition (NC).

Design

Cross sectional study.

Subjects

Patients with a clinical diagnosis of AD, PD, MCI, or NC were imaged. Images with poor quality and of those with diabetes mellitus, glaucoma, or vitreoretinal disease were excluded from analysis.

Methods Intervention or Testing

All participants were imaged using the Zeiss Cirrus HD-5000 with AngioPlex (Carl Zeiss Meditec, Software Version 11.0.0.29946) and repeat OCTA images were obtained for both eyes. Perfusion density (PFD), vessel density (VD), and Foveal avascular zone (FAZ) area were measured from 3 × 3 mm and 6 × 6 mm OCTA images centered on the fovea using an ETDRS grid overlay.

Main Outcome Measures

Intraclass correlation coefficients were used to quantify repeatability of PFD, VD, and FAZ area measurements obtained from imaging.

Results

3 × 3 mm scans of 22 AD, 40 MCI, 21 PD, and 26 NC participants and 6 × 6 mm scans of 29 AD, 44 MCI, 29 PD, and 30 NC participants were analyzed. Repeatability values ranged from 0.64 (0.49-0.82) for 6 × 6 mm PFD in AD participants to 0.87 (0.67-0.92) for 3 × 3 mm PFD in AD participants. No significant differences were observed in repeatability between NC participants and those with neurodegenerative disease.

Conclusions

Overall, similar OCTA repeatability was observed between NC participants and those with neurodegeneration. Regardless of diagnostic group, macular OCTA metrics demonstrated moderate to good repeatability.

Financial Disclosures

The authors have no proprietary or commercial interest in any materials discussed in this article.

Aphakic contact lens use for improved handheld optical coherence tomography imaging in pediatric aphakic patients

Handheld optical coherence tomography (OCT) makes it possible to acquire intraoperative and clinical imaging in infants and children for whom standard OCT is not possible. In patients with a retinal pathology who are left aphakic after surgery, however, image clarity is affected by insufficient refractive correction with handheld OCT. We describe a technique for supplementing the refractive power of the handheld OCT device with an aphakic contact lens to improve image clarity.