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Revolutionizing Retinal Care: Home OCT Devices Promise Precision and Accessibility for AMD and Beyond

  • Epidemiology and Burden:

    • Age-related macular degeneration (AMD) affects ~20 million in the US; diabetic retinopathy (DR) affects over 11 million.

    • AMD costs ~$47 billion annually to US employers and health systems.

    • Both conditions are leading causes of adult blindness, driven by neovascularization and exudation.

  • Current Treatment Paradigms:

    • Standard treatment: Intravitreal anti-VEGF injections (e.g., ranibizumab, bevacizumab) for neovascular AMD (nAMD) and DR, guided by optical coherence tomography (OCT).

    • Monthly injections yield best visual outcomes but increase patient and physician burden.

    • Pro-renata (as-needed) protocols reduce injections but require monthly visits, risking undertreatment.

    • Treat-and-extend (TREX): Monthly injections until retinal drying, then extended intervals; most common for nAMD in the US (TREX-AMD trial showed similar outcomes to monthly dosing).

    • Risks of undertreatment: Poorer visual outcomes; discontinuation linked to visual deterioration.

    • Anti-VEGF risks: Endophthalmitis, retinal detachment, intraocular inflammation (rare).

  • Challenges in Care:

    • Barriers to adherence: Transportation issues, frequent visits, and geographic distance to clinics.

    • Excessive treatment intervals in TREX may lead to undertreatment and worse outcomes.

  • Non-OCT Home Monitoring:

    • Amsler grid: Ubiquitous, low-cost, but low sensitivity (67%) for nAMD detection.

    • Smartphone apps (e.g., MyVisionTrack, MultiBits): Inconsistent diagnostic accuracy for nAMD.

    • Alleye app: 80% correlation with decreased visual acuity (VA) or increased macular thickness during COVID-19 triage.

    • ForeseeHome (FDA-approved 2009):

      • Preferential hyperacuity perimeter; detects metamorphopsia from choroidal neovascularization.

      • Sensitivity 85%, specificity 84% for nAMD (higher than Amsler grid).

      • HOME trial: ForeseeHome + TREX reduced VA loss (-4 vs. -9 letters) compared to TREX alone.

      • Detected smaller choroidal lesions with better VA outcomes; >80% maintained VA ≥20/40 long-term (ALOFT study).

      • Cost-effective: $35,663 per QALY (below $50,000 threshold).

  • FDA-Approved Home OCT: SCANLY:

    • First FDA-approved home OCT (2024, Notal Vision) for nAMD; patient-operated, automated.

    • Mechanism: 830 nm spectral-domain OCT; captures 88 B-scans (3×3 mm field, 10,000 A-scans/second); uploads to Notal Health Cloud.

    • Notal OCT Analyzer (NOA): AI-driven convolutional neural network; quantifies intraretinal (IRF) and subretinal fluid (SRF) with 10 nL total retinal fluid (TRF) threshold.

    • NOA performance: IRF detection accuracy 0.851, sensitivity 0.822, specificity 0.865; outperforms retina specialists (accuracy 0.805).

    • Patient experience: 71% wanted to continue after 6 months; 93% successful self-imaging (mean age 79.5); 88% scans ≤1 minute.

    • Compliance: 6.3 scans/week, 99.3% good quality, 86.5% quantifiable by NOA.

    • Feasibility study (Blinder et al.):

      • 77% eyes achieved TRF ≤10 nL post-injection.

      • 41% injections given when TRF >10 nL; 75% reduced TRF to ≤10 nL in 6.7 days.

      • Mean 18.5-day lag between fluid recurrence and injection (TRF 86.9 nL at injection).

    • Limitations: Lower success with VA <20/320 (<50% vs. 80–90% for VA ≥20/320); no interventional trial completed yet.

  • Non-FDA-Approved Home OCT Devices:

    • SELFF-OCT (Visotec GmbH):

      • Low-cost full-field OCT (<$1,000); applied to AMD, DR, RVO, etc.

      • 94.1% successful imaging, 76% adequate quality; sensitivity 0.94, specificity 0.95 for nAMD treatment need.

      • Poorer signal-to-noise ratio vs. SD-OCT.

    • MIMO-OCT (MIMO AG):

      • SD-OCT with single line or low-resolution volume scans; mean retinal thickness difference 4.52 μm vs. in-office OCT.

      • High inter-rater reliability (>0.95).

    • OCT Health prototype:

      • SD-OCT; 100% study eye, 94% fellow eye successful imaging.

      • High fluid detection (AUC 0.95 IRF, 0.97 SRF).

  • Future Directions: DRCR Protocol AO:

    • Phase 3 RCT (NCT05904028): Compares SCANLY-guided treatment vs. TREX for nAMD (600 eyes, 80 sites).

    • Treatment protocol: Faricimab injections; 10 nL TRF threshold triggers office visit if ≥21 days since last injection.

    • Outcomes: VA change, injection frequency, visits, fibrosis/atrophy rates, fluid dynamics, costs (completion 2027).

    • Ancillary study: Monitors fellow eyes at risk for nAMD.

  • Challenges and Implementation:

    • Reimbursement: CPT code 606T requires monthly physician review; estimated 10.5 hours/month for 350 nAMD patients (60% adoption).

    • Cost concerns: Potential negative pressure on provider reimbursements.

    • Unanswered questions: Efficacy vs. TREX, real-world adoption, workflow impact, applicability to DR/RVO.

    • Patient perception: Favorable views; high interest in self-tracking and telemedicine among patients and ophthalmologists.

Citation

Bordbar DD, Bhatnagar A, Weng CY. Use of Home Optical Coherence Tomography for Retinal Diseases. Int Ophthalmol Clin. 2025;65(1):41-46. doi:10.1097/IIO.0000000000000546