Maculopathy vs. Optic neuropathy

1. ROLE OF OCT IN NEURO-OPHTHALMOLOGIC DISEASES. ERWIN D. PALISOC, MD, PhD, MHA, FPAO A/Prof. & Chairman, Department of Ophthalmology MCU College of Medicine.

No financial/proprietary interests.

OUTLINE OF LECTURE. Diagnosis Disease Monitoring Prognosis Newer developments.

Assessment of Afferent Visual Pathway. Function Structure (can lag behind function) Subjective -- Objective.

Can OCT diagnose optic disc edema?. Can OCT differentiate the various etiologies of optic disc edema/optic neuropathy?.

A prospective case-control study comparing optical coherence tomography characteristics in neuromyelitis optica spectrum disorder- optic neuritis and idiopathic optic neuritis Xiujuan Zhao', Wei Qiu2, Yuxin Zhangl, Yan Luo', Xiulan Zhangl, Lin Lul• and Hui Yang' •.

Cirrus OCT (Carl Zeiss Meditec ). Spectralis (Heidelberg Engineering).

Basic Anatomy: Layers of the Retina. VITREOUS RETINE HOROID Retinal Nerve Fiber Layer Ganglion Cell Layer Inner Plexiform Layer Inner Nuclear Layer Outer Plexiform Layer Outer Nuclear Layer External Limiting Membrane Myoid Zone Photoreceptor Integrity Line (PIL) aka Ellipsoid Zone, IS/OS Junction Interd igitation Zone Retinal Pigment Epithelium Bruch's Membrane (masked by RPE reflection).

GCL-IPL (Cirrus). GCC ( Spectralis ). R mac horizontal.

Usually confirms an optic neuropathy (chronic) but does not show underlying cause*.

Mews RE 111109. Mews RE 111116. OD: Acute loss of vision 3 days Normal fundus, RAPD+ Retrobulbar optic neuritis?.

OD AZOOR confirmation on mfERG. Right Eye Field View me61h4md75 2291 8-14-2012 14-47-43 Right Left Eye Field View me61h4md75 2291 8-14-2012 14-28-39 Left 4 6 8 10 12 o 2 4 6 8 10 12 14nV/'*.

Real vs. Pseudo-disc swelling. Vitreo -papillary traction.

Real vs. Pseudo-disc swelling. Buried Drusen EDI better than UTZ or conventional OCT for detection of buried drusen 12/68 patients with ONH Drusen detected with EDI-OCT missed by US.

Real vs. Pseudo-disc swelling. Serial /repeated measurements: Pseudopapilledema pRNFL thickness = stable Papilledema pRNFL thickness might ↑ or ↓.

Hyperemia of the Optic Disc. Dilation of the existing disc surface capillary net.

Image. Chronically elevated ICP (months to years) leading to deterioration of Optic Nerve function.

Visual field defects include:. - Nasal field loss.

Symptomatic stage Im • 1.0 Pre symptomatic stage 4w 1.0 1.0 2m 3m 0.10 12m CF.

Greater hemispheric (sup/inf) difference in NAION than optic neuritis*.

RNFL and ONH:Optic Disc Cube 200x200 OD os R NFL Neuro-retinal Rim Thickness RNFL Thickness —cr- zontal Iso Iss 113 Clock.

Macular Ganglion Cell Analysis ( mGCL ) as GCL+IPL or GCC.

Old NAION. 23. . . abstract. abstract. abstract. abstract.

OCT shows mild ↑ pRNFL thickening or subtle optic disc swelling1.

4. EMB Toxic Optic Neuropathy (ETON). Patients with early ETON have normal or thickened RNFL at time of diagnosis Average global RNFL thickness at the time of diagnosis: 101.2 ± 17.0 microns Global & sectoral RNFL thicknesses were N or thickened when compared to age-matched normal database They display good visual recovery 6 months after discontinuation of EMB.

Neurological Diseases. Multiple Sclerosis Correlation with visual impairment GC-IPL better than pRNFL 1 Alzheimer’s Disease ↓ pRNFL , GCC, macular volume 2 Parkinson’s Disease & Progressive Supranuclear Palsy Worse pRNFL , GC-IPL in PSP 3 Migraine with aura ↓ foveal and peripapillary vessel density 4.

pRNFL/mGCL+IPL is useful for monitoring disease progression in chronic optic neuropathies.

previously known as Pseudotumor Cerebri. Incidence peaks in the 3RD decade of life.

Modified Dandy Criteria for Diagnosis of IIH Documented Elevated ICP, typically ≥25cm H2O in adults during a properly performed lumbar puncture, measured in the lateral decubitus position Normal CSF Composition No evidence of hydrocephalus, mass, structural, vascular, or meningeal lesion on MRI scan or contrast-enhanced CT-Scan for typical patients, and MRI scan and MRV for all others Normal Neurologic Examination: Unilateral or Bilateral Cranial Nerve VI Palsy is excluded Signs and symptoms representing increased ICP: Headache, Transient Visual Obscurations, Papilledema.

idiopathic intracranial hypertension (IIH). Empty Sella.

Grade 1 Grayish C-shaped halo surrounding the disc* Sparing of the temporal disc margin Radial nerve fiber striation disruption Grade 2 Halo becomes circumferential* Nasal border elevation No major vessel obscuration Grade 3 Obscuration of at least one vessel leaving the disc' (arrow) Elevation of all borders Circumferential halo Grade 4 Obscuration of a major vessel on the disc. Complete elevation including the cup Circumferential halo Grade 5 Obscuration of all vessels on the disc and leaving the disc* All features of Grade 4.

OCT FINDINGS IN IIH. FIG 1. Raised intracranial pressure can alter the position and angular displacement of Bruch membrane on OCT..

Idiopathic intracranial Hypertension (IIH). 1 week later.

IIH 1.5 years later. ONH and RNFL OU Analysis:optic Disc Cube 200x200 OD OS 175 RNFL Klap Neuro-retinal Rim Thickness 800 TEMP —00 os SLP RNFL DISC Ceter Extractod Hori7mtal Tormqram —.00 os 200 100 TAP 30 Extrewtf%l Torrxvrarn RNFL DEC Cater Extractod I-Wizontal Torruvarn Vertical Torru:vrarn.

Ganglion Cell OU Analysis: OD Thickness Map Fovea: 101, 104 OD Sectors OD Deviation Map 87 83 79 Macular Cube 225 150 75 OD OS Thickness Map Fovea: 99, 101 OS Sectors e os OS Deviation Map 85 86 86 OD pm OS pm 84 84 Average GCL + IPL Thickness Minim-n GCL + IPL Tt•ickness.

EMB Toxic Optic Neuropathy (ETON). Changes in the retinal-nerve-fiber layer due to Ethambutol Toxic Optic Neuropathy Delos Reyes, et al. Phil. J Ophthalmology Vol. 34, No.1, pp.26-30 (2009).

C. Prognosis. Loo JL et al(BJO 2015) Compressive optic neuropathy due to anterior pathway meningiomas Normal pre-treatment pRNFL (i.e. no optic atrophy) + shorter duration of symptoms = better recovery Similar for pituitary lesions.

C. Prognosis. Normal pRNFL is ~ 100 microns But what is the minimum? Floor effect Stratus OCT Blind eyes from non-glaucomatous optic neuropathy Residual pRNFL thickness ~ 45 μ m.

NLP pRNFLT SD-OCT Spectralis 34.2 μ m (1) 31.9 μ m (2) Cirrus 55.9 μ m (2) Stratus 45 μ m.

232 277 248 229 243 234 286 260. Macula Cube Macula thickness ILM-RPE thickness (microns).

Newer Developments. Handheld OCT Enhanced depth imaging (EDI) OCT Retinal single layer analysis Swept-Source OCT/OCT Angiography Newer Analysis Algorithm.

OCT Angiography. Compared with Fluorescein angiography No dye, non invasive, quick Uses “motion contrast imaging” to visualize blood flow Does not show leakage/pooling/staining.

OCT Angiography. In general optic atrophy (any cause)  ↓ peripapillary retinal flow corresponds to optic atrophy 1-3 pRNFL better than OCTA for assessment of optic atrophy? Useful in ischemic optic neuropathy?.

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OCT-A papers mostly on ischemic optic neuropathy as compared to others….

Ischemic optic neuropathy. Diagnosis OCT-A detect microvascular defects and vessel density reduction in acute cases of AAION 1 , NAION 1-3 No blockage from fluorescein leakage.

Normal RNFLT: 109 microns. Acute Optic Neuritis RNFLT: 344 microns.

NOVEL APPLICATIONS. Deep Learning (AI) using OCT RNFL/GC-IPL 1 - Glaucomatous vs. Non-glaucomatous optic neuropathy Binocular OCT pupillometry (AS-OCT) 2 Transdermal OCT to identify superficial temporal arteries 3 - Comparison with ultrasound? Visualize Spontaneous Visual Pulsation 4 - Infrared Videography ( Spectralis OCT).

49. R NFL O ptical T exture A nalysis (ROTA). Chris Leung et al. Submitted to Nature Biochemical Engineering.

50. abstract.