Outer Retinal Tubulation Imoro Zeba Braimah, MBChB, FGCS, FWACS Paper presented at the Medical Knowledge Fiesta, GCPS, 15th September 2016.

INTRODUCTION SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY

INTRODUCTION Branching tubular structures- outer nuclear layer of retina round or ovoid hyporeflective spaces with hyperreflective borders on SD-OCT. SD-OCT= spectral-domain optical coherence tomography, ORT=outer retinal tubulation, CME= cystoid macular edema Image courtesy of Sandrine A. Zweifel 1. Zweifel SA, Engelbert M, Laud K, et al: Outer retinal tubulation: a novel optical coherence tomography finding. Arch Ophthalmol 2009; 127: 1596–1602.

Case 66 years, Male with Choroidal Neovascular membrane both eyes-5yrs duration. Came for follow up – April 2016 Had monthly injections of intravitreal anti-vascular endothelial growth factors (anti-VEGF) agents in right eye bevacizumab-12 injections Ranibizumab-6 injections.

Past History First seen in KBTH-16/05/2014- sudden painless loss of vision Right eye, micropsia, metamorphopsia and inability to read– 2 days duration. Had diabetes mellitus and hypertension under control Examination Right Eye Left Eye Visual acuity CF at 4 metres CF at 2 metres Intraocular pressure 15mmHg Lens Nuclear sclerosis grade 1 Dilated fundus examination Chorioretinal scar, haemorrhagic pigment epithelial detachment in macular Chorioretinal scar, subretinal fibrosis, involving fovea centre

Fundus Photograph and SD-OCT at presentation B C E D F Fundus Photograph and SD-OCT at presentation

Diagnosis and Treatment Diagnosis- Choroidal neovascular membrane(CNVM) Both eyes. Right active, left eye fibrotic. Plan of treatment Intravitreal injection of anti-VEGF right eye Observe left eye

Visual acuity 6/18 CF at 2 m B A C E F D Images A,B,C- Shows SD OCT Scans of the right eye at presentation and Images D, E, and F- shows the SD OCT scans after 3 injections of intravitreal bevacizumab in same eye

15 Months after Initial Bevacizumab Injection Acuity right eye 6/18 Intravitreal bevacizumab stopped and Ranibizumab started September 2015

24 Months after Initial Bevacizumab Injection Right Eye Left Eye Visual acuity 6/18 CF at 4 m Intraocular pressure 14mmHg SD-OCT of both eyes with ORT in the left eye

26 Months after Initial Bevacizumab injection Right Eye Left Eye V. acuity 6/60 CF at 4 m

27 Months after Initial Bevacizumab Injection Right Eye Left Eye Visual acuity 6/18 CF at 4 m SD-OCT Right eye showing new onset PED and Left Eye showing ORT

SD-OCT RIGHT EYE WITH HEMORRHAGIC PED AND LEFT EYE WITH ORT 29/08/2016 28 months SD-OCT RIGHT EYE WITH HEMORRHAGIC PED AND LEFT EYE WITH ORT

Diagnosis Right Eye Choroidal neovascular membrane(CNVM)with persistent Intraretinal fluid and pigment epithelial detachment Left Eye fibrotic CNVM with OUTER RETINAL TUBULATION

OUTER RETINAL TUBULATION(ORT) Occur due to rearrangement of degenerating/surviving photoreceptors Advanced degenerative retinal disorders. Image courtesy of Sandrine A. Zweifel 1. Zweifel SA, Engelbert M, Laud K, et al: Outer retinal tubulation: a novel optical coherence tomography finding. Arch Ophthalmol 2009; 127: 1596–1602.

DISEASE ASSOCIATIONS Neovascular AMD(nvAMD) Gyrate atrophy Pseudoxantoma elasticum Bietti crystalline dystrophy Pattern dystrophy Stargardts disease Retinitis pigmentosa Best Disease Adult vitelliform foveomacular dystrophy Zweifel et al 2009 Goldberg et al 2013 Iriyama et al 2013 Dolz-Marco et al 2013 Braimah et al 2016

Clinical Significance of ORT May simulate Cystoid macular edema and subtretinal fluid Associated with poor visual acuity outcome in nvAMD Indicator of disease severity Lee et al 2014 Faria- Correia et al 2013 Espina et al 2015 Goldberg et al 2013

Composite image of the right eye of a 32-year-old man with Best disease with stable ORT over a follow-up of 3 years

CONCLUSION ORT was identified in the left eye with fibrotic CNVM and worse visual acuity. It is important to identify ORT in eyes with CNVM to avoid unnecessary treatment