Retina: Examination and Interpretation - APVCapvc.ca/notes/2019notes/Wilkie7-vet.pdf1 Retina: Examination and Interpretation David A. Wilkie DVM, MS, Diplomate ACVO Professor Emeritus

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Retina: Examination and Interpretation

David A. Wilkie DVM, MS, Diplomate ACVO

Professor EmeritusThe Ohio State University

[email protected]

Retina

Optic Nerve

Tapetum

RetinalBloodVessel

ChoroidalVessels

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Retina Examinationn Routine physical examinationn Patient with a visual

disturbancen Differential diagnoses include:

n systemic infectious diseasen vascular disordersn Hypertension/hyperviscoscityn central nervous system

disease

Retina Examinationn Clinicians should realize this is the only

location in the body where blood vessels and the central nervous system can be seen directly.

Retina Examinationn In addition, the high blood flow of the

choroid makes it very susceptible to blood-borne infectious and neoplastic diseases.

Know Equipment & Anatomy!

I can�t see a thing?

Maze Test Finoff & Magnification

Anyone over 40?

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Pupillary Light Reflex

!

Dazzle Reflex

Hey!That�s Bright

Cotton Ball Menace Response

Intraocular Exam Intraocular Exam

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Indirect Ophthalmoscopy Indirect Ophthalmoscopy

Direct Ophthalmoscopy

PanOptic

This is an indirect ophthalmoscope

Courtesy of Dr. David Ramsey

Ocular ultrasound

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ElectroretinographyInterpretation

Let’s build a fundus

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Fundic Examinationn Optic nerve

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Fundic Examinationn Optic nerve

n Sizen Elevation/Depression Too

Small

TooBig

TooSunken

JustRight

Fundic Examinationn Optic nerve

n Sizen Elevation/Depression

n Retinal blood vesselsn Colorn Marginn Hemorrhage

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Peri-vascular Cuffing Lipemia Retinalis

Hyperviscosity Vascular Attenuation

Vascular AttenuationFundic Examination

n Optic nerven Size/colorn Elevation/Depression

n Retinal blood vesselsn Colorn Marginn Hemorrhage

n Reflectivity

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Fundic Examinationn Optic nerve

n Sizen Elevation/Depression

n Retinal blood vesselsn Colorn Marginn Hemorrhage

n Reflectivityn Hyper vs Hypo

Which is correct – Hyper or Hypo?

Which is correct – Hyper or Hypo?Angle of Light Reflection

Angle of Light ReflectionComplete Retinal Degeneration

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Focal Retinal Degeneration Hyporeflective

Hyporeflective

Are You

Ready Yet?

The world of normal variation…Here we go…

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The message is:you need to look at the retina more often to know normal variations before interpreting abnormalities

Abnormalities – Retina

Progressive Retinal Atrophy n American & English Cocker Spanieln Collien Miniature Poodlen Akitan Tibetan Terriern Labrador Retrievern Irish Settern Miniature Schnauzern Norwegian Elkhoundn Briardn Siberian Huskyn Portugese Water Dog

Progressive Retinal Atrophyn night blindness (nyctalopia)n progress to total blindness with timen pupils may be dilated and the PLR slow

and incompleten Tapetal hyperreflectionn Pale optic discn Vascular attenuation

Labrador retriever

3yr

4yr

3yr

5yrSpringer spaniel

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American Cocker Spaniels - OptiGen® PFK test & prcd-PRA test American Eskimo Dogs - OptiGen® prcd-PRA test Australian Cattle Dogs - OptiGen® prcd-PRA test Australian Shepherds - OptiGen® CEA/CH test & prcd-PRA test Australian Stumpy Tail Cattle Dogs - OptiGen® prcd-PRA test Basenjis - OptiGen® PK test Border Collies - OptiGen® CEA/CH & CL tests Briards - OptiGen® CSNB test Bullmastiffs - OptiGen® Dominant PRA & CMR tests Cardigan Welsh Corgis - OptiGen® rcd3-PRA test Chesapeake Bay Retrievers - OptiGen® prcd-PRA test Chinese Cresteds - OptiGen® prcd-PRA test Cockapoos - OptiGen® prcd-PRA test Coton de Tulear - OptiGen® CMR test Dachshunds - OptiGen® NARC test Doberman Pinschers - OptiGen® NARC test Dogue de Bordeaux (French Mastiff) - OptiGen® CMR test English Cocker Spaniels - OptiGen® prcd-PRA & Familial Nephropathy tests English Springer Spaniels - OptiGen® PFK test Entlebucher Mountain Dogs - OptiGen® prcd-PRA test Finnish Lapphunds - OptiGen® prcd-PRA test German Shorthaired Pointers - OptiGen® CD test Golden Retrievers - OptiGen® prcd-PRA test Great Pyrenees - OptiGen® CMR test Irish Setters and Irish Red & White Setters - OptiGen® CLAD & rcd1-PRA tests

Kuvasz - OptiGen® prcd-PRA test Labradoodles - OptiGen® prcd-PRA test Labrador Retrievers - OptiGen® prcd-PRA & NARC tests Lancashire Heelers - OptiGen® CEA/CH test Lapponian Herders - OptiGen® prcd-PRA test Mastiffs (Old English) - OptiGen® Dominant PRA & CMR tests Miniature Poodles - OptiGen® prcd-PRA test Miniature Schnauzers - OptiGen® Type A-PRA test Newfoundlands - OptiGen® Cystinuria test Nova Scotia Duck Tolling Retrievers - OptiGen® CEA/CH & prcd-PRA tests Portuguese Water Dogs - OptiGen® prcd-PRA test Rough Collies - OptiGen® CEA/CH test Samoyeds - OptiGen® XL-PRA test Shetland Sheepdogs - OptiGen® CEA/CH test Siberian Huskies - OptiGen® XL-PRA test Sloughis - OptiGen® rcd1a-PRA test Smooth Collies - OptiGen® CEA/CH test Spanish Water Dogs - OptiGen® prcd-PRA test Swedish Lapphunds - OptiGen® prcd-PRA test Toy Poodles - OptiGen® prcd-PRA test Whippets: Longhaired -

Genetic TestingRetinal Detachment

Retinal Detachmentn Hypertension

n Systolic pressure exceeds 180 mmHg, the diastolic exceeds 95 mmHg.

n Etiologies of hypertension:n Renal -#1n Diabetes #2n Hyperthyroidismn Pheochromocytoman Idiopathic

Feline hypertension

Feline hypertension Feline hypertension

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Retinal Detachment n Immune-mediated

n Uveo-Dermatologic Syndrome or VKHn Akita, Samoyed and Siberian Husky

Pre Tx Pre Tx

Post Tx Post Tx

Retinal Detachment n Infectious

Retinal Detachment n Hyperviscosity

Retinal Detachment n Neoplastic

Lymphosarcoma

Retinal Detachment – Breed Associated

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Retinal Dysplasia Retinal Dysplasia

Retinal Dysplasia

Retinal Dysplasia n The most severe form of retinal dysplasia occurs as

a non-attachment of the retina resulting in blindness in the affected eye

Sudden Acquired Retinal Degeneration Syndrome

(SARDS)n Acute onset blindnessn PLR is variable from fixed and dilated

or sluggish to normaln No visible fundic abnormalities on

initial presentationn 2-3 months the typical appearance of

generalized retinal degeneration will be present

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SARDS

n History of polyuria, polyphagia, polydypsia and weight gain

n On serum biochemical profile increased alkaline phosphatase (steroid isoenzyme), cholesterol or liver values may suggest mild Cushings or hepatic disease.

SARDS

n Depending on the PLR the differential diagnoses are:n Retrobulbar optic neuritis (Dilated

and non-responsive pupil) n Cortical blindness (normal PLR)

SARDS

n Definitive diagnosis of SARDS requires an electroretinogram to differentiate it from these diseases

n A normal ERG response indicates normal retinal function n Visual Evoked Potentialn Cerebrospinal fluid tapn MRI or CT scan

Abnormalities – Optic Nerven Micropapilla/Optic Nerve Hypoplasian Coloboman Papilledema/Papillitis/Optic Neuritisn Optic Nerve Atrophy/Degeneration

Micropapilla/Optic Nerve Hypoplasia

n Congenital abnormality of the optic nerve.

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Optic Nerve Hypoplasia

Optic Nerve Degeneration

Coloboman Pit or defect in the optic nerve and

often adjacent fundusn Collie Eye Anomalyn Multiple ocular anomalies

Papilledema/Papillitis/Optic Neuritis

n Papilledeman non-inflammatory

swelling of the optic nerve

Papilledema/Papillitis/Optic Neuritis

n Papillitis n inflammation of

the optic nerve

Optic Nerve Atrophy/Degeneration

n Gray, flat optic nerven Vascular attenuationn Cupping or

depression of the optic nerve head -Glaucoma

n Peripapillary hyper-reflectivity