sign in sign up
<<
Home , Globe rupture

7/8/17

Lecture Outline

• Medical History • • Distance Exam • Nasolacrimal System Geng the Most Out of Your • Assessing Vision • Third Ocular Exam • Neuro- • Conjuncva and Exam • Kimberly Hsu, DVM, MSc, DACVO • Schirmer Tear Test (STT) • Care for Animals Anterior Chamber St. Charles, IL • Intraocular Pressure (IOP) • and (630) 444-0393 • Fluorescein Stain • [email protected] • Retroilluminaon • Vitreous & Fundic Exam

Medical History From a distance

• Time of onset and progression? Recurrent? • Behavior/mentaon/navigaon • Facial symmetry (ears, eyelids, lips) • Discomfort or pain? • Eyelid posion; palpebral fissure size • Ocular discharge? • Ocular and nasal discharge • Change in appearance or color? • Corneal clarity and reflecvity (tear film) – • Concurrent systemic health? Purkinje images brisk or dull/irregular? • size and posion • Uni vs. bilateral? – Look from above • Vision in light? Vision in dark? • Globe color • Orbital palpaon and globe retropulsion

1 7/8/17

Assessing Vision Neuro-Ophthalmology made simple!

• Distance exam Test Nerves Tested Tips Palpebral Reflex CN5 (sensory) If absent, touch the face, • (Medial/lateral canthus CN7 nasal planum, etc. to Maze test – bright/dim light touch to elicit blink) confirm – Pylons or trap the dog in the corner using Menace Response Rena, CN2 Avoid air flow, (Menacing hand gesture Cerebellum, Cortex smulang vibrissae; common items in room (ie. garbage can, chair, to elicit blink/ CN7 blink or avoidance etc.) withdrawal) considered + Dazzle Reflex Rena, CN2 Use a bright light! • Coon ball test (Bright light to elicit CN7 blink) • Neuro-ophthalmic Exam Pupillary Light Reflex Rena, CN2 Indirect PLR helpful if iris (Light causes pupillary CN3 not easy to see constricon) (ie. , etc.) Oculocephalic CN8, CN3, CN4, CN6 (“Doll’s eye”)

Schirmer Tear Test Measuring Intraocular Pressure (IOP)

• Do this first! Factors that can elevate IOP • Dorsoventral eyelid manipulaon • Boom eyelid, lateral 1/3rd • Lateral eyelid manipulaon • Normal is 15-25mm/min • Brachycephalic dogs especially sensive to changes in eyelid posion – Varies with conformaon • Pressure on jugular veins, ght neck collars – Brachycephalic dogs need more tears (>18-20mm/ • Aempted eyelid closure min) – Proparacaine if ocular surface pain – If borderline, look for signs of keras, history of • Excitement conjuncvis, etc. • Thickened or abnormal (ie. corneal edema)

2 7/8/17

Does the IOP fit your paent?! The many uses of fluorescein stain!

• Normal 15-25mmHg • Detecng corneal ulcers – Hydrophilic corneal stroma stains + • IOP decreases with age – Lipophilic Descemet’s membrane does not stain! – <10mmHg is oen seen in older dogs • Tear Film Break Up Time (tear film quality or evaporaon) • >25mmHg (usually in 40s and 50s) – Apply 2-3 drops of fluorescein • Uveis (usually <10mmHg) – Open the eyelids and watch for dark spot to form – Normal is >20s – Early glaucoma should be suspected if IOP is – Most qualitave KCS dogs have TFBUT of <10s normal with moderate to severe uveis! • Seidel Test (aqueous humor leakage with corneal rupture) • Jone’s Test (nasolacrimal patency)

Light and magnificaon are your Retroilluminaon friends! • Dark and dim light • Materials to Gather • Pupil size, shape and symmetry • STT - do 1st! – Focal light source (ie. Finoff • transilluminator) • Obstrucons in normally transparent Neuro-ophthalmic exam – Magnifying Loupes (ie. before dilaon Opvisor) structures obscure the fundic reflex • Do not dilate unless IOP is – Direct ophthalmoscope – normal – Indirect lens (28D, 20D) Cornea, aqueous humor, lens, vitreous • Minimize handling of the – Schirmer Tear Test • Oen helps to see subtle , corneal blood eye with deep corneal – Fluorescein Stain vessels, etc. ulcers – Tropicamide • Nuclear sclerosis (centered symmetrical circular – Proparacaine relucency) vs. (irregular, oen more – Sterile eye wash obstrucve) – Coon p applicators

3 7/8/17

Eyelids Nasolacrimal System

• Periocular discharge • Nasolacrimal system largely encased in bone – Perform STT if increased mucous • Check for tear staining of medial canthus • Dermas or blepharis • Purulent discharge, swelling near medial canthus (indicator – Localized or diffuse for dacryocys) • Palpebral fissure size and shape • Eyelid posion • Look for occlusion, narrowing or absence of nasolacrimal – /, eyelid laxity puncta • Proparacaine to differenate spasc vs. anatomical entropion • Jone’s test • Abnormal hairs – Useful in non-brachycephalic dogs only! – Dischiae, ectopic cilia, • Highly variable – mesocephalic dogs up to 14 minutes – Corneal lesions oen correspond to the locaon of abnormalies • Brachycephalic dogs oen >30 minutes or no passage • Meibomian glands • Nasolacrimal flush – Masses – If nasolacrimal obstrucon is suspected – Inflammaon, etc. – NL flush: 24G catheter, 3cc syringe with eye wash, fluorescein

Third Eyelid (TEL) Conjuncva and Sclera

• Examine at rest then gently retropulse globe through upper lid to elevate TEL Conjuncva Sclera – Omit retropulsion if risk of globe rupture • Change in color • Changes in contour or • Examine posterior surface using fixaon forceps – Hyperemia most common thickness • Prolapsed gland of the TEL (Cherry Eye) • Chemosis • Changes in scleral “show” – Check carlage too • Surface irregularies • Changes in color • Neoplasc masses • Discharge, increased • Irregularies: follicular conjuncvis, plasmoma, trauma surface moisture vs. dryness • Foreign bodies • Changes in color: depigmentaon, hyperemia, etc. • Subconjuncval hemorrhage or emphysema • TEL posion changes with globe posion!

4 7/8/17

Conjuncval vs. Episcleral Blood Cornea Vessels • Bulbar conjuncva (thin light vessels) overlies • Change in color, loss in transparency the sclera/episclera (thick dark straight • Changes in contour vessels) • Corneal ulcers – superficial, indolent, stromal, descemetoceles • Conjuncval hyperemia – surface epithelial – Indolent: loose edges – wicking of FLST, touch with a disease vs. episcleral hyperemia – intraocular Q-p! – Descemetoceles don’t take up stain! disease • Surface irregularies • Changes in diameter – Measure diameter in mm (STT strips work well) to compare

Anterior Chamber Iris and Pupil

• Anterior chamber depth and symmetry • Changes to iris color and texture – Look from the side – Iridal hyperpigmentaon, , masses, etc. • Anterior chamber clarity • Altered pupil shape or posion – Aqueous flare? Hyphema? ? Fibrin – Iris atrophy, synechiae, etc. clots? Pigmented cysts? • Altered pupil size • Hypopyon is usually ventral so look down (under lower – (ie. uveis, Horner’s Syndrome), (ie. eyelid) renal detachment, glaucoma) – Slit beam • Altered pupil color – Loss of iris detail – Cataract, vitris, etc.

5 7/8/17

Lens Fundic exam

• Use of Purkinje images and • Grading cataracts • Dilate! • Systemac exam retrolluminaon – Incipient (Punctate) • Indirect ophthalmoscopy – – Nerve • Lens opacity – Immature (Tapetal reflex sll greatest field of view – Blood vessels visible) • Altered size 1. Find the reflex at “arm’s – Tapetal and Non-tapetal – Mature (Tapetal reflex fundus – Flat, resorbing lens: obscured) length” hypermature cataract – Quadrants – Hypermature (Wrinkled, 2. Insert your lens (28D or – Intumescent with shallow Liquifying) 20D), move lens in and out • chamber: diabec cataract, Pracce!!! – Morganian (Liquefied) unl opc nerve in focus rapid onset juvenile cataract 3. Maintain alignment • Huge individual variaon • Altered shape 4. If you lose the image, – Anterior surface smooth vs. repeat! irregular (hyper? • Direct ophthalmoscopy • Altered posion (set to 0D, same eye as – Anterior chamber depth paent’s) – Aphakic crescent 1. Find the reflex > 2-3cm

Fundic Exam Recommended ocular exams

• Rena Opc Nerve All diabec dogs – 80% will get a cataract • Change in color • Change in size – At higher risk for KCS • Changes in tapetal • Color • All brachycephalic dogs – check tear film, corneal reflecvity pigment, etc. • Changes in vasculature – • Breeds at risk for ocular disease diameter, color, etc. – Golden Retrievers for Pigmentary Uveis • Elevaon or detachment • Iridal hyperpigmentaon, cataract,uveal cysts, etc. – Cairn Terriers for Ocular Melanosis • Scleral pigment, iridal hyperpigmentaon etc. • All hypertensive cats – Vitreal and renal hemorrahage = end organ damage

6