What's an Eyeball?: Veterinary Ophthalmology for the LVT

1. What’s an Eyeball??
Veterinary Ophthalmology for the LVT
Katee Murphy, LVT
Mark Nipper, LVT
Upstate Veterinary Specialties
Ophthalmology Department

2. Basic Anatomy
https://s-media-cache-ak0.pinimg.com/736x/c5/ae/e9/c5aee959546c20b9ee40211a9a9e5784.jpg

3. Conjunctiva Cornea Cornea
Anterior Chamber Anterior Chamber Lens Capsule
Lens Capsule Retina Vitreous
Anatomy and it’s Disease

4. Gross Examination
Things you can see when they walk in the door
 Redness
◦ How red is it and Where on the eye is it
 Pain
◦ Blepharospasm (squinting)
◦ Rubbing/Pawing at face
◦ Depressed mentation
 Position of eyelids (3rd eyelid too)
 Discharge
◦ Quantity, color, character
 Strabismus, nystagmus
 Pupil Assessment
 Globe symmetry, shape and size
◦ Buphthalmos, exophthalmos, enophthalmos
 Vision
◦ How many things did they bump into on the way to the room

5. The 2-foot Away Exam

6. Basic Ophtho History: Ocular
 Chief Complaint
 Signs of discomfort
◦ Rubbing, pawing, squinting
◦ Flinching when approached
◦ Resistance to mouth opening, aggression
 Vision changes
◦ Bumping into things
◦ Can’t see toys/treats
◦ Getting lost or disoriented
◦ Poor or well lit area
 Duration of problem
◦ When were signs first noted
◦ Stable, progressive, Off & On
 Changes in appearance
◦ Redness (Where)
◦ Cloudiness (Where)
◦ Discharge
(quantity/quality)

7. Basic Ophtho History: Systemic
 General medical history
◦ Systemic Disease
 Diabetes
 Cardiac (blood pressure)
 Cushings, Thyroid, etc
◦ Systemic Medications
 Steroids, Baytril, etc
 History of trauma
◦ Needs to be a definite event
◦ Trauma rarely the real cause
 Family History
◦ Sometimes useful
 Travel History
◦ Out of Northeast
◦ Especially for uveitis

8. Tools for the exam
 VERY dark room
 Light source- bright focused beam
◦ Finhoff transilluminator is best
 Pair of magnifying loupes
 Direct ophthalmoscope
 Schirmer tear test strips
 Fluorescein stain
 Tonometer
◦ Not a Schiotz
 Proparacaine and Tropicamide
 Eye wash
 Cotton balls or a laser to test vision

9. One of the most
important things is a
dark room.
This is a picture of how
dark your room should
be.

10. Basic Ocular Diagnostic Tests
 Think TPR…
◦ Basic health status for the body, right?
◦ You TPR every case that comes in, right?
 The TPR for the eye is:
◦ Schirmer Tear Test
◦ Tonometry for glaucoma
◦ Stain for corneal health
 These are simple practice building, money making tests that the
LVT is more than capable of doing
 We should be doing an “Ocular TPR” for every pet that comes in
with an eye problem

11. Schirmer Tear Test (STT)
 BEFORE YOU DO ANYTHING ELSE!!
◦ This test should be done FIRST
◦ DO NOT apply any solutions/ointments to eye or flush out any
debris prior to test.
◦ Mucous can be removed with dry gauze to allow access to
eyelids
◦ DO NOT perform test on a ruptured cornea, descemetocele or
melting ulcer… but you should still do the healthy eye
◦ Corneal irritation can increase tear production

12. Schirmer Tear Test
 Always Measure BOTH EYES
 Don’t touch any part of test strips other than the very end (oils on fingers can alter
readings)
 Hook curved end of strip over middle to lateral third of lower lid (between third eyelid
and lower lid)
 Hold strip in place for 60 seconds
◦ If unable to hold in for full 60sec, stop and record mm/30 sec or # of seconds
held in eyelids
◦ Quickly replace and adjust time if strip falls out
◦ Starting over will decrease overall tear measurement
 Immediately record where the line of moisture ends on strip
◦ STT I (before proparacaine)
 Measures basal and reflexive tear production
 Normal dog ~20 mm/min (prefer >25mm)
 Normal cat 3-35 mm/min (Really not that useful in cats)
◦ STT II (after proparacaine)
 Measures basal tear production only
 Really only used academically

14. Tonometry
 Should be performed on EVERY PATIENT with a presenting ocular
complaint (unless perforated or melting)
 Always measure BOTH EYES
 Normal ~ 10-20 mmHg
◦ Low may indicate uveitis
(but not always)
◦ High (>20-25mmHg) is glaucoma
 May not be clinical
 TonoPen and TonoVet are two most accepted instruments
 Other Instruments, Less commonly used
 Cannot obtain artificially low measurement, but can produce
artificially high measurements very easily
 Proper restraint is crucial for accurate results

15. Applanation Tonometry
 Tono-Pen Vet or Tono-Pen Avia (ergonomic)
 IOP determined by measuring the force required to
flatten a given area of the cornea
 Requires topical anesthesia

16. Calibration of Tono-pen
 Should be calibrated every 1-2wks
 Without cover, spray canned air in all the holes on tip of Tonopen
 Allow to warm to room temp (5-10min)
 Hold nose towards floor with Tonopen cover on
 Push black button twice quickly until Tonopen reads “CAL”
 Wait for Tonopen to read “UP”
 Flip 180° (nose towards ceiling)
 Repeat calibration until Tonopen reads “Good”
 Holding your hands as steady as possible helps this process to go
smoothly. Sometimes it will get stuck in “calibrate” mode. If this
occurs, either push the button until it snaps out of it, or if you can,
just set it down and come back to it in ~10min.

17. Calibration of Tono-Pen

18. IOP Measurement
 Apply topical anesthetic
 Sanitary latex cover placed over tip
◦ Make sure it is stretched enough to cover tip but not so much that it
alters IOP readings
 Press black button once, double hyphen will appear
 Tonometer tip must be directly perpendicular to corneal surface
◦ Try to measure clear, smooth cornea when possible
 Gently “tap” on the corneal surface
◦ Audible “chirp” is heard for each acceptable reading
 Average of measurements calculated internally
◦ Audible “beep” is heard
◦ Error percentage displayed
 < 5% - preferred
 < 10% - acceptable
 20% and over - unacceptable

19. IOP Measurement
 Proper Restraint
◦ No pressure around neck
◦ Very minimal eyelid manipulation
◦ Light pressure on boney areas of head
 Proper Position
◦ Sternal Position Preferred
◦ Nose parallel to floor, looking straight forward

20. Handling Handling Handling

21. Video on this page

24. IOP Measurement Mistakes

25. Manipulation IOP  over
Lateral eyelid extension with both jugular veins
compressed
+ 17.6 mm Hg
Lateral lid extension + 16.5 mm Hg
Dorsoventral lid extension + 6.4 mm Hg
Manual compression of both jug veins + 3.0 mm Hg
Manual compression of ipsilateral jug vein only + 0.3 mm Hg
Baseline - minimal eyelid
restraint
Maximal ventral and
dorsal extension of lids
Lateral lid extension
Klein et al, JAVMA 2011

26. Fluorescein Stain
 Corneal stroma will retain stain
 Corneal epithelium and descemet’s membrane will not
 Use individual strips to prevent bacterial contamination
 Stain pattern and uptake vary depending on type of corneal
ulcer/disease
◦ Glaucoma can actually cause a diffuse patchy stain uptake
 Important to always check IOP!
 ULCER DOES NOT = TRAUMA
 Other uses
◦ Jones test – assess nasolacrimal duct patency
◦ Tear film break up time (TFBUT)

27. Fluorescein Stain
 Wet end of strip with sterile eye wash solution (water
or Proparacaine doesn’t activate Fluorescein
molecules as well)
 Apply stain to conjunctiva or sclera
◦ DON’T TOUCH CORNEA WITH STRIP
 Flush out excess stain with sterile eye wash
 Alternatively: remove plunger on 3cc syringe, insert
fluorescein strip and fill with sterile eye wash, leave
enough room for plunger to be reinserted. Use 1-2
drops in each eye
 This syringe must be discarded at the end of each
day

29. Bacterial Culture and Sensitivity
 Ideally done after STT and before anything else
 Topical anesthetic can be used so it will not hurt and its use will
not interfere with results
 Keep in mind the eye is swimming in bacteria normally so
this may not be all that useful
 Mucoid discharge does not equal an infection, no matter
what color it is. It might, but usually not.

30. Common Medications

31. Questions?

32. Ophtho Terminology
 OD- Right Eye
 OS- Left Eye
 OU- Both Eyes
 PLR-
 Menace-
 Dazzle-
 Episcleritis-
 Subconjunctival Tissue-
 Flare-
 Edema-
 Blepharospastic-
 Chemosis-
 Ephiphora

33. Ophtho Terminology
 Anisocoria (an-ahy-suh-kawr-ee-uh)- pupils are different sizes
 Blepharospasm (blef-er-uh-spaz-uh m)- spasm of the orbicularis oculi
muscle resulting in eyelid closure (squinting)
 Buphthalmos (buph·thal·mos)- enlargement of the eye due to glaucoma
 Canthus (Medial and Lateral)- corners where upper and lower lids meet
 Cataract- opacity of the lens: congenital, age, disease, trauma
 Chemosis- conjunctival edema
 Descemetocele (děs'ə-mět'ə-sēl‘)- deep corneal ulcer with exposure of
basement membrane of the corneal endothelium, 1 cell layer left
 Distichia (dis-tick-e-uh)- extra hairs along the lid margin
 Ectopic Cilia – hairs growing through the congunctiva toward cornea
 Ectropion- rolling out of eyelids
 Entropion- rolling in of eyelids
 Enophthalmos- abnormal “sunken” position of the globe within orbit

34. Terminology
 Enucleation- Eye removal
 Epiphora (ih-pif-er-uh)- overflow of tears
 Episcleritis- inflammation of the connective tissue immediately exterior
the sclera
 Exophthalmos- abnormal “protruding” position of the globe from orbit
 Hyalitis- evidence of inflammation within the vitreous body
 Hyphema- blood in the anterior chamber
 Hypopyon- white blood cells in the anterior chamber (often a white blob
that settles at base of anterior chamber
 Keratitis- inflammation of the cornea
 Lagophthalmos- incomplete eyelid closure to cover eye
 Microphthalmos- small eye - congenital
 Miosis- pupil constriction
 Mydriasis- pupil dilation
 Nystagmus- abnormal eye movement, often continuous
 Phthisis Bulbi- “shrunken” globe due to disease process

35. Terminology
 PLR
 Sequestrum
 Strabisumus
 Tapetum
 Trichiasis
 Uveitis
 Iris Atrophy

36. Pupil Assessment
 Size
 Shape
◦ Dysoria
◦ Normal
 Dog: round pupil
 Domestic Cat: vertical slit
◦ Generally pupils all have
a round shape when
dilated
 Symmetry
◦ Anisocoria
 Position
◦ Corectopia
 Reaction to light
◦ Direct and indirect PLR’s

37. Orbit
 Palpate orbital bones
◦ Lacrimal, zygomatic, frontal, sphenoid, palatine,
maxillary
 Exophthalmos vs enophthamos vs
buphthalmos
 Jaw opening
◦ Pain or resistance to
jaw opening

38. Eyelids
 Conformation
◦ Entropion, ectropion, ptosis, blepharospasm,
macropalpebral fissure, micropalpebral fissure
 Discharge
◦ Epiphora, mucoid, hemorrhagic etc

39. Eyelids
 Abnormal lashes
◦ Distichiasis, trichiasis, ectopic cilia
 Blepharitis/periocular skin
◦ Alopecia, crusting, hyperpigmentation,
hypopigmentation, scaling

40. Eyelids
 Neoplasia
 Meibomian glands
◦ Cysts/sty, inflammation,
redness, swelling,
neoplasia

41. Always evert the lid!

42. Neurophthalmic Exam
 Neurologic responses/reflex
◦ Menace response
◦ Palpebral reflex
 Lateral, medial, ventral, dorsal stimulation
◦ Dazzle reflex
◦ Direct and indirect pupillary light reflexes
(PLR)
 Extent and speed of PLR

43. Examination of Anterior Segment
 Ideally performed in
dim or ambient
lighting
◦ Magnifying loupes
◦ Finoff transilluminator
 Can be put on a direct
ophthalmoscope
 Preferred to pen light
 Brighter and more
focused light beam
◦ Slit lamp used by
Ophthalmologists
 Higher magnification
 Stronger light source
 Variable slit widths etc

44. Third Eyelid
 Elevate by gently pressing on the
globe through the upper eyelid
◦ DO NOT PERFORM IF RISK OF
GLOBE PERFORATION
 Location at rest
◦ Ddx if elevated at rest
 Orbital disease, Horner’s, Phthsis bulbi,
retraction of globe due to pain, etc
 Leading edge
◦ Check for ulceration, masses,
hyperemia, depigmentation,
thickening

45. Third Eyelid
 Gland of the third eyelid
◦ Prolapse of the gland of the third eyelid
“Cherry eye”

46. Third Eyelid
 Gland of the third eyelid
◦ Neoplasia, masses, ulcerated surface

47. Third Eyelid
 Cartilage of the third eyelid
◦ Scrolled “T” cartilage or tips
◦ Inversion vs eversion
 Changes in color
◦ Hyperpigmentation, hyperemia,
depigmentation
 Irregularities of surface or margin
◦ Pannus, KCS, follicles
◦ May indicate chronicity
http://davidlwilliams.org.uk/wp-
content/uploads/archivesite/pic258.jpg

48. Third Eyelid
 Foreign bodies
◦ Always evaluate under the third eyelid for
any foreign material

49. Conjunctiva
 Palpebral vs bulbar
http://www.enpevet.de/Lexicon/GetMedia.aspx?mediaid=f06a3219-4630-11df-874a-73f5125785b0

50. Conjunctiva
 Changes in color
◦ Hyperemia, pigmentation, anemia, icterus
 Discharge
◦ Mucopurulent, mucoid, serous, purulent,
dried or crusted exudate
 Subconjunctival hemorrhage,
emphysema

51. Conjunctiva
 Conjunctival masses, follicles, nodules
 Conjunctival thickening
◦ Chronic inflammation
 Chemosis

52. Nasolacrimal System
 Only visible portions = upper and lower
puncta
 Clinical signs of disease
◦ Epiphora, mucoid mucopurulent or
mucohemorrhagic discharge
 Jones test
◦ Assessment of fluorescein dye passage through
to nostrils
 Dacryocystitis
◦ Dermatitis or blepharitis, generally at the medial
canthus
◦ Swelling or abscessation near medial canthus
 Punctal occlusion vs ductal occlusion

53. Cornea
 4 layers
◦ Epithelium
◦ Stroma
◦ Descemet’s
membrane
◦ Endothelium
http://www.aafp.org/afp/2004/0701/afp20040701p123-f2.jpg

54. Cornea
 Change in corneal diameter
◦ Buphthalmos
◦ Microphthalmos
◦ Phthsis bulbi

55. Cornea
 Change in color
◦ Blue: edema
◦ Red: vascularization
 Determine if deep or
superficial
◦ Yellow: infiltrate
 Highly suggestive of
infection

56. Cornea
 Change in color
◦ Brown: pigmentation
 Indicates chronicity
◦ White: scar, leukoma,
lipid, calcium etc

57. Cornea
 Change in contour
◦ Keratoconus
◦ Deep
ulcers/descemetoceles
◦ Masses/nodules
elevated from surface
 Granulation tissue
 Neoplasia
 Raised scar or pigment
◦ Protrusion of tissue
from the surface
 Iris prolapse
 Bulging descemetocele

58. Sclera
 Only the anterior portion
is visible on exam
◦ Visualized through the
thin bulbar conjunctiva
 Thinning
◦ Staphyloma, buphthalmos
◦ Underlying choroid visible
(pigmented)
 Scleral nodules
◦ Below conjunctival
surface
 Can see freely moveable
conjunctiva above nodules

59. Sclera
 Scleral rupture
◦ Change in contour: generally
due to globe rupture at limbus
◦ Usually a history of trauma
◦ Pigment or masslike
protrusion
 Inflammation
◦ Increased redness, scleral or
episcleral injection
◦ Tortuous or engorged blood
vessels
 Pigment changes
◦ Melanosis, neoplasia
Peterson-Jones VO 200

60. Anterior Chamber
 Space between the
iris and posterior
cornea
◦ Filled with aqueous
humor
 Assess globe from
the side
◦ Easiest to view from
the lateral aspect

61. Anterior Chamber
 Clarity
◦ If view of the iris face is not clear, consider anterior chamber
debris vs decreased corneal clarity
 Depth
◦ Increased
 Posterior lens luxation, microphakia, buphthalmos, post-cataract surgery
◦ Decreased
 Anterior lens luxation, aqueous misdirection glaucoma, iris or ciliary body
tumors, cysts, iris bombe, intumescent cataract

62. Anterior Chamber
 Contents
◦ Hyphema, hypopyon,
aqueous flare, iris cysts,
foreign bodies, anterior lens
luxations, neoplasia, PPM’s,
vitreous, anterior synechiae
etc

63. Iris and Pupil
 Evaluate pre and post-
dilation
◦ Iris face better visualized
pre dilation
◦ Posterior iris and ciliary
body better visualized
post dilation
 Altered shape (dyscoria)
or position (corectopia)
◦ Anterior or posterior
synechiae
◦ More than one aperture
 Iris coloboma, persistent
pupillary membranes, iris
atrophy, iris hypoplasia

64. Iris and Pupil
 Altered iris color
◦ Iris rubiosis, hyper or hypopigmentation,
neoplasia, abscess, uveitis,
heterochromia irides

65. Iris and Pupil
 Altered texture
◦ Neoplasia, cyst, granuloma/abscess

66. Iris and Pupil
 Altered pupil size
◦ Horner’s (or other neurologic disease),
glaucoma, uveitis, lens luxation,
pharmacologic
 Iridodenesis
◦ Posterior lens luxation, surgical aphakia or
pseudophakia
 Altered pupil color
◦ Posterior segment abnormalities
 Cataract, vitreous syneresis, asteroid hyalosis,
vitreous hemorrhage, retinal detachment

67. Lens
 Shape
◦ Lenticonus, lentiglobus, spherophakia,
intumescent or hypermature cataract, lens
material extruding through lens capsule rupture
 Position
◦ Luxation, subluxation, aphakic crescent

68. Lens
 Opacities
◦ Cataract vs nuclear
sclerosis
◦ Lens capsule pigment,
intralenticular hemorrhage
◦ Congenital abnormalities
 Persistent hyaloid artery
 Persistent hyperplastic
primary vitreous
 Persistent tunica vasculosa
lentis

69. Superficial Corneal Ulcer
 Ulcer confined to loss of corneal
epithelium
◦ Fluorescein stain positive
 Not obviously infected
◦ No infiltrate, mild if any corneal
edema
◦ +/- neovascularization
 Broad spectrum antibiotic
coverage
◦ Neopolybac ointment, tobramycin
solution
 Consider atropine depending on
degree of discomfort
 Recheck in 2-3 days to ensure
ulcer is not progressing in depth

70. Deep Corneal Ulcer
 Any stromal loss present
◦ Visible divot or depression of corneal surface
 Culture and cytology samples should be taken
prior to any irrigation or fluorescein staining
 Topical fluoroquinolone
◦ Ofloxacin penetrates intact corneal epithelium,
ciprofloxacin does not
 Topical atropine
◦ Caution in small patients
◦ Use ointment in cats
 Do not use any ointments if eye is at risk for or
has perforated
 Oral antibiotics, oral anti-inflammatories
 Discuss referral as ulcers of any stromal depth
can progress to perforation in a matter of hours
◦ If declined, recheck in 1-2 days to ensure depth is
not progressing

71. Keratoconjunctivitis Sicca (KCS)
 Irrigation of globe 2x daily to remove
debris
 Topical lacrostiumulant
◦ Cyclosporine
 Optiummune = cyclosporine 0.2%
 Also available in 1% or 2%
◦ Tacrolimus 0.03%
 Topical antibiotic or antibiotic/steroid
combination
◦ Neopolybac if concurrent corneal
ulceration
◦ Neopolydex if no corneal ulceration
 Topical lubricants
◦ Optixcare gel, Genteal severe gel
◦ Apply as often as required for lubrication

72. Glaucoma
 Immediate referral as permanent
blindness occurs within hours of
elevated IOP
 Primary glaucoma
◦ Cosopt (dorzolamide 2%/timolol 0.5%)
q 8 hours
◦ Latanoprost q 12 hours
◦ +/- Mannitol
◦ +/- Aqueouscentesis
 Secondary glaucoma
◦ Treat underlying cause of glaucoma
◦ Cosopt (dorzolamide 2%/timolol 0.5%)
q 8 hours
◦ Latanoprost q 12 hours
 DO NOT USE IF GLAUCOMA IS
SECONDARY TO LENS LUXATION

73. Uveitis
 Clinical signs
◦ Episcleral injection, miosis, aqueous cell or flare,
blepharospasm, iris rubiosis, corneal edema, ocular
hypotension
◦ Hyphema, hypopyon
 Screening diagnostics
◦ CBC/Chem/UA/T4
◦ Infectious disease titers – dependent on geographic location
 Treatment
◦ Topical anti-inflammatories
 Neopolydex, pred acetate
 Ensure fluoroscein stain negative prior to initiating treatment with a
topical steroid
◦ Topical cycloplegic – atropine
◦ Oral anti-inflammatories
◦ Oral antibiotics
 If no improvement within 24 hours or if IOP is elevated
(secondary glaucoma) refer for evaluation

74. Blindness
 Acute vision loss
◦ Immediate referral for best chance for definitive diagnosis and possible restoration of vision
 Optic neuritis
◦ Oral immunosuppressives are most effective when given early in the course of disease
 Retinal detachments
◦ Exudative, rhegmatogenous, dialysis/disinsertion
◦ Cats: most common cause is hypertension
 Exudative or bullous retinal detachments
 Check systolic blood pressure on all cats with the presenting complaint of blindness or vision changes
 Drug induced retinopathy
 Specific retinopathies
◦ Immune mediated – VKH, IMTP, IMHA, Systemic lupus
◦ SARDS vs IMR
 Infectious retinopathy – dependent on geographic location
 Retinal degeneration
◦ PRA or other inherited retinopathies
◦ Secondary to glaucoma