Pediatric ophthalmology (Proceedings) - Veterinary Healthcare


Pediatric ophthalmology (Proceedings)


• Basic Pediatric Ophthalmic Examination (minimum database)
      - Menace response- not present until 2-3 months of age
      - Palpebral reflex, Dazzle reflex, Pupillary Light Reflex
      - Direct examination with head loops, direct ophthalmoscope
      - Schirmer tear test (can be lower in puppies, ~10mm/min)
      - Fluorescein stain
      - Tonometry (normal to be slightly higher, ~20-25mmHg)

• Normal Pediatric Exam Findings
      - Corneal epithelial opacities
      - Heterochromia iridis
      - Lens capsule pigment deposition
      - Neonate tapetal reflex (blue until 4 months of age)
      - Subalbanotic fundus in blue-eyed animals

• Pediatric Ophthalmic Abnormalities
      - ADNEXA
          ■ Dermoids (congenital mass of tissue in an abnormal position)
          ■ Eyelid agenesis (feline)- involves upper eyelid coloboma; bilateral; can have other anomalies: persistent papillary membranes, choroidal colobomas
          ■ Entropion- temporary eyelid eversion (<11mo. of age), Hotz Celsus (>11mo.)
          ■ Ectropion- Outward rolling of eyelid
                o Conjunctival tissue is exposed
                o Lagophthalmos (inability to close lids completely) may occur
                o Low grade conjunctivitis is most common
          ■ Macroblepharon - Abnormally large palpebral fissure
                o Lagophthalmos leading to instability of pre-corneal tear film which can lead to keratitis
                o A required feature in St. Bernard, Clumber Sp, and Bloodhound
                o Canthalplasty may help reduce size of palpebral fissure
          ■ Distichiasis
                o Hairs that arise from the meibomian gland duct openings
                o In most cases, they are not clinically relevant because fine hairs float in the pre-corneal tear film
                o Can cause irritation and a reflex lacrimation, blepharospasm, conjunctivitis, keratitis, ulceration
                o Cryotherapy for removal
          ■ Ectopic cilia
                o A variant of distichiasis- cilia emerges through the palpebral conjunctiva
                o Typically occurs in upper eyelid
                o Blepharospasms (can be intense)
                o "Non-healing" ulcer in a young dog typically in dorsal cornea
                o Excessive lacrimation
                o Sharp surgical excision, +/- cryotherapy
          ■ Caruncular trichiasis- usually benign, can cause keratitis and eipiphora
          ■ Prolapse gland of the third eyelid
                     Weakness in connective tissue attachment between nictatating membrane ventrum and periorbital tissues
                     Typically occurs prior to 2 years of age
                     Chronic conjunctivitis and discharge
                     Tear production is initially greater than normal eventually becoming subnormal
                     Surgical replacement recommended- anchoring or pocket technique
          ■ Bent cartilage
                     Eversion or inversion (rare) of the shaft of the cartilage of the third eyelid
                     Inherited in German Shorthair pointer, but seen in other breeds
                     Thought to result from rapid growth of the posterior portion of the cartilage compared to that of the anterior portion
          ■ Papilloma – canine oral papilloma virus in young animals
                     Lesions can occur on the eyelid, conjunctiva, or cornea
                     Most spontaneously regress, but ocular forms may not
                     Wide excision if needed, +/- cryotherapy
          ■ Imperforate punctum/ micropunctum- unilateral or bilateral epiphora
                     Most common malformation of the nasal-lacrimal duct
                         • None, cosmetic
                         • Excise conjunctiva over opening and cannulate for 3 weeks
          ■ Lacrimal gland aplasia and hypoplasia – zero tears at a young age, unilateral, small breed dogs


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