Resolving dry eye in RGP wearers

3/9 stain

• when the corneal surface isn't adequately resurfaced with tears after the blink
• edge of GP lens holds lid away from corneal surface during blink
• incomplete blinking
• may see vascularized limbal keratitis

Adjusting the fit to minimize excessive edge lift and inferior position

Strive for superior lens position by:

• decreasing diameter
• reduce CT
• +/- lenticulars
• reduce edge clearance
• steepen PC radius
• narrow PC width
• reduce edge thickness

Patient CL compliance handout from AOA

What You Need to Know About Contact Lens Hygiene & Compliance
http://www.aoa.org/x8024.xml

Vogt-Koyanagi-Haraa (VKH) syndrome

• bilateral granulomatous panuveitis associated with serous retinal detachments, optic disc edema, neurologic abnormalities and skin pigment changes
• systemic manifestations: tinnitus, vitiligo, alopecia, headache and meningismus
• T cell-mediated autoimmune process directed against melanocyte antigens
• more prevalent in Asians, Latinos and American Indians
• women slightly > men
• any age but usually 4th-6h decades of life

4 phases

• prodromal
• acute uveitic (poor VA, severe AC inflammation w/ or w/o posterior synchiae)
• convalescent
• chronic recurrent (RPE alterations, widespread loss of choroidal melanocytes producing a sunset-glow fundus and choroidal Dalen-Fuchs-like nodules, cutaneous vitiligo, poliosis and alopecia)

Complications

• catarct, glaucoma, CNV, subretinal fibrosis, ERM, macular atrophy

Treatment

• prompt initiation of high-dose systemic corticosteroid therapy (1 to 1.5 mg/kg/day) concurrent with a corticosteroid-sparing immunosuppresive agent) , tapering patients off within 2-3 months
• rapid and aggressive treatment is important to minimize disease duration and lessen the risk of progression into a chronic recurrent form of disease and reduce the incidence of systemic and ocular complications

Lagophthalmos evaluation/treatment

May lead to corneal exposure --> keratopathy --> ulceration/infections keratitis

Taking the history
recent trauma or surgery involving the head/face/eye
past infections e.g. herpes zoster
past symptoms suggestive of thyroid disease or obstructive sleep apnea

Testing the lids and globe
ask patient to look down and gently close both eyes
lagophthalmos is present when a space remains b/w the upper and lower eyelid margins in extreme downgaze
measure this space with a ruler
record the blink rate an the completeness of blink
test cranial nerve function (pay attention to ocular motility and the strength of the orbicularis oculi muscle by evaluating the force generated on attempted eyelid closure)
presence and quality of Bell's phenomenon should be noted (cornea is better protected when the eye rolls upward on attempted closure of the eyelids)

Testing the cornea
test corneal sensitivity by applying soft cotton to the unanesthetized cornea and comparing the blink reaction with that of the fellow eye
describe presence of PEE with NaFl
record TBUT

Etiology

Facial nerve (VII)

• innervates frontalis muscle (raises the eyebrow) and the orbicularis oculi muscle (closes the eyelid)
• loss of function of the VII nihibits eyelid closure, blink reflex, and lacrimal pumping mechanism
• also innervates the muscles of facial expression including the zygomaticus (elevate the cheeks) and corrugator supercilii and procerus (depress the eyebrow) which help facial symmetry

Trauma

• VII is susceptible to blunt trauma or laceration along it's bony course
• fractures to the skull base or mandible can damage the nerve or one of its branches
• neurosurgical procedures

Cerebrovascular accidents

• VII receives its blood supply from the anterior inferior cerebellar artery (susceptible to ischemic damage)

Bell's Palsy

• idiopathic VII palsy thought to be associated with an acute viral infection or reactivation of herpes simplex virus

Tumors

• acoustic neuromas in the cerebellopontine angle and metastatic lesions are most commonly associated with lagophthalmos
• need MRI with gadolinium

Infections, immune-mediated causes

• less common causes: Lyme disease, chickenpox, mumps, polio, Guillain-Barre syndrome, leprosy, diphtheria and botulism

Mobius' syndrome

• rare, congenital condition with CN palsies (esp. VI and VII), motility disturbances, limb anomalies and orofacial defects

Eyelids

damage or degeneration of any of the eyelid tissue structures (skin/subcutaneous tissue, orbicularis oculi muscle, orbital septum, orbital fat, muscles of retraction, tarsus, conjunctiva) may inhibit good eyelid closure

Cicatrices

• chemical or thermal burns
• ocular cicatricial pemphigoid
• Stevens-Johnson syndrome
• mechanical trauma
• above may cause scarring of the soft tissues or retractor muscles

Eyelid surgery

• excessive removal of eyelid skin or muscle (blepharoplsty, tumor excision)
• overcorrection in ptosis repair

Proptosis

• exophthalmos in thyroid ophthalmopathy

Enophthalmos

• aquired causes (orbital blowout fractures, orbital fat atrophy from trauma, infection, inflammation, aging or wasting disease such as linear scleroderma or HIV-AIDS)
• phthisical or prephthisical eye
• scirrhous carcinomas leading to contraction of orbital fat

Floppy eyelid syndrome

• result of severe laxity and flexibility of the superior and inferior tarsal plates
• may be associated with obstructive sleep apnea

Symptoms

• FBS and tearing
• pain in AM from increased corneal exposure and dryness during sleep
• blurry vision from unstable TF

Work-up and treatment

• Medical treatment and supportive care for the cornea (non-preserved artifical tears at least QID, ointments QHS/PRN, moisture gogles, methylcellulose)
• Tarsorrhaphy (suturing lateral 1/3 of eyelids, temporary or permanent)
• Gold weight implantation (gold is inert and doesn't show through thin skin of eyelid)
• Uper eyelid retraction and levator recession (for lagophthalmos due to thyroid ophthalmopathy)
• Lower eyelid tightening and elevation (tightenting procedure will improve apposition fo the lower eyelid to teh globe and decrease tearing)
• Ancillary surgical procedures (facial surgery)

Myasthenia Gravis

• autoimmune disorder in which antibodies prevent the neurotransmitter acetylcholine from attaching to muscle receptors, thereby interfering with muscle contractions
• characterized by fatigability of voluntary eye movements (diplopia worsens as day progresses, improves with sleep)
• can present with diplopia, ptosis or both

Tests

• sustained upgaze: patients will show a gradual worsening as the levator muscle fatigues
• ice pack test: apply a cold pack to the eyelid for 5 minutes (cold temp allows Ach to have more time to react with the muscle receptors), check for improvement in ptosis
• sleep test: have the patietn take a nap in the exam chair for 30-45 minutes, check for improvement in ptosis
• Tensilon is an IV cholinergic drug that typically shows improvement in muscle function within seconds

Treatment

• Mestinon (cholinergic drug) and immunosuppresive therapy (neurophthalmology)
• if medications don't eliminate ptosis/diplopia, may try prismatic corrections and ptosis crutches

Differentials

• 3rd nerve palsy: has vertical and horizontal component
• skew deviation: usually appears with concomitant hypertropia and other abnormal eye movements such as nystagmus
• disease of the orbit: neoplastic, inflammatory, infectious, traumatic can cause proptosis, lid retraction, periorbital edema, conjunctival hyperemia, disc edema

Determining Prism

Sheard's criterion

• Prism needed = 2/3 (phoria) - 1/3 (compinsating fusional vergence)
• eg: pt has 6 XP and BO to blur is 6, the prism needed is 2/3 (6) - 1/3 (6) = 2 BI

Percival's criterion

• Prism needed = 1/3 (greater limit of BI or BO range) - 2/3 (lesser limit of BI or BO range)
• eg: pt has 6 XP and BO ranges of 6/10/8 and BI range of 21/26/22, prism needed = 1/3 (21) - 2/3 (6) = 3 BI

Parks-Bielschowsky Three Step Test (for head tilts "torticollis")

• Which eye is hyper in primay gaze?
• In which horizontal gaze does hyperdeviation increase?
• In which direction of head tilt does the hyperdeviation increase?
• right hyper --> right gaze --> right tilt = LIO
• right hyper --> right gaze --> left tilt = RIR
• right hyper --> left gaze --> right tilt = RSO (most common cause of vertical dipl.)
• right hyper --> left gaze --> left tilt = LSR
• right hyper --> right gaze --> right tilt = RSR
• right hyper --> right gaze --> left tilt = LSO (most common cause of vertical dipl.)
• right hyper --> left gaze --> right tilt = RIR
• right hyper --> left gaze --> left tilt = RIO

Postures and Treatments

• Left head turn --> Right gaze preferred --> LLR or RMR paresis --> give yoked prism base left
• Right head turn --> Left gaze preferred --> RLR or LMR paresis --> give yoked prism base right
• Left head tilt --> Right hyperdeviation --> RSO paresis (most common cause of vertical diplopia)--> BD over right eye if longstanding
• Right head tilt --> Left hyperdeviation --> LSO paresis (most common cause of vertical diplopia)--> BU over left eye if longstanding
• Head tip back --> Downgaze preferred --> V-pattern exotropia or A-pattern esotropia --> BU yoked prism
• Chin depressed --> Upgaze preferred --> A-pattern exotropia or V-pattern esotropia --> BD yoked prism

Coding Dry Eye

Ocular findings:

• Tear film insufficiency (375.15) -- test show decreased TF; for punctal plugs diagnosis
• Keratoconjunctivitis sicca, not specified as Sjogren's (370.33) -- observation of "inflammation of the conjunctiva and cornea, characterized by "horny"-looking tissue and excess blood in these areas"
• Punctate keratitis (370.21)
• Exposure keratitis (370.34)
• Sjogren's syndrome (710.2)

Patient symptoms:

• Eye pain (379.91) -- may be used for all levels of eye discomfort, e.g. burning/stinging
• Redness of eyes (379.93) -- r/o episcleritis (379.01) and scleritis (379.00)
• Epiphora (375.20) -- dry eye due to reflex tearing

Procedure diagnastic codes:

• External ocular photography (92285) -- photos need to document the efficacy of treatment or the progression of the disease, and not just enhance the medical record or billable procedures
• Bandage contact lenses (92070) -- covers fitting and supply of lens