Strabismus and Eye Muscle Surgery G Vike Vicente

Strabismus and Eye Muscle Surgery G. Vike Vicente M. D. Eye Doctors of Washington G. Vicente, MD

• • Dr. Vicente Strabismus review outline: Horizontal strabismus – – – Anatomy review Nomenclature review Accommodative esotropia • – – – – – Infantile esotropia Viral & Diabetic esotropia Sensory strabismus Pseudostrabismus Duane’s syndrome Exotropia Convergence insufficiency Phorias Tropias Eye Muscle Surgery • • • Pediatric Bifocals? Recession Resection Vertical Strabismus – – – Parks’ Three step test Superior Oblique Palsy Brown Syndrome Inferior Oblique Overaction DVD- Dissociated Vertical Deviation Blow out Fracture

Skin Conjunctiva Tenon’s layer Eye Muscles Left eye G. Vicente, MD

Superior Oblique/Trochlear Muscle Eye Muscles Left eye Superior Rectus Muscle Medial Rectus Muscle Lateral Rectus Muscle Inferior Oblique Muscle G. Vicente, MD

Nomenclature • • Orthorphoria o Esophoria E Esotropia ET Intermittent Esotropia E(T) • • Exophoria X Exotropia XT Intermittent Exotropia X(T) At near X(T)’ convergent divergent • Right Hypertropia. RHT G. Vicente, MD

Right Hypertropia G. Vicente, MD

Strabismus Why is it Important? • Preserving Stereo acuity 8 yo with worsening X(T) Intermittent Exotropia. • Enlarging Visual field – for Pts with ET. • Appearance – Would you hire me? – Would you date me? – Is there something wrong with you? . . . • Diplopia G. Vicente, MD

Strabismus Why operate? Diplopia Can be a very debilitating symptom affecting lifestyle and quality of life. G. Vicente, MD

Accommodative esotropia n n n Typically presents around age 2 years, may present acutely. Always put +3. 00 sph OU when you see an ET for the first time. If its improved or resolved think Accom ET! Why is there ET with Accommodation? Eyes will usually converge when accommodation is attempted. If high hyperope then must accommodate, if accommodating then will converge, cross, specially at near.

Accommodative ET n n n n Use cyclogyl to measure Rx (wait 40 minutes) Recheck 4 weeks later with glasses, If still some ET present, use Atropine to make sure you measured the full CRx Tell parents they eyes will continue to cross every time the glasses come off. Always give full CRx, cycloplegic refraction for suspected Accom ET. Child might not like full CRx Use Atropine when using hyperopic glasses for the first time, it will break the accommodative spasm and allow the pt to get used to the glasses.

emmetropia CRx = +5 D hyperopia, no accommodation +3 D +5 D hyperopia (lets say the pt is able to accommodate 3 D, so effectively they are only +2 D hyperope) +5 D Rx +3 D accom spasm = +8 D, pt is only a +5. 00 so Pt ends up feeling like a -3. 00 D myope with your Rx My son does not like the glasses you recommended, The optician was right, they are too strong

+5 D +3 D +0 D With Atropine, no accommodation, no convergence for distance Pt happy, MD happy

Accommodative ET, AC/A = Accommodative convergence / accommodation n An accom ET crosses because he/she has normal AC/A. n Ie of high AC/A: n n n an emmetrope, WRx = plano OU pt At Distance they are ortho At near they are 25 PD ET’ They are over converging for a normal amount of accommodation. This is a high AC/A ratio.

AC/A n n Example of a pt with low AC/A? who underconverges? +8. 00 hyperope who is ortho at near and distance. They have adapted to their hyperopia by under converging.

Infantile Esotropia Syndrome n n n n Aka congenital esotropia Esotropia usually present by age 6 months Not improved with hyperopic Rx Most pts will never have good stereo Associated with inferior oblique over action And DVD, dissociated vertical deviation. The 2 latter conditions may not be present initially must remember to warn parents that if they occur in the future it is not the surgeon’s fault.

Infantile esotropia continued n n n Must rule out other causes CN 6 palsy from birth? Often spontaneous resolution Remember some variable, intermittent strabismus is expected until 4 months of age.

Esotropia associated with Viral illness n n n Often self limited, will spontaneously resolve in 3 -6 months. Acute Not improved with hyperopic glasses. Consider ruling out neoplastic causes. Treat/prevent amblyopia in the mean time

Esotropia associated with Diabetes n n n Abducens, lateral, CN 6 usually affected. Isolated unilateral palsy Ischemic Usually resolves after 4 -6 months. Consider Botox in the meantime, to which muscle… The medial rectus

Botox injection to Medial Rectus For temporary lateral rectus ischemic palsy

Sensory strabismus - Peds n n Young pts with poor monocular vision will often develop esotropia in that eye. OKAP NOTE: : : : DOES YOUR PEDS PT HAVE ESOTROPIA BECAUSE THEY CAN NOT SEE OUT OF THAT EYE? WHY? CATARARCT, RETINOBLASTOMA, MACULAR SCAR, ANISOMETROPIA?

Sensory strabismus- adults n Adult with poor monocular vision will often develop exotropia. n n Think dense cataract X 5 years Warn pt about possible post op diplopia and need for strabismus surgery Pt may have lost the ability to fuse. Think monovision, or unilateral under correction Lasik pt who had undiagnosed intermittent exotropia.

Pseudo ET Orthophoria Esotropia G. Vicente, MD

Initially the baby has a “button nose, with a very flat nasal bridge. The baby lids cover the medial white part of the eyes causing the appearance of the eyes being crossed. As the nasal bridge develops and grows forward it will drag the medial portion of the lids inward reducing the appearance of the eyes being crossed. 1 Pseudo ET G. Vicente, MD

Initially the baby has a “button nose, with a very flat nasal bridge. The baby lids cover the medial white part of the eyes causing the appearance of the eyes being crossed. As the nasal bridge develops and grows forward it will drag the medial portion of the lids inward reducing the appearance of the eyes being crossed. 2 Pseudo ET G. Vicente, MD

Initially the baby has a “button nose, with a very flat nasal bridge. The baby lids cover the medial white part of the eyes causing the appearance of the eyes being crossed. As the nasal bridge develops and grows forward it will drag the medial portion of the lids inward reducing the appearance of the eyes being crossed. 3 Pseudo ET G. Vicente, MD

Initially the baby has a “button nose, with a very flat nasal bridge. The baby lids cover the medial white part of the eyes causing the appearance of the eyes being crossed. As the nasal bridge develops and grows forward it will drag the medial portion of the lids inward reducing the appearance of the eyes being crossed. 4 Pseudo ET G. Vicente, MD

Exotropia n n n n n Intermittent is very common How symptomatic are they? Make sure they have BCVA glasses Diplopia? Often familial, so what? Dad had it too. “What hump? ” Intermittent exotropia can breakdown over time, check serial stereo. If worsening think surgery. Most common time of pediatric surgery is 7 years old. Can the pt converge?

Convergence insufficiency n n n Seen in kids who have trouble reading Adults with Parkinson’s disease Consider n n n Convergence exercises by a pediatric optometrist, or at home exercises with special software Decreasing add in bifocals to extend reading distance (holding reading material further away) Prisms, may used at times.

Nomenclature • • Orthorphoria o Esophoria E Esotropia ET Intermittent Esotropia E(T) • • Exophoria X Exotropia XT Intermittent Exotropia X(T) At near X(T)’ convergent divergent • Right Hypertropia. RHT G. Vicente, MD

Cover – Uncover test Orthophoria, normal No complaints, asymptomatic G. Vicente, MD

Cover – Uncover test Esophoria, abnormal, common Only seen when eye is covered Often asymptomatic, no complaints Note OS does not move. G. Vicente, MD

Cover – Uncover test Exophoria, abnormal, common Only seen when eye is covered Note OS does not move Often asymptomatic, no complaints. G. Vicente, MD

Alternate cover test • Remember to allow the pt time to fixate on the target, give them a minute. • Then quickly cover the other eye to prevent the pt from regaining fusion. • But do not go back and forth quickly because the pt will not have time to refixate.

Alternate Cover test Exotropia, intermittent May be visible with or without alternate cover May have intermittent diplopia, especially when tired or sick Mom sees misalignment every now and then. G. Vicente, MD

Alternate Cover test Exotropia, Constant May be visible with or without alternate cover May or may not have constant diplopia G. Vicente, MD

Cover Uncover test Left Exotropia, Constant May be visible with or without alternate cover Right eye preference G. Vicente, MD

Cover Uncover test Left Exotropia, Constant May be visible with or without alternate cover Right eye preference Note: no eye movement, so be sure to check both sides G. Vicente, MD

Normal Convergence Insufficiency G. Vicente, MD

Constant Strabismus Workup, acute presentation, nerve palsy – (Case of newly acquired left CN 6 in a 55 yo male) – Ischemic, GCA – Neoplastic • Invasive • Paraneoplastic • Compressive • Nerve regeneration – Longstanding breakdown. – Sensory – Degenerative CNS, Parkinson’s, MS – Infectious • Myositis (trichinosis) – Iatrogenic • Post non-strabismus surgery • Cataract, retrobulbar blocks (nerve damage vs. contracture) • Glaucoma, valves • Lasik – Mechanical • Trauma • Blow out Fracture • Tumor G. Vicente, MD

More Types of Strabismus – Convergent, Esotropia • • • – – Accommodative Congenital or infantile Acquired, CN 6 palsies Divergent, Exotropia Vertical, Torsional and Oblique • • Parks 3 Step test Superior Oblique Palsies – • • – Tucks vs. IO recessions Inferior Oblique Over action (V patterns) DVD’s Dissociated Vertical Deviation Complex Cases • • Adjustable vs Fixed sutures. Re-ops – • • Different measurements based on eye fixation Optics Angle Kappa G. Vicente, MD

How much to operate… 20 Alternate Cover test with Prism Exotropia, Constant Use prism to quantitate the deviation. Change prism power until movement is neutralized. Use this number to plan surgery G. Vicente, MD

Exotropia • Remember to measure while fixating at a far distance. • Also use +3. 00 sph in front of each eye to eliminate the accommodative convergence component at distance. • Consider 30 minute patch test to break fusion and really see how bad the XT can get.

How much to operate? – How much to operate • Tables: • Personal experience • • • • Dosages (surgical) bilat , 2 muscles ie for ET 40 PD recess 5. 5 mm both MR ET XT PD Rec Rst Rec Resect 15 3 3 4 2. 5 20 3. 5 4 5 3 25 4 5 6 4 30 4. 5 6 7 5 35 5 7 7. 5 5. 5 40 5. 5 7. 5 8 6 50 6 8 9* 7 60 6. 5 8. 5 10* 8

Where to operate? Option A: recess, loosen bilateral MR Medial Recti. Option B: recess Left MR and resect, tighten Left Lateral Rectus LLR RMedial Rectus L Lateral Rectus G. Vicente, MD

Large ET (65 PD) , bilateral MR recession, and LLR resection 3 d post op preop 1 month post op G. Vicente, MD

How much to operate -Patient preference § Case of monocular 85 yo BF with sensory XT § one eye or two? § Pt wished to not have OD operated, understood risk of under correction. § Therefore only recessed LMR 7 mm and LLR 6 mm. § Pt had some residual XT 15 -20 PD, but was happy, therefore surgeon was happy too. G. Vicente, MD

§ Sutures: – – § Most stitches used in eye surgery are thinner than human hairs. They will dissolve on their own over 6 weeks. They make your eye feel scratchy for the first few weeks. The antibiotic ointment and a cool compresses will alleviate this symptom if it occurs. Adjustable sutures What to expect after surgery – § Some double vision is normal for the first few weeks after eye muscle surgery. Precaution: – – – § Surgical Notes General post op hygiene Eye rubbing Can my child swim after his or her eye surgery? Length of surgery and recovery G. Vicente, MD

Notes on Anesthesia – Notes on Anesthesia § § General Pediatric anesthesia doctors Risk of Gen. Anesthesia in children Primary MD clearance G. Vicente, MD

Complications and Risks or surgery § § § Infection (1 in 3 years, Tx oral Abx) Nausea (Tx: Phenergan, etc. ) Blood loss – (what blood loss, maybe a little more than corneal surgery) § § § Loss of sight? (globe perforation) Scar tissue Diplopia Residual or consecutive strabismus Oculo-Cardiac Reflex – Bradycardia – Tx: Atropine G. Vicente, MD

When to operate? Or …When NOT to operate? • • • Prisms – – Fresnels Permanent prisms Occlusion (non-operable, CNS disease) BCVA (sharp image will often help pt fuse) G. Vicente, MD

When not to operate cont. • Botox – best for small, new, noncontractile strabismus, ie ischemic CN 6 palsy. – Or very variable strabismus ie cerebral palsy, to prevent contracture and save time. • Exercises, best for convergence insufficiency X(T)’. • Small Magnitude (<8 PD) • Tolerability, symptoms – head position, career, lifestyle • Surgeon aggressiveness, cut, cut • Pre-existing Amblyopia – (how much to treat before surgery? ) • Angle Kappa pseudo XT…