CNP III: Sx Management

Points to remember

• Wait for 6/12 stability before Sx

 Conservative management in the interim

 Post-op care should and will involve conservative

treatment

 Don’t forget this

 Surgery  to regain BSV/improve

function/psychosocial

Pharmacological

• Botulinum Toxin (pg187 A&D)

 Weaken un-opposed antagonist

 Prevent contracture

 Maintain BV

 Unsuitable for Sx

• Diagnostic

 Mimics surgery

• Bupivacaine

 Local Anaesthetic – has a myotoxic effect

 Strengthen u/a muscle

• Shortens and stiffens muscle

 Up to 10^ of deviation

 Combined with BT

Surgery Re-cap

Aims

 Straighten the eye : functional or non-

functional

 Restore/maintain concomitance

 Relieve symptoms

 Minimal number of procedures

 Reversible surgery if possible

 Changes in position of insertion or muscle length

results in change in magnitude or direction of force

• Weakening procedures

– Recession

– Myectomy

– Fadenisation

– Disinsertion

• Strengthening procedures

– Resection/ Advancement

– Tuck

Surgery: III - Complete

Total- difficult!

 Treat the exotropia

 Patient expectations

 Ptosis

 Ansons and Davis

 SO anterior medial transposition

 LR medial transposition

 Horizontal muscle Sx with or without traction sutures

 Partial

 Dependent on residual function and muscles affected

 Pilocarpine 1% for photophobia

 Importance of Orthoptic investigation to this planning

7

III CNP

What are we left with.......

• Complete/Inferior Div/Superior Div

 Exotropia - could be large

 Hyper or Hypo

 Combination of H & V

 May need to tackle one at a time  multiple

procedures

• Advice to patient

Complete total III CNP  difficult:

 Large recession of MR and resection of LR

 Traction sutures to anchor eye in new position

 Expect post-op diplopia

 Exo can re-occur

III – Traction Sutures

• Traction Sutures (Kahir, Dawson and Lee, 2008)

 LR recess, MR resect

 Adduction traction suture (6/52)

 30/33 left with ‘good alignment’ based on patient satisfaction

 Mean improvement – 47PD

• Yonghong et al (2008)

 Isolated or combined muscle surgery where appropriate

 Good alignment

 No treatment yields consistently excellent results

• Flanders et al (2012)

 Good functional and cosmetic outcome

 Muscle involvement dependent

 Residual muscle function

 Complications of horizontal and vertical deviation

III CNP – Divisional

Superior Division

• Mild u/a

 Weaken contralateral IO

 If small angle in pp

 Recess contralateral SR (balancing the deviation)

 Recess contralateral SR and ipsilateral IR (if large angle in pp)

• Marked u/a or limitation

 Transposition of horizontal recti

III CNP – Divisional - inferior

• Similar to Complete III

 Exotropia  MR recess, LR resect

• Vertical deviation

 SR recession

IV Surgery decisions e.g. Scott/Knapp

• What are we left with......

 Hyper

 Torsion

 Decision based on

 Deviation in pp

 Position of maximum deviation

 Position of maximum symptoms

 Measurement

 Motility

IV Surgery decisions e.g. Scott/Knapp

• Class 1- 7  not all use this system

 Based on tackling the largest deviation/ motility problem

• Hyper

 Strengthen SO

 Weaken IO

 Balance out  recess contralateral IR

• Torsion

 Harada Ito

Surgery: IV

Hatz, Brodsky and Killer (2006)

 Isolated IO Sx

 Favourable up to 15PD in pp

Durnian and Marsh (2011)

 SO Tuck

 71% success with one procedure

 Vertical and torsion improved

 ‘One tightness fits all’

Nishimura and Rosenbaum (2002) – Harada Ito

 Reduction from 10.7o 1.0 o 2 months post-op (p<0.05)

 Regression between 2 months and 2 years follow-up (5.3o)

Murray, Marsh and Newsham (2021)

 Reduction in torsion post-op (p<0.01), remained for 12/12

 Regression to pre-op measurement

 Significantly reduced V-eso pattern (p<0.05)

6th sx

Esotropia-

• Worse for distance

 Total vs Partial

• LR resect, MR recess

• Transpositions

Partial VI – Ansons and Davis (2014)

 Concomitant

• Recess / Resect (poss x3 muscles if >30^)

 Incomitant (pp)

• Pt has dev in pp, worse in lat gaze

• Recess / Resect with Faden’s

 Incomitant (lat gaze)

• Pt has no dev in pp but dev in lat gaze

• Contralateral MR Faden

• Recession contralateral MR

Surgery: VI

 Role of BT here in planning

 Leiba et al (2010)

• Vertical transpositions and MR BT

• Pre-op (38PD) to 3/12 post op (4PD) – p =0.0004

• Pre-op to final follow-up (8PD) – p = 0.003

• 73% no diplopia pp at final follow-up

• 32% did have vertical deviation at final follow-up (n=3)

 Holmes et al (2002)

• Long term outcomes chronic VI (24/12)

• 52% fully successful

• 75% partially successful

• Concluded chronic VI require 2 surgical

procedures

Total VI – Ansons and Davis (2014)

No residual function of LR

 Full muscle transposition

 Less risk of anterior segment ischemia

 Partial muscle transposition

 Hummelsheim’s (lateral trans of vertical recti)

 Jensen’s (union of vertical to lateral recti)

General Surgical Principles: Isolated muscle paresis

Summary of Management

Indications for further investigations are aetiological

dependent

 6/12 waiting time for recovery before Sx or other

permanent options

 Vascular palsies tend to recover well

 BT may be an adjunct to surgery

 Post-operative care

 Back to Conservative!!