COMPLICATIONS OF SQUINT SURGERYSIVATEJA CHALLA

Only surgeons who do not have complications are those who do not

operate and those that lie about having no complications

A perfect result from strabismus surgery could include the following :

(1) Minimum immediate postoperative discomfort

(2) No apparent conjunctival scars

(3) Normal palpebral fissures

(4) Normal versions and ductions

(5) Orthotropia

(6) Equal and normal visual acuity

(7) Normal stereo acuity

Classified as

Per operative Immediate postoperative Late postoperative

PER OPERATIVE

Surgery to the wrong muscle

Scleral perforation

Haemorrhage

Detached or lost muscle

1.Surgery to the wrong muscle If surgical exposure is inadequate wrong muscle can be picked up Likely between IO and adjacent IR or LR

Avoidance : Give gentle tug to muscle and see effect on eye to know the

action Adequate conjunctival incision to get proper exposure Craniofacial dysostosis whole orbits excyclotorted and muscle

insertions are abnormal.

Mx : once error is recognised corrective surgery should be carried out

2.Scleral perforation

Penetration of the sclera occurs in the normal course of strabismus surgery, while perforation of the sclera represents a complication.

Cause Conjunctival limbal incision made with blade Disinserting tight rectus muscle with tenting of thin sclera Passing sutures for muscle fixation

Area of thin sclera behind muscle insertion

2.Scleral perforation

Recognition Probably goes unrecognised in many eyes Depends on severity of perforation Surgeon often feels that the needle pass was too

deep and immediately suspicious that the perforation may have occurred.

Recognized scleral perforations are often heralded by small piece of uveal or a bead of vitreous on the tip of the suture needle.

Do indirect ophthalmoscopy if suspected.

2.Scleral perforation

Avoidance Do not TENT UP the sclera while cutting muscle from insertion Have adequate exposure Needles should be placed in sclera with a short shallow track with

the widest dimension of the needle parallel to sclera Keep in mind.. 1.high myopes 2.monocular pts undergoing Sx on sound eye 3.connective tissue diseases

2.Scleral perforation

Hang-back recession

An non absorbable suture is secured in the muscle near the insertion and a second suture is placed 2 mm posterior to the insertion.

The muscle between the two sutures is then cut

The sutures are tied together to create a hang-back recession

2.Scleral perforation

Resections2.Scleral perforation

Management

Most are small and self sealing

Simple perforation without prolapse of vitreous or uvea should be left untreated

If uvea or vitreous prolapses or if the defect is large, it should be closed with sutures, with or without a scleral graft, and further prophylactic treatment to the retina should be considered

2.Scleral perforation

3.Haemorrhage Significant haemorrhage rarely complicate squint surgery. Excessive bleeding promotes scar tissue formation So try to reduce bleeding from all sites

Risk factors

Bleeding disorders Anti coagulants Re-surgery

Injury to ant ciliary vessels

Injury to vortex veins Scleral perforation

Avoidance Careful dissection coupled with awareness of the location of the

vortex veins Blood dyscrasias should be uncovered preoperatively in the

course of securing an adequate history Use gentle diathermy to keep operative field free of blood Vasoconstrictors such as phenylephrine drops can be used prior

to surgery

Treatment Severed vortex vein apply pressure, can use cautery diffuse orbital haemorrhage lateral canthotomy Can use osmotic agents to control IOP after severe orbital

haemorrhage

4. Detached or lost muscle one of the most devastating complications that a strabismus

surgeon can. No portion of muscle is attached to sclera Both muscle and capsule retracted posteriorly in to orbit May occur during intra op period or early post op period Most commonly affected muscle is MR.

Aetiology :1.Pterygium sx2.After squint sx3.After FESS4.Retinal surgery with buckling procedures

If occurs intra op… Try to retrieve immediately

avoid purposeless exploration in search of a lost muscle, because may worsen resulting in hemorrhage, fat intrusion and other complications.

later repair is far superior to the damage that may occur during aimless exploration.

Post operatively… Usually presents within hours to days after sx Large consecutive strabismus with duction deficit ma be

present Exploration is required

Avoidance

Careful suture placement securely in to muscle Ensure good firm bites while attaching muscle to sclera Do not tug or jerk muscles during surgery limit dissection of the posterior intermuscular septum, muscle

capsule, and check ligaments

Management of lost rectus muscle

Lost muscle retracts in to the orbit down in to its sheath in Tenon's capsule

Management of lost rectus muscle

SR and LR tends not to retract in to globe because of attachment to oblique muscles IR has attachment to IO, so easy to find MR , most difficult because no attachments at all.

IMMEDIATE POSTOPERATIVE Slipped muscle Immediate under and over correction Anterior segment ischemia Prolapsed Tenon's capsule Inclusion of plica semilunaris in conjunctival closure Conjunctival inclusion cyst Diplopia Post op infection Dellen Fat adherence syndrome

Slipped muscle

Definition : disinserted rectus muscle, which, after reattachment to the globe, retracts posteriorly within its muscle capsule, while the empty muscle capsule remains attached to the sclera

causes Failure of suture to include

all fibres of muscle and only capsule has been secured.

One of the suture holding the muscle becomes disinserted

C/F’SSYMPTOMS : Weakness of ductions in the direction of gaze Eye usually deviated away from affected muscle.

C/F’sSIGNS : Positive spring back test Positive see through test

NORMAL SPRING BACK TEST POSITIVE TEST

SEE THROUGH TEST

TREATMENT Locate muscle capsule , carefully follow posteriorly , isolate the

muscle , secure with sutures, bring back contact with globe

Prevention Full thickness locking bites which incorporate the muscle, and

not just the muscle capsule True locking bite at muscle border

Immediate under and over correctionCauses Insufficient or excessive surgery performed for the angle of squint Scarred muscle Slipped muscleAvoidance Reconsider surgical dosage in at risk patients Use adjustable suturesManagement treated according to Cooper's dictum; that is, as they were new

cases with appropriate medical, optical, orthoptic, or surgical remedies

Can wait and watch If slipped muscle take up for sx immediately

Anterior segment ischemia

70%

30%

Risk factors

Rare but potentially sight threatening complication

Signs and symptoms Mild cases show iris ischemia demonstrated with iris angiography Severe cases may include changes in pupil shape and reactivity,

postoperative uveitis, cataract, keratopathy, hypotony , and eventual loss of vision and even phthisis bulbi in rare cases.

Treatment

Because signs are Similar to uveitis, many treat with corticosteroids

Mild cases with topical steroids, severe with oral

Prevention

Prolapsed Tenon's capsule

Occasional Occurs through conjunctival incision Prevention appose conjunctiva properly

or suture Treatment large amount should be

excised and small amounts responds well to topical steroids

Inclusion of plica semilunaris in conjunctival closure

occur following strabismus surgery using a limbal incision Occurs due to suturing of plica to conjunctiva adjacent to limbus

May lead to cosmetically unsightly scar and lead to restriction of movements

Open and cut at conjunctival edge

Prevention

Conjunctival inclusion cyst Infrequent complication May occur anywhere but most commonly occur adjacent

to conjunctival incisions or near the new muscle insertion into the sclera

thought to arise from inclusion of conjunctival epithelial cells into the substantia propria or the sclera

These cells proliferate and later forms a cyst Tends to enlarge over time so better to remove on

recognition Treatment remove cyst intact

Diplopia Few pts may have diplopia in early post op period

Management : Patching may be required in acute phase Should be left to settle spontaneously by suppression esp in

children and young adults persisting more than a few days may require treatment with

prisms If these remedies fail, reoperation to relieve the diplopia may be

necessary

Post op infection

Serious infections are very uncommon Pre septal cellulitis or sub conj abscess may occur Endoph is extremely rare Potential source of infection may be normal flora

Treatment Mild conjunctivitis topical antibiotics Preseptal cellulitis and orbital cellulitis oral antibiotics Sub conj abscess drain the abscess Endophthalmitis intra vit antibiotics/PPV

Dellen

clearly defined excavations at the margin of the cornea Usually with in first 2 weeks D/T localised evaporation and dehydration of cornea Usually seen with limbal approach Common after resections compared to recesssions TREATMENT corneal rehydration by using lubricants

Fat adherence syndromeprogressive restrictive strabismus associated with the intrusion of extraconal orbital fat into the sub-Tenon’s or episcleral space during surgery

come into contact with the extraocular muscles, the sclera and/or other orbital connective tissue elements

fibrous scar develops

scar then contracts and leads to progressive strabismus with inhibition of ocular movement

Prevention

If small amount protrudes during sx can be reposited If large amount of fat protrudes during sx hemostat can be placed

at site of defect and excised.

Avoid damage to posterior tenons capsule Do not do blind sweeps for hooking muscles Avoid over aggressive dissection

Treatment Surgery very difficult Outcomes are very poor goal of treatment is to align the eyes in the

primary position and restore the ocular movements as much as possible

LATE POSTOPERATIVE

Inferior oblique adherence syndrome eye lid retraction

Eye lid retraction or advancement

Mainly associated with surgeries on vertical rectus muscles. Because sheath of these muscles attached to inner surface of lids Bothersome alteration of eyelid position is less likely to occur

following recessions and resections of 5 mm or less

Prevention Generous dissection around of the attachments

between the vertical rectus muscles and the eyelids can be performed at the time of surgery to prevent postoperative eyelid changes.

Inferior oblique adherence syndrome

Fat adhesion syndrome scar formation mainly if sx done to IO muscle

Eye progressive pulled downwards and cannot be elevated in FDT.

Prevention : Never hook IO blindly Take care not to bresk post tens capsule

Treatment : surgical area should be dissected carefully and adhesions lysed

until passive ductions are free

THANK YOU