Indications
- non-compensated convergent strabismus, divergent strabismus
- diplopia/asthenopia
- cosmetic reasons
Differential diagnosis
- DVD (dissociated vertical deviation)
Alternative therapy
none/botulinum toxin/prisms
Preoperative
- diagnosis (including orthoptic status, good quality frontal, side and up-gaze pictures)
- consent form: always mention risk of undercorrection, overcorrection, double vision, scarring, recurrence, need for revision surgery
- anaesthesia: general anaesthesia
- anticoagulation: adjust antiplatelet or anticoagulant medication if possible (stop Aspirin® 10 days before surgery; Marcoumar® INR >= 1.2 on the day of surgery; new anticoagulants (Eliquis®, Lixiana®, Xarelto® etc.): stop 2 days before, on the day of surgery and 2 days after surgery)
Preparation
- preoperatively: check that anticoagulation has been stopped, clean skin, no creams, no make-up, no skin tanning if skin lasers are planned
- 3x Tetracaine SDU® 1% eye drops (every 5 minutes)
- 2x Alphagan® eye drops 10 minutes apart to reduce bleeding
Surgical setup
- operating table: supine position, elevate head if needed to reduce bleeding, surgical loupes or operating microscope, bipolar cautery
- Barraquer eyelid speculum, Castroviejo calipers, 2x anatomical tying forceps (conjunctiva forceps, e.g. Tuebingen tying forceps), 1x fine toothed tying forceps (e.g. Castroviejo 1x2 teeth 0.3mm 10cm), 1x fine Paufique forceps
- 3x Graefe muscle hooks (small/medium/large), 1x Jameson muscle hook, 1x Bonn retractor, 1x muscle spatula, 1x muscle clamp
- curved Westcott scissors, Stevens tenotomy scissors, fine Castroviejo needle holder, Desmarres eyelid retractor (small/medium), surgical basin
Disposables
- Hibidil® solution, ice-cold NaCl solution
- sterile drape with plastic film for the lashes, marking pen, gloves
- dental rolls for haemostasis, compresses for haemostasis, lubricating gel for the cornea
Sutures
- 6-0 double-armed S-14 Vicryl® for muscles
- 8-0 Vicryl® for conjunctiva
Surgical technique
Tetracaine eye drops. Skin disinfection. Cover with a drape exposing both eyes, with protective film for the lashes. Hibidil® disinfection of the conjunctiva. Protect the cornea with lubricating gel.
Perform a traction test. Conjunctival peritomy, dissect and expose the muscle, engage the muscle with the hook. Dissect Tenon's capsule from the muscle.
Rectus muscle recession: secure the muscle with 6-0 Vicryl® at the insertion, use a muscle clamp if needed. Separate the muscle from the insertion. Mark the recession distance on the sclera with a marking pen. Reinsert the muscle on the sclera in lamellar fashion with the 6-0 suture. Refold the conjunctiva over the muscle. Conjunctival suture with 8-0 Vicryl®.
Rectus muscle resection: mark the resection distance on the muscle. Secure the muscle with 6-0 Vicryl® at the markings. Separate the secured muscle from the sclera. Remove the stump if needed. Reinsert the muscle on the sclera in lamellar fashion with the 6-0 suture. Refold the conjunctiva over the muscle. Conjunctival suture with 8-0 Vicryl®.
Tobradex® ointment. Pad the eye for a few hours if needed.
Postoperative
- elevate head, wear glasses to train binocular vision as soon as the eye pad is removed
- Tobradex® eye drops 4 times a day
- Tobradex® ointment before sleeping
- lubricating eye drops 4 times a day if needed
- Prednisone 40-40-20-20mg for 4 days p.o.
- Paracetamol 1g every 6-8 hours if needed (max 4g/day)
Follow-up
- 1 day postop: check wound, pain, diplopia
- 7 days postop: orthoptic assessment; wound healing assessment and adjust topical medication
- 3 weeks postop: orthoptic assessment, wound healing; schedule next appointment depending on findings
