aCase 9a

by Dr.Chua

A 3-month-old baby girl (Figure 1) was referred from another hospital because of a right upper lid coloboma which was present since birth. There was also a notch on her nose. Otherwise, her development was normal. There was no family history. Examination showed a upper lid coloboma of 50% of the upper lid width. There was a flap of skin attached to the cornea centrally. The corneal exposure was present when the patient slept. Fortunately, the cornea appeared intact as the mother has been applying lubricant at night for the past few months.

A decision was made to close the defect and the patient underwent a lid closure procedure.

Figure 1.Right upper lid coloboma of 50% of the upper eyelid with a flap of skin

attached to the cornea centrally.

a. What additional examination should be performed?

Fundal examination and refraction.

In congenital upper eyelid defect there's a full-thickness defeciency involving the conjunctiva, tarsus, orbicularis and skin. Most cases occur in isolation. The exact mechanism of upper lid coloboma is unknown and many possibilities have been put forward. In our patient, the notch on the nose and the unilateral coloboma suggest that amniotic membrane band may be responsible.

Unlike iris coloboma, an assocaited choroidal coloboma is uncommon in upper lid coloboma but examination under anaesthesia during the operation should be performed. Ametropia is common in upper lid coloboma and refraction should be performed.¹ In this patient, the refraction was: +0.50 /-1.25 X 80 RE and +0.50 /-1.00 X 90 LE.

b. In adult, Cutler-Beard's technique and lower lid transposition flap are often used to correct  a large upper lid defect. Why are these techniques not suitable for an infant?

Both Cutler-Beard's technique and lower lid transposition flap are excellent techniques for replacing large upper lid defect. However, both techniques involves two-stage operations in which the visual axis have to be occluded for a certain period of time. This can lead to occlusion amblyopia in infants and should be avoided if possible.

c. Name three appropriate techniques for closing the defect in this patient.

1. Tenzel flap with direct closure after fashioning the edge of the defect. This is the simplest techniques but leaves the patient with a long scar in the lateral canthal region.²

2. Replacement of the conjunctiva with an oral mucosa graft and a sliding skin flap as described by Hauben and Tessler.³ In this operation (see Figure 2), the tarsal plate is not replaced but the authors did not find this a problem.

Figure 2. Closure of coloboma by Hauben and Tessler.

3. Tarsoconjunctival sliding flap with advancement skin flap.⁴ This operation resemble the Hugh's flap except that the tarsoconjunctival flap is moved medially to cover the defect. This technique was choosen to close the defect in this patient.

Figure 3. Examination of the lid before reconstruction showed normal lateral upper lid but the medial lid was attached to the bulbar conjunctiva. Estimation of the defect was made by pulling the lateral and medial edges together. The skin flap attached to the cornea was dissected free from the cornea and sclera. A tarsoconjunctival flap is made by first cutting horizontally at 4mm from the lid margin to avoid the marginal artery. The horizontal cut was the same length as the width of the defect. A vertical cut was performed to complete the flap. The medial lower edge of the tarsonjunctival flap was sutured to the tarsus of the medial eyelid. The lateral edge of the tarsoconjunctival flap is sutured to the lower edge of the lateral eyelid. To reduce lid tension during closure, a canthotomy was performed. The flap was covered with the skin flap dissected free from the eye. To avoid epithelium growing into the lid margin and cause cornea rubbing, the skin was sutured to 2 mm from the edge of the flap.

Figure 4. Right upper lid appearance at 2 day post-operative.

Reference:

1. Seah LL, Choo CT, Fong KS. Congenital Upper Lid Colobomas: Management and Visual Outcome. Ophthalmic Plastic and Reconstructive Surgery. Vol. 18, No. 3, pp 190–195.

2. Mustarde JC Repair and Reconstruction in the Orbital Region (Hardcover). Churchill Livingstone; 3rd edition (January, 1991)

3. Hauben D J, Tessler Z. One-stage Reconstruction of a Large Upper Lid Defect in a Newborn. Plast. Reconstr. Surg. 1989;83:337-40.

4. DiFrancesco LM, Codner MA, McCord CD. CME. Upper lid reconstruction. Plast. Reconstr. Surg. 2004; 114:98e-107e.