Ectropion (Fig 12-1) is an outward turning of the eyelid margin and may be classified as
Most cases seen in a general ophthalmology practice are involutional, with horizontal eyelid laxity being the primary cause. Horizontal lower eyelid tightening is the common component in surgical repair of the various types of ectropion (see the section “Horizontal eyelid tightening”). Congenital ectropion of the eyelid is rare and is discussed in Chapter 10 of this volume and in BCSC Section 6, Pediatric Ophthalmology and Strabismus.
Involutional ectropion results from horizontal eyelid laxity in the medial or lateral canthal tendons or both. Untreated, this condition leads to loss of eyelid apposition to the globe and eversion of the eyelid margin. Chronic conjunctival inflammation with hypertrophy and keratinization results from mechanical irritation and drying of the conjunctival surface. Involutional ectropion usually occurs in the lower eyelid because of the effects of gravity on a horizontally lax lower eyelid.
Horizontal eyelid tightening
The lower eyelid can be tightened by a variety of surgeries. Horizontal laxity can be detected by the snapback test or the distraction test. Lateral stretching of the eyelid at the time of the preoperative evaluation helps the surgeon assess whether lateral canthal resuspension would return the eyelid to its normal anatomic position (Fig 12-2A). In the lateral tarsal strip procedure, the tarsus is sutured directly to the lateral orbital rim periosteum (Fig 12-2B). The goal of this procedure is to correct the position of the eyelid while maintaining the horizontal dimension of the palpebral fissure and a sharp, correctly positioned lateral canthal angle (Video 12-1).
Lateral tarsal strip procedure. Courtesy of Bobby S. Korn, MD, PhD.
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Laxity of the lower limb of the medial canthal tendon can be diagnosed by demonstration of excessive lateral movement of the lower punctum with lateral eyelid traction. Repair of medial canthal laxity is more challenging than repair of horizontal lower eyelid laxity, as the anterior and posterior limbs of the medial canthal tendon surround the lacrimal sac. The repair may be complicated by a kinking of the canaliculus or distraction of the punctum away from the globe, with resultant epiphora.
Medial spindle procedure
In cases of mild medial ectropion with punctal eversion, a medial spindle procedure can be performed. The procedure involves a horizontal fusiform excision of conjunctiva and eyelid retractors 4 mm inferior to the puncta, followed by inverting sutures for closure (Fig 12-2C). In cases with associated horizontal eyelid laxity, lateral canthal tightening (see Fig 12-2B) may be used in conjunction with this procedure.
Figure 12-2 Lower eyelid tightening. A, Lateral stretching of the eyelid demonstrates the potential of lower eyelid tightening. B, Lateral tarsal strip procedure: anchoring the tarsal strip to periosteum inside the lateral orbital rim. C, Medial spindle procedure: outline of excision of conjunctiva and retractors.
(Part A courtesy of Bobby S. Korn, MD, PhD; illustrations by Christine Gralapp.)
Repair of lower eyelid retractors
Retractor laxity, disinsertion, or dehiscence may be associated with ectropion, especially when the eyelid is completely everted, a condition known as tarsal ectropion. Attenuation or disinsertion of the inferior retractors may occur as an isolated defect or may accompany horizontal laxity in involutional ectropion. When both defects are pre sent, repair of the retractors is combined with horizontal tightening of the eyelid.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.