Entropion & Ectropion

Normal eyelid position depends on a balance of anatomic forces: horizontal lid tension (from the medial and lateral canthal tendons), vertical retractor function (lower lid retractors, levator), and orbicularis oculi tone. Entropion is inward rotation of the eyelid margin and ectropion is outward rotation, both most commonly affecting the lower eyelid and resulting from an imbalance of these external and internal forces.¹

Involutional entropion results from horizontal lid laxity, lower lid retractor attenuation/disinsertion, and orbicularis override, allowing the margin to rotate inward. Involutional ectropion results primarily from horizontal lid laxity (canthal tendon laxity) combined with gravitational effects, allowing the margin to fall away from the globe. Other causes include cicatricial changes (trauma, surgery, chronic inflammation, skin disease), paralytic ectropion (facial nerve palsy), and spastic entropion (orbicularis override from chronic irritation).

Both conditions cause ocular irritation and loss of proper eye protection.¹ Entropion causes foreign body sensation from inward-turned lashes; ectropion causes epiphora and exposure-related dryness.

Key differentials: trichiasis without frank entropion, floppy eyelid syndrome (often with obstructive sleep apnea), blepharospasm without true malposition, and distinguishing cicatricial from involutional etiology, which changes surgical planning.

Diagnosis is clinical: inspection of lid position on primary gaze and downgaze, plus formal horizontal laxity assessment via the snap-back test and lower lid distraction test.² Untreated disease can progress to recurrent conjunctival/corneal inflammation, conjunctival neovascularization, corneal abrasion, or perforation.¹

Surgical repair is definitive treatment for both conditions. A study of lower eyelid entropion/ectropion repair (including modified Wheeler's method for entropion) found significant symptom and grading-scale improvement, with very good functional/esthetic results in 70% overall and over 80% with modified Wheeler's specifically; recurrence occurred in 12-18% of cases with only minor complications, and quality of life improved significantly.¹ For involutional ectropion, the lateral tarsal strip procedure achieved a 95% success rate and 86% excellent postoperative position in 85 eyelids, with no significant correlation between preoperative severity and surgical improvement, and mild self-limited complications resolving within about a week.²

• Both conditions are most commonly involutional, driven by horizontal lid laxity
• Snap-back test and lower lid distraction test are essential bedside laxity assessments²
• Surgical repair produces significant, durable relief with low complication rates¹
• Lateral tarsal strip performs well regardless of preoperative ectropion severity²
• Common pitfall: attributing tearing/irritation to dry eye without examining lid position
• Common pitfall: failing to distinguish cicatricial from involutional etiology