A 68-year-old man from rural India presents with a 6-month history of progressive eye irritation, foreign body sensation, and tearing in the left eye. On examination, the lower eyelid margin is turned inward, with the lashes rubbing against the cornea. Corneal abrasion is noted on fluorescein staining. The patient reports the symptoms worsen when he squints or during windy conditions. What is the most likely diagnosis?

Explanation

## Diagnosis: Entropion of the Lower Lid ### Clinical Presentation The patient presents with the classic triad of entropion: 1. **Inward turning of the eyelid margin** — the lower lid is inverted 2. **Lash-cornea contact** — causing corneal abrasion and irritation 3. **Tearing and foreign body sensation** — secondary to corneal irritation ### Key Distinguishing Features | Feature | Entropion | Ectropion | |---------|-----------|----------| | Lid margin direction | Inward (toward globe) | Outward (away from globe) | | Lash position | Against cornea | Away from cornea | | Corneal involvement | Abrasion/ulceration common | Rare | | Tearing | Due to irritation | Due to punctal malposition | | Age of onset | Elderly (involutional) | Elderly (involutional) | **Key Point:** Entropion = **inward** turning; Ectropion = **outward** turning. The mnemonic **"IN-tropion = IN-ward"** helps distinguish them. ### Pathophysiology in This Case At age 68, this patient most likely has **involutional entropion** — the most common type in the elderly. Causes include: - Horizontal lid laxity (lower lid retractor dehiscence) - Medial canthal tendon weakness - Orbicularis oculi overaction with age **Clinical Pearl:** Squinting and windy conditions worsen entropion because they increase orbicularis contraction, pulling the lid margin further inward. ### Management Approach ```mermaid flowchart TD A[Entropion diagnosis]:::outcome --> B{Severity and impact?}:::decision B -->|Mild, no corneal involvement| C[Conservative: lubricants, protective eyewear]:::action B -->|Moderate with abrasion| D[Temporary: Botox injection or tape]:::action B -->|Severe with ulceration| E[Surgical: Lower lid retractor plication or horizontal tightening]:::action C --> F[Monitor for progression]:::action D --> G{Response adequate?}:::decision G -->|Yes| H[Repeat or proceed to surgery]:::action G -->|No| E E --> I[Permanent correction]:::outcome ``` **High-Yield:** Involutional entropion is the most common type in elderly patients; mechanical entropion (from trauma/scarring) is less common. Surgical correction is definitive. ### Why Corneal Abrasion Occurs The inturned lashes directly abrade the corneal epithelium with each blink, causing pain, tearing, and risk of secondary infection or ulceration if untreated.