How to diagnose a retained contact lens in the eye?

Diagnosing a Retained Contact Lens in the Eye

To diagnose a retained contact lens in a patient's eye, perform a thorough examination including double eversion of the upper eyelid and sweeping of the fornices with a cotton-tipped applicator, as these are essential steps that can reveal hidden lenses that may have migrated into the superior fornix.

Clinical Presentation of Retained Contact Lenses

Patients with a retained contact lens may present with:

• Unilateral symptoms (key indicator)
• Persistent or recurrent conjunctivitis resistant to treatment
• Redness, pain, irritation
• Increased tearing
• Light sensitivity
• Blurry vision
• Mucous discharge
• Eyelid swelling that may mimic a chalazion 1
• Foreign body sensation

Diagnostic Approach

1. History Taking

• Ask about contact lens wear history, including:
  • When the patient last remembers removing lenses
  • Any history of "lost" or "missing" lenses
  • Type of lenses used (soft lenses may fold and be more difficult to detect) 2
  • Compliance with recommended wear schedule

2. Physical Examination

• Examine visual acuity with and without correction
• Evaluate the conjunctiva for injection, papillary reaction, and discharge
• Assess corneal health for edema, staining, or infiltrates 3
• Examine the eyelids for swelling or masses that could be mistaken for chalazia 1

3. Critical Examination Techniques

• Standard lid eversion - Examine the tarsal conjunctiva
• Double eversion of the upper eyelid - Essential for detecting lenses trapped in the deep superior fornix 2, 4, 5
• Fornix sweeping - Use a moistened cotton-tipped applicator to sweep the superior fornix 2
• Fluorescein staining - May help identify corneal damage or outline a transparent lens

High-Risk Scenarios

Be particularly vigilant for retained contact lenses in patients with:

• Unilateral chronic conjunctivitis resistant to treatment 5
• History of a "lost" contact lens
• Recurrent unilateral eye infections
• Unique orbital anatomy that may trap lenses in the fornices 6
• Persistent foreign body sensation in one eye
• Asymmetric symptoms between eyes

Common Pitfalls to Avoid

1. Failing to perform double eversion of the upper eyelid
2. Misdiagnosing as chronic blepharitis or conjunctivitis without investigating for a foreign body
3. Overlooking the possibility of a retained lens in patients with persistent unilateral symptoms
4. Assuming a lens couldn't remain in the eye for extended periods (cases report lenses retained for up to 15 years) 6, 4
5. Relying only on patient history of lens removal (patients may forget or be unaware of a retained lens)

Management After Diagnosis

Once a retained contact lens is identified:

1. Remove the lens carefully
2. Evaluate for corneal damage or infection
3. Treat any secondary infection with appropriate antibiotics
4. Consider topical corticosteroids for inflammatory reactions
5. Schedule follow-up to ensure resolution of symptoms

Remember that soft contact lenses may fold, discolor, or adhere to the conjunctiva over time, making them difficult to identify as foreign bodies 2. A high index of suspicion and thorough examination techniques are essential for diagnosis.