COMPLICATIONS OF CONTACT LENS WEAR
COMPLICATIONS OF CONTACT LENS WEAR
1. Intolerance: Some people find wearing contact lenses intolerable.
2. Corneal complications:
- Corneal abrasion
- Corneal edema
- Corneal vascularisation
- Microbial keratitis (Pseudomonas, Acanthamoeba)
- Sterile corneal infiltrate.
3. Giant papillary conjunctivitis
4. Hypoxia:
- Cornea is deprived of oxygen from the tear film by the presence of the contact lens.
- The cornea becomes edematous & new vessels may develop in the limbal area.
5. Sensitivity:
- May develop in response to the preservative (thiomersal) in the cleaning & soaking solution.
- This results in allergic conjunctivitis.
OVERWEAR SYNDROME
- Occurs when hard lenses are worn for too long.
- Infrequent with soft contact lenses.
- Plate-like epithelial defect (corneal abrasion) in the center of the cornea.
Symptoms
- eye pain
- redness
- lacrimation
- photophobia.
Prevention
- strict adherence to wearing time restriction
- including not wearing lens during sleep.
- important to stop wearing contact lenses.
TREATMENT
- Initially prophylactic antibiotics & cycloplegic agents to alleviate pain.
- Later focus on refitting the patient nto a more oxygen permeable lens material.
- Discontinuing all contact lenses.
- Cold compresses & systemic analgesics are helpful to relieve symptoms.
MICROBIAL KERATITIS DUE TO CONTACT LENS
- 15% to 50% of people using contact lenses will develop acute keratitis or corneal ulcers at some time in their lives.
- P.aeruginosa is the etiological agent in greater than 40% of these cases.
Organism causing microbial keratitis in contact lens user are:
- Pseudomonas (most common)
- Acanthamoeba (2nd most common)
- Pneumococcus
- Staphylococcus
- Haemophillus
- Candida albicans
- Aspergillus niger
CORNEAL HYPOXIA
- Increase in local temperature, microtraumas on the corneal epithelium.
- Biofilm formation on the lens are the factors contributing to this problem.
Clinical signs & symptoms:
- ocular pain, watering, photophobia
- conjunctival injection & grayish mucopurulant discharge.
- Biomicroscopic examination of a patient with microbial keratitis shows a diffusely infiltrated lesion that is often central in location.
- This infiltrate appears as white spot on the cornea.
TREATMENT
- Discontinuation of the contact lenses
- Topical antibiotics (eye drops or ointment)
- Cycloplegics to give rest to the eye.
Exam Important
- Giant papillary conjunctivitis occurs as an allergic response to Contact lens.
- Complication of soft contact lens is Folliculosis.
- Most common infection in contact lens users is Pseudomonas.
- A soft contact lens users has corneal keratitis cause is Pseudomonas infection.
- A soft contact lens wearer developed pain & itching of the eye & showed a reticular pattern on the corneal epithelium the cause could be Acanthamoeba.
Keratitis in contact lens wearer is caused by:
- Pseudomonas (most common)
- Acanthamoeba (2nd most common)
- Pneumococcus
- Staphylococcus
- Haemophillus
- Candida albicans
- Aspergillus niger
- Corneal complications of contact lens use Acanthamoeba keratitis, Corneal infiltrate & Corneal vascularization.
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