Potential Ocular Complications of Allergic Conjunctivitis
Allergic conjunctivitis can lead to several serious ocular complications including corneal neovascularization, scarring, ulceration, and in severe cases, vision loss if not properly managed. 1
Types of Allergic Conjunctivitis and Associated Complications
Seasonal/Perennial Allergic Conjunctivitis
- Minimal local complications 1
- Associated with:
- Dry eye syndrome
- Meibomian gland dysfunction with mucin hyperproduction
- Allergic rhinitis 1
Vernal Keratoconjunctivitis
- More severe complications including:
- Eyelid thickening and ptosis
- Conjunctival scarring (predominantly superior tarsal) and cicatrization
- Corneal neovascularization, thinning, ulceration, and infection
- Shield ulcers/corneal plaques
- Visual loss
- Limbal stem cell deficiency
- Keratoconus
- Corticosteroid-induced cataract and glaucoma 1
Contact Lens-Related Allergic Reactions
Contact Lens-Related Keratoconjunctivitis
- Corneal neovascularization (focal, diffuse, or circumferential)
- Superior epitheliopathy and corneal scarring
- Limbal stem cell deficiency
- Central progression into the pupillary area affecting vision 1
Giant Papillary Conjunctivitis (GPC)
- Tarsal scarring
- Ptosis
- Corneal abrasions/erosions 1
Medication/Preservative-Induced Keratoconjunctivitis
- Corneal epithelial erosion
- Persistent epithelial defects
- Corneal ulceration
- Pannus formation
- Corneal and conjunctival scarring
- Symblepharon (adhesion between bulbar and palpebral conjunctiva)
- Punctal occlusion
- Limbal stem cell deficiency 1
Complications Related to Treatment
Topical Corticosteroid Complications
- Intraocular pressure elevation
- Cataract formation
- Masking of infection 2
Oral Antihistamine Complications
- Induction or worsening of dry eye syndrome
- Impairment of the tear film's protective barrier 2
Topical Decongestant Complications
- Rebound hyperemia ("conjunctivitis medicamentosa") with prolonged use 2
Risk Factors for Complications
- Delayed or inadequate treatment 3
- Self-management with over-the-counter medications without proper diagnosis 3
- Prolonged exposure to allergens 2
- Use of contact lenses during active inflammation 4, 5
- Improper use of topical medications, especially corticosteroids 2
- Comorbid conditions like dry eye syndrome 6
Prevention of Complications
Proper Medication Management
- Use preservative-free artificial tears to dilute allergens and inflammatory mediators 2
- Employ dual-action topical antihistamine/mast cell stabilizers as first-line therapy 2
- Use topical corticosteroids only under ophthalmologist supervision and for short durations 2
- Remove contact lenses before instilling drops and wait at least 10 minutes before reinsertion 4, 5
Contact Lens Considerations
- Consider refitting with silicone hydrogel or daily disposable lenses 7
- Discontinue contact lens wear during acute allergic episodes 7
- Maintain proper lens hygiene 1
Monitoring and Follow-up
- Regular follow-up visits including visual acuity measurement and slit-lamp examination 2
- Monitor intraocular pressure when using topical corticosteroids 2
- Prompt referral to ophthalmologist for:
- Visual loss
- Moderate or severe pain
- Corneal involvement
- Lack of response to therapy
- Recurrent episodes
- Suspected vernal keratoconjunctivitis or atopic keratoconjunctivitis 2
Special Considerations
- Allergic conjunctivitis frequently overlaps with other anterior ocular disorders, including infectious conditions and dry eye syndrome, complicating diagnosis and treatment 3
- Only about 10% of patients with ocular allergy symptoms seek medical attention, increasing risk of complications from suboptimal therapy 3
- Children with vernal keratoconjunctivitis require specialized ophthalmologic care to prevent vision-threatening complications 8
By understanding these potential complications and implementing appropriate management strategies, the risk of long-term ocular damage from allergic conjunctivitis can be significantly reduced.