Guidelines on the diagi osis and treatment of conjunctivitis

VI. Iatrogenic conjunctivitis (IAC)

Iatrogenic conjunctivitis is induced by local or systemic treatment, which may be related or unrelated to an ocular problem. This entity can be subdivided into four groups:

I. Induced by local drugs. 2. Induced by systemic medication. 3. Induced by appliance, e.g., contact lenses. 4. Miscellaneous (vaccination).

A. Local drug (chemical)-induced conjunctivitis Local drug- induced conjunctivitis may be caused by the medication or the additives (mainly preservatives). The responses may manifest as acute allergic reactions, or as a delayed hypersensitivity reaction.

Symptoms There are no specific complaints. Symptoms include irritation, foreign body sensation, soreness, watering and itching. Itching suggests hypersensitivity while symptoms that occur immediately on applying medi- cation are indicative of a direct irritative problem (epinephrine, beta- blockers, etc).

Signs There is a degree of hyperaemia and chemosis while variable papil- lae and follicles may also be seen. In severe cases, there may be conjunctival fibrosis and possible symblepharon formation, mainly in the lower fornices. The picture may be of cicatricial or ocular pemphigoid. The lid margin may also be involved (Photo 3 2 ) .

Photo 32. Iatrogenic conjunctivitis (IAC): The conjunctival and palpebral reactions in this case were induced by the local instillation of pilocarpine. (Provided by Dr. Pleyer).

Iatrogenic conjunctivitis (IAC) S37

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Znvesfigarions The history will often identify the offending agent. Tests may be performed as indicated. Biopsy of the conjunctiva in suspected ocu- lar cicatricial pemphigoid may be necessary. Skin tests for the detection of delayed hypersensitivity reactions to various allergens could be of help in specific cases.

Treatment There is no specific treatment but the offending agent should be discontinued. If a preservative is at fault unpreserved drugs may be substi- tuted. Treatment with artificial tears may be helpful.

B. Systemic medication-induced conjunctivitis This may mani- fest as Stevens-Johnson syndrome or as a tear film problem, or other non specific immune reactions.

C. Foreign body-induced conjunctlvitls This is seen mainly in contact lens wearers and is usually referred to as giant papillary conjunctivitis (GPC), but may also less frequently be induced by ocular prostheses and suture materials (Photo 33). It is a response to chronic mechanical irritation, an immune reaction to lens and prosthetic deposits or due to the toxic effects of cleaning and sterilising solutions.

Photo 33. Giant papillary conjunctivitis (GPC): The papillae formation in this case followed the use of hard contact lenses. Note the more uniform appearance of these papillae and the fact that they cover evenly the entire surface of the tarsal plate. (Provided by Dr. BenEzra).

Symptoms A careful history will usually suggest this diagnosis. Lens intolerance is the main feature. Redness, itching, burning, watering, foreign body sensation and blurred vision are exacerbated shortly after inserting the lens. In the case of an ocular prosthesis, the main symptoms are itching, discomfort and variable discharge, while with suture induced conjunctivitis, continuous itching and irritation are present.

Signs In contact lens-induced disease, papillae are always present. They are best delineated by the use of fluorescein and can vary in size. There is bulbar conjunctival hyperaemia and chemosis with a variable sticky mucous discharge. Deposits are seen on the contact lens surfaces. In suture-induced conjunctivitis, the papillae correspond to the location of the sutures. In

S38 D. Ben Ezra et a1

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prosthetic induced disease, the papillae are diffuse with copious mucous discharge.

Investigations A history is usually diagnostic. Other laboratory tests are unnecessary in most cases.

Treatment The most effective modality of treatment of these cases is removal of the foreign body (e.g. the contact lens). In some cases of giant papillary conjunctivitis (GPC), patients may resume contact lens wear using a different type of lens material (e.g., switching from soft to hard lenses). Good lens hygiene, efficient lens care and frequent change of the lenses may also be helpful. In some cases, the use of mast cell stabilisers such as sodium cromoglycate or nedocromil sodium may be helpful. The use of cortico- steroid eye drops in these cases is strictly contraindicated. In suture-induced conjunctivitis, removal of the offending sutures is necessary.

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