A Textbook of Clinical Pharmacology and Therapeutics

Sodium cromoglicateor nedocromildrops are widely
used in the longer-term treatment of allergic conjunctivitis.
Sodium cromoglicatein particular is very safe and only
causes local stinging as its main side effect.

DRUGS FOR AGE-RELATED MACULAR

DEGENERATION

Pegaptanib and ranibizumab are two newly licensed
agents for the treatment of age-related macular dege-
neration. They work by inhibiting the new blood vessel for-
mation that is characteristic of this disease, by blocking
the action of vascular endothelial growth factor (VEGF), and
are given by periodic intravitreal injection. Bevacizumabis
another VEGF inhibitor that has been used in this condition
because of its considerably lower cost, but its use in this
situation is presently unlicensed because of lack of robust
evidence of efficacy and safety; currently, its licensed indica-
tions are metastatic colorectal or breast carcinoma (see
Chapter 48).

LOCAL ANAESTHETICS AND THE EYE

Oxybuprocaineandtetracaineare widely used in the eye as

topical local anaesthetics. Proxymetacainecauses less initial

stinging and is useful in paediatric patients. Tetracainecauses

more profound anaesthesia and is suitable for minor surgical

procedures. Oxybuprocaineor a combination of lidocaine

andfluoresceinis used for tonometry. Lidocainewith or

withoutadrenalineis often injected into the eyelids for minor

surgery. Lidocaineis also often injected for surgical proced-

ures on the globe of the eye.

ADVERSE EFFECTS ON THE EYE OF

SYSTEMIC DRUG THERAPY

One of the most devastating ocular complications of systemic

drug therapy is the Stevens Johnson syndrome (erythema

multiforme major). Ocular involvement occurs in up to two-

thirds of patients, of whom approximately one-third suffer

permanent visual sequelae. Table 52.5 illustrates the diversity

of adverse ocular effects of drugs.

428 DRUGS AND THE EYE

Table 52.5:Adverse ocular effects of drugs

Drug class or drug Ocular structure affected Adverse ocular effects

Anticholinergic drugs (anti- Lacrimal apparatus Dry secretions, ocular irritation and burning

spasmodics; tricyclic anti-

depressants, phenothiazines,

first-generation antihistamines)

Cholinergic agents (methacholine, Lacrimal apparatus Increased tear secretions

neostigmine)

Amiodarone

Amodiaquone Corneal – microdeposits Few symptoms, but reduced vision and ocular

Phenothiazine discomfort

Gold

Glucocorticosteroids and antimitotics Lens Cataract formation

(e.g. busulfan, nitrogen

mustards)

Anticholinergics Lens Impaired accommodation – blurred vision

Oral contraceptives, sulphonamides, Lens Lens hydration increased – blurred vision

tetracyclines

Anticholinergics in people with Intra-ocular pressure is increased Reduced visual acuity

glaucoma; systemic and

topical glucocorticosteroids

Chloroquine

Ethambutol Optic nerve Retrobulbar neuritis, optic atrophy; permanent

Chloramphenicol visual loss may occur

Digoxin Retina Impaired yellow–green vision

Sildenafil Retina Blue vision

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