effects side ocular induced-Drug •   PART7  

Ocular side effects

Systemic administration

Certain

1. Myopia

2. Photophobia

3. Blurred vision

4. Eyelids or conjunctiva

a.Erythema

b.Edema

c.Yellow or green discoloration or deposits (doxycycline, tetracycline, minocycline)

d.Angioedema

e.Urticaria

5. Sclera – blue-gray dark blue, or brownish scleral pigmentation (minocycline) (Fig. 7.1c)

6. Enlarged blind spot

7. Visual hallucinations

8. Aggravates keratitis sicca

9. Contact lens intolerance

Probable

1. Intracranial hypertension

a.Pupil signs

b.Extraocular muscle paresis and paralysis

c.Papilledema

d.Decreased vision

e.Enlarged blind spot

2. Myasthenia gravis (aggravates)

a.Diplopia

b.Ptosis

c.Paresis of extraocular muscles

Possible

1. Subconjunctival or retinal hemorrhages secondary to drug-induced anemia

2. Eyelids or conjunctiva

a.Lupoid syndrome

b.Erythema multiforme

c.Stevens-Johnson syndrome

d.Lyell’s syndrome

Conditional/Unclassified

1. Retinal pigmentation (minocycline)

Local ophthalmic use or exposure – topical application or subconjunctival injection

Certain

1. Irritation

2. Eyelids or conjunctiva

a.Allergic reactions

b.Conjunctivitis – non-specific

3. Overgrowth of non-susceptible organisms

4. Keratitis

5. Yellow-brown corneal discoloration (with drug-soaked hydrophilic lenses)

Local ophthalmic use or exposure – intracameral injection­

Certain

1. Uveitis

2. Corneal edema

3. Lens damage

Fig. 7.1c  Minocycline blue pigmentation of the sclera.

Ocular teratogenic effects

Probable

1. Corneal pigmentation – permanent

Clinical significance

Systemic or ocular use of the tetracyclines rarely causes ­significant ocular side effects. While a large variety of drug- ­induced ocular side effects have been attributed to tetracyclines, most are reversible. This group of drugs can cause intracranial hypertension. This is most commonly reported with tetracycline and minocycline. Minocycline possibly possesses greater lipid solubility as it passes into cerebral spinal fluid, therefore it may cause this side effect more readily. Increased intra­ cranial pressure is not dose related and may occur as early as 4 hours after first taking the drug or may occur after many years of drug usage. While the papilledema may resolve once the drug is discontinued, the visual loss may be permanent (Chiu et al 1998). Paresis or paralysis of extraocular muscles may occur secondary to intracranial hypertension. This can occur in any age group. Gardner et al (1995) feel that this side effect may be related to an underlying genetic susceptibility. Many patients are obese, which is a risk factor for intracranial hypertension and clouds the picture of the role of causation of this drug in this disease. However, most who work in this area feel that tetracycline can cause intracranial hypertension. The tetracyclines have been implicated in aggravating or unmasking myasthenia gravis with its own associated ocular findings. Tetracycline has caused hyperpigmentation in light-exposed skin and yellow-brown pigmentation of lightexposed conjunctiva after long-term therapy. This occurs in about 3% of patients taking 400 to 1600 g. Oral minocycline can cause scleral pigmentation. The pigmentation is most prominent in sun-exposed areas. However, minocycline can cause hyperpigmentation in non-sun-exposed areas, i.e. the roof of the mouth (Fraunfelder and Randall 1997). The pigmentation may resolve over a number of years if the drug is discontinued, or the stain may be permanent. This side effect may be an indication to stop the drug for cosmetic reasons (Fraunfelder and Randall 1997). Yellow-brown discoloration of the cornea can occur if hydrophilic contact lenses are presoaked in tetracycline prior to ocular application. Bradfield et al (2003) described retinal pigmentation after oral minocycline in one case. All tetracycline agents are photosensitizers and they may enhance any or all light-induced ocular changes.