Can oral contraceptives cause blindness?

Fråga: Can oral contraceptives cause blindness?

Sammanfattning: The occurrence of blindness during the use of oral contraceptive has been described and reviewed. Reported ocular side effects include: decreased vision, retinal vascular disorders, visual fields, retrobulbar or optic neuritis, papilloedema secondary to pseudotumor cerebri, decreased tolerance to contact lenses and myppia.

Svar: The occurence of ocular side effects during the use of oral contraceptives has been described and reviewed (1-5). The reported side effects include: decreased vision, retinal vascular disorders (occlusion, hemorrhage, retinal or macular edema, spasms), visual fields (scotomas - central or paracentral, constriction, quadrantanopsia or hemianopsia), retrobulbar or optic neuritis, decreased tolerance to contact lenses and myopia. There is evidence that retinal thrombosis and optic neuritis may be associated with oral contraceptives (2).

McQueen in reviewing the medical literature on adverse reactions of hormonal steroid contraceptives emphasized that embolism was the major hazard and suggested as the pathogenesis an enhanced coagulability in association with impairment of fibrinolytic activity. The oestrogenicity of an oral contraceptive seems to determine its propensity to induce thromboembolic disease and this may be substantially or even preponderantly contributed by the progestagen component (6). Permanent blindness can result if the retina is infarcted due to occlusion of the central retinal artery or with ischemic lesions of the visual cortex supplied by the posterior cerebral arteries. Infarction of the optic nerve is also a cause of loss of visual acuity and field defects (7). Oral contraceptive-induced papolloedema is due to intracranial hypertension (pseudotumor cerebri) and hormonal imbalance may be a factor in the naturally occuring syndrome (8). Secondary optic atrophy may follow chronic papilloedema (7).

Westerholm in reviewing the literature on adverse reactions of hormonal contraceptives pointed out that migraine and headache were the most common complaints in women using oral contraceptives (9). This is relevant with respect to the possible visual vasoconstrictive effects of migraine (10). West and West after reviewing the electroencephalograms of women with headaches on oral contraceptives concluded that a state of latent migraine can be activated by oral contraceptives and suggested that oral contraceptives may provoke cerebral vasospasm in a small number of women of a certain genotype (11).

Patients on oral contraceptives may become intolerant to contact lenses due to corneal oedema as a result of generalized water retention (9). Steel et al suggested that a rapidly progressive type of retinopathy may be associated with oral contraception in diabetics (12). Petursson et al recommend that patients with the following factors: retinal or intraocular evidence of neovascularization, vasculitis, thromboembolic disorders, vascular occlusive or macular disease, transient ischemic attacks, ocular symptoms due to migraine and aggravated with the use of oral contraceptive, macular edema, and pseudotumor cerebri with secondary papilledema should be discouraged from using this form of contraception. It has also been suggested that women on estrogens should have periodic ocular examination, including funduscopy (13).

Twenty one cases of ocular side effects associated with oral contraceptives have been reported to the National Board of Health and Welfare including 12 cases of retinal vascular disorders, three cases of sight disorders, two cases of decreased vision, two cases of visual fields, one case of diplopia and one case of eye irritation (14). We recommend that this case be reported to the Swedish Adverse Drug Reaction Committee at the National Board of Health and Welfare.