Medicinal maculopathy

Anti-malarial drugs

Chlorokvin (nivaquine, avlocor) and hydroxychloroquine (plaquenii) are quinolone derivatives used in the prevention and treatment of malaria, as well as in the treatment of rheumatoid arthritis, systemic lupus erythematosus and cutaneous lupus erythematosus. Chloroquine is also recommended in the treatment of disorders in calcium metabolism in sarcoidosis. Antimalarial drugs are melanotropic and are excreted from the body very slowly, which leads to their accumulation in melanin-containing structures of the eye, such as retinal pigment epithelium and choroid. Retinotoxicity and corneal deposits are two major side effects of antimalarial drugs on the part of the eyes. Changes in the retina are infrequent, but potentially dangerous, whereas corneal changes (funnel-shaped keratopathy) that are observed extremely often do not pose a danger.

1. Chloroquine retinotoxicity is associated with the total cumulative dose. The daily dose does not normally exceed 250 mg. A cumulative vine of less than 100 g or a duration of treatment of less than 1 year is very rarely associated with retinal damage. The risk of toxicity increases significantly when the cumulative dose exceeds 300 g (ie 250 mg daily for 3 years). However, there are reports of patients receiving a cumulative dose exceeding 1000 g but not having retinal damage. If necessary, chloroquine can be used in case of ineffectiveness of other drugs.
2. Hydroxychloroquine is less dangerous than chloroquine, and the risk of retinoxicity in its use is negligible if the daily dose does not exceed 400 mg. The doctor should recommend hydroxychloroquine instead of chloroquine in all cases, when possible.

[1], [2], [3]

Chloroquine maculopagia

•  The condition preceding maculopathy is characterized by normal visual acuity, but lack of a foveal reflex. This is accompanied by the development of fine granular changes in the macula, which can be combined with a mild violation of color vision and small scotomas on the red Amslеr grid pattern. This condition is reversible if the drug is withdrawn.
•  Early maculopathy is characterized by a moderate decrease in visual acuity (6 / 9-6 / 12). The study of the fundus reveals a subtle change in the macula, characterized by central foveolar pigmentation, surrounded by a depigmentation zone (the retinal pigment epithelium atrophy zone), which in turn is enclosed in a hyperpigmentation ring. The lesion can be better detected on the PHAG than with ophthalmoscopy, since the foci of atrophy of the retinal pigment epithelium are identified as the "final" defect. This stage is reversible upon discontinuation of the drug.

1. Developed maculopathy is characterized by a more pronounced decrease in visual acuity (6 / 18-6 / 24) and an obvious picture of macular lesion of the "bull eye" type.
2. Severe maculopathy is characterized by a significant reduction in visual acuity (6 / 36-6 / 60) with a common zone of atrophy of retinal pigment epithelium surrounding the favus.
3. The final stage of maculopathy is characterized by a significant decrease in visual acuity and a significant atrophy of retinal pigment epithelium with "exposure" of large choroidal vessels. Arterioles of the retina can also thin out and accumulations of retinal pigment epithelium can develop on the periphery of the retina.

Screening

Control over the condition of patients taking hydroxychloroquine is not required. In clinical practice, chloroquine can also be administered without fear to patients who do not need routine repeated ophthalmic examinations or the use of complex tests. At the same time it is enough to study the visual acuity and eye fundus.

The patient can independently use the Amsler mesh once a week, and in case of detection of violations, it is necessary to refer him to an ophthalmological examination.

An ophthalmologist can use a number of more complex techniques, such as examining visual fields, the threshold of macular sensitivity, testing color vision, contrast sensitivity, PHAG, and electrooculography, if necessary.

[4], [5], [6], [7], [8]

Toxic crystalline maculopathy

Tamoxifen

Tamoxifen (nolvodex, emblon, noltan, tamofen) is a selective estrogen receptor blocker used in some patients in the treatment of breast carcinoma. Its some systemic and local (eye) side effects are rare with a daily dose of 20-40 mg. Toxicity to the retina can sometimes develop in patients with an increase in the dose of the drug and is characterized by the appearance, as a rule, in the macula of both eyes of relatively safe numerous yellow, crystalline, ring-like deposits that persist even when treatment is withdrawn. Other, more rare side effects from the eyes are funnel-shaped keratopathy and optic neuritis, which are reversible upon cancellation of treatment. Since maculopathy is very rare, standard screening is not justified.

Thioridazine

Thioridazine (melleril) is used in the treatment of schizophrenia and other psychoses. Normally, the daily dose is 150-600 mg. At a dose exceeding 800 mg per day, even a few weeks may be sufficient to reduce visual acuity and disturb the tempo adaptation. Clinical signs of progressive toxicity in relation to the retina are:

• Violation of pigmentation by the type "salt with pepper" with the involvement of the central region and the middle periphery of the retina.
• Rough plaque pigmentation and focal absence of retinal pigment epithelium and chorio capillaries.
• Diffuse absence of retinal pigment epithelium and chorio capillaries.

Chlorpromazine

Chlorpromazine (largactil) is used as a sedative and a desire for schizophrenia. The daily dose is usually 75-300 mg. Defeat of the retina develops with an increase in the daily dose over an extended period and is characterized by the appearance of a nonspecific accumulation of pigment and granularity. Among other non-harmful side effects from the eyes, it is possible to isolate the deposition of yellow-brown granules on the anterior capsule of the lens and endothelial deposits of the cornea.

Canthaxanthine

It is a carotenoid used to improve sun tanning. Continuous use can lead to the bilateral appearance of small, shiny, yellow deposits located symmetrically at the rear pole in the form of a "donut". The deposits are localized in the superficial layers of the retina and are safe.

Methoxyflurane

Methoxiflurane (penlhrane) is a drug used for general inhalation anesthesia. It is exchanged with oxalic acid, which combines with calcium in an insoluble form of salt (calcium oxalate) and deposited in tissues, including retinal pigment epithelium. Prolonged use can lead to secondary hyperoxalosis, renal failure, and to the deposition of harmless crystals in retinal vessels.