Retinitis pigmentosa associated with vitiligo

ARTICLE

Auteur(s) : Parvin MANSOURI¹, Mohammadreza MORTAZAVI², Mohammadhossein MALEK MADANI³, Maria MAZAHERI⁴

¹ Department of Dermatology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran.
² Dermotologist, Department of Surgery, Wound Healing Research Group, University of Alberta, Edmonton, Alberta, Canada.
<mortazavir@yahoo.com>
³ Department of Ophthalmology, Farabi Hospital, Tehran University of Medical Sciences, Tehran, Iran.
⁴ Occupational Medicine, Tehran University of Medical Sciences, Tehran, Iran.

We have read three interesting papers in recent issues of the European Journal of Dermatology about the treatment of vitiligo [1-3].
Although treatment of vitiligo is one of the most important aspects of this common dermatologic disease, its etiology (which remains unclear) and its association with other diseases are also important. We herein report a rare association of vitiligo and retinitis pigmentosa.
A 33-year-old man presented with progressive diminishing vision for about 25 years and depigmented skin lesions for about 15 years. His past history was negative for hearing loss and any other significant illness.
The skin examination showed bilateral, symmetrical, depigmented patchy lesions (vitiligo) around the mouth and eyes (figure 1A), over the chin and neck, chest, back of the hands and extensor surfaces of the forearms and elbows. The hair was not affected.
The ophthalmologic evaluation of both eyes revealed that the visual acuity was less than 20 out of 400. The anterior segment showed normal findings in the slit-lamp examination. Fundoscopy (of both eyes) revealed optic disc pallor, attenuated retinal vessels, and diffuse pigmented patches and «bone spicule» formation (mainly in mid-periphery). All of these clinical findings were in favor of the diagnosis of retinitis pigmentosa. Electroretinography (ERG) showed flattening of the waves, indicating a marked reduction of both rod and cone signals.
Fluorescein retinal angiography revealed increased background hyperfluorescence due to retinal pigment epithelium (RPE) depigmentation, severe narrowing of the arteries, areas of RPE and choroidal atrophy in mid-periphery in the early transit phase (figure 1B); and diffuse hyperfluorescences indicative of leakage at the optic disks and peri-papillary area, together with cyst-like leakage in the macula, in the late transit views (figure 1C).
Physical examinations of other areas of the body, including the auditory system, showed normal findings.
There was no consanguineous relationship between his parents. The family history of vitiligo was positive in his father, uncle, paternal grandfather and the cousin and aunt of his father. His cousin, a 26-year-old man, had retinitis pigmentsa without vitiligo. There was a positive history of diabetes mellitus in his paternal family including his father, aunt and grandfather. His aunt and his father’s cousin were blind but were not available for further work-ups.
Laboratory investigations including complete blood count, liver and thyroid function tests, fasting blood sugar, blood urea nitrogen, serum cholesterol and triglyceride, LE cells and anti-DNA antibody, all were within normal limits. Audiometric tests were normal.
The depigmented lesions of the skin were unaffected by several medications including topical corticosteroids and methoxypsoralen. There was no therapeutic modality for his eye complaints.
We believe that our observed association between vitiligo and retinitis pigmentosa is more than a random association. Most of the other reported cases with this association, revealed other concurrent abnormalities including hearing loss, poliosis, axonal polyneuritis, and familial juvenile parkinsonism.
Melanocytes are present in other areas of the body besides the skin, including the leptomeninges, the retinal pigment epithelium, the uveal tract and the inner ear. Therefore, it is not surprising that immunologic and (or) genetic processes which destroy melanocytes in the skin can also affect other tissues such as the eyes, the ears and the central nervous system.
The Hallmark of vitiligo is the destruction and marked absence of melanocytes and melanin in the epidermis. Several non-cutaneous disorders are known to occur in association with vitiligo, including thyroid disease (hyper and hypothyroidism), pernicious anemia, Addison’s disease, diabetes mellitus, hypoparathyroidism and myasthenia gravis. Alopecia areata, halo nevus, malignant melanoma, morphea and lichen sclerosus are among the cutaneous disorders associated with vitiligo.
In addition to depigmentation of the eyelids and poliosis of eyelashes and eyebrows, several ocular conditions may occur in association with vitiligo.
The association of vitiligo with inflammation of the uveal tract in Vogt- Koyanagi-Harada syndrome and sympathetic ophthalmia is well-established.
Although the association of vitiligo with tapetoretinal degenerations has been demonstrated on several occasions, association with typical retinitis pigmentosa is reported infrequently. Albert et al. [4] in a systematic study of a large number of vitiligo patients (223 cases) demonstrated a significantly increased prevalence of non-specific retinal pigment epithelium (RPE) hypopigmentation, compared with a control population. Only two of their cases had true retinitis pigmentosa and vitiligo simultaneously, which one of them had a family history of vitiligo. In addition, one of their patients had inverse retinitis pigmentosa.
In another concurrent investigation, Wagoner et al. [5] examined 154 consecutive patients with uveitis for vitiligo and compared the results in order to determine the nature of the relationship between vitiligo and ocular diseases. Of the 129 patients whose uveitis had an unknown cause, seven (5.4%) had vitiligo, poliosis, or early graying of hair, of which the incidence in the general population is 0.5%. None of their patients revealed an association of vitiligo and retinitis pigmentosa.
Other large studies on vitiligo patients [6, 7] revealed discrete areas of depigmentation with associated pigment hyperplasia involving the choroids and RPE [6], choroidal nevi, focal retinal hypopigmented spots and pigment clumps but no documented case of retinitis pigmentosa.
Tang et al. [8] showed that the vitiligo (mi vit) mutation has several prenatal and perinatal effects on the retinal pigment epithelium, and later leads to extensive, progressive degeneration of photoreceptor cells in the neural retina of homozygous affected mice. As early as two weeks of age, homozygous mutants showed a significant reduction of rod- dominated maximum ERG a-wave and b-wave amplitude, like the early functional abnormalities in human retinitis pigmentosa. Interestingly, Evans and Smith have also shown, in vitiligo mutant mice, elevation of retinyl esters in the mutant RPE [9]. n

1. Coskun B, Saral Y, Turgut D; Topical 0.05% clobetasol propionate versus 1% pimecrolimus ointment in vitiligo. Eur J Dermatol 2005; 15(2): 88-91.

2. Ongenae K, Van Geel N, De Schepper S, et al. Management of vitiligo patients and attitude of dermatologists toward vitiligo. Eur J Dermatol 2004; 14(3): 177-81.

3. Van Geel NAC, Ongenae K, Vander Haeghen YMSJ, et al. Autologous transplantation techniques for vitiligo: how to evaluate treatment outcome? Eur J Dermatol 2004; 14(1): 46-51.

4. Albert DM, Wagoner MD, Pruett RC, et al. Vitiligo and disorders of the retinal pigment epithelium.Br J Dermatol 1983; 67: 153-6.

5. Wagoner MD, Albert DM, Lerner AB, et al. New observations on vitiligo and ocular disease. Am J ophthalmol 1983; 96(1): 16-24.

6. Albert DM, Nordlund JJ, Lerner AB. Ocular abnormalities occurring with vitiligo. Ophthalmology 1979; 86: 1145-58.

7. Handa S, Kaur I. Vitiligo: clinical findings in 1436 patients. J Dermatol 1999; 26(10): 653-7.

8. Tang M, Pawlyk BS, Kosaras B, et al. ERG abnormalities in relation to histopathologic findings in vitiligo mutant mice. Exp Eye Res 1997; 65(2): 215-22.

9. Evans BL, Smith SB. Analysis of esterification of retinoids in the retinal pigmented epithelium of the Mitf (vitiligo) mutant mouse. Molecular Vision 1997; 3: 11-4.