Daylight Photodynamic Therapy in the Treatment of Actinic Keratosis in Carriers of Oculocutaneous Albinism: Report of Three Cases

Daylight photodynamic therapy as a treatment for actinic field change in patients diagnosed with oculocutaneous albinism in sub-Saharan Africa

BACKGROUND

Oculocutaneous albinism (OCA) is a genetically inherited condition, whereby melanin is reduced or absent in the skin. A lack of melanin predisposes people to actinic damage and skin malignancies. In Tanzania, a resource-limited country, the treatment of choice for precancerous skin lesions is cryotherapy.

OBJECTIVES

To investigate whether daylight photodynamic therapy (dPDT) is a safe and well-tolerated treatment for actinic field change in the OCA population in Tanzania.

METHODS

Twelve participants with actinic damage were recruited from a Standing Voice skin surveillance clinic and treated with dPDT. Study participants completed tolerability and acceptability questionnaires at day 5 and 3 months after treatment. A dermatologist assessed their clinical response to dPDT at 3 months.

RESULTS

dPDT was well-tolerated and acceptable to the majority of patients. Actinic damage was reduced by 25-90%. No skin cancers developed during the treatment.

CONCLUSIONS

This pilot study suggests that dPDT is a safe and tolerable treatment for actinic damage in people with OCA in Tanzania. Further work is required to compare the efficacy of dPDT against other topical therapies for actinic field change.

Clinical and Mutation Spectrum of Autosomal Recessive Non-Syndromic Oculocutaneous Albinism (nsOCA) in Pakistan: A Review

Oculocutaneous albinism (OCA) is an autosomal recessive syndromic and non-syndromic defect with deficient or a complete lack of the melanin pigment. The characteristics of OCA appears in skin, hair, and eyes with variable degree of pigmentation. Clinical manifestations of OCA include nystagmus, photophobia, reduced visual acuity, hypo-plastic macula, and iris trans-illumination. There are eight OCA types (OCA1–8) documented with non-syndromic characteristics. Molecular studies identified seven genes linked to the OCA phenotype (TYR, OCA2, TYRP1, SLC45A2, SLC24A5, C10orf11, and DCT) and one locus (OCA5) in consanguineous and sporadic albinism. The complications of OCA result in skin cancer and variable syndromes such as Hermansky–Pudlak syndrome (HPS) Chediak–Higashi syndrome (CHS). In the Pakistani population, autosomal recessive non-syndromic OCA is common and is associated with a large number of consanguineous families, and mutations in genes of non-syndromic types are reported. This review highlights the updates on the genetic mutation of OCA genes reported from Pakistani families. Several studies reported the genetic mutations in OCA1, OCA2, OCA3, OCA4, and OCA6 albinism in Pakistani families. A locus, OCA5, was also reported from the Pakistani population, but the gene has not been identified. A new type of OCA8 was identified due to the DCT gene mutation, and it is also reviewed here.