Original paper
Influence of phototherapy on dry eye syndrome in patients with psoriasis

Introduction : Psoriasis is a common skin disease frequently treated by photo- or photochemotherapy. However, exposure to ultraviolet light may damage the eye organ.
Aim : To assess the frequency of dry eye symptoms in patients treated with photo- or photochemotherapy.
Material and methods : The study group consisted of 36 (18 males and 18 females, aged 21 to 73 years; mean age: 47.7 ±14.2 years) patients being treated for psoriasis with photo- or photochemotherapy. Twenty-eight of 36 (77.8%) patients participated in the control examination 3 months after therapy. All patients underwent careful dermatological and ophthalmological examination (both before and 3 months after the treatment) including Schirmer’s test and break-up time assessment. Mean disease severity according to PASI was 17.7 ±10.0 points, mean disease duration 14.5 ±14.3 years, and mean duration of current psoriasis exacerbation – 3.9 ±4.0 months.
Results: Symptoms suggesting dry eye syndrome were noticed in 12/36 patients before and 13/28 after phototherapy (p = 0.38). The mean value of Schirmer’s test in 28 patients who were examined twice was 16.6 ±8.2 mm (right eye) and 20.2 ±8.4 mm (left eye) at baseline compared to 16.7 ±7.6 mm (right eye, p = 0.98) and 17.6 ±8.2 mm (left eye, p = 0.08) after treatment. The mean break-up time value was 14.8 ±7.9 mm (right eye) and 15.8 ±7.5 mm (left eye) before treatment compared to 14.4 ±5.4 mm (right eye, p = 0.8) and 14.2 ±5.0 mm (left eye, p = 0.26) after photo- or photochemotherapy.
Conclusions : It could be supposed that phototherapy might induce or exacerbate symptoms of dry eye syndrome. A single phototherapy cycle seems not to be connected with a risk of dry eye, but repeatedly applied therapy would probably increase that risk.