A novel iris transillumination grading scale allowing flexible assessment with quantitative image analysis and visual matching

Vision-Related Quality of Life in Danish Patients with Albinism and the Impact of an Updated Optical Rehabilitation

(1) Background: Albinism is characterized by a lack of pigment in eyes, hair, and skin and developmental changes in the eye such as foveal hypoplasia. Patients require optical rehabilitation due to low vision, refractive errors, and photosensitivity. We aimed to assess vision-related quality of life in patients with albinism and to evaluate how this was affected by optical rehabilitation. (2) Methods: Patients with ocular or oculocutaneous albinism were invited for the study. Free-of-charge optical rehabilitation was provided as needed, including filters, glasses for near or distance, contact lenses, magnifiers or binoculars. Vision-related quality of life was assessed prior to and after optical rehabilitation using the visual function questionnaire (VFQ39) and the effect of optical rehabilitation was evaluated after accounting for age, gender, and visual acuity. (3) Results: Seventy-eight patients filled out the VFQ39 at the initial visit. Fifty patients (64.1%) returned the questionnaire 3-6 months after optical rehabilitation. The mean age of included patients was 35.9 years (standard deviation 16.6), and their best corrected distance visual acuity was 56 ETDRS letters (range 3-81). The VFQ39 composite score improved significantly from a median of 62.5 (range 14.2-77.0) to 76.5 (20.6-99.6). Significant improvements were seen for ocular pain, social functioning, mental health, role difficulties, and dependency, whereas self-assessed distance or near visual functions did not change. (4) Conclusions: Optical rehabilitation improved the self-reported vision-related quality of life in Danish patients with albinism on a number of parameters related to leading an independent and worry-free life, whereas visual improvement for distance and near tasks was likely limited by the nature of the disease and by the fact that most patients already had access to some optical aids prior to the study.

Photosensitivity and filter efficacy in albinism✰

PURPOSE

To describe the prevalence and severity of photosensitivity in patients with albinism, and to compare with ocular features and how this correlated with use and choice of optical filters.

METHODS

Cross-sectional study on 81 participants with ocular or oculocutaneous albinism. An ophthalmic evaluation including visual acuity, contrast sensitivity and evaluation of iris translucency and fundus hypopigmentation was performed. Participants were offered optical rehabilitation with testing of a wide panel of filters. The associations between ocular characteristics, subjective photosensitivity complaints, and filter choice were evaluated.

RESULTS

Photosensitivity was rated as "some" to "worst imaginable" in 77.8% of participants. Severity of photosensitivity correlated significantly with fundus hypopigmentation (p = 0.04) but not with iris translucency (p = 0.14) and it was worse in those with poor visual acuity but there was no association between photosensitivity and contrast vision. Seventy-four new pairs of spectacles were prescribed in the study. All outdoor spectacles contained a filter, whereas 26.5% of new indoor spectacles did not. Relatively neutral filter colors (gray, brown or a combination of gray and brown with other colors) and low transmission were preferred.

DISCUSSION

Photosensitivity is common in albinism, but research targeting treatment is limited. Color and neutral filters with a low light transmission were preferred, with participants having a large number of spectacles, presumably to meet their needs in different situations.

One-year pilot study on the effects of nitisinone on melanin in patients with OCA-1B

BACKGROUND. Oculocutaneous albinism (OCA) results in reduced melanin synthesis, skin hypopigmentation, increased risk of UV-induced malignancy, and developmental eye abnormalities affecting vision. No treatments exist. We have shown that oral nitisinone increases ocular and fur pigmentation in a mouse model of one form of albinism, OCA-1B, due to hypomorphic mutations in the Tyrosinase gene.

METHODS. In this open-label pilot study, 5 adult patients with OCA-1B established baseline measurements of iris, skin, and hair pigmentation and were treated over 12 months with 2 mg/d oral nitisinone. Changes in pigmentation and visual function were evaluated at 3-month intervals.

RESULTS. The mean change in iris transillumination, a marker of melanin, from baseline was 1.0 ± 1.54 points, representing no change. The method of iris transillumination grading showed a high intergrader reliability (intraclass correlation coefficient ≥ 0.88 at each visit). The number of letters read (visual acuity) improved significantly at month 12 for both eyes (right eye, OD, mean 4.2 [95% CI, 0.3, 8.1], P = 0.04) and left eye (OS, 5 [1.0, 9.1], P = 0.003). Skin pigmentation on the inner bicep increased (M index increase = 1.72 [0.03, 3.41], P = 0.047). Finally, hair pigmentation increased by both reflectometry (M index [17.3 {4.4, 30.2}, P = 0.01]) and biochemically.

CONCLUSION. Nitisinone did not result in an increase in iris melanin content but may increase hair and skin pigmentation in patients with OCA-1B. The iris transillumination grading scale used in this study proved robust, with potential for use in future clinical trials.

TRIAL REGISTRATION. ClinicalTrials.gov NCT01838655.

FUNDING. Intramural program of the National Eye Institute.

Oral nitisinone may improve melanin pigmentation in patients with the OCA-1B form of albinism due to hypomorphic mutations in the tyrosinase gene.