Treatment of Port-wine Mark in Sturge-Weber Syndrome Using Topical Timolol

• Appearance of Port-wine Mark at treatment site [ Time Frame: 12 months ] [ Designated as safety issue: No ]
  Changes of color and size of PWM at treatment site will determine efficacy of the topical timolol.
  
  

Port-wine mark (PWM) represents a congenital capillary malformation,characterized by dilation and malformation of dermal capillaries that lack endothelial proliferation. It is frequently seen in the facial distribution of the trigeminal nerve. PWM persists throughout life and involves ~0.3% of the population. Although PWMs are found in other circumstances, ~ 3% of patients with facial PWM are also afflicted with Sturge-Weber syndrome. PWMs are cosmetic entities that often have serious social consequences, producing psychological trauma to both children and their parents. PWM does not involute with time, and, if left untreated, can develop deep purple coloration, tissue hypertrophy, and nodularity.

Laser therapy, which selectively destroys specific targets within the skin, is currently the most commonly used approach for treating PWM, although complete blanching of the PWM after laser is rarely achieved for most patients, and only 10-45% of patients with Sturge-Weber have shown satisfactory outcomes. Complications of pulsed dye laser treatment for PWM include pyogenic granuloma, scabbing, cutaneous scarring, and permanent hypo/hyperpigmentation. Laser treatment is relatively contraindicated in children with darker skin coloration due to the resulting hypopigmentation which may be equally unsightly. Laser treatment causes substantial discomfort and pain to patients, and often requires general anesthesia in children. This is particularly true since earlier treatment in infancy is desirable and yields increased successful resolution of the PWM. The hypertrophic PWM in later years is resistant to any treatment. Recently, propranolol was reported to successfully treat capillary hemangioma in infants.13 While the mechanism by which beta blockade improves hemangioma is unclear, ß2-mediated vasoconstrictive effects and the ensuing apoptosis of capillary endothelial cells may contribute to the positive therapeutic results.

Oral application of propranolol can cause severe systemic complications, including bronchospasm, vasospasm, hypoglycemia, hypotension, severe bradycardia, heart block, and congestive heart failure. Topical timolol solution, a β-blocker, has shown a similar ability to reduce capillary hemangioma of eyelids with little or no systemic effects in a small pilot study. Similar to capillary hemangioma, which is a proliferative lesion characterized by increased endothelial cell turnover, PWM is a capillary malformation with abnormal endothelial cells and large surface area of dilated capillaries. Thus, both capillary hemangioma and PWM share the similar characteristic of abnormal capillary endothelial cells.

This pilot study is designed to explore the potential role of topical timolol in the management of PWM. As PWM is so frequently associated with Sturge-Weber syndrome, a disorder in which approximately 50% of patients will develop glaucoma, this study will be conducted in an ophthalmology setting.

This study will consist of two arms. One group will receive timolol and the second group a placebo preservative free artificial tear gel. The groups will be divided with a ratio of 1:1 and the Timolol group will be matched with the placebo group by PWM location, age and race.

Both medications are to be applied and rubbed in by fingertip to the treatment site twice a day for 6 months by subject's parents/guardian. (Treatment site: 1x1 cm at inferior edge of facial PWM)

Follow-up schedule: 1 week after treatment initiation and then every 2 months for a period of six months.