Ablation of vitreous tissue with a high repetition rate erbium:YAG laser.

PURPOSE: To quantify erbium (Er):YAG laser ablation of vitreous in relation to different pulse repetition rates < or = 200 Hz, in order to examine the feasibility of laser for removal of vitreous gel (photovitrectomy) in clinically acceptable times. METHODS: Fresh porcine vitreous samples and saline controls were ablated in air with an Er:YAG laser connected to a sapphire fiber at pulse energies between 1.0 and 21.2 mJ and at pulse repetition rates between 10 and 200 Hz. Net ablation rates were determined by weight measurement. RESULTS: Reproducible and constant ablation rates were found for given laser parameters. Net ablation rates increased linearly with pulse repetition rate and nonlinearly with pulse energy. Expanded laser parameter domains permitted vitreous ablation rates as low as 1 microg/s to as high as 1031 microg/s. Ablation rates did not differ significantly between vitreous and saline. CONCLUSIONS: The study documents clinically useful vitreous ablation rates that scale linearly with high repetition rates of Er:YAG laser, and suggests directions for further development of laser technology for enhanced removal of vitreous and other tissues. However, nonlinear effects of pulse energy also exist, indicating need for careful examination of ablation characteristics in various instruments.

[Systematic sebaceous nevus with multiple secondary tumors as the chief symptom of Schimmelpenning-Feuerstein-Mims syndrome]. / Systematisierter Naevus sebaceus mit multiplen sekundären Neubildungen als Leitsymptom des Schimmelpenning-Feuerstein-Mims-Syndroms.

A women presented with a systematized sebaceous nevus of the head and neck. She had developed multiple basal cell carcinomas and sebaceomas in the nevus over the past 3 years after a period of about 55 years without any changes. Detailed medical history and physical examination revealed a constellation of findings suggesting a syndrome. Besides ptosis and a congenital, vascular corneal clouding at the right, there was hypoplasia of the right maxillary sinus, a right labyrinthine deafness and recurrent inguinal herniae on the right. The Schimmelpenning-Feuerstein-Mims-Syndrome was diagnosed.

Coincidence of multiple, disseminated, tardive-eruptive blue nevi with cutis marmorata teleangiectatica congenita.

A 71-year-old woman reported a slow progression of multiple bluish dark asymptomatic macules and papules on the pretibial region of both lower legs for over 30 years. At birth a left-sided hypoplasia of the leg including the buttock accompanied by a connatal vascular nevus had been diagnosed. The ipsilateral deep veins of the pelvis and leg had a normal anlage. Histopathological examination revealed multiple blue nevi of the common type. The association of multiple blue nevi and cutis marmorata teleangiectatica congenita with limb hypoplasia has not previously been reported and is discussed in this paper. One could speculate whether these symptoms represent a new syndrome, because by thorough examination the NAME syndrome could be ruled out.

[Dapsone in granulomatous rosacea]. / Dapson bei granulomatöser Rosazea.

We report on two patients with granulomatous rosacea and another patient with granulomatous perioral dermatitis who responded well to dapsone. Dapsone has a pharmacological double function as both an antibiotic and an antiphlogistic drug. Before the introduction of isotretinoin, dapsone had its place in the treatment of severe acne. To date, its use in granulomatous rosacea has not been described. When hematologic parameters are monitored, dapsone is considered a safe and cost-effective drug, especially in countries where isotretinoin is not readily available. However, the definite value of dapsone in granulomatous rosacea should be established by a controlled study.