tetracycline and Corneal-Neovascularization

To describe ocular and vascular findings in a patient with multiple endocrine neoplasia type 2B.. Case report of a 31-year-old male who was referred for ocular assessment following diagnosis of a carotid artery dissection and multiple vascular anomalies.. Clinical examination revealed a marfanoid habitus, myelinated corneal nerve fibers, neuromas in the perilimbal area, conjunctival hyperemia with peripheral corneal neovascularization, and posterior blepharitis. Diagnosis of multiple endocrine neoplasia type 2B was confirmed by genetic testing of the RET proto-oncogene. Genetic screening for hereditary aortic and peripheral vasculopathies failed to reveal an underlying cause for the vascular findings. We noted improvement of the ocular surface disease with topical corticosteroids and oral tetracyclines.. Ophthalmologists play a vital role in recognizing this rare but lethal malignancy. We report on a patient with apart from characteristic ocular findings also staphylococcal hypersensitivity and widespread systemic vasculopathy.

Topics: Administration, Ophthalmic; Administration, Oral; Adult; Blepharitis; Cornea; Corneal Neovascularization; Eye Neoplasms; Glucocorticoids; Humans; Male; Multiple Endocrine Neoplasia Type 2b; Nerve Fibers, Myelinated; Neuroma; Proto-Oncogene Mas; Proto-Oncogene Proteins c-ret; Tetracycline

Venom from the ringhals cobra (H. haemachatus) caused extensive chemosis, prolonged corneal edema and marked miosis when applied locally to the eyes of two strains of rabbits: Buskat (albino) and Chinchilla (pigmented). In the pigmented rabbits, the corneal edema progressed to complete corneal opacification with corneal and conjunctival neovascularization that remained unchanged until the end of the experiment (70 d). In the albino rabbits the corneal cloudiness and conjunctivitis cleared within three weeks of venom instillation. Treatment with heparin and tetracycline markedly improved the corneal opacification syndrome, while treatment with specific antivenom resulted only in partial improvement. It is postulated that the venom owes its ocular effects to its cardiotoxin, the only venom fraction capable of inducing the corneal opacification syndrome. The protective effect of heparin is probably through its electrostatic binding to the cardiotoxin in the venom. Tetracycline could form ionic bonding at several sites in the strongly basic cardiotoxin. The corneal opacification syndrome was associated with the ability of the snakes to spit since venoms from the other non-spitting cobras were devoid of this activity.

Topics: Animals; Antivenins; Corneal Neovascularization; Corneal Opacity; Elapid Venoms; Female; Heparin; Male; Rabbits; Snakes; Species Specificity; Tetracycline