Differential expression of vascular endothelial growth factor implies the limbal origin of pterygia.

OBJECTIVE: To study the distribution of isoforms of vascular endothelial growth factor (VEGF) and its receptors VEGFR1 and VEGFR2 in pterygia and to compare it with that in healthy conjunctivas. DESIGN: Nonrandomized comparative (cadaver controlled) study with histopathologic correlations. METHODS: Tissue specimens from 75 patients treated for primary pterygia were analyzed using immunohistochemical studies as well as different molecular biological examinations. Healthy conjunctivas from 33 patients treated for cataracts as well as specimens from the conjunctiva, limbus, and lens of both eyes of 12 body donors served as controls. TESTING: Surgical specimens of pterygia and normal conjunctiva specimens were processed with paraffin, sectioned, stained using specific antibodies against VEGF and its receptors, and examined by light microscopy. The other part of both groups of specimens as well as specimens from body donors were prepared and analyzed by means of reverse-transcription polymerase chain reaction (RT-PCR), real-time RT-PCR, enzyme-linked immunosorbent assay, and Western blots. MAIN OUTCOME PARAMETERS: Vascular endothelial growth factor and VEGFR1 and VEGFR2 were analyzed to indentify the splice variants of VEGF as well as the distribution and amount of VEGF and both receptors in pterygia and the control tissues. RESULTS: In analysis of specimens from pterygium patients as well as normal conjunctivas, VEGF121 and VEGF165 were identified as the only VEGF splice forms expressed. In addition to VEGF, VEGFR1 and VEGFR2 were detected in pterygia and conjunctivas and immunostained within the epithelium of pterygia and conjunctivas and on intrapterygial and intraconjunctival endothelial cells. Levels of VEGFR1 and VEGFR2 mRNA were lower in pterygia than in conjunctivas but similar in limbal and pterygium samples. Vascular endothelial growth factor levels were higher in pterygia than in conjunctivas, but were similar in the limbus and pterygia. CONCLUSIONS: The results reveal similar behaviors in limbal and pterygium epithelial cells in terms of VEGF and VEGFR expression, with the presumption that pterygia arise from limbal epithelial cells and that human conjunctivas are not a suitable control for the analysis of pterygia. Moreover, the results suggest that VEGF might play an active role in the physiology of conjunctival epithelial cells.

Upper and lower eyelid reconstruction for severe disfiguring necrobiotic xanthogranuloma.

BACKGROUND: Necrobiotic xanthogranuloma is a rare disease featuring generalized xanthomatous inflammatory skin lesions associated with paraproteinemia and possible lymphoproliferative diseases. Eyelid involvement can be unilateral or bilateral and ranges from minor xanthelasma-like lesions to severe ulcerative disease with consecutive keratitis and scleritis. CASE REPORT: The authors report the case of a 67-year-old woman with extensive necrobiotic xanthogranuloma involving the eyelids, head and neck, anterior chest, and both upper and lower extremities. Periorbital involvement caused severe upper and lower lid ectropium with chronic conjunctival inflammation and unilateral exposure keratitis. During a persistent period of low disease activity, granulomatous lesions and scars were widely excised, lids partially shortened and large full-thickness skin grafts applied. Uninvolved parts of the upper arms had to serve as donor sites, as other possible donor sites were not available. After successful reconstruction of the left side and no local recurrence of the disease, the right side was corrected in the same way. Full eyelid closure was achieved and skin grafts healed without complications. No recurrence of the disease appeared at the sites of operation, despite continuous new lesions elsewhere. CONCLUSION: Severe cicatricial eyelid deformation caused by necrobiotic xanthogranuloma can be treated with success by excision and free skin grafting. The mechanisms of recurrence at excision sites described by others remain unclear, but at least during phases of low activity, the described treatment is safe and recurrence is not to be expected.