RESUMO
Adequate visualization and identification of the posterior hyaloid, epiretinal membranes and the internal limiting membrane are of paramount importance in modern vitreoretinal surgery. "Chromovitrectomy" is a term used for describing the vital dyes use in order to stain these transparent tissues and facilitate their manipulation during vitreous surgery. This article reviews the indications, applications and characteristics of vital dyes in vitreoretinal surgery. Various dyes are currently being used in routine clinical procedures, however the ideal staining agent has not yet been found. Any dye which is injected intravitreally has the potential to become toxic. Triamcinolone acetonide is used to highlight the vitreous and is particularly beneficial in determining the attachment of the posterior hyaloid to the underlying retina. Trypan blue stains epiretinal membranes and facilitates their complete removal. Both indocyanine green and brilliant blue G stain the internal limiting membrane properly, however concerns over indocyanine green toxicity have made surgeons switch to brillliant blue G as a safer alternative.
RESUMO
PURPOSE: To compare the incident rates of sustained elevation of intraocular pressure (IOP) after uncomplicated pars plana vitrectomy for idiopathic epiretinal membrane and the unoperated fellow eye. METHODS: Retrospective multicenter study of 198 patients who underwent pars plana vitrectomy for an idiopathic epiretinal membrane that was followed for at least 12 months. The diagnosis of sustained IOP elevation was defined as an elevation of IOP ≥ 24 mmHg or an increase of ≥ 5 mmHg in the IOP from baseline on 2 separate visits that warranted the initiation of ocular hypotensive therapy. The main outcome measured was the development of sustained IOP elevation as defined above. RESULTS: Patients were followed for an average of 47.3 ± 24 months (range, 12-106 months). In the vitrectomized eyes, 38 of the 198 (19.2%) patients developed elevated IOP compared with 9 of the 198 (4.5%) unoperated fellow eyes (P < 0.0001, Fisher exact test; odds ratio, 4.988). Possible risk factors include a family history of open-angle glaucoma (P = 0.0004 Fisher exact test; odds ratio, 7.206) and cataract surgery (P = 0.0270 Fisher exact test; odds ratio, 2.506). CONCLUSION: Uncomplicated PPV seems to increase the IOP, particularly in those who are pseudophakic and have a family history of open-angle glaucoma. This increase in IOP may lead to glaucomatous damage if not managed appropriately. Patients with a previous PPV need to be followed by an ophthalmologist to monitor the IOP in the vitrectomized eye.
