Vitreoretinal complications in Yemeni patients with keratorefractive surgery

To evaluate vitreoretinal complications in patients undergoing laser keratorefractive surgery. This retrospective observational non-comparative clinical study was carried out between June 2005 and March 2008, and included 4691 consecutive laser keratorefractive surgery procedures for 2480 patients performed in the Department of Refractive Surgery, Yemen Magrabi Hospital, Sana'a, Yemen. Patients were followed up for 12-36 months. The preoperative patient evaluation included manifest and cycloplegic refractions, uncorrected visual acuity, best spectacle-corrected visual acuity, slit-lamp biomicroscopy, and dilated vitreoretinal assessment. Retinal diseases were recorded and analyzed during the preoperative and postoperative care. Sixty-five [1.4%] of the 4691 eyes had posterior segment pathology requiring intervention. In the preoperative assessment, 57 eyes had prophylactic laser photocoagulation for retinal lesions. Seven eyes developed posterior vitreous detachment postoperatively, and 4 of these required prophylactic laser therapy for lattice degeneration and retinal breaks. Two eyes [0.04%] developed rhegmatogenous retinal detachment, which occurred spontaneously. One patient developed cystoid macular edema in both eyes. Most complications are related to the refractive outcome or to corneal and anterior segment injury. Posterior segment complications are rare, but dilated vitreoretinal assessment is important before and after laser keratorefractive procedures. Patients with suspicious retinal lesions need a comprehensive vitreoretinal evaluation by a retinal specialist

Vitrectomia farmacológica e descolamento do vítreo posterior / Pharmacological vitreolysis and posterior vitreous detachment

O vítreo exerce papel crucial na patogênese de vários distúrbios vitreoretinianos. As alterações moleculares e estruturais fisiológicas do gel vítreo evoluem para a liquefação e culminam com o descolamento do córtex vítreo posterior (DVP). A ocorrência do descolamento do vítreo posterior influencia positivamente o prognóstico de pacientes diabéticos, com maculopatias e vasculopatias. Abordaremos o conceito da vitrectomia farmacológica que se refere ao uso de agentes que alteram a organização molecular do vítreo, num esforço de reduzir ou eliminar seu papel na gênese de doenças vítreo-retinianas, sendo o seu objetivo final, o descolamento total do vítreo posterior. Vários agentes têm sido estudados durante a última década, porém, existem várias limitações na aplicabilidade clínica destes compostos. Nesse artigo de revisão, iremos abordar os diferentes agentes e os seus mecanismos de ação sobre a matriz extracelular e a interface vítreo-retiniana.

Vitreous dynamic in cystoid macular edema

Eyes suffering from various conditions, such as aphakia, diabetic retinopathy, peripheral uveitis, branch vein occuluslon, or retinitis pigmentosa, are predisposed to vitreous detachment. When vitreous detachment occurs, the vitreous can remain attached to the macula due to a frim vitreomacular adhesion. This partial posterior vitreous detachment associated with continuous vitreous traction to the macular area can lead to the development of cystoid macular edema. Two types of vitreous traction have been observed: traction with narrow vitreous strand, and traction with broad vitreoretianal adhesion. Another suggested mechanism by which the posterior vitreous can cause cystoid macular edema is vitreous contraction without vitreous detachment, producing tractional forces at sites of firm vitreoretinal adhesions that are located at the optic disc and macula. Cystoid macular edema is often accompanied by leakage from dilated retinal capillaries at the optic disc