RESUMEN
Avaliaram-se a biocompatibilidade e a biodegradabilidade do sistema de liberação controlada de poli-lactato-co-glicolato (PLGA) no tratamento com ciprofloxacina das ceratites por Staphylococcus aureus em coelhos. Foram utilizados 20 coelhos, distribuídos em quatro grupos (G). Os animais dos G1, G3 e G4 foram inoculados com 2,5µL da bactéria - 108UFC, no estroma corneano. Os do G2 não receberam a aplicação do inóculo. O tratamento foi realizado com solução salina básica para os animais do G1, micropartículas de PLGA contendo ciprofloxacina nos animais dos G2 e G4 e colírio de ciprofloxacina naqueles do G3. Suabe e biópsia da superfície ocular foram coletados para cultura. Apenas um animal do G1 apresentou cultura positiva para S. aureus. Exame histológico revelou a presença bacteriana em todos os animais do G1 e em dois animais do G3. Também foi constatada reação inflamatória no local da aplicação do sistema de liberação controlada. O tratamento com micropartículas de PLGA foi eficiente no tratamento de ceratites bacterianas, ao eliminar por completo a presença do S. aureus, mas entretanto não foi completamente biocompatível e biodegradável após cinco dias.
The biocompatibility and biodegradability of the controlled delivery system of Poly-Latic-Co-Glucolatic (PLGA) in the treatment of Staphylococcus aureus keratitis with ciprofloxacin in rabbits were evaluated. Twenty rabbits divided into four groups (G) were used. G1, G3 and G4 animals were inoculated with bacterial 2.5µL (108CFU) in the corneal stroma, and G2 animals did not receive the application of inoculum. The treatment was performed with basic saline solution in G1 rabbits, micro particles of PLGA containing ciprofloxacin in G2 and G4 animals, and ciprofloxacin eye drops in G3 rabbits. Swab and biopsy of the ocular surface were collected for culture. Only one animal in G1 had positive culture for S. aureus in the processed material. Histological examination showed a bacterial presence in all animals in G1 and two animals in G3. Inflammatory reaction was noted at the application site of the controlled release. Data analysis showed that treatment with micro particles of PLGA was effective in treating bacterial keratitis, completely eliminating the presence of S. aureus, but it was not being completely biocompatible and biodegradable after five days.
Asunto(s)
Animales , Conejos , Queratitis/veterinaria , Conejos/microbiología , Staphylococcus aureus/inmunología , Biodegradación Ambiental , Glicolatos , Ácido Láctico , Ensayo de Materiales/veterinariaRESUMEN
OBJECTIVE: To evaluate clinical and refractive results of myopic angle-supported intraocular lenses (IOLs). DESIGN: Prospective, noncomparative case series. PARTICIPANTS: Twenty-one eyes of 12 patients (7 female) with a mean age of 29.5 years and a follow-up of 24 months. The prospective study included highly myopic eyes (more than -11.00 diopters [D]) with spectacle-corrected visual acuity better than 20/200. METHODS: Twenty-one eyes underwent implantation of a single-piece IOL with Z-shaped haptics for angle support (each haptic with two footplates) and an optical zone of 4.5 mm (NuVita, Bausch & Lomb Surgical, Irvine, CA). The dioptric power of the IOL was calculated considering refraction, keratometry, and anterior chamber depth (specific nomogram), and its diameter was determined by adding 0.5 mm to the corneal diameter. MAIN OUTCOME MEASURES: We evaluated the following clinical and refractive data: visual acuity without and with correction (VAsc and VAcc), spherical equivalent (SE) obtained under cycloplegia, slit-lamp biomicroscopy, keratometry, applanation tonometry, endothelial cell count, ultrasound pachymetry, gonioscopy, indirect ophthalmoscopy, subjective complaints, and descriptions of complications. RESULTS: Mean postoperative VAsc was 20/74. Mean preoperative VAcc (20/50) increased to 20/30; 65% gained at least two lines of VAcc, and no eye had a decrease in VAcc. Preoperative SE (-18.95 D) evolved to -2. 06 D, stabilizing after one month. Iris retraction (pupil ovalization) more than 0.5 mm was noted in eight eyes (40%). Mean keratometry, corneal astigmatism, and ultrasound pachymetry were stable during the study (P > 0.01). Significant endothelial cell loss was demonstrated in the second year. Gonioscopy showed 70 (87. 5%) footplates ideally positioned with no iris depression. Reports of glare and haloes in dark environment were considered light in 80% and not referred in 20%, and spectacles were used for residual refraction in 75%. Intraocular lens exchange was needed in one eye because of undersizing, and the IOL was removed in one eye because of chronic inflammatory reaction associated with ocular hypertension (this patient was excluded from the statistical analysis). CONCLUSIONS: This report demonstrates good efficacy for correction of high myopia by the phakic IOL used during the two years of follow-up. Long-term complications (safety) such as iris retraction and endothelial cell loss remain a concern.