Corneal graft survival after therapeutic keratoplasty for Acanthamoeba keratitis.

PURPOSE: To describe corneal graft survival and visual outcome after therapeutic penetrating keratoplasty in patients with Acanthamoeba keratitis (AK) that is unresponsive to clinical treatment. METHODS: Retrospective study. Thirty-two patients with AK who underwent therapeutic penetrating keratoplasty (tPK) from August 1996 to August 2005 were included. Data relating to clinical features, visual acuity, surgical technique, graft survival and complications were collected. Graft survival was evaluated by the Kaplan-Meier method and comparisons were performed using the Log-rank test. RESULTS: Most patients (62.5%) were female. Mean age [+/- standard deviation (SD)] was 35 (+/- 13) years (range 15-68 years). All patients were contact lens wearers. Eighteen patients (56%) presented paralytic mydriasis and glaucoma during the treatment. Thirteen patients (40%) developed glaucoma after surgery; eight of them (61%) required a second PK because of graft failure. Of the 32 keratoplasty eyes, 56.2% presented graft failure at any follow-up point. Forty-five per cent of graft failures occurred before the 12 month follow-up, so 55% remained clear in the first year after surgery. Twelve patients underwent a second PK; seven of them failed and 45% were clear at 1 year. Two patients presented graft recurrence of amoebic infection. There was no significant difference in graft survival when eyes with or without mydriasis were compared (P = 0.40). Eyes with glaucoma presented a significantly shorter graft survival (P = 0.01). CONCLUSION: Penetrating keratoplasty is a treatment option for eyes that are unresponsive to clinical treatment infections. However, graft survival is poor; postoperative glaucoma is frequent and is associated with shorter graft survival.

Contrast sensitivity in deep anterior lamellar keratoplasty versus penetrating keratoplasty.

PURPOSE: To compare the measurements of contrast sensitivity at a distance in patients submitted to penetrating keratoplasty versus patients submitted to deep anterior lamellar keratoplasty for keratoconus treatment. METHODS: Contrast sensitivity of 15 subjects submitted to penetrating keratoplasty and 15 subjects submitted to deep anterior lamellar keratoplasty have been analyzed through the Functional Acuity Contrast Test (F.A.C.T) 301. RESULTS: There was no statistically significant difference between the measurements for penetrating keratoplasty and deep anterior lamellar keratoplasty. CONCLUSION: Contrast sensitivity was similar among the subjects submitted to penetrating keratoplasty and to deep anterior lamellar keratoplasty for keratoconus treatment.

Contrast sensitivity in deep anterior lamellar keratoplasty versus penetrating keratoplasty

PURPOSE: To compare the measurements of contrast sensitivity at a distance in patients submitted to penetrating keratoplasty versus patients submitted to deep anterior lamellar keratoplasty for keratoconus treatment. METHODS: Contrast sensitivity of 15 subjects submitted to penetrating keratoplasty and 15 subjects submitted to deep anterior lamellar keratoplasty have been analyzed through the Functional Acuity Contrast Test (F.A.C.T®) 301. RESULTS: There was no statistically significant difference between the measurements for penetrating keratoplasty and deep anterior lamellar keratoplasty. CONCLUSION: Contrast sensitivity was similar among the subjects submitted to penetrating keratoplasty and to deep anterior lamellar keratoplasty for keratoconus treatment.

OBJETIVO: Comparar as medidas de sensibilidade ao contraste à distância entre pacientes submetidos à ceratoplastia penetrante e pacientes submetidos à ceratoplastia lamelar anterior profunda para tratamento do ceratocone. MÉTODOS: Sensibilidades ao contraste de 15 pacientes submetidos à ceratoplastia penetrante e de 15 pacientes submetidos à ceratoplastia lamelar anterior profunda foram analisadas através do Functional Acuity Contrast Test (F.A.C.T®) 301. RESULTADOS: Não existiu diferença estatisticamente significante entre as medidas em ceratoplastia penetrante e ceratoplastia lamelar anterior profunda. CONCLUSÃO: Sensibilidade ao contraste foi similar entre os pacientes submetidos à ceratoplastia penetrante e à ceratoplastia lamelar anterior profunda para tratamento do ceratocone.

Corneal transplantation in a developing country: problems associated with technology transfer from rich to poor societies.

PURPOSE: To evaluate the results of penetrating corneal transplantation at a university hospital in Brazil. METHODS: A prospective cohort study was conducted on 146 patients who underwent penetrating keratoplasty at the University Hospital, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil. The participants were followed postoperatively for 36 months or until graft failure. RESULTS: In this period, 49% of the grafts lost transparency. All the corneal diseases analysed were present in about the same proportions, except for keratoconus and bullous keratopathy, which showed 3% and 73% rates of graft oedema, respectively. Only 8% of the failures could be attributed to rejection. Other variables such as age, multiple surgeries and previous eye conditions could not explain the high rate of graft failure. Non-adherence to postoperative care increased with age, with a significant association between this behaviour and the rate of graft failure in the older age group. Keratoconus seems to be much less demanding and bullous keratopathy seems to be more exigent in terms of corneal transplantation than other corneal diseases. CONCLUSION: Although it involves an apparently simple surgical procedure, corneal transplantation is a demanding enterprise that can lead to very poor results under unfavourable conditions.