Peripheral Reconstructive Lamellar Keratoplasty for Late Ectasia After Penetrating Keratoplasty in Keratoconus Eyes.

PURPOSE: To describe outcomes of customized peripheral anterior lamellar keratoplasty (PALK) for late ectasia of the donor-recipient junction after penetrating keratoplasty (PK) for keratoconus. METHODS: This was a single-center, retrospective review of 33 eyes (28 patients) that developed ectasia restricted to the graft-host junction; 17 eyes underwent PALK using lamellar resections of 8- to 11-mm width starting at the external margin of the previous PK and suturing a same-size donor graft (annular or segmental). Five eyes were excluded from analysis because of postoperative complications unrelated to the technique. RESULTS: The average time between PK and diagnosis of secondary ectasia was 28 years (range 9-49 years). Slit-lamp examination showed localized thinning and elongation of the scar at the graft-host junction with well-defined biomicroscopic limits. Preoperatively, the mean keratometric measures were K1: 44.8 ± 4.8 D and K2: 54.1 ± 4.8 D and postoperatively K1: 47.5 ± 3.5 D and K2: 50.8 ± 2.6 D. The mean improvement in corrected visual acuity was 10 lines, and mean cylinder improved from 9.3 ± 2.1 D to 3.3 ± 1.4 D. All cases showed anatomical and refractive improvement. CONCLUSIONS: With long-term follow-up, late post-PK ectasia becomes an increasing problem. PALK can be a successful surgical option to reinforce the ectatic area while preserving a functional clear PK. By adding donor corneal tissue, PALK restores the ectatic area, improves visual acuity, keratometric values, and astigmatism, and preserves the functional graft while avoiding the higher risks of a larger diameter PK.

Assessing ectasia susceptibility prior to LASIK: the role of age and residual stromal bed (RSB) in conjunction to Belin-Ambrósio deviation index (BAD-D) / Avaliação de suscetibilidade para ectasia antes de LASIK: o papel da idade e do leito estromal residual em conjunto ao índice Belin-Ambrósio (BAD-D)

Purpose: To compare the ability to detect preoperative ectasia risk among LASIK candidates using classic ERSS (Ectasia Risk Score System) and Pentacam Belin-Ambrósio deviation index (BAD-D), and to test the benefit of a combined approach including BAD-D and clinical data. Methods: A retrospective nonrandomized study involved preoperative LASIK data from 23 post-LASIK ectasia cases and 266 stable-LASIK (follow up > 12 months). Preoperative clinical and Pentacam (Oculus; Wetzlar, Germany) data were obtained from all cases. Mann-Whitney's test was performed to assess differences between groups. Stepwise logistic regression was used for combining parameters.The areas under the Receiver Operating Characteristic (ROC) curves (AUC) were calculated for all parameters and combinations, with pairwise comparisons of AUC (DeLong's method). Results: Statistically significant differences were found for age, residual stromal bed (RSB), central corneal thickness and BAD-D (p<0.001), but not for sphere, cylinder or spherical equivalent (p>0.05). ERSS was 3 or more on 12/23 eyes from the ectasia group (sensitivity = 52.17%) and 48/266 eyes from the stable LASIK group (18% false positive). BAD-D had AUC of 0.931 (95% CI: 0.895 to 0.957), with cut-off of 1.29 (sensitivity = 87%; specificity = 92.1%). Formula combining BAD-D, age and RSB provided 100% sensitivity and 94% specificity, with better AUC (0.989; 95% CI: 0.969 to 0.998) than all individual parameters (p>0.001). Conclusion: BAD-D is more accurate than ERSS. Combining clinical data and BAD-D improved ectasia susceptibility screening. Further validation is necessary. Novel combined functions using other topometric and tomographic parameters should be tested to further enhance accuracy. .

Objetivo: Comparar a capacidade de detectar risco de ectasia no pré-operatório de LASIK usando o clássico ERSS (Ectasia Risk Score System) e índice Belin- Ambrósio (BAD- D) do Pentacam; e para testar o benefício de uma abordagem combinada, incluindo BAD-D e dados clínicos. Métodos: Estudo não randomizado retrospectivo envolveu dados pré-operatórios de LASIK de 23 casos que evoluíram para ectasia pós-LASIK e 266 casos estáveis após LASIK com acompanhamento mínimo de 12 meses. Dados préoperatórios clínicos e do Pentacam (Oculus, Wetzlar, Alemanha) foram obtidos para todos os casos. O teste de Mann-Whitney foi realizado para avaliar as diferenças entre grupos. Regressão logística foi utilizada para combinar parâmetros. As áreas sob as curvas Receiver Operating Characteristic (ROC; AUC) foram calculadas para todos os parâmetros e as combinações. Comparações de pares das AUC foram realizadas com método de DeLong. Resultados: Foram encontradas diferenças estatisticamente significativas para a idade, residual leito estromal (RSB), espessura corneana central e BAD- D (p <0,001), mas não para a grau esférico, cilindro ou equivalente esférico (p > 0,05). ERSS foi de três ou mais em 12/23 olhos do grupo ectasia (sensibilidade = 52,17 %) e 48/ 266 olhos do grupo LASIK estável (18% falso positivo). BAD- D teve AUC de 0,931 (IC 95%: 0,895-0,957), com corte de 1,29 (sensibilidade=87%, especificidade=92,1%). A fórmula que combinou BAD-D, idade e RSB, gerou 100% de sensibilidade e especificidade de 94%, com melhor AUC (0,989, IC 95%: 0,969-0,998) do que todos os parâmetros individuais (p>0,001). Conclusão: BAD-D é mais preciso do que ERSS. Combinações de dados clínicos e os BAD-D melhorou a capacidade de identificação ...