AIM:To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data.METHODS:This prospecti...AIM:To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data.METHODS:This prospective longitudinal non-comparative clinical trial evaluated 88 eyes of 88 patients(age 18-62 y)with keratoconus diagnosis from two Spanish centers.Ferrara ring segment(AJL Ophthalmic)implantation was performed in all cases,using the mechanical procedure in 25 eyes(28.4%)and a femtosecond laser-assisted procedure in 63 eyes(71.6%).The ring segments implanted in each case were selected using a new optimized nomogram that considered variables such as anterior corneal asphericity and astigmatism or the discrepancy among astigmatism and coma orientations.Visual,refractive,corneal topographic,aberrometric,and pachymetric changes after surgery were evaluated during a 3-month follow-up.RESULTS:The implants induced a significant refractive change as well as an improvement in uncorrected(UDVA)and corrected distance visual acuity(CDVA;P<0.001).Postoperative CDVA of 0.10 log MAR or better was achieved in 28.4%and 46.5%of eyes,respectively.Two eyes(2.3%)lost two or more lines of CDVA whereas a total of 53.5%of eyes gained lines of CDVA.A significant central anterior and posterior corneal flattening was induced(P≤0.003),with a significant reduction of anterior(P<0.001)and posterior corneal astigmatisms(P=0.048),and a change in anterior asphericity(P<0.001).Total primary coma(6 mm pupil)change was also statistically significant(preoperative 3.66±3.04μm vs postoperative 2.33±2.26μm,P<0.001).No significant differences were found in the effect of ring segments between cases implanted using the mechanical and femtosecond techniques(P≥0.101).CONCLUSION:The implantation of Ferrara rings based on the nomogram evaluated is safe and effective for promoting a visual rehabilitation in keratoconus,with a relevant control of primary coma aberration.展开更多
基金Supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal (RYC-2016-20471)
文摘AIM:To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data.METHODS:This prospective longitudinal non-comparative clinical trial evaluated 88 eyes of 88 patients(age 18-62 y)with keratoconus diagnosis from two Spanish centers.Ferrara ring segment(AJL Ophthalmic)implantation was performed in all cases,using the mechanical procedure in 25 eyes(28.4%)and a femtosecond laser-assisted procedure in 63 eyes(71.6%).The ring segments implanted in each case were selected using a new optimized nomogram that considered variables such as anterior corneal asphericity and astigmatism or the discrepancy among astigmatism and coma orientations.Visual,refractive,corneal topographic,aberrometric,and pachymetric changes after surgery were evaluated during a 3-month follow-up.RESULTS:The implants induced a significant refractive change as well as an improvement in uncorrected(UDVA)and corrected distance visual acuity(CDVA;P<0.001).Postoperative CDVA of 0.10 log MAR or better was achieved in 28.4%and 46.5%of eyes,respectively.Two eyes(2.3%)lost two or more lines of CDVA whereas a total of 53.5%of eyes gained lines of CDVA.A significant central anterior and posterior corneal flattening was induced(P≤0.003),with a significant reduction of anterior(P<0.001)and posterior corneal astigmatisms(P=0.048),and a change in anterior asphericity(P<0.001).Total primary coma(6 mm pupil)change was also statistically significant(preoperative 3.66±3.04μm vs postoperative 2.33±2.26μm,P<0.001).No significant differences were found in the effect of ring segments between cases implanted using the mechanical and femtosecond techniques(P≥0.101).CONCLUSION:The implantation of Ferrara rings based on the nomogram evaluated is safe and effective for promoting a visual rehabilitation in keratoconus,with a relevant control of primary coma aberration.
