Evaluation of changes in visual acuity,contrast sensitivity and aberrations in patients with keratoconus after corneal collagen cross-linking

Purpose: to assess and compare preoperative refractive,aberrometric,topographic,and contrast sensitivity (cs) measurements with postoperative values after corneal collagen cross-linking (cxl) in patients with progressive keratoconus. methods: twenty-two eyes of 11 patients with keratoconus were enrolled in this prospective study. uncorrected distance visual acuity (udva),best spectacle corrected visual acuity (bscva),cs,and higher order aberrations (hoas) were evaluated at baseline and 1,3,6,and 8 months after surgery. results: the mean total hoas of the included patients were 2.24,2.34,2.28,2.17,and 2.03 μm before and 1,3,6,and 8 months after cxl,respectively. a significant reduction in corneal hoas including vertical coma,vertical and horizontal trefoil and spherical aberration was observed 6 and 8 months after cxl.udva and bscva improved significantly in all patients who completed the follow-up period (p = 0.001). although mean cs declined significantly 1 month postoperatively,it improved significantly after 3,6,and 8 months (p< 0.001). maximum keratometry was significantly lower 8 months postoperatively compared to the preoperative value. (p = 0.006). conclusions: cxl seems to improve ucva,bscva,and cs and reduce most corneal hoas in progressive forms of keratoconus. zarei-ghanavati siamak 1 eye research center,khatam al-anbia hospital,mashhad university of medical sciences,mashhad khakshour hamid 2 eye research center,khatam al-anbia hospital,mashhad university of medical sciences,mashhad vejdani mohammadreza 3 eye research center,khatam al-anbia hospital,mashhad university of medical sciences,mashhad ghooshkhanei haleh 4 eye research center,khatam al-anbia hospital,mashhad university of medical sciences,mashhad vejdani amirhosein 5 eye research center,khatam al-anbia hospital,mashhad university of medical sciences,mashhad nottingham j. practical observations on conical cornea. london: churchill,london; 1984; p. 1-19. kennedy rh,bourne wm,dyer ja. a 48-year clinical and epidemiologic study of keratoconus. am j ophthalmol 1986;101:267-273. rabinowitz ys. keratoconus. surv ophthalmol 1998;42:297-319. li x,rabinowitz ys,rasheed k,yang h. longitudinal study of the normal eyes in unilateral keratoconus patients. ophthalmology 2004; 111:440-446. krachmer jh,feder rs,belin mw. keratoconus and related non-inflammatory corneal thinning disorders. surv ophthalmol 1984;28:293-322. stein ha,stein rm,freeman mi. the ophthalmic assistant: a text for allied and associated ophthalmic personnel. canada: elsevier mosby; 2006. p. 396. owens h,gamble g. a profile of keratoconus in new zealand. cornea 2003;22:122-5. wagner h,barr jt,zadnik k. collaborative longitudinal evaluation of keratoconus (clek) study: methods and findings to date. contact lens anterior eye 2007;30:223-232. georgiou t,funnell cl,cassels-brown a,o'conor r. influence of ethnic origin on the incidence of keratoconus and associated atopic disease in asians and white patients. eye (lond) 2004;18:379-383. weed kh,macewen cj,giles t,low j,mcghee cn. the dundee university scottish keratoconus study: demographics,corneal signs,associated diseases,and eye rubbing. eye (lond) 2008;22:534-541. ziaei h,jafarinasab mr,javadi ma,karimian f,poorsalman h,mahdavi m,shoja mr,katibeh m. epidemiology of keratoconus in an iranian population. cornea 2012;31(9):1044-1047. maeda n,fujikado t,kuroda t,mihashi t,hirohara y,nishida k,et al. wavefront aberrations measured with hartmann-shack sensor in patients with keratoconus. ophthalmology 2002;109:1996-2003. applegate ra,hilmantel g,howland hc,tu ey,starck t,zayac ej,et al. corneal first surface optical aberrations and visual performance. j refract surg 2000;16:507-514. wollensak g,spoerl e,wilsch m,seiler t. endothelial cell damage after riboflavin-ultraviolet-a treatment in the rabbit. © 2017 journal of ophthalmic and vision research published by wolters kluwer - medknow.