title: Impact of keratoconus, cross-linking and cross-linking combined with photorefractive keratectomy on self-reported quality of life.
abstract: OBJECTIVE
  To assess the effect of stage 1 keratoconus (KC) and of the 2 prevalent KC therapeutic options: (1) corneal collagen cross-linking (CXL) and (2) CXL combined with topography-guided photorefractive keratectomy (t-PRK) on self-reported quality of life (QOL) by means of the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ 25).
  
  
  METHODS
  Thirty-two patients with bilateral KC stage 1 (KC group) and best-corrected visual acuity of 20/20 in both eyes were prospectively recruited. Of them, 19 KC patients underwent typical CXL treatment (CXL group), whereas 13 underwent CXL combined with t-PRK treatment (tCXL group). Only the eye with the most advanced condition received the treatment. Subjects responded to the NEI-VFQ 25 1 day before the treatment and 1 year postoperatively. Thirty-nine age-matched contact lens users formed the control group. NEI-VFQ 25 subscale and total scores were associated with spherical equivalent, mean keratometry, and a series of Scheimpflug imaging-derived corneal variance indexes by means of the Spearman correlation coefficient and multivariate linear regression analysis.
  
  
  RESULTS
  Preoperatively, significant differences were detected between the KC group and the control group in VFQ 25 total and all subscale scores (P < 0.05), except "general health," "color vision," and "peripheral vision" domains. According to the multivariate linear regression analysis, the index of height decentration was the most significant predictor of VFQ 25 total score (b = 0.943; P = 0.016). Postoperatively, significant differences were detected in "mental health" and "dependency" VFQ 25 domains for both the CXL and tCXL groups (P = 0.05). Furthermore, the tCXL group demonstrated significant differences in the "near activities" (P = 0.04), "role limitations" (P = 0.02), and "driving" (P < 0.01) subscale scores.
  
  
  CONCLUSIONS
  Our results suggest that KC exerts a significant impact on KC patients' QOL, even in its early stages with normal best-spectacle-corrected visual acuity. Moreover, both CXL and CXL combined with t-PRK seem to exert a beneficial impact on self-reported QOL, suggesting that they should be applied as soon as possible.
authors.affiliation: Department of Ophthalmology, University Hospital of Alexandroupolis, Alexandroupolis, Greece. labiris@usa.net
authors.forename: Georgios
authors.initials: G
authors.lastname: Labiris
authors.forename: Athanassios
authors.initials: A
authors.lastname: Giarmoukakis
authors.forename: Haris
authors.initials: H
authors.lastname: Sideroudi
authors.forename: Maria
authors.initials: M
authors.lastname: Gkika
authors.forename: Michael
authors.initials: M
authors.lastname: Fanariotis
authors.forename: Vassilios
authors.initials: V
authors.lastname: Kozobolis
mesh_terms: D000328:Adult; D003094:Collagen / Q000378:metabolism; D003131:Combined Modality Therapy; D003319:Corneal Stroma / Q000378:metabolism; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy / Q000523:psychology* / Q000601:surgery / Q000628:therapy*; D008297:Male; D018903:Photorefractive Keratectomy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011446:Prospective Studies; D011788:Quality of Life / Q000523:psychology*; D012256:Riboflavin / Q000627:therapeutic use; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin