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Impact of type I Boston keratoprosthesis implantation on vision-related quality of life
  1. Marcus Ang1,2,3,4,
  2. Ryan Man3,
  3. Eva Fenwick2,3,
  4. Ecosse Lamoureux2,3,
  5. Mark Wilkins4,5
  1. 1 Singapore National Eye Centre, Singapore
  2. 2 Duke-NUS Medical School, Singapore
  3. 3 Singapore Eye Research Institute, Singapore
  4. 4 Moorfields Eye Hospital, London, UK
  5. 5 Institute of Ophthalmology, University College London, London, UK
  1. Correspondence to Dr Marcus Ang, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore; marcus.ang{at}


Aim To determine the impact of type I Boston keratoprosthesis (KPro) implantation on vision-related quality of life (VRQoL).

Methods Prospective study in 33 patients (mean age 56±12 years, 67% male) with bilateral corneal blindness, who underwent a KPro implantation at a single tertiary eye hospital (June 2011–July 2015). VRQoL was evaluated using the Impact of Vision Impairment Questionnaire (IVI) at baseline and at 3–6 months postsurgery, after stabilisation of best-corrected visual acuity (BCVA). Rasch analysis was used to transform the IVI responses into interval-level measures comprising the ‘reading’, ‘mobility’ and ‘emotional’ subscales with effect sizes calculated for pre-post VRQoL scores.

Results Mean preoperative BCVA was counting-fingers at 2 feet in the operated eye (20/240 fellow eye). Preoperative VRQoL scores: −2.27, –2.91 and −3.06 logits for the reading, mobility and emotional subscales, respectively. Device retention rate was 90% over the follow-up period (mean 26±12 months). We observed large gains for reading and mobility of 1.92 logits (effect size 0.88), and 2.64 logits (effect size 0.89) respectively, with a moderate gain in the emotional subscale of 2.11 logits (effect size 0.59). These improvements did not vary significantly with BCVA on multivariate analysis (all p>0.05).

Conclusion We observed a differential short-term improvement to VRQoL after KPro implantation with a significant impact on emotional well-being, which may not be fully explained by visual improvement alone. Further studies are required to confirm if these improvements in VRQoL are sustained in the long-term and are generalisable to other populations.

  • Cornea
  • Prosthesis
  • Treatment Surgery

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  • Contributors All authors met the ICJME criteria: 1) substantial contributions to conception and design, acquisition of data or analysis and interpretation of data; 2) drafting the article or revising it critically for important intellectual content and 3) final approval of the version to be published.

  • Competing interests None declared.

  • Patient consent Obtained.

  • Ethics approval Moorfields Eye Hospital Ethical Review Board.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement Additional unpublished data may be obtained from the corresponding author.

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