Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) scleral device compared to keratoplasty for the treatment of corneal ectasia

Am J Ophthalmol. 2014 Nov;158(5):974-82. doi: 10.1016/j.ajo.2014.07.016. Epub 2014 Jul 21.


Purpose: To compare the ocular characteristics and visual outcomes of eyes with corneal ectasia that were fitted with the Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) scleral device to those that underwent keratoplasty.

Design: Retrospective, comparative case series.

Methods: We reviewed the charts of consecutive patients with corneal ectasia that were evaluated for PROSE or underwent keratoplasty at our institution. Clinical data, topographic indices, and corneal thickness were reviewed, and eyes were stratified according to the Amsler-Krumeich classification for severity of ectasia. Only the more severe eye of each patient was included in the study. We compared visual acuity before and after PROSE fitting or keratoplasty. For PROSE evaluations, achievement of satisfactory fit and continued wear at 1 year of follow-up were recorded.

Results: From 2010 to 2012, 36 patients underwent PROSE evaluation for corneal ectasia while 37 patients underwent keratoplasty for the same indication. All eyes were successfully fitted with the PROSE device. Eyes in the keratoplasty group had more severe ectasia than eyes in the PROSE group (P = .038). Visual acuity was achieved more rapidly in the PROSE cohort compared to keratoplasty, and mean visual acuity was significantly better for all eyes (P < .0001) and when including only eyes with stage 4 ectasia (P < .001). More eyes with stage 4 ectasia achieved 20/25 visual acuity after PROSE than after keratoplasty (P = .003). At 1 year follow-up in the PROSE cohort, Snellen acuity was 20/28 (P = .108 vs keratoplasty), improving to 20/25 with over-refraction (P = .006 vs keratoplasty).

Conclusions: Eyes with advanced corneal ectasia can be successfully fitted with the PROSE device, and the visual acuity outcome for stage 4 ectasia was better and more rapid compared to keratoplasty. The acuity remained excellent with 1 year of follow-up. PROSE evaluation should be considered in patients with advanced corneal ectasia before proceeding to keratoplasty, especially if the ectasia is deemed stable.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Contact Lenses*
  • Cornea / pathology
  • Cornea / surgery*
  • Corneal Diseases / pathology
  • Corneal Diseases / physiopathology
  • Corneal Diseases / surgery*
  • Corneal Topography
  • Corneal Transplantation / methods*
  • Dilatation, Pathologic / pathology
  • Dilatation, Pathologic / surgery
  • Ecosystem
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Prosthesis Design
  • Prosthesis Fitting
  • Refraction, Ocular
  • Retrospective Studies
  • Sclera / surgery*
  • Surveys and Questionnaires
  • Tomography, Optical Coherence
  • Treatment Outcome
  • Visual Acuity*