Original ArticleKeratoconus Natural Progression: A Systematic Review and Meta-analysis of 11 529 Eyes
Section snippets
Inclusion Criteria
Prospective or retrospective studies including patients with untreated keratoconus. One or more outcome measure(s), including visual acuity: best-corrected visual acuity (BCVA) or uncorrected visual acuity (UCVA), refraction, corneal curvature measures: steep keratometry (K2), mean keratometry (Kmean), or maximum keratometry (Kmax), thinnest pachymetry, corneal transplantation rates, corneal scarring incidence, and patient-reported outcome measures (PROMs). Studies including 10 or more patients
Study Selection
Our search yielded 3950 publication titles, of which 41 were included in our systematic review and 23 were incorporated into the meta-analysis. The study selection process is shown in Figure 1. The experimental and patient characteristics of included studies are outlined in Table 1.25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61
Study Quality
Five of the 41 studies included in the systematic review were RCTs,
Discussion
We report a systematic review and meta-analysis of keratoconus natural history data including 11 529 eyes from 41 publications. Our meta-analysis of 12-month outcomes found that younger patients progress more aggressively: patients younger than 17 years old are likely to have more than 1.5 D of Kmax progression. Patients with steeper Kmax demonstrated more severe progression: patients with greater than 55 D Kmax are likely to progress by at least 1.5 D Kmax; in addition, Middle Eastern patients
References (76)
- et al.
Assessment of health-related quality of life after corneal transplantation
Am J Ophthalmol
(1997) - et al.
Epithelium-off photochemical corneal collagen cross-linkage using riboflavin and ultraviolet a for keratoconus and keratectasia: a systematic review and meta-analysis
Ocul Surf
(2014) - et al.
Corneal collagen crosslinking for progressive keratoconus in Saudi Arabia: one-year controlled clinical trial analysis
Saudi J Ophthalmol
(2015) - et al.
Keratoconus: contact lens or keratoplasty?
Ophthalmology
(1988) - et al.
Progression of keratoconus in patients wearing pancorneal toric edge rigid gas-permeable contact lenses
Cont Lens Anterior Eye
(2014) - et al.
Tomographic indices as possible risk factors for progression in pediatric keratoconus
J AAPOS
(2016) Transepithelial corneal collagen crosslinking for progressive keratoconus in a pediatric age group
J Cataract Refract Surg
(2013)- et al.
Two-year interval changes in Orbscan II topography in eyes with keratoconus
J Cataract Refract Surg
(2008) - et al.
Epithelial-disruption collagen crosslinking for keratoconus: one-year results
J Cataract Refract Surg
(2013) - et al.
Prognostic factors for the progression of keratoconus
Ophthalmology
(1994)
Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study: methods and findings to date
Cont Lens Anterior Eye
A randomized, controlled trial of corneal collagen cross-linking in progressive keratoconus: three-year results
Ophthalmology
30 years of contact lens prescribing for keratoconic patients in Turkey
Cont Lens Anterior Eye
Baseline factors predictive of incident penetrating keratoplasty in keratoconus
Am J Ophthalmol
Reduced precision of the Pentacam HR in eyes with mild to moderate keratoconus
Ophthalmology
Enhanced ectasia detection using corneal tomography and biomechanics
Am J Ophthalmol
Keratoconus: age of onset and natural history
Optom Vis Sci
Longitudinal changes in corneal irregular astigmatism and visual acuity in eyes with keratoconus
Jpn J Ophthalmol
Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study
Invest Ophthalmol Vis Sci
Clinical performance and fitting characteristics with a multicurve lens for keratoconus
Eye Contact Lens
Early diagnosis of keratoconus with Orbscan-II anterior system
J Huazhong Univ Sci Technol Med Sci
evolution profiles of different corneal parameters in progressive keratoconus
Cornea
Progression of keratoconus by longitudinal assessment with corneal topography
Invest Ophthalmol Vis Sci
Keratoconus follow up by elevation topography
Rev Mex Oftalmol
Longitudinal changes in corneal curvature in keratoconus
Cornea
Quantitative evaluation of the natural progression of keratoconus using three-dimensional optical coherence tomography
Invest Ophthalmol Vis Sci
Treatment of progressive keratoconus by riboflavin-UVA-induced cross-linking of corneal collagen: ultrastructural analysis by Heidelberg Retinal Tomograph II in vivo confocal microscopy in humans
Cornea
Global consensus on keratoconus and ectatic diseases
Cornea
Corneal collagen cross-linking for treating keratoconus
Corneal collagen cross-linking in keratoconus: a systematic review and meta-analysis
Sci Rep
The role of Scheimpflug imaging derived parameters in the progression of keratoconus: a systematic review and retrospective study
Invest Ophthalmol Vis Sci
Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement
PLoS Med
Joanna Briggs Institute Reviewers’ Manual
Proper method for calculating average visual acuity
J Refract Surg
mice: multivariate imputation by chained equations in R
J Stat Softw
R: A Language and Environment for Statistical Computing
Conducting meta-analyses in R with the metafor package
J Stat Software
Cited by (0)
Supplemental material available at www.aaojournal.org.
Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
A.C.F.: Support – Northcote Scholarship.
S.L.W.: Support – Sydney Medical School Foundation.
HUMAN SUBJECTS: No human subjects were included in this study. IRB/Ethics Committee ruled that approval was not required for this study. All research adhered to the tenets of the Declaration of Helsinki. All participants provided informed consent.
No animal subjects were used in this study.
Author Contributions:
Conception and design: Ferdi, Nguyen, Gore, Allan, Rozema, Watson
Analysis and interpretation: Ferdi, Nguyen, Gore, Allan, Rozema, Watson
Data collection: Ferdi
Obtained funding: N/A
Overall responsibility: Ferdi, Nguyen, Gore, Allan, Rozema, Watson