1. Scheimpflug and OCT analysis of posterior keratoconus
Alexandra Abdala Figuerola M.D.
Alejandro Navas M.D., M.Sc.
Arturo Ramirez-Miranda M.D.
Erick Hernandez-Bogantes M.D.
Andrew Olivo Payne M.D.
Enrique O. Graue-Hernandez M.D., M.Sc.
Department of Cornea and Refractive Surgery
Instituto de Oftalmologia
“Fundacion Conde de Valenciana”
Mexico City, Mexico
Dr. Ramirez-Miranda and Dr. Navas are consultants for Carl Zeiss Meditec.
Dr. Ramirez-Miranda is a speaker of Thea Laboratoires.
The remaining authors have no financial or proprietary interest in the materials presented herein.

2. Introduction In 1930, Butler described posterior keratoconus.
It is a rare non-inflammatory corneal disorder characterized by posterior corneal bulge.
It is classified in generalized posterior keratoconus and circumscribed posterior keratoconus.
It can be sporadic or congenital due to a development defect and it is usually unilateral.

3. Purpose
To report a case-series of 4 eyes with posterior keratoconus; evaluating corneal Scheimpflug topographic changes and corneal optical coherence tomography (OCT).

4. Methods Descriptive study design
Three patients diagnosed with posterior keratoconus
Underwent: Slit-lamp examination, corneal optical coherence tomography and Scheimpflug topography

5. Case 1 OS OS 20/70 20/70 33-year-old male
Decreased visual acuity on OS OS OS
20/70
20/70

7. Case 2 OD OS 20/400 20/300 45-year-old female
Decreased visual acuity OU OD OS OD
20/400
20/300

9. Case 3 OS 20/100 7-year-old male with corneal opacity on his OS
Both Parents and twin brother with unremarkable corneas OS
20/100

10. Results
Localized central and paracentral keratoconus was diagnosed in 4 eyes.
Scheimpflug analysis reported no steepening of the anterior corneal curvature map, instead anterior surface flattening in case 1.
Case 2 reported an area of anterior corneal steepening corresponding to the posterior bulge
OCT showed posterior corneal curvature changes

11. Conclusions
Posterior keratoconus was initially described as having a normal anterior surface, which has been proven the opposite in topographic modeling
Scheimpflug technology and OCT can be an excellent and helpful diagnostic tool in order to report posterior curvature changes and anterior surface alterations
Mannis MJ, Lightman J, Plotnik RD. Corneal topography of posterior keratoconus. Cornea Jul;11(4):351-4.
Rao SK, Padmanabhan P. Posterior keratoconus. An expanded classification scheme based on corneal topograghy. Ophthalmology Jul;105(7):