Posterior keratoconus-clinical aspects and anterior segment optical coherence tomography findings: A case report.

PURPOSE: To describe a case of Posterior Keratoconus (keratoconus posticus); its clinical condition, corneal, refractive response to intracorneal ring implantation (MyoRing), anterior segment optical coherence tomography findings; and micro incisional cataract surgery outcome.

METHODS: Case report.

RESULTS: The case was studied with high resolution anterior segment optical coherence tomography (OCT), epithelium OCT, corneal topography, and aberrometry. A MyoRing was implanted and after the development of cataract, microincisional cataract surgery was performed. A large hyperopic shift was observed following the ring implantation. Calculation of the intraocular lens showed poor predictability.

CONCLUSIONS: Posterior keratoconus is a rare corneal congenital disorder characterized by a posterior corneal elevation. Surprisingly, on the total corneal aberrometry, the coma is within normal levels; in the anterior and posterior corneal aberrometry, all the low order and high order aberrations are outside of normal parameters. The epithelial thickness is normal on the contrary to anterior keratoconus. Micro incisional cataract surgery can be safely performed in these eyes, although a refractive surprise is expected due to errors in the intraocular lens calculation.