BACKGROUND: Microcornea is a genetic condition where the corneal diameter is 10mm or less in an otherwise normal-sized eye. It can occur unilaterally or bilaterally. Microcornea has been associated with a number of ocular and systemic conditions including cornea plana. Cornea plana is a condition where the corneal curvature is extremely flat commonly 30-35D. It has been associated with high hyperopia, however, mild hyperopia and myopia are possible.
CASE REPORT: A 16 year old female was referred to the Michigan College of Optometry Clinic for a contact lens evaluation. Corneal topography was performed which demonstrated very flat corneas OU. Simulated K values were OD 31.12/32.00@096, OS 30.62/32.62@102. Manifest refraction and visual acuities were OD +3.75-0.75x170(20/20), OS +7.25-1.00x005(20/100). The cover test showed a 10pd constant esotropia at distance and near with accompanying amblyopia of the left eye. Slit lamp examination revealed microcornea and cornea plana with a normal anterior chamber depth OU. Retinal evaluation was normal OU. The patient refused to wear spectacles because she was quite active in sports. Using topography as an aid, we used simulated K's to order trial RGP lenses. The following lenses parameters were ordered in fluoroperm 60 material, lenticular design: OD OAD 8.5, OZD 7.4, BC 10.80, Rx +3.75; OS OAD 8.5, OZD 7.4, BC 10.90, Rx +8.00. At dispensing both lenses showed alignment patterns with adequate peripheral clearance, but as expected the lenses rode inferiorly on the flat corneas. VA's achieved were OD 20/15, OS 20/100. Subsequent follow-up exams showed no corneal insult and she was able to wear the lenses all waking hours. We also recommended safety eyewear to be worn over the contact lenses when playing sports. CONCLUSION: This case report demonstrates that patients with microcornea and associated cornea plana can be fit successfully with RGP lenses.