Because of the extreme central flattening that can occur post-penetrating keratoplasty (PKP), these cases represent a unique scleral lens fitting challenge to optimize central and optical zone clearances.
This case report illustrates the use of the sMap3D virtual precision fit software to design a lens to vault over a localized conjunctival/scleral obstacle.
Virtual fitting designed a 5.5D reverse geometry lens with high accuracy in predicted central clearance and peripheral fit, avoiding multiple stepwise changes and remakes, simplifying lens fitting and reducing patient chair time.
This case illustrates that scleral shape rather than size and weight of the lens can sometimes be the major contributing factor to scleral lens decentration.
Backgound: Toric haptic scleral lens designs are prescribed more often than in previous years. Recent interest in mapping the sclera and conjunctiva is proving that scleral shape is highly variable and may explain the difficulty in fitting some patients with scleral lenses
Corneal and scleral elevation topography changes after corneal hydrops in keratoconus cases. View our full clinical poster about this topic.
Scleral lens fitting can be challenging in the presence of localized conjunctival/scleral elevations (pingueculae or filtering blebs) in the area of the lens landing zone. We report on a case that was virtually fit successfully with a new corneal-scleral topography system.
Designing scleral lenses to fit over or around irregularities poses unique fitting issues. A new corneo-scleral topography device and software (sMap3D, Precision Ocular Metrology) is now able to accurately map these irregularities.
Toric haptic scleral lens designs are prescribed more often than in previous years. Recent interest in mapping the sclera and conjunctiva indicates that scleral shape demonstrates interocular and individual variability, which may explain the difficulty in fitting some patients with scleral lenses.
The advent and use of scleral mapping tools has improved the scientific approach to scleral lens fitting by measuring topographical shape of the sclera beyond the limbus, namely the sagittal height of the eye (SAG) at the diameter of the scleral lens and the amount of scleral asymmetry.