Keratoconus is already a complex condition, but when combined with corneal grafts, previous trauma, and highly irregular eye shape, achieving good vision becomes significantly more challenging.
At our clinic, we routinely manage these advanced cases, particularly where conventional approaches have failed.
The challenge
We recently managed a patient with:
– Keratoconus in both eyes
– Bilateral corneal grafts (penetrating keratoplasty)
– History of significant eye trauma
– Previously fitted scleral lens with vision limited to 6/15, localised lens touch on the graft, extreme suction making removal difficult.
Why standard fitting falls short
Traditional scleral lens fitting relies on trial lenses and estimation.
In highly irregular, post-graft eyes:
– Trial lenses often do not align properly
– Localised pressure can occur over the graft
– Extreme corneal steepness makes lenses unstable
In this case, the cornea was so steep that trial lenses could not be reliably assessed on-eye.
A more advanced approach
For complex eyes, we move beyond trial fitting and use full ocular surface mapping (SMap 3D profilometry) to design lenses based on the exact shape of the eye.
One of the most complex lenses we have designed
In this case, we designed one of the most complex scleral lenses we have produced:
– Complete clearance of the graft
– Sagittal depth: 8286 microns (~8.3 mm)
– Large diameter: 18.5 mm (to improve stability and reduce suction)
– Decentered optics to align with the patient’s true visual axis
– Elliptical treatment zone to match the asymmetric cornea
Final customised scleral lens.
The larger diameter and specialised geometry improve stability, reduce suction, and protect the corneal graft.
With this customised approach:
No compromise to graft integrity
Vision improved to:
Right eye: 6/7, Left eye: 6/6, Comfortable wear achieved for extended periods, Reduced suction and easier removal
What this means
Cases like this are often considered “too difficult” or “end-stage” from a contact lens perspective.
But with the right tools and experience, outcomes can be significantly improved.
We regularly see patients who:
– Still want better quality vision
– Have failed previous scleral or RGP lenses
– Have undergone corneal grafts or other surgery
– Have been told they are “hard to fit”
We focus on:
– Precision fitting using ocular surface mapping
– Custom lens designn- not trial-and-error
– Long-term corneal and graft protection
– Achieving clear, stable, comfortable vision