Case Studies
Female, age 30. Teenage onset keratoconus
A corneal lens had been worn successfully in the early stages after diagnosis, but
gave increasing discomfort as it aggravated a proud epithelial nebula, seen here
at the apex of the cornea. A corneal transplant was offered, but the patient declined,
preferring to try further contact lens options.
A sealed RGP scleral lens was an uncomplicated fitting exercise. The final lens
had full corneal clearance, totally relieving the discomfort. After three years
of alternating between corneal and scleral lenses, the patient has switched entirely
to use of the scleral lens only.
Female age 55. Teenage onset keratoconus
Corneal lens fitting was impossible with such a protrusive profile. A scleral lenses
offered an opportunity for a conservative management option irrespective of the
highly protrusive corneal topography. A large donor for a transplant would have
been required, bringing the junction into proximity to the limbal arcades, thereby
increasing the risk of rejection.
Sealed RGP scleral lens leaving a glancing contact zone was a straightforward process,
giving a satisfactory 6/18 VA with comfortable full day wear.
Female age 55. Exposure Keratitis
This patient suffered an acoustic neuroma at age 52. The tumour was successfully
excised, but leaving a residual facial nerve palsy with consequent poor lid closure
on the right side.
The continuous exposure led to gross scarring and vacularisation, and unaided vision
of counting fingers. A sealed RGP scleral lens was fitted, retaining a full and
constant pre-corneal fluid reservoir. The visual acuity improved to 6/36 and the
progress of the veovascularisation was held in status quo.
Female, age 50. Acute Stevens Johnson sensitivity to routinely prescribed sulphonamides
at age 25.
Clinical History
Spectacle VA: <6/60
Rigid lens potential VA: 6/24
Fellow eye:
nil L/P, wears cosmetic shell.
Contact lens history
1981. An impression PMMA scleral lens was issued after recovery from the acute phase.
This was worn successfully for 23 years.
1998. Tolerance to the PMMA lens began to be more difficult, so a preformed RGP
sealed scleral lens, fitted with corneal clearance, was issued. Her tolerance improved,
but the VA was inferior. A second lens with central corneal contact gave a significant improvement in VA and, surprisingly, was more comfortable.
2000. The RGP scleal lens has been worn for 24 months with improved tolerance compared
to the PMMA lens. The patient also reported an improvement in clarity of vision.
The recorded VA was much the same as before, at 6/24, although 6/18 has been recorded
on some occasions.
Male, age 55. Late onset keratoconus diagnosed age 45.
There was a rapid development of a very protrusive globic type corneal profile lead
to significant visual loss over a four year period leaving no worthwhile improvement
with spectacles. Rigid corneal lens fitting was unsuccessful due to discomfort and
instability of the lens in situ. The other eye had developed hydrops, which had
more or less resolved, but refitting with contact lenses had been postponed. The
profile was much the same as the right eye, having a similar outcome with corneal
lenses prior to the hydrops episode. A scleral lens was suggested as a final option
before a transplant. The idea was immediately taken up by the patient who did not
want an eye operation if there was a feasible alternative. A sealed RGP scleral
lens was fitted clear of the cornea at the visual axis and a glancing contact at
the cone apex. Following issue, he built up to all day wear within one week. Visual
acuity was 6/9. To date, the lens has been worn trouble free for 24 months.
Female age 15. Congential cataract and ptosis.
The congenital cataract was removed but following post surgical complications, the
eye was left with counting fingers only. Approaching her mid teens, she became more
appearance conscious and asked if any non surgical option was available to improve
the appearance. A sealed RGP scleral lens was a starightforward fitting exercise
and made a significant raise in the level of the upper lid from just at the upper
pupil margin by a further 2 to 3mm.
Advanced keratoconus which was unfittable with a corneal, but an RGP non ventilated
scleral retained a fluid reservoir without corneal contact.
Moderate keratoconus with a corneal erosion caused by the edge of an RGP corneal
lens. A non-ventilated RGP scleral provided an opportunity for recovery while retaining
useful vision.
Salzmann’s type corneal changes causing severe visual degradation and discomfort
fitted with a non-ventilated RGP scleral lens