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Grand Round : Piggy-back of a large diameter RGP lens to restore visual acuity on a legally
blind patient.
(a) Case History
G.L. is a Caucasian patient of 59 y.o. seen for the first time in September 2007.
He was referred by a cornea specialist to be fitted with a bandage contact lens on the left
eye as part of the treatment of a neurotrophic cornea that was developed after a cataract
surgery with IOL implant. Over time, this cornea had developed a central scar and a
recurrent erosion. Other treatment options failed to improve this condition. Senofilcon A
contact lenses was tried and fitted with success (Acuvue Oasys, Johnson & Johnson
Vision Care, Jacksonville, FL). Considering the difficulty to handle his contact lens, due
to his reduced vision (20/100), the patient was authorized to wear it on a continuous
basis. Since then, the patient was seen every 2 weeks to remove the lens, replace it and to
monitor the corneal condition.
The right eye was lost secondary to an endophtalmitis that occurred after a
second surgery for a retinal detachment in 2006. At the moment of the first visit the
patient was wearing an ocular prosthesis on the right eye. He is considered legally
blinded and had been under treatment with a psychiatrist over the last 2 years because of
a severe depression linked with the lost of his sight. He is also affected by diabetes type I
that is under control with oral medication. In addition to that, he is taking testerone
cypionate, vitamines B-12 and E, NSAID (naproxen), calcium, clonazepam (Rivotril),
trazodone (Desyrel), anti-depressor paroxetil (Paxil). He is using also ocular drops:
hyperosmotic agent (Muro-128, HS).
In March 2008, considering that the condition of the left eye was stable but not
really improved, the corneal specialist decided to proceed with a keratectomy. This
procedure failed and a second one was tried 4 months later, without more success. It was
then decided to perform an auto-graft, that allows to rotate the cornea in order to move
the central erosion away from the visual axis. This procedure did not help a lot to
improve patient’s visual acuity and it took over 6 months to rule out post-op
inflammation with steroids (Flarex, BID). The vision dropped to 20/400 sue to severe
corneal edema, inflammation and distortion caused by the stitches of the graft. The
patient was also found steroid responder after a few weeks of treatment and IOP reached
31 mm Hg in June 2008. It was then decided to taper and to stop the steroids.
Hyperosmotic agent was maintained and comfort drops were applied at least TID to
rehydrate the cornea. Due to the toxicity of all medications combined and the fact that the
lens was worn on an extended-wear, the corneal health was not that good, showing
diffuse SPK grade 2 and a trace of vascularization at 4h00 reaching the graft junction.
There was a conjunctival hyperemia grade 2 associated with this condition. Moxifloxacin
drops were added BID as a prophylactic agent. In November 2008, corneal specialist
considered to add Vexol for a short term treatment to improve the corneal condition. This
helped to improve the vision up to 20/100 at the end of December 2008 and the IOP
remained under control. This treatment lasted for another 6 weeks when the IOP raised
again. The steroids were slowly tapered and the hyperosmotic agent ceased.
Moxifloxacin was maintained but reduced to DIE dosage. Corneal specialist talked about
performing a keratoplasty on the left eye but the patient declined this option, considering
all the risks associated with the procedure.
In July 2009, the condition of the patient was slightly improved. Cornea did show a
diffuse SPK grade 1and conjunctival hyperemia was reduced to grade 1. Edema of the cornea was
less present and the neovascularization was stable. The patient took only comfort drops and
moxifloxacin DIE and was still wearing his soft bandage contact lens on a 2-weeks continuous
wear basis.
In December 2009, patient asked about other options to consider in order to improve his
visual acuity. At that moment, with the bandage lens on (8,4/-1,75), his vision was 20/200,
improvable to 20/80 with stenopeïc hole. Considering the status of the cornea, rigid gas
permeable lens on a piggy back system was considered.
(b) Pertinent Findings
Topographic map of the left eye, over the bandage lens (-2,00; BC 8,4), showed an
irregular surface with Sim K of 37,25 x 50,50 @95. Over-refraction did not improve the visual
acuity. The first lens tried was a Rose K lens for Irregular Cornea. This lens is characterized with
a larger diameter (11,2 mm) and a system of peripheral curves that allows a better centration of
the lens on an irregular surface. Unfortunately, the lens was riding too low and the patient was not
comfortable.
(c) Treatment, management
A lens with a larger diameter was then considered. Corneo-scleral lens (SO2 Clear, Art
Optical) was tried with success. Even if the fluo pattern was slightly irregular in shape, there was
a fair pooling over the graft and no bearing on the graft junction as expected. Peripheries aligned
well with the conjunctiva and the lens was stable on the eye. Patient was comfortable with the
lens on. The only point was that the diameter tried was slightly too small for the corneal diameter.
In fact, the lens was hitting the nasal limbal area upon blinking, where the stictches are closer to
the limbus. Infero-nasal area was also exposed dependending on the movement of the eye. It was
decided to increase the diameter by 0,5 mm. Final parameters were BC 8,04, Diameter of 14,5
and power of -1,50, leading to a visual acuity of 20/80+2, which was a big improvement for the
patient.
At the delivery, the lens was considered a bit too steep, a bubble remaining constantly
under the lens . This was probably due to the fact that the larger diameter ordered was not
compensated by a flatter base curve, leading to an increased sag value of the lens. However, the
lens delivered provided with a surprising visual acuity of 20/60 improvable to 20/40-2 with -0,50
over-refraction. Consequently, a new lens was ordered as follows: BC 8,15 Diameter of 14,5 and
power of -2,00. At the delivery, the lens was slightly decentered toward the steeper part of the
cornea but covered well the cornea and the nasal limbal area. Fluoresceine pattern was evaluated
as irregular showing pooling of less than 100 microns superiorly and a feather’s touch on the
infero-temporal side, near the graft junction. There was no real touch between the lens and the
cornea as expected in such cases.
Bandage soft lens was not changed even if a higher DK /t could have been considered a
better option, considering a piggy back system. In fact, Air Optix Night& DAY (Ciba Vision,
Duluth, GA) was considered and tried but the modulus of the lens on such an irregular cornea was
not appropriate. The lens did not fit well with flutting on the nasal side, where the cornea is the
steepest.
Handling could have been an issue for the patient but he did wear rigid contact lenses
when he was 20 y.o. Due to the larger diameter of this lens, it was easy for the patient to find it in
the case, considering its low vision, and to insert it appropriately. The soft lens remained on the
eye for a continuous wear. To remove the RGP lens, we educated the patient to use a plunger
(DMV removing device). Again, this is considered safe based on the large diameter of the lens,
its stable position and the presence of a soft lens under it. There is no way that the patient can
alter the corneal tissue with the plunger. Patient was able to insert and remove the lens at least
twice at the delivery visit. Everybody was reassured that handling would not be a problem
anymore. Patient had the biggest smile in its face, knowing that his vision was now partly
restored after almost 3 years living as a blind person. It was a real and unique experience to
witness the emotions brought by the possibilities to see well again.
Care regimen for the rigid lens was recommended as follows: Boston Simplus (Bausch &
Lomb, Rochester, NY), with instructions to rub, rinse and store the lens for overnight soaking.
We did not recommend a continuous wear of the RGP lens even if it was made from a high DK
material (Boston XO).
Patient had been seen every 2 weeks since then and his ocular condition remained stable.
He is still enjoying his new vision and is interested to consider to come back to work.
(d) Diagnosis
This monocular patient presents an irregular neurotrophic cornea that also shows
post-graft characteristics. He is considered legally blinded by the fact that his best
corrected visual acuity, prior to RGP contact lens fit, was under 20/200.
(e) Discussion
This case report presents an interesting case where optometry can change positively the
lives of other individuals as it happens sometimes in specialty contact lens cases. The challenges
brought by this case are numerous:

To restore the corneal condition in co-management with a cornea specialist

To deal with the reduced level of acuity of the patient that can’t handle soft
bandage contact lenses and consequently to consider continuous wear on an
altered corneal tissue

To consider a new corneal profile after 2 keratectomy that failed and 1 auto-graft
that dislocated the corneal apex and increased corneal irregularity

To fit a RGP lens that would be stable and easy to handle
Recurrent erosion and neurotrophic ulcers could be treated with many options. Intensive
lubrication and/or the use of a bandage contact lens are indicated. Surgical treatments such as
keratectomy, corneal puncture, laser phototherapeutic keratectomy (PTK) are among t the most
favored procedures.
The fact that the patient is monocular did not seem to restrain the corneal specialist in his options
but the patient declined, at the last, the final option offered to perform a penetrating keratoplasty.
Condition of the patient did not restrain us as well to consider continuous wear in such cases. In
such fragile corneas, we have to balance the pros of maintaining the lens in place and the cons
that continuous wear can trigger infections and inflammatory reactions. With the use of
antibiotics in prophylaxis and a close follow-up as it was maintained over the years, it is
considered beneficial to adopt a continuous 2-weeks schedule of wear.
RGP contact lenses are appropriate to restore a corneal profile on distorted corneas or after a
corneal surgery, like the auto-graft. This is, in fact, the only way to improve the vision and to
reduce the level of optical aberrations. With a sutured cornea, it is mandatory to protect the graf
junction from any touch or insult, especially when sutures are still present. The way the contact
lens is prescribed should allow to vault the cornea without creating excessive pooling in other
parts of the cornea.
Larger RGP lenses become more and more popular because they offer the convenience of the
RGP lenses without their initial discomfort. Larger lenses are also more stable on the eye, which
is suitable in fragile corneas. Finally, dust particles and debris can not easily penetrate under a
larger diameter lens, which is a plus for patients exposed to challenging environments.
In this case, a large diameter lens was tried without success because of the corneal profile and the
fact that the apex was severely decentered after the auto-graft procedure. A larger corneo-scleral
lens was considered and fitted with success because most of the support for this lens comes from
the conjunctiva and not from the cornea. The way that lens was fitted is slightly different from
other cases with similar larger lenses, because we wanted to vault the entire cornea. Habitually,
corneo-scleral lenses are supported in part by the corneal tissue. All that it was allowed here was
a feather’s touch, outside of the graft junction area, without a true touch at any location of the
corneal tissue.
(f) CONCLUSION
Larger diameter contact lenses have to be considered the new standard of care in the management
of irregular and post-graft cases. This includes corneo-scleral, semi-scleral and true sclera lenses.
Obviously, the learning curve to fit and dispense these lenses is present but the results are so
rewarding for the patients and the practitioner that it worths the effort to get use to this newest
technology and to adopt it. In this case, it changed literally the life of a patient, restoring his
vision to the point that he considers to come back to work.
Among all the larger diameter lenses, corneo-scleral lenses reperesent the easiest ones to fit and
should be even considered as a day-to-day product when RGP lenses are considered as the
number one option to fit on a patient.