Fitting Keratoconus/Irregular Cornea Patients
Dr. Bruce Anderson and Dr. Robert Maynard
Case 1: R. R.
Patient presented in October 1996 for fitting of contact lenses. He had RK in 1993 with 5 enhancements afterwards. He felt his vision was extremely poor, especially at night, and he needed better vision for playing baseball. He had 8 spoke cuts OD and 9 spoke cuts OS with T-cuts 360 degrees between every spoke. Entering visual acuities were OD 20/40-2 slow OS 20/25-2 slow.
We performed keratometry, topography, and refraction:
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OD +1.75-2.25x100 = 20/25+2 slow K’s: 35.75=34.12x108
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OS +0.75-1.25x095 = 20/20-2 slow 35.25=32.87x107
Due to the flatness of his K readings, we began the trial fit with ortho K lenses. Even with the flatness of the lenses, we were still dealing with bubbles over the pupil and problems with edge breakaway. After 3 pairs of lenses and 6 months, we ended up with post-surgical aspheric lenses, which brought his VA down to OD 20/20 slow and OS 20/25- slow. The most difficulty we have had with this patient has been his wish to always see better.
He was asked to return to us in 6 months for a check and polish. The patient is very non-compliant, and returned again in October 1998, at which time we had to refit him. Again, it took about 3 pair of lenses, and 7 months, with lenses with a higher degree of asphericity. His VA was brought back down to 20/20- OU. Again, he was asked to return in 6 months for a check and polish. He returned in March 2001, with no refit this time.
He was last seen in our office in January 2006, where we refit him with a Surgilens OU. His visual acuity was restored to OD 20/25- and OS 20/20. This fit took only 1 ˝ months, but 3 pair of lenses.
Oxyflow HDS 100
| 8.54 | Base | 8.44 |
| -4.37 | Pwr | -4.37 |
| 11.5 | Diam | 11.5 |
| .12 | Cntr Th | .12 |
| 8.75x.5 | SC | 8.75x.5 |
| 10.80x.5 | PC | 10.80x.5 |
| HVY | Blend | HVY |
| 9.1 | OZ | 9.1 |
| 8.9 | Cap | 8.9 |
Both lenses center up to the superior limbus, OD slightly temporal. We no longer have the dimple veil problem that we had been experiencing, and we have good tear flow beneath the lens.
As usual, he has been asked to return to us in 6 months for a check and polish, or sooner if need be.
OD
OS
-- END OF CASE #1 --
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Case 2: D. B.
Patient presented in January 2003 for fitting of both eyes. He had undergone RK in 1995 and LASIK in 1998 and complained of terrible night vision and blurry vision all of the time. His cornea was extremely irregular with associated scarring from the original RK. Entering visual acuity was OD 20/80-1 and OS 20/100 with OU 20/60.
We performed keratometry and topography, as well as doing a refraction.
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OD -2.00-0.75x013 = 20/25-1 poor
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OS +3.00-5.00x098 = 20/25-1 poor
So we also had a severe case of anisometropia to deal with. Based on the topographies, we began trial fitting with ComfortKone lenses.
We began with very large lenses for stability and achieved a great deal of success, initially, improving his visual acuity. However, as he wore the lenses more, we began to have a problem with dimple veil developing directly over the pupil, especially OS. After the second lens, we started fenestrating the OS lens to help remove the dimple veil and allow better tear flow. We were also having trouble with corneal edema on the left eye. The final lens for the OS involved an oval OZ and five fenestrations. Comfort was good and VA was OD 20/25 slow and OS 20/30-1, which he still maintains today.
His final lenses are:
Oxyflow HDS
| 7.80 | Base | 7.50 |
| -5.25 | Pwr | -5.50 |
| 11.2 | Diam | 10.6 |
| .12 | Cntr th | .19 |
| 8.80x.7 | SC | 8.50x.85 |
| 10.00x.5 | PC | 10.50x.85 |
| 8.4 | OZ | 6.8x7.8 oval |
| 8.2 | Cap | 6.8 with 5 fenestrations |
Due to his dry eyes, he was place on Systane morning and night, and Blink drops TID on a continuing basis. He was instructed to return to the office every 6 months for a follow up visit, as well as a lens polish, or sooner if any problems developed.
At this time, we have found no better solution for his problems than the one we are pursuing.
OD
OS
-- END OF CASE #2 --
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Case 3: L. C.
Patient presented in August of 2001 for fitting of his right eye. He had undergone a corneal transplant in 1999 due to mismanagement and treatment of herpes simplex keratitis. He had suffered a great deal of corneal scarring and edema at 7:30 in front of the pupil, as well as damage to the iris. At the time, he was also suffering some mild macular edema. His entering visual acuity was >20/400
The transplant was extremely irregular. We performed keratometry and topography. We then proceeded to a trial fitting of rigid gas permeable lenses.
We used a Surgilens trial fitting kit for our initial fitting. After two trial lenses, we had enough information to order our initial lens.
The initial lens actually did quite well, though it did have to be modified in office several times. Dr. Maynard blended the inside curves, as well as openes the fit, which tended to tighten up with length of wear. It took 3 lenses to find a satisfactory fit, all involving flattening the secondary curve. We used a high dK material and a reverse geometry lens:
Oxyflow HDS
- Base = 8.04
- Pwr = +3.75
- Diam = 10.3
- Cntr Th = .24
- SC = 7.63x.6
- PC = 10.8x.5
- OZ = 7.7
- Cap = 7.7
With this lens, he achieved 20/40 vision. Due to some issues with dry eyes and mild blepharitis, he was instructed in the use of lid scrubs and artificial tears on an ongoing, regular basis. He was also instructed to return every six months for a check up and lens polish, or sooner if a problem developed.
On his last visit here in January 2006, he was maintaining his 20/40 vision. We have referred him back to his ophthalmologist to inquire on whether removing some iris tissue across his pupil could improve his BCVA. Here is his most recent lens and specs:
Boston XO 8.13 +4.00 10.8 .27 7.50x.4 10.80x.5 8.6 8.6
-- END OF CASE #3 --
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Case 4: birthdate 1956
Note: The fitting history was condensed to emphasize the pertinent information
Penetrating Keratoplasty ( secondary to keratoconus) Refit - Left Eye
Patient: 49-year-old male.
History: Patient has a history of keratoconus in both eyes with a penetrating keratoplasty in the left eye approximately 25 years ago. He presents for refitting of a contact lens for the left eye, which his previous lens had been uncomfortable and unstable on the eye. He had discontinued wearing the lens due to the discomfort.
Refraction: OS: -4.50 -8.00 x 090 20/50 acuity
Slit lamp evaluation of the left eye revealed a well-healed corneal transplant with a clear central cornea. The interface between the host and the donor tissue was smooth and flat without obvious plateauing. All sutures had been removed. The anterior chamber was deep and clear. The superficial cornea was clear with minimal staining.
Topography was performed and is enclosed.
This patient was fit using trial lenses. The initial trial lens used was: -3.00/7.30 BC/ 9.6 Dia. The over refraction was -7.50 with 20/25 Acuity. The lens was fitting on K on the horizontal meridian. There was excessive lift off inferior and excessive pooling of fluorescein superior. The lens was designed with topography as a guide to determine the amount of toricity in the initial order. The trial lens was used as a guide in the flat meridian. The initial contact lens design ordered was:
Bitoric / Paragon HDS 100 / Plasma Tx / Lenticular
OS 46.50 • 51.00 / -10.00 • -14.50 / 10.2 / STD (.35/8.55 // .40/10.50)
Bitoric BC / Drum Power / Dia / PC
This contact lens was dispensed approximately two weeks after ordered. The acuity of the lens was 20/20 -0. There was a +0.25 over refraction, 20/20 acuity. Evaluation of the contact lens, showed that the lens was fitting on contour across the central cornea. There was slight inferior lift and pooling. In the horizontal meridian the contact lens was slightly tight.
The patient called approximately three days after receiving the contact lens, stating that the vision was excellent; however, the lens was somewhat irritating. A follow-up was performed the next day. At the follow-up, acuity with the contact lens was 20/25-. There was a +0.25 over refraction, with no vision improvement. Evaluation of the fit of the contact lens revealed that it was fitting somewhat tight in horizontal meridian. There was 2+ punctate staining at the 3 and 9 o’clock position. There was on contour bearing across the central portion of the contact lens.. The edge in the superior region at 1 to 2 o’clock was slightly tight. At this visit, I blended the contact lens with a 12.25 tool to loosen the PCs. Also, a new contact lens was ordered. The second contact lens ordered was:
Bitoric / Paragon HDS 100 / Plasma Tx / Lenticular
OS 46.50 • 51.00 / -10.00 • -14.50 / 10.2 // .35/9.10 • .4/11.75
Bitoric BC / Drum Power / Dia / PC
The peripheral curves on the new contact lens were designed to be 0.55 mm. flatter for the secondary curve and the peripheral curve was 1.25 mm. flatter for the reason to lift the peripheral edge curves.
The new contact lens was dispensed one week later. The patient reported good comfort with the lens. Evaluation of the fit revealed that the peripheral edges of the lens showed adequate lift and was not tight as seen previously with the initial contact lens. The lens was dispensed and a follow-up was scheduled for two weeks. Acuity was 20/20 with a plano over refraction.
A final follow has not been made yet as this fit is still in progress.
Points of Discussion:
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Use of a bitoric on Pks
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Manipulation of the PCs to improve comfort
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Diameter of lenses for PKs
-- END OF CASE #4 --
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Case 5: birthdate 1966
Keratoconus Refit
Patient: 39-year-old Female.
History: Patient had a history of keratoconus in both eyes; however, significantly more advanced in the left eye. She did not wear any correction in the right eye, in that her uncorrected acuity in this eye was good. She was wearing in the left eye a Softperm lens with an Rx of : -2.75/7.7/14.3. She had been having problems with discomfort and short wearing time with the contact lens. After several hours of wearing the lens, her eye would become very red and irritated. The acuity in the right eye was 20/30 with the lens. Acuity in the right eye uncorrected was 20/20, the left eye was 20/400 with the lens removed.
Slit lamp evaluation of the right eye was essentially normal with no obvious signs of keratoconus. The contact lens on the left eye was centering well and exhibited less than 1/4mm of movement. The lens was removed and the cornea was evaluated. The left eye revealed 1+ thinning, a slight Fleischer’s Ring and there was also 1+ punctate staining. There was also 1+ limbal edema/microcysts.
Refraction: OD -0.25 Sphere 20/20-0
OS -7.00 -2.00 x 073 20/200
Topography was performed and is enclosed. Evaluation of the topography of the right eye does not show any obvious cone or changes as typically seen with keratoconus. The left eye revealed a moderate central cone, which was fairly obvious.
I proceeded with the contact lens fitting of the left eye using the SynergEyes hybrid lens. The initial trial lens placed on the eye was 7.40 BC with a peripheral skirt of 8.70. This lens was fitting tight and did not show any significant movement. Fluorescein was placed on the eye, and there was significant pooling of fluorescein under the cental region of the contact lens. A second trial lens placed on the eye was: 7.60 BC with 8.90 peripheral skirt. This lens revealed slight edge lift off. The third trial lens placed on the eye was a 7.50 BC with a -3.00 Power, 8.80 peripheral curve. This lens centered well and exhibited approximately 1/4 to ˝ mm. movement. With an over refraction of -0.50, the acuity was 20/25. The initial contact lens order for the left eye was:
SynergEyes
OS -3.50 / 7.5 / 8.8 / 14.5
Power/ BC / SC / Dia
The initial contact lens was dispensed approximately two weeks later. Acuity with the lens was 20/25-3. There was +0.50 over refraction with 20/25 acuity. The contact lens exhibited approximately ½ mm movement. The lens was dispensed with a wearing schedule and solutions provided.
The next follow-up was approximately two weeks later. At which time, the patient stated that the lens was somewhat irritating and felt tight on her eye. Acuity with the contact lens was 20/30. There was a plano over refraction. The contact lens was only moving approximately 1/8 mm. After removing the contact lens and fluorescein being instilled, there was noted significant central punctate staining and slight peripheral corneal edema.
A new trial lens was placed on the eye, with an Rx of: -3.00/7.60 BC/ 8.90 SC/ 14.5 Dia. The lens appeared to be fitting adequately with approximately 1/2 to 3/4 mm movement. There was no edge lift off with the trial lens during this evaluation.
The new contact lens was ordered with a prescription of:
SynergEyes
OS 7.6 / -2.75 / 8.9 / 14.5
BC / Power / SC / Dia
This lens had not been dispensed at the time of this case report.
Points of discussion:
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Refit of Softperm to synergeyes
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Tightening of the Synergeyes lens over time
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Effect of the Softperm on the topography
-- END OF CASE #5 --
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TOPOGRAPHIES
First Topography
Second Topography
Third Topography
Case 4 Topography-A
Case 4 Topography-B
Case 5 Topography-A
Case 5 Topography-B
-- END OF TOPOGRAPHIES --
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