CASE STUDY I - Dr. Benoit

Patient KW, 29-year-old male, presented for a complete eye exam.

• CC: Constant awareness of his GP contact lenses (they are 14 months old). Was told by previous doc, "This is the best we can do."
• Eye Hx: 8 years of CL wear, first toric SCL then GP. Had fluctuating VA with SCL, seems better with GP. Entering VA with CLs: 20/20 OD,OS with NI on over-refraction.
• Ant. Seg. Eval.: CLs clean, no scratches. Sup. central position with lid attachment, sl. excessive movement in all POG.
• Fluorescein: Aligned centrally, sl. mid-periph. touch (area ~ 7.2 mm in diameter), Sl. excessive periph. clearance.
• Cornea: tr 3 & 9 SPK, no vasc. changes
• Conj.: tr injection in 3 & 9 area

How do we solve the comfort issue? CLICK HERE FOR THE SOLUTION.

CASE STUDY II - Dr. Kendall

This case is from 1993. A 48-year-old male has been wearing "hard" (according to his history, so it's possible they were PMMA) for over five years, for a minimum of 15 hours per day. Every time he is examined by his ophthalmologist, he has removed his lenses the day before. His chief complaint to me was that he was having glare and double vision out of his right eye, and the image was larger out of his new glasses prescribed by the ophthalmologist. He had not worn his contacts on the initial visit.

The glasses were verified to be:
        OD +2.50 - 2.37 x 090   VA of 20/30=
        OS -2.00 - 1.00 x 162   VA of 20/20

The patient indicated his eyes had always been similar, even to the point he could switch contacts between the eyes.

Manual Ks were:
        OD 44.75   44.00@ 65 Distortion 2+
        OS 46.12   44.87@155

Manifest:
        OD +2.50 -2.00 x 085   20/30=
        OS -2.25 -0.50 x 160   20/20

The goal was to rehabilitate the right cornea, get him back into full time contact lens wear, and to be able to get him to see more comfortably out of his glasses.

Possible strategies, nowadays, might be to use a reverse geometry lens for both eyes. This could improve unaided vision for the OS, while allowing a lens to center well on the right eye, permitting the cornea to reduce the distortion and decrease the plus. Not having the luxury of a topographer, or much experience with RGP contacts back then, I chose to first start with an aspheric design.

The first design was chosen to be:
        OD 9.4 Diam BC 44.25 -1.62 (power determined by diagnostic fitting)
        OS 9.4 Diam BC 45.12 -3.00

The one-week follow-up revealed an increase in minus over the manifest for both eyes.
        OD plo - 1.25 x 085   20/40
        OS -2.75 - -0.25 x 150   20/20

There was a small over refraction for the OS, but the lens seemed to move and center well. The OD however, tended to ride temporally. Ks for the OS were virtually unchanged, and the OD's were becoming more spherical (45.00). The OS was adjusted for the over refraction, and the OD was steepened (45.37) to try to get it to center better.

One month later the OD manifest was -2.50 -1.00 x 85 20/25=. The lens still didn't center as well as I would have liked, while the OS was just fine. I wanted to find a lab who would let me adjust their proprietary posterior curves. I wanted a smaller OZ, or different asphericity in the OZ. We went to a 9.5 diameter with an 8.3 OZ, and because the guy was presbyopic, we added a panafocal curve as well. This new lens centered much better. The patient realized his goals of being able to wear contacts full time, yet being able to switch to glasses, and be comfortable, if desired.

CASE STUDY III - Dr. Kendall

30-year-old male with a chief complaint of reduced distance acuity with his soft torics; he feels his vision is getting worse. He has been wearing soft torics for 12 years, and the most recent pair is two years old. He wears them on a daily-wear basis approximately 14 hours per day.

Entering acuities with the contacts are OD 20/30 OD and 20/25+ OS. The lenses look clean, move and center well (verifed by biomicroscopy they are torics). The patient does have a fair amount of limbal injection, and superficial neovascularization 360 degrees in both eyes.

Manual Ks:
        OD 44.87   44.00 @ 180 Distortion 2 +
        OS 44.37   43.87@ 180 Distortion 2 +

Manifest:
        OD -4.75 -0.25 x 165   20/20
        OS -5.75 -0.50 x 25   20/20

The first thing that strikes me as strange is why the guy is wearing torics at all, and especially for 12 years. The only indication was with his spectacles which matched his manifest, with the exception of -1.00 cylinder OU. It is clear the torics' age, or oxygen permeability, have affected his corneas, resulting in less cylinder. After discussion with the patient about his options, he decided to go with gas perms, rather than be forced to resort to spectacles until his corneal problem resolved.

The first lenses were determined to be aspheric in design:
        OD 9.3 Diam 44.37 -5.00 lenticular
        OS 9.3 Diam 44.25 -6.00 lenticular

The one-month visit showed a -0.25 increase in cylinder, and the Ks revealed no more distortion. The patient was happy he could be refit immediately, without having to rely upon his glasses.

I think the above case shows how gas perms can solve problems not only of corneal distortion, but of patient dilemmas concerning going cold turkey and being forced to wear glasses.

CASE STUDY IV - Dr. Bennett

Initial Summary: This patient was a long-time rigid extended wear patient who presented with reduced wearing time, redness and lens awareness. Her slit lamp observations (unilateral) are shown with white light and fluorescein in Figures 1 and 2.

1) What is the condition?
2) How do you treat it?
3) How could it be prevented?

Figures 3 and 4 show the condition after one week of treatment.

Fig. 3	Fig. 4