Case One

32-year-old w.f. 16-year GP wearer in our practice. Lost OS CL and needs replacement ASAP.

Rx: OD -3.00-0.75x180; OS -2.50-0.75x180.

Ks: 44.50/45.50@90 OU.

Current CL specifications: OS 7.60 -2.50 9.5 .14ct 8.30 oz IC .3/9.30 PC .3/11.00 Medium blend .10 edge.

Exact duplicate ordered as rush from lab. Received next day and verified by technician. Lens picked up by patient without seeing doctor. Two days later, patient calls with complaint of discomfort with new lens.

Patient examined: VA 20/20, CL clean, positions superior centrally with good movement in all POG. Fluorescein pattern shows alignment centrally with good peripheral clearance but junctional bearing is present.

1. What is the likely cause of the patient's complaint?
2. How can this be remedied?
3. How could this have been prevented? 

Case Two

25-year-old w.m. Patient is new to the area and is presenting for a routine exam. Patient has worn GP lenses for about 2 years. Vision with glasses and CLs is about equal. Can only wear lenses 8 hours a day at most due to persistent awareness. Also has spectacle blur for 2 to 3 hours after lens wear. Last doctor said fit, etc., was as good as could be expected. Patient would like to continue with contact lenses if wear time and comfort can be improved.

Rx: OD -4.00-3.00x180 ; OS -4.50-2.75x180.

Ks: OD 44.50/47.37@95 ; OS 44.25/47.12@88. Mires are slightly distorted OU.

Current CLs: OD 7.40 -4.75 9.5 .12ct; OS 7.45 -5.25 9.5 .12ct. Material unknown.

Both lenses have a central to superior central position. Movement is good but each CL drops after the blink. Fluorescein pattern shows central bearing with a large area of pooling inferiorly OU. External examination / corneas appear normal.

1. What is the most likely cause of the patient's complaints? 
2. Would this explain the corneal distortion also? 
3. What would be the best GP lens in this case? 

Case Three

27-year-old w.m. New to office. GP wearer, off and on, for sports over several years. Would wear full-time but the lenses are hard to remove after just 1 to 2 hours' wear.

Previous records show CLs to be Envision design: OD 7.90 +3.50 9.2; OS 7.90 
+3.25 9.2.

Previous Rx: OD +3.50-1.25x175: OS +3.00-1.00x5.

Previous Ks: OD 42.12/43.50@90; OS 42.25/43.50@90.

Examination today shows Rx and Ks unchanged. VA 20/20 with spectacles. Anterior segment evaluation at the slit lamp is normal. Patient's CLs inserted, VA 20/25 OD, OS. OU with NI on over-refraction. Both lenses position centrally to inferior centrally and drop quickly after the blink.

Fluorescein pattern shows apical clearance with good peripheral clearance.

1. What can be done to improve the positioning and movement in this case? 
2. Will this decrease adhesion? 
3. What effect would a different polymer have?

Case Four

On 12-6-99, GK, a 44-year-old, presents to me for a contact lens refit, after her routine exam. Present GPs are 4 years old. She has been wearing these parameters for 9 years. First out of SGP II material … the most recent pair are Boston 7.

Prior to that there was a 10-year history of PMMA wear, followed by 10 years of another gas permeable design.

No complaints. Average wearing time 8 to 10 hours. Uses B & L Gas perm solutions. No regular enzyme use. Recently she lost her left lens so she is presently wearing an older spare pair of same parameters.

The lenses centered, occasionally drifting temporally, revealing an intra-palpebral type design. They moved well with the blink. There was good tear exchange. Fluorescein pattern revealed a basic alignment relationship. There was a ring of relatively more bearing in the mid-peripheral area just before the PC’s, but not enough to consider the fit steep.

There were some cracks and crazes on the older L lens.

There were several areas of old VLK (vascularized limbal keratitis) in the temporal and medial aspects of both corneas. There was no SPK In those areas, just the mottling and areas of Fluorescein pooling of the altered cornea tissue.

Lens verification:

• OD 7.80 -6.00 9.0/8.0
• OS 7.78 -7.50 9.0/8.0

According to her old records, these lenses were made out of Boston 7 material. The left base curve should have been a 7.75, but other than that, they were the parameters ordered.

Since everything looked reasonable, duplicate lenses were ordered.

The right eye gets red and irritated nasally. She stopped wearing the new lens. Returned to her old right lens. Things were fine. The redness went away. She reinserted the new right lens 3 days ago. Things seem OK. The left lens is fine.

This is what the right eye looked like (click each for a larger image):

Assessment, Plan to be discussed

GK basically did not wear the lenses. Maybe for a little bit here and there. She inserted the lenses about ½ hour ago. Eye feels much better.

VA OD 20/20 OS 2020-

Assessment, Plan to be discussed

After Modification:

Right eye doing much better since modification. Max WT = 4 hours (at my request). VA 20/20

Assessment and Plan to be discussed

Lenses feel just OK…not great.

VA OD 20/20

The area involved seemed slightly more elevated that usual. Another modification with the 12.50 tape and pad were performed.

If things were not acceptable then, another lens would be remade with flatter pc’s and possibly a larger diameter.

Lens is doing fine. No complaints

VA OD 20/20

Assessment and Plan to be discussed

Case Five

On 10-16-00, SSL, a 54-year-old Asian female was referred to me for an evaluation of her left GP lens. She had complaints that night vision was a problem. There was a language barrier but I think I ascertained that the she was having a lot of haze and glare. The present lens was 3 to 4 years old. I had no old records. She uses Boston cleaner (cleans at night) and conditioner with no enzyme.

She is pseudophakic OD with no distance Rx.

VA OS 20/30 OR PL

The lens is a high-riding, lid-attached fit. When attached to the lids the Fluorescein pattern is aligned, but if the lenses are released there is a flat oval present. (See below.)

Other than a few clogged meibomian glands, the rest of the biomicroscopic picture was unremarkable. A few front surface scratches were noted on the front surface.

Lenses were verified: Material unknown

Assessment and Plan to be discussed

After 15 minutes, VA OS 20/50 + …variable OR NI

Lens still positioned as a high-riding, lid-attached fit but seems to cover the pupil better. What tests could be performed to help us solve the problem of decreased vision?

What should be the next lens order?

After 15 minutes, VA OS 20/40 OR -.25 to -.50 20/30

Lens was verified. Will discuss parameters.

The lens is still a high-riding, lid-attached fit; however, it is definitely lower on the pupil and the patient should have less flare and glare. When the lens is released from the eyelids there is a definite horizontal band of bearing; however, when the lens attaches to the lid, there is almost a light 3 and 9 bearing pattern.

What do we do next?

SSL feels the lens is too strong. Topography will be performed today.

Positioning and Fluoro pattern looks identical to last visit.

Topography revealed the typical inferior steeping of a high-riding lens; however there was definitely an astigmatic component in the central area of the cornea.

Lens was redesigned: Boston ES + edge lentic.

Final visit: 1-8-01

Distance vision good