CASE STUDY I - Dr. Rinehart
The patient is a 12-year-old female with no contact lens wearing history. Medical and ocular histories are unremarkable.
Unaided DVA: 20/70 OD, OS
Subjective refraction:
OD -1.00 sphere 20/20
OS -1.00 -0.50 x 090 20/20
Ks: OU 44.00/44.00 @ 090
Diagnostic fitting using the BE lens:
OD Apical radius = 7.56, Eccentricity = 0.44, Diagnostic lens diam = 11.0
OS Apical radius = 7.63, Eccentricity = 0.42, Diagnostic lens diam = 11.0
Diagnostic lens:
OD BC 8.15, tangent (cone angle) 53.87, effective sag 1.5846
OS BC 8.25, tangent 54.16, effective sag 1.5658
The above lenses were worn overnight and the patient seen the next morning prior to lens removal. At that time were observed on the eye. Upon removal:
Unaided DVA: OD 20/20, OS 20/20
Subjective refraction: OD, OS -0.25 sphere 20/20
Ks:
OD 43.00/43.00 @ 090
OS 42.50/42.75 @ 090 mires clear OU
Topography: OU well centered treatment zones
The fact that the treatment zone is centered and the amount of refraction change is input into the BE software and the final lens parameters are determined.
OD BC= 8.24, Pwr = +1.75, tangent =53.37, effective sag =1.5831
OS BC = 8.31, Pwr = +2.00, tangent = 53.60, effective sag = 1.5700
At the end of one week of lens wear averaging 10 hours per night
Unaided DVA: OD, OS 20/20
Subjective refraction:
OD +0.50 sphere 20/20
OS + 0.25 sphere 20/20
Ks:
OD 42.25/41.75 @ 090
OS 42.25/42.00 @ 090
Biomicroscopy: unremarkable OU
Topography: is below
After 18 months of lens wear the patient is still wearing her lenses several nights per week and is very happy with her vision.
Unaided DVA: OD, OS 20/20
Subjective refraction:
OD +0.50 sphere 20/20
OS Plano - 0.25 x 060 20/20
Ks:
OD 42.00/42.00 @ 090
OS 41.75/41.75 @ 090 mires clear OU
Biomicroscopy: unremarkable OU
Topography: well centered treatment zone
This patient has continued to benefit from the effects of orthokeratology.
CASE STUDY II - Dr. Rinehart
This patient is an 18-year-old female who is currently wearing 2 week disposable lenses that she removes nightly.
She was referred to me by another OD for orthokeratology. The patient's medical and ocular histories are unremarkable.
Unaided DVA: OD, OS 20/250
Subjective refraction:
OD -3.50 - 0.25 x 160 20/20
OS -3.50 - 0.50 x 170 20/20
Ks: OD, OS 42.25/43.00 @ 090 mires clear
Diagnostic fitting was performed to determine the lowest sagittal depth lens that would
provide good centration and 1 mm movement or less. The initial lenses were dispensed from inventory:
OD BC = 8.82, AC = 8.04, diam 10.6, sag 1659 microns
OS BC = 8.94, AC = 8.04, diam 10.6, sag 1659 microns
The patient was instructed to put the lenses on prior to going to bed and upon waking lubricate the
lenses and for this visit only wear the lenses to the office. At the time she was seen she had worn the lenses for 9-1/2 hours. OD lens was
slightly stuck; that is, it began to move with minimal manipulation. OS showed a nice "bull's eye" fluorescein pattern.
Unaided DVA: OD 20/25 slow OS 20/25
Subjective refraction: OD Pl sphere only OS -0.50 sphere only
Ks:
OD 40.25/40.75 @ 090 # 1/2
OS 40.25/40.25 @ 090 no distortion
Topography: as shown
Everything remained unremarkable with the exception of very subtle apical staining
(grade 1 or less) OU at the one week visit. At the 3 week visit there was no sign of staining on the right eye,
but the left eye still showed some apical staining and the patient was symptomatic.
Unaided VA: OU 20/25 to 20/20
K's OU 39.75/40.00 @ 090 no distortion
Topography: below
To eliminate the apical staining OS, what lens changes should be made? Assume that the lens is clean and that the patient did not injure herself.
At the end of 2 months of treatment:
Unaided DVA: OD, OS 20/20
Subjective refraction:
OD +0.25 – 0.75 x 180 20/20
OS + 0.75 sphere 20/20
Ks:
OD 39.25/40.00 @ 090 no distortion
OS 38.25/38.50 @ 090 no distortion
Biomicroscopy: shows no corneal staining OU
Topography: shows well centered treatment zones
The patient's next scheduled visit is for August 2004.
CASE STUDY III - Dr. Herzberg
Initial Exam:
White female age 30
Occupation: FAA — Looks at terminals all day directing aviation
Prior medical history: Negative for any disease
Medication: None
FHx: Cancer father
Ocular history: Mildly nearsighted; wears soft lenses:
R 8.6 -1.25 Ciba softcolors evergreen
L 8.6 -1.50 Ciba softcolors evergreen
Findings:
Uncorrected OD 20/30 OS 20/30 OU 20/30
OD: -.75-.25 x 180 20/20
OS: -1.00 20/20
K readings:
OD: 43.75/45.50 x 90
OS: 43.75/45.00 x 86
Initial lens of choice:
CRT R Right 8.1 +.50 10.5 525 RZD 33LZA
L Left 8.1 +.50 10.5 525 RZD 33 LZA
Notes at fitting:
R: RZD looks steep edge profile notes good fit
L: Looks right on
Conclusion: Fit flatter RZD OD
Refit OD with 8.10 +.50 10.5 .500 33
Findings: Right lens rides high; lens RZD appears still steep
Refit 8.10 +.50 10.5 475 RZD 34 LZA
Findings: Lens rides slightly high
Conclusion: Send patient home to wear overnight to clarify fit
Follow-up: Next day AM 11/4, patient complains things look fuzzy.
Topography: Temporal shift right lens, both CLs fit slightly high.
K readings: Right 43.00/44.75 Left 43.50/44.75
Slit lamp: Negative
Conclusion: Lens may be too flat on RZD. LZA profile needs to be loosened?
Refit left eye with 34 LZA.
Left looks good but not sure about right. Sent patient back home with
instructions to wear CL at night again with an off day next day.
Follow-up: 11/7. Patient wore lens previous night. Now has double vision.
Topography: Decentration of right CL up and out. Bowtie pattern now.
Astigmatism seems worse. Left eye is ok 20/20.
Conclusion: Alignment is off. LZA is too steep and RZD is too flat.
Refit OD 8.2 +.50 10.5 500 RZD 33 LZA
Conclusion: Fit looks better right eye. Wear CLs nightly next few days.
Follow-up: 11/11. Patient reports fuzzy vision right eye with haloes.
Findings: Right CL decenters superior temporal and island formation central.
K readings: Right 43.00/44.75
Slit lamp: Negative
Conclusion: Treatment ineffective. LZA is too steep with flat RZD.
Patient told to wear nightly. New lens ordered.
Follow-up: 11/18. Patient reports haloes better but vision needs
improvement OD. Acuity today is 20/20 OD, OS, OU.
Refit: OD 8.2 +.50 10.5 550 RZD 33 LZA
Conclusion: Excellent centration and fit. Patient instructed to wear nightly.
Follow-up: 11/25. Patient began wearing lens every second night with good success.
Conclusion: Continue w/every second day.
CASE STUDY IV - Dr. Herzberg
Patient is a Chinese American female referred by the parents of her classmate. Patient had seen another doctor previously but never wore the Rx.
Findings:
Acuity: right 20/200 left 20/100 OU 20/100
Rx:
Right -1.25 -.75 x 15 20/20
Left -1.50-.50 x 165 20/20
K readings:
R: 42.25/43.87
L: 42.75/43.87
Lenses selected by guide provided by Paragon and then adjusted for alignment fit at RZD with no edge lift.
Fitting:
CRT R: 8.3 +.50 10.5 RZD 525 LZA 33
L: 8.3 +.50 10.5 RZD 525 LZA 33
Lens centration excellent with alignment pattern in RZD and no edge lift noted.
Patient asked to wear contact lenses that night and return for follow-up next day.
After removing lenses: Findings:
Rx: OD plano OS -.25
Acuity: 20/20 OD, OS, OU
Topography: Excellent patterns showing well centered lenses.
Slit lamp: Negative
Patient instructed to wear contact lenses nightly.
Followup: Patient wearing lenses every night. Reports excellent vision with both eyes.
Findings:
Rx: OD plano OS -.25
Acuity: 20/20 OD, OS, OU
K readings:
Right: 40.87/41.87
Left: 41.87/42.75
Topography demonstrates a slight island in the central cornea of the left eye. Both lenses center well with the right lens treating slightly more effectively.
Conclusion: Monitor patient at future visits and perhaps reduce sagittal depth of the RZD to treat island.
Patient will return in May 2004.
