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2004 Global Orthokeratology Symposium 遠視・老眼に関する発表文

Corneal Refractive Therapy for Hyperopia and Presbyopia
Jerome A. Legerton, OD, MS, MBA, FAAO San Diego, CA

The Anatomy is identical - Minor parameter difference

*Presbyopia Research Design
・ 4 site, 5 subjects, protocol controlled
・ Inclusion Criteria;
・ 45 years of age with at least +1.00 add requirement
・ BSCVA of at least 0.04 logMAR(20/50) or worse at either distance or at near
・ Two arms:
-Myopia up to -6.00 with up to -1.75D refractive cylinder
-Emmetropia (within 0.50 in each meridian)
・ Standardized examination protocol
・ Calibrated for three illumination levels
・ Minimum 12 feet testing distance, high and low contrast logMAR; high contrast near at 40cm
・ Fit with conventional CRT for 1 month with target for emmetropia; at 1 month if within ±0.50 fit with investigational lenses for presbyopia
・ Methods:
・ High and Low contrast distance logMAR under mesopic, photopic, high photopic; near high contrast logMAR under photopic
・ Three pupil size measures
・ Subjective and objective measures of multifocality
・ Quality of life questionnaire
・ Wash out to determine return to baseline

*Primary Endpoint
・ Simultaneous Distance and near high contrast acuity ≦ 0.24 logMAR (20/32-2)
-Baseline eyes must be 0.4 logMAR (20/50) or worse at either distance or near
-3 Month post treatment 13 of 52 eyes met endpoint criteria (25%)

---Room for improvement---

*MRSE with Treatment
Subset / Measure Baseline One Month Three MonthPresbyopia
Myopiaw/wo Astigmatism 58 -2.63D 49 -0.36D 39 -0.49D
Emmetropia 32 0.00D 26 +0.29D 13 +0.16D
Under-treatment for eyes with myopia at 3 months could masquerade as treatment for presbyopia

*Focal Interval Overlap
・ Premise
-An aspheric optical system does not have a single manifest refraction endpoint; hence the focal interval is more reliable than an arbitrary point within the interval
・ Hypothesis
-In the presence of simultaneous (aspheric) optics the focal interval should increase at distance and near
-The distance and near plus and minus blur ranges should overlap if multifocality is achieved

*Focal Interval Results
・ Myopia arm: 20 of 39 eyes (51.3%) demonstrated a distance and near focal interval overlap of ≧ 0.50D
・ Emmetropia arm: 7 of 13 eyes (53.8%) demonstrated a distance and near focal interval overlap of ≧ 0.50D

*Objective Multifocality
・ Myopia arm: 10 of 39 eyes (25.6%) demonstrated a significant topographic objective measure of multifocality
・ Emmetropia arm: 5 of 13 eyes (38.5%) demonstrated a significant topographic objective measure of multifocality

*Summary of Results
・ Distance Tx is effective:
-88.5% (46 of 52) eyes demonstrated 0.24 logMAR at distance; yet only 13 (25%) demonstrated 0.24 logMAR at both distance and near
・ Near Tx falls short
-25% (13 of 52) achieve simultaneous 0.24 logMAR
-51.9% (27 of 52) show focal interval overlap
-28.8% (15 of 52) demonstrate objective multifocality

---Device must be improved to provide better near vision---

・ Hyperopia:
-More clinical evidence will help to better understand the correction of hyperopia. A protocol controlled multisite clinical trial will prove valuable to profile orthoK for hyperopia and will provide the basis for product labeling and FDA market clearance.
・ Presbyopia:
-Additional feasibility clinical investigation with modified central add parameters will prove useful to refine the device prior to the pivotal phase of the investigation.

Presented on July 24 at 2004 Global Orthokeratology Symposium