Session Title: Refractive II
Session Date/Time: Saturday 04/02/2012 | 08:30-11:00
Paper Time: 08:36
Venue: Grand Ballroom
First Author: : M.Wang UNITED STATES
Co Author(s): :
Purpose:
The proposed mechanism of action in SSP for presbyopia is increasing the circumlental space. This study evaluates the improvement in DCNVA with SSP and PMMA implants (PresView Scleral Implants: PSI Refocus Group, Dallas, TX) at 6, 12 and 18 months post-op in emmetropic presbyopes.
Setting:
FDA monitored Investigational Device Exemption (IDE) site in the United States in Nashville, TN with Dr. Ming Wang.
Methods:
A prospective study was performed which measured DCNVA monocularly and binocularly under standardized mesopic illumination preoperatively and at 6, 12, and 18 months post-operative successful SSP with PSI on 68 eyes of 34 consecutive patients in the USA FDA monitored IDE study at Nashville, TN. Patient inclusion criteria required 20/20 distance corrected visual acuity (DCVA), manifest refraction spherical equivalent between +0.75D, with1.00D or less astigmatism, and 20/50 or worse DCNVA. Patients were encouraged to aggressively use artificial tears and to increase illumination in favor of using glasses when reading in the early post-op time frame. Results at these time intervals were then compared. RESULTS Pre-op mean DCNVA was 20/64 ranging from 20/50 to 20/100. Post operatively 59%, 73%, and 88% of the eyes read 20/40 or better monocular DCNVA at 6, 12 and 18 months respectively. Binocular DCNVA of 20/40 or better was achieved with 76%, 77% and 100% of the patients at the same time intervals.
Conclusions:
The Hemholtz theory states loss of accommodation is largely due to lens hardening. However, patients with similar degrees of presbyopia can have varying lens hardening, as seen during phacoemulsification cataract surgery. On the other hand, the correlation between decline in CLS and loss of accommodation is high (r-squared = 0.92). If SSP increases the CLS as is proposed, it may be restoring true accommodation. This theory is supported by the improvement in clinical outcomes over time (suggesting a rehabilitation of the accommodative system), as well as greater improvement in OU acuity once the triad of accommodation is achieved.
Financial Disclosure:
... research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented, ... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented
