Laser Scleral Microporation (LSM) Safety & Efficacy

LSM improves uncorrected intermediate and near visual acuity as well as distance corrected near and intermediate visual acuity with stable distance vision.

In an early pilot study of LSM (N=22 Patients) visual acuities were measured using standard early treatment diabetic retinopathy study (ETDRS) charts. Patient near and intermediate visual acuities showed statistically significant improvements following LSM treatment. Patient distance visual acuity also improved after the LSM treatment. Data collection is ongoing.

The accommodation improvements of LSM appears to be stable over time. In a pilot study, effective range of focus (EROF), true physiological accommodation, and pseudoaccommodation were measured in 6 eyes of 3 patients (average age 59.3 years) for up to 13 years postoperatively after LSM treatment. Measurements were done using wavefront aberrometry with the iTrace dynamic aberrometer (Tracey Technologies, Houston, TX). The EROF is the range of focus with acceptable blur and is the sum of the true physiological accommodation and the pseudoaccommodation.

LSM Mean Stereopsis improved from less than 70” than 60” at 1 yr and continued to improve at 24mos. This is unique to LSM Procedure. Most corneal based presbyopic treatments reduce stereopsis and can lead to asthenopia.

The procedure spares conjunctival tissue and preserves tissue via small transconjunctival 225um spot size. There is minimal risk due to the procedure being performed off the visual axis. The LSM procedure can therefore improve visual function without touching the optics of the eye. This avoids any side effects such as halos, starbursts and glare that can occur when the eyes natural optics are modified to create multimodality for various distances to of hypotony with a trained surgeon. The proprietary collagen matrix allows for easy intraoperative management of any micro perforation with no lasting impact.

Results up to 24 months from a single arm Taiwan Clinical Trial at Chang Gung Memorial Hospital for patients 40 years or older with presbyopia requiring a minimum of 1.5D reading add and best corrected distance of 20/40 or better in otherwise health eyes have been analyzed. All patients achieved improvement of near and intermediate vision. Visual Function and acuity improvement had clinical significance. The subjects gained an average of 1.5D added accommodative reading power after the procedure. No statistical change was noted in UDVA post operatively. Stereoacuity was improved by the procedure. Patient satisfaction was high post operatively and sustained over 24 months in this group of Asian eyes. Preliminary results of the Taiwan IRB monitored clinical trial of the LSM procedure utilizing the Er:YAG laser appears to show promise for restoring range of visual performance for near and intermediate visual tasks without compromising distance vision and without touching the visual axis.