Monday, October 31, 2011

Abstract: Once again, dry eye gets short shrift in LASIK studies

I guess I'm on the warpath this morning.

Refractive surgery research at its best.

This abstract...

1) Purports to assess dry eye amongst its outcome measures (after all, it's the #1 complication so they'd better pay it lip service)
2) Then it uses the most unreliable not to mention barbaric method to evaluate dry eye (Schirmer)
3) Then it doesn't tell us what the dry eye results were, because naturally, only vision matters.

Come on guys, surely you can do better than this.

A prospective, randomized, fellow eye comparison of WaveLight Allegretto Wave Eye-Q versus VISX CustomVue™ STAR S4 IR™ in laser in situ keratomileusis (LASIK): analysis of visual outcomes and higher order aberrations.

To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs), contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK) using wavefront (WF) guided VISX CustomVue and WF optimized WaveLight Allegretto platforms.

In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients), with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, root-mean-square (RMS) value of total and grouped HOAs, contrast sensitivity, and Schirmers testing.

Mean values for UDVA (logMAR) were -0.067 ± 0.087 and -0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909). UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000). In the WF optimized group, total HOA increased 4% (P = 0.012), coma increased 11% (P = 0.065), and spherical aberration increased 19% (P = 0.214), while trefoil decreased 5% (P = 0.490). In the WF guided group, total HOA RMS decreased 9% (P = 0.126), coma decreased 18% (P = 0.144), spherical aberration decreased 27% (P = 0.713) and trefoil decreased 19% (P = 0.660). One patient lost one line of CDVA secondary to residual irregular astigmatism.

Both the WaveLight Allegretto and the VISX CustomVue platforms had equal visual and safety outcomes. Most wavefront optimized HOA values trended upward, with a statistically significant increase in total HOA RMS. Eyes treated with the WF guided platform showed a decreasing trend in HOA values.

Clin Ophthalmol. 2011;5:1339-47. Epub 2011 Sep 20.
Moshirfar M, Betts BS, Churgin DS, Hsu M, Neuffer M, Sikder S, Church D, Mifflin MD.
John A Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USA.

1 comment:

Looking for information on dry eye prevention said...

nice blog and information, very technical I understood about 5% =) but found some very informative links too.

keep up the good work and writing, Will