Transcript Accuracy of Predicted Refractive Error in Resident

ASCRS – 2008
Chicago,Illinois USA
Accuracy of Predicted Refractive
Error in Resident-Performed
Cataract Surgery Using Partial
Coherence Interferometry
Nickolas P. Katsoulakis, M.D., Paul B. Greenberg, M.D., Dina Gewaily, M.M.S.,
Theodoros Filippopoulos, M.D., and Sunil K. Rao, M.D.
Ophthalmology Section, Department of Veterans Affairs Medical
Center, Providence, R.I.
Division of Ophthalmology, The Warren Alpert Medical School of
Brown University, Providence, R.I.
Purpose:
• To determine the accuracy of predicted post-operative
refractive error in a cohort of U.S. veterans undergoing
resident-performed cataract surgery that had
preoperative axial length measurements using partial
interferometry (PCI).
Methods:
• Retrospective review of patients who had extracapsular
cataract extraction by phacoemulsification with in-thebag intraocular lens implantation between February 2006
and May 2007 at a Veterans Affairs Medical Center.
• All cases were performed by resident surgeons with
attending supervision with preoperative axial length
biometry performed by PCI (Zeiss IOLMaster, Carl Zeiss
Meditec AG). Inclusion criteria were patients with (a)
recorded pre-operative target and post-operative
refractions after at least one month of follow-up and (b)
post-operative visual acuities of 20/50 or better.
Results:
• 148 cataract surgeries were performed between
February 2006 and May 2007 with preoperative biometry
performed using PCI.
• 64 eyes met inclusion criteria; 41 eyes were excluded
due to inability to obtain adequate measurements using
PCI.
Results:
• 60 males and 4 females
• Mean age: 71.8 ± 9.4 years (range: 53-90)
• Mean pre-operative BCVA: 0.42
• Mean post-operative logMAR BCVA: 0.02
• Mean absolute deviation from target refractive error:
0.49D (SD=0.40)
• 87.5% of patients were within 1D of target refraction and
100% were within 2D
Eyes
within*
Eleftheriadis†
Rose
Kiss
Katsoulakis
± 0.5 D
84% (67%)
N/A
56%
60.9%
± 1.0 D
96% (90%)
85%
89%
87.5%
± 1.5 D
100% (98%)
N/A
94%
98.4%
± 2.0 D
(100%)
100%
100%
100%
MAE‡
0.29 (0.49)
0.42
0.48
0.49
* Percentage of eyes within 0.50 D, 1.00 D, 1.50 D, and 2.00 D of intended refraction.
† Values in parentheses are refractive outcomes for patients whose IOL calculations were
performed theoretically using the SRK II formula.
‡ Mean absolute error.
Conclusions:
• The accuracy of target refractions in patients undergoing
resident-performed cataract surgery at a Veterans Affairs
Medical center is comparable to prior studies in which
preoperative biometry was performed using PCI.
• A significant percentage of patients in this cohort were
unable to have PCI axial length measurements due
primarily to dense lens opacity.
References:
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