Inaccuracy of intraocular lens power prediction for cataract surgery in angle-closure glaucoma.
OBJECTIVE
To assess the accuracy of intraocular lens (IOL) power predictions for cataract surgery in eyes with primary angle-closure glaucoma (ACG). Because of shifting of the capsular bag apparatus and shortening of the axial length, preoperative calculation of IOL power may be inaccurate for eyes with ACG.


METHODS
This retrospective comparative case series comprised of 42 eyes from 42 patients with primary ACG and 45 eyes from 45 subjects with normal open-angles undergoing uneventful cataract surgery. Anterior segment biometry including anterior chamber depth, lens thickness, and axial length were compared. Using the SRK-II formula, the powers of the implanted IOL and the actual postoperative spherical equivalent (SE) refractive errors were compared between the two groups. Also, the absolute values of differences between predicted and residual SE refractive errors were also analyzed for each group.


RESULTS
In ACG patients, anterior chamber depth and axial length were shorter and the lens was thicker than normal controls (all p < 0.001). Even though residual SE refractive error was not significantly different (p = 0.290), the absolute value of the difference between predicted and residual SE refractive error was 0.64 +/- 0.50 diopters in AGC patients and 0.39 +/- 0.36 diopters in control subjects (p = 0.012). The number of eyes that resulted in inaccurate IOL power predictions of more than 0.5 diopters were 21 (50.00%) in the ACG group, but only 12 (26.67%) in the control group (p = 0.043).


CONCLUSIONS
IOL power predictions for cataract surgery in ACG patients can be inaccurate, and it may be associated with their unique anterior segment anatomy.
Kang
Sung Yong
SY
Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seodaemun-Gu, Seoul, Korea.
Hong
Samin
S
Won
Jung Bin
JB
Seong
Gong Je
GJ
Kim
Chan Yun
CY
D001699:Biometry; D002387:Cataract Extraction; D005123:Eye / Q000033:anatomy & histology / Q000473:pathology; D015812:Glaucoma, Angle-Closure; D019654:Lens Implantation, Intraocular; D012189:Retrospective Studies