Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Jul 22:2020:7395081.
doi: 10.1155/2020/7395081. eCollection 2020.

The Impact of Changes in Corneal Back Surface Astigmatism on the Residual Astigmatic Refractive Error following Routine Uncomplicated Phacoemulsification

Larysa Tutchenko  1   2 , Sudi Patel  3 , Oleksiy Voytsekhivskyy  2 , Mykhailo Skovron  2 , Olha Horak  2
Affiliations

The Impact of Changes in Corneal Back Surface Astigmatism on the Residual Astigmatic Refractive Error following Routine Uncomplicated Phacoemulsification

Larysa Tutchenko et al. J Ophthalmol. .

Abstract

Purpose: To determine the significance of any association between intersessional changes in ocular residual astigmatism (RA) and astigmatism at corneal front (FSA) and back (BSA) surfaces following uneventful routine phacoemulsification.

Methods: Astigmatism was evaluated by autorefractometry and subjective refraction and at both the corneal surfaces with Orbscan II™ (Bausch & Lomb) over central 3 mm and 5 mm optical zones at 1, 2, and 3 months after routine phacoemulsification in 103 patients implanted with monofocal nontoric intraocular lenses (IOLs, one eye/patient). Data were subjected to vector analysis to determine the actual change (Δ) in astigmatism (power and axis) for the refractive and Orbscan II findings.

Results: The number of cases that attended where ΔRA was ≥0.50 DC between 1 and 2 months was 52 by autorefractometry and 36 by subjective refraction and between 2 and 3 months was 24 by autorefractometry and 19 by subjective refraction. Vector analysis revealed significant correlations between ΔFSA and ΔRA for data obtained by autorefractometry but not by subjective refraction. At all times, ΔBSA was greater than ΔFSA (p < 0.01). Key findings for ΔBSA values over the central 3 mm zone were between (A) the sine of the axis of ΔRA (y) and sine of the axis of ΔBSA (x) for the data obtained by autorefractometry (between 1 and 2 months, y = 0.749 - 0.303x, r = 0.299, n = 52, p=0.031) and subjective refraction (between 2 and 3 months, y = 0.6614 - 0.4755x, r = 0.474, n = 19, p=0.040) and (B) ΔRA (y) and ΔBSA (x) powers between 2 and 3 months postoperatively for the data obtained by autorefractometry (ΔRA = 0.118 ΔBSA + 0.681 r = 0.467, n = 24, p=0.021) and subjective refraction (ΔRA = 0.072 ΔBSA + 0.545 r = 0.510, n = 19, p=0.026).

Conclusion: Changes in the ocular residual refractive astigmatic error after implanting a monofocal nontoric IOL are associated with changes in astigmatism at the back surface of the cornea within the central optical zone.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no conflicts of interest.

Figures

Figure 1
Figure 1
Change in astigmatism at the corneal back surface over the central 3 mm zone (x axis) and the corresponding change in residual refractive astigmatic error determined by autorefractometry (y axis) between 1 and 2 months postoperatively. All units are in diopters.
Figure 2
Figure 2
Change in astigmatism at the corneal back surface over the central 3 mm zone (x axis) and the corresponding change in residual refractive astigmatic error determined by autorefractometry (y axis) between 2 and 3 months postoperatively. All units are in diopters.
Figure 3
Figure 3
Change in the sine of the axis of astigmatism at the corneal back surface over the central 3 mm zone (x axis) and the corresponding change in the sine of the axis of residual refractive astigmatic error determined by autorefractometry (y axis) between 1 and 2 months postoperatively. All units are sine of axis in degrees (°).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Cheng L.-S., Tsai C.-Y., Tsai R. J.-F., Liou S.-W., Ho J.-D. Estimation accuracy of surgically induced astigmatism on the cornea when neglecting the posterior corneal surface measurement. Acta Ophthalmologica. 2011;89(5):417–422. doi: 10.1111/j.1755-3768.2009.01732.x. - DOI - PubMed
    1. Preussner P.-R., Hoffmann P., Wahl J. Impact of posterior corneal surface on toric intraocular lens (IOL) calculation. Current Eye Research. 2015;40(8):809–814. doi: 10.3109/02713683.2014.959708. - DOI - PubMed
    1. Klijn S., Sommen C. M. V. D., Sicam V. A. D. P., Reus N. J. Value of posterior keratometry in the assessment of surgically induced astigmatic change in cataract surgery. Acta Ophthalmologica. 2016;94(5):494–498. doi: 10.1111/aos.13003. - DOI - PubMed
    1. Oshika T., Tomidokoro A., Tsuji H. Regular and irregular refractive powers of the front and back surfaces of the cornea. Experimental Eye Research. 1998;67(4):443–447. doi: 10.1006/exer.1998.0558. - DOI - PubMed
    1. Koch D. D., Ali S. F., Weikert M. P., Shirayama M., Jenkins R., Wang L. Contribution of posterior corneal astigmatism to total corneal astigmatism. Journal of Cataract & Refractive Surgery. 2012;38(12):2080–2087. doi: 10.1016/j.jcrs.2012.08.036. - DOI - PubMed

LinkOut - more resources