July 2018
Volume 59, Issue 9
Open Access
ARVO Annual Meeting Abstract  |   July 2018
Develop a novel nomogram for manual astigmatic keratotomy to correct mild astigmatism during cataract surgery utilizing ORA and Verion.
Author Affiliations & Notes
  • Ming Chen
    Ophthalmology, University of Hawaii, Honolulu, Hawaii, United States
  • Michael Reinsbach
    Ophthalmology, Nassau university, New York, New York, United States
  • Nathan Wilbanks
    Ophthalmology, University of Virginia, Charlottesville, Virginia, United States
  • ChaoKai Chang
    Taipei Nobel eye clinic, Taipei, Taiwan
  • Footnotes
    Commercial Relationships   Ming Chen, None; Michael Reinsbach, None; Nathan Wilbanks, None; ChaoKai Chang, None
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science July 2018, Vol.59, 5746. doi:https://doi.org/
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      Ming Chen, Michael Reinsbach, Nathan Wilbanks, ChaoKai Chang; Develop a novel nomogram for manual astigmatic keratotomy to correct mild astigmatism during cataract surgery utilizing ORA and Verion.. Invest. Ophthalmol. Vis. Sci. 2018;59(9):5746. doi: https://doi.org/.

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      © ARVO (1962-2015); The Authors (2016-present)

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Purpose : Opticwave Refractive Analysis (ORA, an Interferometer) and Verion (image guide system) are high tech equipment that can measure astigmatism and axis intraoperatively during cataract surgery for correction or enhancement. This study intended to develop a novel nomogram with the assistance of using ORA/Verion in manual astigmatic correction and validated the superioity with the group without using ORA and Verion in Manual Astigmatic Keratotomy (MAK).

Methods : 60 consecutive adult cataract surgery cases with regular astigmatism of 0.5D to 1.25D in 2017 were included for study. All cases were aligned the cylinder axis with Verion pre-operatively. MAK were done before phaco according to an old nomogram. ORA then were performed to obtain axis and remaining cylinder power after phaco and IOL implantation. Extensions of MAK were done with keratome starting with (5 degree for 0.5D correction over both side of keratotomy) for eyes with remaining cylinder of 0.5 D or more until cylinder diopter to be below 0.5±0.1D . The mean degrees of extension (5 degree ± 2.5 the degree to old nomogram were formulated to develop the new nomogram (table 1).
60 consecutive similar cases using the old nomogram by the same surgeon that MAK were done without using ORA and Verion for enhancement in 2016 were reviewed for comparison.

Results : 3 month post-op examination of the ORA and Verion group ( which assist to form the novel nomogram) demonstrated the proportion of post-op cylinder less than 0.5D was 87% in comparison to without of 70% (p<0.05)( figure 1).

Conclusions : Using high technology equipment for the first time in the literature to develope a novel nomogram for MAK may provide better outcome in mild astigmatic correction in cataract surgery compare to the empirical old nomogram.
Future prospective study to further confirm the validity of this novel nomogram is warranted.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.



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