April 2014
Volume 55, Issue 13
Free
ARVO Annual Meeting Abstract  |   April 2014
Measurability of partial coherence interferometry
Author Affiliations & Notes
  • Jae-hyung Kim
    Ophthalmology, Chungbuk National University Hospital, Cheongju-si, Republic of Korea
  • Tae Hwan Moon
    Ophthalmology, Chungbuk National University Hospital, Cheongju-si, Republic of Korea
  • Moses Kim
    Ophthalmology, Chungbuk National University Hospital, Cheongju-si, Republic of Korea
  • Ju Byung Chae
    Ophthalmology, Chungbuk National University Hospital, Cheongju-si, Republic of Korea
  • Footnotes
    Commercial Relationships Jae-hyung Kim, None; Tae Hwan Moon, None; Moses Kim, None; Ju Byung Chae, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science April 2014, Vol.55, 2532. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Jae-hyung Kim, Tae Hwan Moon, Moses Kim, Ju Byung Chae; Measurability of partial coherence interferometry. Invest. Ophthalmol. Vis. Sci. 2014;55(13):2532.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: Although partial coherence interferometry (PCI) provides more accurate and reproducible measurements of ocular axial length (AL) than conventional contact ultrasound methods, PCI is less useful in measuring AL in eyes with severe media opacity. To date, however, no studies have assessed the minimum near infrared ray intensity required for PCI measurements of AL. We therefore measured the minimum near infrared ray intensity required for consistent measurements of AL and analyzed media opacities in patients with media opacities that precluded measurement using PCI.

Methods: Two types of PCI (IOLmaster, ALscan) were used, with two polarizing lenses (Kenko PL) attached to the PCI. The near infrared ray intensity of PCI was modified by rotating the axis of one PL at intervals of 5 degrees. The right eye of one volunteer was measured three times, with the AL and signal to noise ratio (SNR) recorded 5 times for each measurement. Reduction of light intensity was theoretically estimated using Malus’ law. We retrospectively reviewed the medical records of patients unmeasurable by PCI (ALscan) from May to September 2013.

Results: AL was measured consistently with both IOLmaster and ALscan, until they reached 55 degrees (83.6% block) and 60 degrees (87.5% block), respectively. In contrast, SNR decreased as light intensity decreased. From May to September 2013, 23 eyes of 237 patients (9.7 %) could not be measured using ALscan due to media opacities, such as severe posterior subcapsular cataract (PSC, 8 eyes), hypermature cataract (2 eyes), and vitreous hemorrhage (13 eyes). The median grades of PSC (LOCS III) and vitreous haze were 4 (range 3-5) and 8 (range 4-8), respectively.

Conclusions: Although 83.6%~87.5% of near infrared rays were blocked or scattered, AL could be measured consistently.

Keywords: 445 cataract • 630 optical properties  
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×