Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2019 Autumn;8(3):204–218.

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2019, Author(s).

This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial 4.0 International License (http://creativecommons.org/licenses/by/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.

PMC Copyright notice

The Center/Surround Index (CSI), Differential Sector Index (DSI), and Opposite Sector Index (OSI) are Calculated based on Eight Arbitrary 45-Degree Sectors of the Corneal Surface. For each Sector Mean Axial Power is Calculated. Sectoral Patterning of the Corneal Surface is Repeated until each Possible Pattern of Sector Distribution is Applied. CSI is the difference of the Area-corrected Corneal Power between a Central 3mm Ring and a 6mm Annulus that Surrounds the Central Ring. DSI is the Greatest difference between any Two Sectors. OSI is the Greatest difference between any Two Opposite Sectors