{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T06:21:10Z","timestamp":1789712470548,"version":"4.0.1"},"reference-count":41,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2021,11,15]],"date-time":"2021-11-15T00:00:00Z","timestamp":1636934400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>The keratometer keratoconus index (KKI) is a diagnostic index for the risk of keratoconus calculated from autokeratometer test values. We partially modified the KKI equation and assessed it without limiting the target age and severity of keratoconus. This retrospective study included 179 eyes of 99 patients with keratoconus and 468 eyes from 235 normal controls. In the modified KKI, oblique astigmatism or against-the-rule astigmatism was defined as \u22651D astigmatism. KKI diagnostic power was analyzed in subgroups of &lt;50 and \u226550-year-old patients, and at different keratoconus stages. Although the sensitivity of modified KKI was comparable with that of original KKI (92.7% vs. 95.5%), modified KKI specificity was significantly higher (79.7% vs. 68.6%) (p = 0.0001). Using the modified KKI, sensitivity reached 100% (4\/4) and specificity, 63.5% (33\/52), in \u226550-year-old patients, while overall sensitivity in keratoconus \u2265stage 2 was 100% (30\/30). In conclusion, the modified KKI proved to be effective in keratoconus screening at all stages. However, it should be noted that false-positive frequency is higher in \u226550-year-old patients.<\/jats:p>","DOI":"10.3390\/diagnostics11112120","type":"journal-article","created":{"date-parts":[[2021,11,15]],"date-time":"2021-11-15T20:46:47Z","timestamp":1637009207000},"page":"2120","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Screening of Keratoconus Using Autokeratometer and Keratometer Keratoconus Index"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5016-0155","authenticated-orcid":false,"given":"Takashi","family":"Kojima","sequence":"first","affiliation":[{"name":"Department of Ophthalmology, Keio University School of Medicine, Shinanomachi 35, Shinjuku-ku, Tokyo 160-8582, Japan"},{"name":"Nagoya Eye Clinic, Nagoya 456-0003, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naoki","family":"Isogai","sequence":"additional","affiliation":[{"name":"Nagoya Eye Clinic, Nagoya 456-0003, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomoya","family":"Nishida","sequence":"additional","affiliation":[{"name":"Nagoya Eye Clinic, Nagoya 456-0003, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomoaki","family":"Nakamura","sequence":"additional","affiliation":[{"name":"Nagoya Eye Clinic, Nagoya 456-0003, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazuo","family":"Ichikawa","sequence":"additional","affiliation":[{"name":"Chukyo Eye Clinic, Nagoya 456-0032, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3473","DOI":"10.2147\/OPTH.S248724","article-title":"Risk Factors for Development of Keratoconus: A Matched Pair Case-Control Study","volume":"15","author":"Almusawi","year":"2021","journal-title":"Clin. 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