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

Search Page

Filters

My NCBI Filters

Text availability

Article attribute

Article type

Publication date

Search Results

239 results

Filters applied: . Clear all
Results are displayed in a computed author sort order. The Results By Year timeline is not available.
Page 1
Incidence and prevalence of keratoconus in Denmark.
Nielsen K, Hjortdal J, Aagaard Nohr E, Ehlers N. Nielsen K, et al. Among authors: hjortdal j. Acta Ophthalmol Scand. 2007 Dec;85(8):890-2. doi: 10.1111/j.1600-0420.2007.00981.x. Epub 2007 Jul 23. Acta Ophthalmol Scand. 2007. PMID: 17645421 Free article.
A clinical comparison of optical and ultrasonic pachometry.
Nissen J, Hjortdal JO, Ehlers N, Frost-Larsen K, Sørensen T. Nissen J, et al. Among authors: hjortdal jo. Acta Ophthalmol (Copenh). 1991 Oct;69(5):659-63. doi: 10.1111/j.1755-3768.1991.tb04857.x. Acta Ophthalmol (Copenh). 1991. PMID: 1776423
Epikeratophakia for high myopia.
Hjortdal JO, Ehlers N. Hjortdal JO, et al. Acta Ophthalmol (Copenh). 1991 Dec;69(6):754-60. doi: 10.1111/j.1755-3768.1991.tb02055.x. Acta Ophthalmol (Copenh). 1991. PMID: 1789090
239 results