Public Defence: Erlend Christoffer Sommer Landsend Erlend Christoffer Sommer Landsend at Institute of Clinical Medicine will be defending the thesis “Congenital Aniridia: Exploring Visual Disabling Manifestations in the Ocular Surface and Ocular Fundus through Clinical and Translational Approaches” for the degree of PhD (Philosophiae Doctor).

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Photo: Sturlason

Trial Lecture – time and place

See Trial Lecture.

Adjudication committee

  • First opponent: Professor Peter A. Netland, University of Virginia School of Medicine, USA
  • Second opponent: Assistant Professor Tora Sund Morken, Faculty of Medicine and Health Sciences, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU)
  • Third member and chair of the evaluation committee: Professor II Trond Buanes, Faculty of Medicine, University of Oslo

Chair of the Defence

Professor Emeritus Terje Lømo, Faculty of Medicine, University of Oslo

Principal Supervisor

Professor Tor Paaske Utheim, Faculty of Odontology, University of Oslo


Congenital aniridia is an eye disease that involves the whole eye. It is primarily characterized by incomplete development – hypoplasia – of the iris and the retinal fovea. Foveal hypoplasia is the main cause of congenital reduced vision in aniridia.

In aniridia, severe complications are common. These include corneal disease – keratopathy –  which leads to progressive opacification of the cornea, pain, and often considerable visual impairment, or blindness. We hypothesized that progression of keratopathy in aniridia is related to dry eye disease. Further, that patients with aniridia have more severe signs of dry eye disease than healthy control individuals, including elevated levels of inflammatory cytokines in the tear fluid. Finally, we proposed that a specific imaging technique – autofluorescence imaging ­of the ocular fundus – could be used to diagnose and evaluate foveal hypoplasia.

First, we studied 35 patients with aniridia and 21 healthy control individuals. An extensive examination of dry eye disease was undertaken, including measurement of cytokine concentrations in the tear fluid. Next, 14 of the 35 aniridia patients underwent autofluorescence imaging of the ocular fundus. The images were compared with 14 age- and gender-matched healthy controls.

We detected more severe dry eye disease in aniridia patients than in healthy individuals. Importantly, dry eye disease was related to development of keratopathy. Aniridia patients had increased levels of a number of pro-inflammatory tear cytokines. Correlations were found between the cytokine concentrations and dry eye disease. Eventually, we found that autofluorescence imaging could be a useful tool in evaluation of foveal hypoplasia, and give information that is not available through other clinical tools.

In conclusion, the thesis brings together two main causes of visual disability in aniridia. The results may help prepare the ground for improved treatment and follow-up of aniridia patients in the future.

Additional information

There will be a light reception for all audiences in the Library, 3. floor, after the disputation.

Contact the research support staff.

Published Jan. 30, 2020 9:57 AM - Last modified Feb. 11, 2020 7:33 AM