Wednesday, May 30, 2012

Abstract: What serial aberrometry might tell or confirm

This one was surprisingly interesting. They performed serial wavefront aberrometry over a 10-second period after the patients blink. (For those who aren't familiar with that, aberrometry measures aspects of your vision such as reduced contrast sensitivity and poor vision quality, not just your vision in terms of what line you can read on the chart and what prescription you need to optimize it.) The pattern of how vision degraded in that time span correlated with what patients said about their vision and also with their clinical dry eye test results, so the authors suggest this test method be incorporated in dry eye evaluation.

Corneal and ocular wavefront aberrations were recorded together with clinical examination results and patient-reported vision-related quality-of-life evaluation results to define the relevance of dynamic optical analysis of the eye in dry eye disease (DED).
Prospective and comparative clinical study.
Forty DED patients and 40 age- and gender-matched control subjects.
Serial measurements of ocular and corneal higher-order aberrations (HOAs) after blink were performed for 10 seconds using the KR-1 aberrometer (Topcon, Clichy, France). Vision-related health-targeted quality of life was evaluated using the Ocular Surface Disease Index (OSDI) questionnaire. The clinical examination included tear film assessment (tear film break-up time and Schirmer I test), ocular surface damage assessment with the Oxford and van Bijsterveld indexes, and Meibomian dysfunction grading. Tear osmolarity also was measured.
The time course of HOAs and modulation transfer function (MTF) was compared between groups and was analyzed in comparison with the OSDI and clinical data in DED patients.
The root mean square of ocular and corneal total HOAs, particularly third-order aberrations, significantly increased over the 10-second period in DED patients, whereas no change occurred in controls. Analysis of MTF revealed progressive degradation of ocular optical quality resulting from loss of contrast at intermediate and high spatial frequencies in DED patients compared with controls. The progression index for corneal HOAs was correlated with the subjective index of patient-reported visual outcomes and with objective clinical findings of tear film and ocular surface damage.
Objective measurement of the time course of HOAs may constitute a new single instrument to evaluate and manage patients with DED because it reliably reflects the completeness of the disease.
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Ophthalmology. 2012 May 14. [Epub ahead of print]
Quinze-Vingts National Ophthalmology Hospital, Paris, France; INSERM, UPMC University Paris, Institut de la Vision, Paris, France.

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