Morphometric analysis of eyelid fissure in patients with eyelid retraction in graves orbitopathy

• Grant number: 12/23105-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2013
• End date: May 31, 2014
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Mário Luiz Ribeiro Monteiro
• Grantee: Thiago Machado Nogueira
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Upper eyelid retraction is the most frequent sign of Graves Orbitopathy (GO). The eyelid retraction is defined by the resting position of the upper eyelid at or above the corneal limbus or when the lower eyelid resting position is situated below the corneal limbus. The eyelid retraction widens the palpebral fissure leading to a larger area exposure of the ocular bulb which can cause eye dryness and damage to the ocular surface. The eyelid retraction also represents a severe cosmetic deformity that can bring difficulties for the social interaction of the patient with GO. Among the preconized therapeutic techniques for the upper eyelid retraction treatment, surgery is presented as the most effective in the inactive phase of GO. Surgery aims at the reduction of the expanded palpebral fissure area in GO and can be performed by different surgical techniques. There is no consensus on which of the techniques is more effective and which one presents fewer complications, therefore comparative surgical trials may be of great importance to answer these questions. In clinical practice, as well as in the studies that analyze the surgical techniques, the measurement of the margin reflex distance is the main form of evaluation of eyelid retraction. However, this method proves itself rather incomplete as it analyzes only the central distance (at 12 o'clock position) between the midpupil and the upper eyelid margin. The margin reflex distance measurement does not contemplate other significant morphometric variables of the upper eyelid retraction, such as contour abnormalities and the palpebral fissure area. Recently, new analytical methods of palpebral fissure morphometry based on digital images have been described. The purpose of this scientific initiation project is to perform more complete and comprehensive measurements of the alterations in the palpebral fissure of the patients with GO using these new methods. With the analysis of the obtained measurements, it will be possible to compare the group of patients with upper eyelid retraction with the previously described normality criteria and also to compare the obtained measurements in different periods after surgical intervention.(AU)