Digital Photography as a Novel Technique of Measuring Ocular Surface Dimensions

Purpose: To introduce a novel technique for measuring ocular surface dimensions using digital photography and computerized image analysis in the context of ptosis repair surgery. Methods: Digital photographs and patient questionnaires on dry eye symptoms were obtained from 31 patients before and after ptosis repair. Patients were examined preoperatively and at 1 and 6 weeks postoperatively. Adobe Photoshop 7.0 (Adobe Systems Incorporated, 345 Parkl Avenue, San Jose, CA 95110-2704, USA) was used to digitally measure palpebral fissure height, fissure width, and ocular surface area (OSA). Similar digital measurements were obtained on 30 control subjects as well. Digital calculations of OSA for control, preoperative, and postoperative groups were compared with other published techniques. Results: Graphical comparison between our method of measuring OSA and the mathematical estimations proposed by previous studies suggests that our method is more precise in measuring OSA, and that it is also better able to identify individual variations of OSA from general population trends. Conclusion: Digital ocular photography combined with computerized image analysis is a fast, easy to use, and reliable method of measuring ocular surface dimensions. In addition to ptosis surgery, this method can be used in other ocular surface studies.