1. University of Verona Eye Clinic Department of Neurological and Motor Science Head: Prof. Giorgio Marchini Prevalence of Corneal Ectasia in Patients With Obstructive Sleep Apnea: Preliminary Results Mattia Passilongo, MD, Emilio Pedrotti, MD, Giorgio Marchini MD, Adriano Fasolo World Corneal Congress VII – San Diego 15-17 April 2015 The authors have no financial interests to disclose

2. The association between Keratoconus and obstructive sleep apnea (OSA) has been established by several studies, but the converse relationship has not yet been examined. This study aims to determine the prevalence of corneal ectasia in a population of patients with OSA. Purpose

3. Retrospective study. We enrolled 178 eyes of 89 patients with diagnosis of OSA. They underwent polysomnography, ophthalmic clinical examination, refraction and corneal structure evaluation. Videokeratographic, aberrometric, and topographic criteria were applied to identify corneal ectasia. Likely presence of Keratoconus was defined by presence of typical ectasia with apical corneal thinning and subclinical keratoconus by the use of Calossi-Foggi index (~ Rabinowitz index). Patients and Methods

4. Population: 75 males and 24 females mean age 64.10+11.78 years 173 normal eye 173 normal eye (none corneal scarring; none slit-lamp signs; typical axial pattern, max corneal power <47 D): - 104 eyes had a low astigmatism < 1 D - 69 eyes (39.76%) had a astigmatism > 1 D 5 eyes 5 eyes (2.81%) with ectasia: 2 eyes - 2 eyes (1,12 %) with Keratoconus (Stage I of Krumeich) 3 eyes - 3 eyes (1.69%) as subclinical Keratoconus Best corrected visual acuity 0.03+0.09 in LogMAR Mean topographic anterior astigmatism 0,96+0,57 D Mean central corneal pachimetry of 578,06+50.77 um Results

5. Elevated Astitgmatism – example right eye VA: 20/20 – 0,50 – 1,50 α 10 LAF: transparent cornea, transparent lens IOP: 12 mmHg Fundus: normal

6. Elevated Astitgmatism – example left eye VA: 20/20 – 2 α 10 LAF: transparent cornea, transparent lens IOP: 13 mmHg Fundus: normal

7. Subclinical Keratoconus – example right eye VA: 20/20 nat LAF: transparent cornea, transparent lens IOP: 12 mmHg Fundus: normal

8. Subclinical Keratoconus – example left eye VA: 20/20 + 0,50 sf LAF: transparent cornea, transparent lens IOP: 12 mmHg Fundus: normal

9. Keratoconus – example right eye (Stage I) VA: 20/20 – 0,50 α 10 LAF: transparent cornea, transparent lens IOP: 12 mmHg Fundus: normal

10. Keratoconus – example left eye (Stage I) VA: 20/20 – 0,50 + 1 α 90 LAF: transparent cornea, transparent lens IOP: 14 mmHg Fundus: normal

11. The prevalence of corneal ectasia observed and at least 3 patients of undiagnosed keratoconus or suspected ectasia may suggest that OSA patients should be referred to ophthalmologists to have their corneas checked since the association between OSA and Keratoconus exist. Conclusions