University of VeronaEye ClinicDepartment of Neurological and Motor ScienceHead: 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 FasoloMattia 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

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

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

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

Elevated Astitgmatism – example right eye

VA: 20/20 – 0,50 – 1,50 α 10LAF: transparent cornea, transparent lensIOP: 12 mmHgFundus: normal

Elevated Astitgmatism – example left eye

VA: 20/20 – 2 α 10LAF: transparent cornea, transparent lensIOP: 13 mmHgFundus: normal

Subclinical Keratoconus – example right eye

VA: 20/20 natLAF: transparent cornea, transparent lensIOP: 12 mmHgFundus: normal

Subclinical Keratoconus – example left eye

VA: 20/20 + 0,50 sfLAF: transparent cornea, transparent lensIOP: 12 mmHgFundus: normal

Keratoconus – example right eye (Stage I)

VA: 20/20 – 0,50 α 10LAF: transparent cornea, transparent lensIOP: 12 mmHgFundus: normal

Keratoconus – example left eye (Stage I)

VA: 20/20 – 0,50 + 1 α 90LAF: transparent cornea, transparent lensIOP: 14 mmHgFundus: normal

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