Abstract
Purpose :
Many studies have shown an increased prevalence of Obstructive Sleep Apnea (OSA) in Keratoconus (KCN) patients compared to that of the general population. To our knowledge, there have been no studies that assess a shared genetic link between KCN and OSA. The AvaGen test from Avellino determines KCN risk using genes implicated in KCN. We predicted that several of those genes may also be implicated in OSA risk. In this feasibility study, we identified patients for a future prospective study examining the shared genetic patterns between KCN and OSA.
Methods :
We identified patients diagnosed with KCN between 2016 and 2021 using the following ICD-10 codes: H18.601-H18.603, H18.609, H18.611-H18.613, H18.619, H18.621-H18.623, H18.629, H18.6, H18.60-H18.62. Of the KCN patients identified, those who’ve undergone polysomnography, noted using CPT codes 95800, 95806, 95807, 95782, were flagged. Chart review was completed to document the Apnea Hypopnea Index (AHI) values to determine presence and severity of OSA. A literature review was completed to understand the current data on genetic profiles of OSA and KCN individually.
Results :
We identified 319 KCN patients, of which 28 had documented AHI values. Of those 28, 25% had severe, 11% had moderate and 7% had mild OSA. Based on the 319 patients, we note a 9% prevalence of OSA per AHI values. Amongst KCN patients who’ve undergone polysomnography, we note an 89% prevalence of mild or worse OSA and a 64% prevalence of moderate or worse OSA. There was a notable rise in sleep studies ordered across all departments at Loyola starting 2020.
Conclusions :
Our data is supportive of prior literature that notes increased prevalence of OSA in KCN patients as prevalence in the general population is around 7%. We’ve identified eight genes within the AvaGen panel that have been implicated in OSA related to factors such as altered dental facial morphology, predilection to chronic intermittent hypoxia, inflammatory signaling pathways, and more. The increase in sleep studies in the last two years is a limitation as patients diagnosed prior to the increase likely do not have documented AHI, possibly artificially influencing the calculated prevalence. This feasibility study was essential in establishing important parameters for the future prospective study assessing shared genetic patterns between KCN and OSA.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.