Abstract
Purpose:
To evaluate the preferred nocturnal sleep position and correlate with optic disc cupping in healthy and glaucomatous patients
Methods:
We prospectively enrolled healthy individuals and treated glaucomatous patients (glaucomatous optic neuropathy and reproducible visual field defect) from August 2012 to October 2012. Key exclusion criteria were previous intraocular surgery or any ocular disease other than glaucoma. All participants underwent a standard questionnaire regarding age, sex and preferred sleep position. Data collected also included intraocular pressure (IOP), optic disc assessment by color stereo photographs, central corneal thickness (CCT) and standard automated achromatic perimetry results (24-2 SITA-Standard, Humphrey Field Analyzer II) from both eyes. The questionnaire and optic disc assessment were performed by two independent investigators in a masked fashion
Results:
A total of 58 patients were included in the study. The mean office measured IOP for eyes of preferred sleeping side was similar to those of non-preferred sleeping side in both glaucomatous (16±3.8 vs 16.1±4.5 mmHg, p=0.79) and non-glaucomatous patients (14.7±2.2 vs 14.6±2.1 mmHg, p=0.81). There was no significant CCT difference between eyes in both groups as well (p≥0.41). Although there was a significant mean cup-to-disc ratio difference between eyes of the preferred sleeping side (0.49±0.23) and fellow eyes (0.42±0.20, p=0.01) in healthy individuals, no significant difference was observed in glaucomatous patients (0.68±0.17 vs 0.73±0.15; p=0.31). Finally, the agreement between the eye of the preferred sleeping side and the eye with larger cup-to-disc ratio (asymmetry defined as a difference ≥0.2) was 74% in healthy individuals, but only 45% in glaucomatous patients.
Conclusions:
In healthy individuals, eyes of preferred sleeping side tend to have larger cups (as determined by cup-to-disc ratio) than the fellow eyes, independently of office measured IOP and CCT values. We believe that the lack of association found in glaucomatous patients could be due to the fact that the disease itself, including its duration, IOP fluctuation and susceptibility of each eye, would play a more important role than the preferred sleeping side in these cases.
Keywords: 633 outflow: trabecular meshwork •
627 optic disc