ABSTRACT
Purpose: Papilledema and peripapillary deformation of Bruch's membrane (BM) are associated with elevated intracranial pressure (ICP). We have developed a novel methodology to measure these parameters using a radial optical coherence tomography (OCT) scan pattern and apply this to test the hypothesis that ICP is associated with volumetric features of ophthalmic structures. Methods: 6-radial OCT B-scans centered over the optic nerve head were acquired in 17 subjects (30 eyes) before lumbar puncture with measurement of ICP (range: 10-55 cm H2O). Internal limiting membrane (ILM) and BM were segmented. Three definitions of BM were studied to account for imaging artifact affecting peripapillary BM: connecting rater-identified BM margins(traditional), connecting rater-identified BM 1.6 mm on either side of the ONH(estimated), and excluding BM in the central 3.2 mm of the images(excluded). Optic nerve head volume (ONHV), BM displacement volume (BMDV) and cup volume (CV) were calculated by interpolating between B-scans. Ganglion cell complex volume (GCCV) was measured in the macula. Linear generalized estimating equations (GEE) modeled ONVH, BMDV, and CV as a function of ICP and GCCV. Results: Increased ONHV was associated with elevated ICP for traditional (p = 0.006), estimated (p = 0.003) and excluded (p = 0.05) BM definitions. Decreased BMDV was associated with elevated ICP for traditional (p < 0.0005), estimated (p < 0.0005) and excluded (p = 0.001) definitions. Decreased ONHV was independently associated with decreased GCCV (p = 0.001) and decreased ICP (p = 0.031) in multivariable models. CV was neither associated with ICP nor GCCV in univariate or multivariable models. Conclusions: Elevated ICP is associated with ONHV increase and BMDV decrease, calculated from OCT images accounting for image artifact. Ganglion cell atrophy affects the relationship between ICP and ONHV. OCT derived volumetric measures of the posterior eye may have application as biomarkers for elevated ICP.
ABSTRACT
Resumen Las manifestaciones oftalmológicas que se relacionan con el síndrome de apnea-hipopnea obstructiva del sueño (SAHOS) incluyen síndrome de párpado flácido y cambios a nivel del nervio óptico asociados con glaucoma, así como neuropatía óptica isquémica anterior no arterítica y papiledema. La prevalencia del síndrome de párpado flácido en pacientes con SAHOS varía entre 2.3% y 32.6%, mientras que de la asociación entre glaucoma y SAHOS oscila entre 2% y 27%. En la población estudiada en Colombia se encuentra una frecuencia de 2.7% de asociación entre glaucoma de presión normal y SAHOS. El glaucoma presente en estos casos es el primario de ángulo abierto, que bien puede cursar con o sin un aumento de la presión intraocular. En cuanto a la neuropatía óptica isquémica y el papiledema, no se dispone de datos acerca de su prevalencia en pacientes con SAHOS. Se recomienda la valoración por oftalmología a los pacientes diagnosticados con este síndrome.
Abstract Ophthalmologic manifestations associated with obstructive sleep apnea-hypopnea syndrome (OSAHS) include floppy eyelid syndrome and changes in the optic nerve related to glaucoma, as well as nonarteritic anterior ischemic optic neuropathy and papilledema. The prevalence of floppy eyelid syndrome in patients with OSAHS ranges between 2.3% and 32.6%, while the association between glaucoma and OSAHS ranges from 2% to 27%. In the population studied in Colombia, an association frequency of 2.7% between normal pressure glaucoma and OSAHS has been found. The type of glaucoma observed in these cases is open-angle primary glaucoma, which may well occur with or without an increase of intraocular pressure. Regarding ischemic optic neuropathy and papilledema, data on their prevalence in patients with OSAHS are not available. An evaluation by ophthalmology is recommended to the patients diagnosed with this syndrome.
