Yoo YJ, et al. J Clin Neurol. 2020 Oct;16(4):646-652. https://doi.org/10.3988/jcn.2020.16.4.646

Background: Optical coherence tomography (OCT) can detect visual alterations associated with Parkinson disease, such as damage to the retinal nerve fiber layer or changes in retinal vasculature. Macula thinning in association with Parkinson disease (PD) remains controversial. Therefore, we conducted a meta-analysis to investigate the central retina thickness in PD measured using spectral-domain OCT (SD-OCT). Methods: We searched PubMed and the Excerpta Medica database to identify studies that compared macular thickness between patients with PD and healthy controls published before July 31, 2021. A random-effects model was used to examine PD-associated changes in macular thickness. Meta-regression analysis was performed by assessing heterogeneity, publication bias, and study quality. Results: Thirty-two studies with a cross-sectional design were selected, including 2118 patients with PD and 2338 controls. We identified significant differences in the thickness of the ganglion cell–inner plexiform layer (standardized mean difference [SMD], –0.41; 95% confidence interval [CI], –0.66 to –0.16; I² = 80%), ganglion cell complex (SMD, –0.33; 95% CI, –0.50 to –0.17; I² = 0%), and of all inner and outer sectors of the macula (SMD range, –0.21 to –0.56; all P < .05) between patients with PD and controls. Discussion: These results corroborate the increased prevalence of changes in OCT measures in individuals with PD, highlighting the efficacy of SD-OCT–determined macular thickness as a biomarker for PD. Our findings may provide helpful guidelines for clinicians in rapidly evolving areas of PD diagnosis.

Optical coherence tomography (OCT) is the most widely used noninvasive imaging technique currently available for ocular structure evaluation [1,2]. With the advent of spectral-domain OCT (SD-OCT) technology with increased axial resolutions and faster scanning speeds relative to earlier-generation time-domain OCT systems, clinical practice has improved [3]. Along with the disc and retinal nerve fiber layer (RNFL) analysis, the ganglion cell-inner plexiform layer (GCIPL) thickness, which reflects the density of the ganglion cell body and the amount of dendrite loss, has been a focus of interest in recent studies. With advancements in technology, the adoption of a macular ganglion cell analysis (GCA) algorithm by SD-OCT had further enabled detailed GCIPL measurements to be performed in the macular region [4,5]. Purpose: We sought to establish normative ranges of the ganglion cell-inner plexiform layer (GCIPL) thickness using spectral domain optical coherence tomography in Korean elderly individuals and to identify factors that influence GCIPL thickness. Methods: We conducted a retrospective, observational study of 114 healthy subjects (75 years old or older) who underwent comprehensive ophthalmic examinations at a single institution. GCIPL thickness was measured with the Cirrus spectral-domain optical coherence tomography system and automatic segmentation. Subjects were divided into two age groups: those younger than 80 years and those 80 years or older, respectively. A cross-sectional analysis was adopted to evaluate associations of GCIPL thickness with sex, age, intraocular pressure, optic disc rim area, axial length, spherical equivalent (SE) refractive errors, astigmatism, and body mass index. Results: The average and minimum GCIPL thicknesses were 80.3 ± 5.6 µm and 76.3 ± 5.9 µm, respectively. The GCIPL thickness was significantly lower in the older group than in the younger group in the inferior, inferonasal, and inferotemporal segments (all p < 0.01). A thinner average GCIPL thickness was strongly associated with increasing age (β =-2.87, p = 0.021) and thinner circumpapillary retinal nerve fiber layer thickness (β = 2.87, p < 0.001) in all segments. Conclusions: GCIPL thickness decreased with age globally and in all segments, even after 75 years of age. Thinner GCIPL was associated with older age and thinner circumpapillary retinal nerve fiber layer. Age-related changes should be considered when using GCIPL thickness to assess glaucoma and other optic neuropathies characterized by retinal ganglion cell loss.

Mucoceles are cystic formations characterized by the presence of mucus-secreting epithelial cells, which enlarge when the excretory duct becomes obstructed. Posterior ethmoidal mucoceles are rare conditions that can lead to severe ocular complications requiring immediate intervention. The close anatomical proximity of posterior ethmoidal mucoceles to the optic nerve underscores their significance. In this case report, we present a case of rapidly progressing compressive optic neuropathy secondary to a posterior ethmoidal mucocele. A previously healthy forty-six-year-old woman presented with sudden visual loss in her left eye, preceded by left-sided headache and periorbital pain. Clinical examination and imaging studies revealed an oval-shaped mass within the posterior ethmoid cell compressing the left optic nerve. Emergency surgery was performed to alleviate optic nerve compression, which successfully relieved periocular pain. However, the patient’s visual acuity and visual field defect remained unchanged postoperatively. Thinning of the ganglion cell layer in the macula region was observed during follow-up examinations. The role of corticosteroids and antibiotics in visual rehabilitation and the impact of delayed surgical decompression on visual outcome remain subjects of debate. Additional cases of mucocele-associated optic neuropathy should be published and analyzed to establish optimal treatment approaches.