UNASSIGNED: The objectives of the study are to assess the peripapillary choroidal thickness (PPCT), retinal nerve fiber layer (RNFL), and optic nerve head (ONH) parameters in multiple sclerosis (MS) patients compared to healthy subjects.
UNASSIGNED: One hundred and twenty-eight eyes from 64 patients were included in this cross-sectional study. Eighty-two eyes of 41 MS patients and 46 eyes of 23 healthy subjects were examined. PPCT and RNFL were measured using spectral-domain optical coherence tomography (OCT). PPCT was measured from the four quadrants around the optic disc at a distance of 1 mm (PPCT-1) and 2 mm (PPCT-2) from the edge of the ONH and the beginning of the retinal pigment epithelium. ONH parameters were measured with Heidelberg retinal tomography (HRT-3). Disease duration, the number of episodes, MS subtypes, and Expanded Disability Status Scale (EDSS) scores were recorded.
UNASSIGNED: The RNFL measurements and the mean PPCT-1 and PPCT-2 were significantly lower in MS patients compared to healthy individuals. PPCT-1 and PPCT-2 were measured as the thickest in the temporal quadrant, followed by the superior, nasal, and inferior quadrants, respectively, in both groups. When the ONH parameters were evaluated, cup/disc area ratio, cup area, and cup volume values were significantly higher, whereas optic rim volume and rim area values were significantly lower in MS patients compared to healthy subjects (p<0.05). We observed significant changes in RNFL and ONH parameters of MS patients in parallel with disease severity determined by EDSS scores and the presence of optic neuritis.
UNASSIGNED: There were significant changes in RNFL thickness, PPCT, and ONH parameters when MS patients were compared with healthy subjects. Assessment of RNFL and PPCT with OCT and ONH with HRT-3 may be useful in the follow-up of MS patients.

To investigate neurovascular changes; including macular vascular density (VD), thickness of the ganglion cell layer (GCL) and optic nerve head (ONH) parameters in episodic migraine patients. 80 eyes of 40 episodic migraine patients were recruited. Thirty patients having a dominant side of migraine headache were statistically analyzed (5 male and 25 female; mean age 31.67 ± 9.54 years) and compared to 25 eyes of 25 healthy volunteers (5 male and 20 female; mean age of 34.4 ± 12.11 years, p = 0.361). The posterior segment was imaged with Topcon DRI optical coherence tomography (OCT) (Triton Swept source OCT Topcon, Japan), and OCT angiography (OCTA). Comparing the dominant side of migraine patients to controls we found a significant decrease of the VD in the central zone of the superficial and deep capillary plexus (SCP, p = 0.01; DCP, p = 0.004) and an enlarged foveal avascular zone (FAZ, p = 0.054). The GCL thickness was significantly reduced in the central ring (GCL + p = 0.042, GCL +  + p = 0.029), as well as the retinal nerve fiber layer (RNFL) thickness in the temporal quadrant (p = 0.021) and border tissue of Elschnig diameter (BTE, p = 0.035). The duration of migraine showed an inverse correlation with SCP in the nasal quadrant (p = 0.016, r = - 0.445) and with all DCP regions [DCP superior (p = 0.004, r = - 0.519), DCP inferior (p = 0.004, r = - 0.519), DCP nasal (p = 0.006, r = - 0.496), DCP temporal (p = 0.005, r = - 0.508), DCP CSF (p < 0.001, r = - 0.634)]. The dominant side compared to the non-dominant side showed a significant deterioration of the VD in the inferior (p = 0.04) and temporal quadrants (p = 0.023); furthermore, a significant decrease in the GCL +  + inner ring thickness (p = 0.046). Microvascular damage and consequent structural alterations of the retina and optic nerve head occur in the eyes of episodic migraine patient in association with the lateralization of the headache.

OBJECTIVE: To evaluate optic nerve head morphology in children with craniosynostosis versus healthy controls.
METHODS: Single-centre, prospective cohort study METHODS: Handheld optical coherence tomography (OCT) was performed in 110 eyes of 58 children (aged 0-13 years) with craniosynostosis. Inclusion criteria were as follows: normal intracranial pressure (ICP) on invasive overnight monitoring, or clinically stable ICP. The latter was defined as stable VA within 1 logMAR line and no papilloedema on fundoscopy for at least four months following OCT, and normal/stable visual evoked potentials. Control data for 218 eyes of 218 children were obtained from a published normative dataset. The main outcome measures were disc width, cup width, rim width and retinal nerve fibre layer (RNFL) thickness (nasal and temporal). Outcome measures were compared using three-way linear mixed model regression analysis (FGFR 1/2-associated craniosynostosis, non-FGFR 1/2-associated craniosynostosis, and controls).
RESULTS: Out of 63 eligible children with craniosynostosis, handheld OCT imaging was successful in 110 eyes of 58 children (92%). Of these, 22 (38%) were female. Median subject age at OCT examination was 53 months (range: 2 to 157; IQR: 39 to 73). Twelve children (21%) had FGFR1/2-associated syndromes (Crouzon, n=6; Apert, n=4; Pfeiffer, n=2). Control data were available for 218 eyes of 218 healthy children. 122 controls (56%) were female. Median control age at OCT examination was 20 months (range: 0 to 163; IQR: 6 to 59). When comparing optic nerve head morphology in craniosynostosis (n=58) versus controls (n=218), disc width was 6% greater (p=0.001), temporal cup width was 13% smaller (p=0.027), rim width was 16% greater (p<0.001) and temporal RNFL was 11% smaller (p=0.027). When comparing FGFR1/2-associated syndromes (Crouzon, Apert and Pfeiffer syndromes, n=12) to the rest of the craniosynostosis group (n=46), disc width was 10% smaller (p=0.014) and temporal cup width was 38% smaller (p=0.044).
CONCLUSIONS: This cohort demonstrated morphological differences of the optic nerve head in craniosynostosis, most markedly in Crouzon, Apert and Pfeiffer syndromes. These findings could help improve ophthalmological monitoring and surgical decision-making in children with craniosynostosis. Further work on longitudinal optic nerve head changes in syndromic and non-syndromic craniosynostosis would be valuable.

OBJECTIVE: To evaluate longitudinal changes in peripapillary vessel density (VD) following coronavirus disease 2019 (COVID-19) using optical coherence tomography angiography.
METHODS: As part of a prospective longitudinal observational study, we studied healthy individuals with a history of mild COVID-19 confirmed via real-time polymerase chain reaction. After recovery, we used the Optovue RTVue XR Avanti machine to perform optic nerve head (ONH) imaging. We also assessed the VD of all vessels and of small vessels in the disc and the radial peripapillary capillary (RPC) network at 1 and 3 months post-recovery.
RESULTS: We included 17 patients (34 eyes; mean age: 36.9 ± 10.2 years, range: 24-62 years) who had recovered from COVID-19. No changes were observed in the ONH parameters. However, there was a noticeable trend of increased small vessel VD values in the RPC. These increases were significant for the peripapillary whole, superior hemifield, inferior-temporal, temporal-superior, and superior-temporal small vessels. Moreover, the evaluation of all vessel VD values in the RPC revealed a significant decrease in the inside disc and a significant increase in a grid-based inferior region.
CONCLUSIONS: COVID-19 may affect VD of the RPC in the ONH, and should be considered in ONH evaluations.

UNASSIGNED: Targeted drug delivery to the optic nerve head may be useful in the preclinical study and later clinical management of optic neuropathies, however, there are no FDA-approved drug delivery systems to achieve this. The purpose of this work was to develop an optic nerve head drug delivery technique.
UNASSIGNED: Different strategies to approach the optic nerve head were investigated, including standard intravitreal and retroorbital injections. A novel SupraChoroidal-to-Optic-NervE (SCONE) delivery was optimized by creating a sclerotomy and introducing a catheter into the suprachoroidal space. Under direct visualization, the catheter was guided to the optic nerve head. India ink was injected. The suprachoroidal approach was performed in New Zealand White rabbit eyes in vivo (25 animals total). Parameters, including microneedle size and design, catheter design, and catheter tip angle, were optimized ex vivo and in vivo.
UNASSIGNED: Out of the candidate optic nerve head approaches, intravitreal, retroorbital, and suprachoroidal approaches were able to localize India ink to within 2 mm of the optic nerve. The suprachoroidal approach was further investigated, and after optimization, was able to deposit India ink directly within the optic nerve head in up to 80% of attempts. In eyes with successful SCONE delivery, latency and amplitude of visual evoked potentials was not different than the naïve untreated eye.
UNASSIGNED: SCONE delivery can be used for targeted drug delivery to the optic nerve head of rabbits without measurable toxicity measured anatomically or functionally. Successful development of this system may yield novel opportunities to study optic nerve head-specific drug delivery in animal models, and paradigm-shifting management strategies for treating optic neuropathies.
UNASSIGNED: Here we demonstrate data on a new method for targeted delivery to the optic nerve head, addressing a significant unmet need in therapeutics for optic neuropathies.

OBJECTIVE: To study the effect of brimonidine on vascular density and flow index of optic nerve head (ONH) and macula in primary open angle glaucoma (POAG) using optical coherence tomography angiography (OCTA).
METHODS: Twenty-three brimonidine-naïve POAG patients were started on brimonidine. They underwent OCTA ONH and macula before commencing brimonidine and one month thereafter. Systemic arterial blood pressure (SABP) and intraocular pressure (IOP) were measured at each visit to calculate mean ocular perfusion pressure (MOPP). The OCT angiograms were analyzed using ImageJ software to calculate ONH and macular flow indices.
RESULTS: Thirty-seven eyes (23 patients) with a mean age of 56.7 ± 12.49 years were included of whom 60.8% were males. Brimonidine was associated with an increase in the superficial flow index (SFI) (P-value = 0.02) and optic nerve head flow index (ONHFI) (P-value = 0.01). Also, superficial vascular density (SVD) for whole image, superior-hemi and fovea increased (P-value = 0.03, 0.02, 0.03 respectively). ONH inferior-hemi vascular density decreased (P-value = 0.01) despite an increase in inferior quadrant retinal nerve fiber layer thickness (RNFLT) (P-value = 0.03). There was no statistically significant correlation between flow indices and MOPP at baseline and follow-up. A moderate negative correlation was found between SVD and DVD at the fovea and MOPP at baseline and follow-up (P-value = 0.03, 0.05) (P-value = 0.02, 0.01) respectively.
CONCLUSIONS: Brimonidine was associated with an increase in SFI, ONHFI and SVD indicating improved GCC and RNFL perfusion in POAG. Despite the increase in inferior quadrant RNFLT, the concomitant decrease in inferior-hemi ONHVD precluded a conclusion of hemodynamically-mediated improvement of RNFLT.

A spayed, 8-year-old female Poodle, weighing 5.7 kg, was presented with the chief complaint of vision impairment. Vision assessment, including pupillary light reflexes, menace response, dazzle reflex, and maze navigation in photopic and scotopic circumstances, revealed a negative response in both eyes except for positive direct pupillary light reflex in the right eye and positive consensual pupillary light reflex from the right eye to the left eye. Systemic evaluation, including neurologic status, blood profile, and thoracic radiographs, did not reveal any abnormalities. Complete ophthalmic examinations, ocular ultrasonography, and electroretinography did not identify a cause of blindness. Upon funduscopy, the left eye exhibited an increased optic disk diameter, blurred optic disk borders, and loss of the physiologic pit, as well as an increase in vascular tortuosity. In the right eye, there were multifocal depigmented areas in the non-tapetal fundus and several pigmented spots surrounded by a region of dull tapetal reflection in the tapetal fundus. The optical coherence tomography revealed severe anterior deformation of the optic nerve head and Bruch\'s membrane in the peripapillary region of the left eye. Magnetic resonance imaging revealed an irregular, broad-based suprasellar mass, with features suggestive of intracranial hypertension, including dorsal displacement of third ventricles, a rightward shift of the falx cerebri, trans-tentorial herniation, perilesional edema, flattening/protrusion of the posterior sclera, and lager optic nerve sheath diameter in left side than right side. This is the first comprehensive report that describes unilateral papilledema in a dog with a brain tumor, using advanced ophthalmic and neuro-imaging modalities.

BACKGROUND: Inherited primary open-angle glaucoma (POAG) in Beagle dogs is a well-established large animal model of glaucoma and is caused by a G661R missense mutation in the ADAMTS10 gene. Using this model, the study describes early clinical disease markers for canine glaucoma.
METHODS: Spectral-domain optical coherence tomography (SD-OCT) was used to assess nine adult, ADAMTS10-mutant (median age 45.6 months, range 28.8-52.8 months; mean diurnal intraocular pressure (IOP): 29.9 +/- SEM 0.44 mmHg) and three related age-matched control Beagles (mean diurnal IOP: 18.0 +/- SEM 0.53 mmHg).
RESULTS: Of all the optic nerve head (ONH) parameters evaluated, the loss of myelin peak height in the horizontal plane was most significant (from 154 +/- SEM 38.4 μm to 9.3 +/- SEM 22.1 μm; p < 0.01). There was a strong significant negative correlation between myelin peak height and IOP (Spearman correlation: -0.78; p < 0.003). There were no significant differences in the thickness of any retinal layers evaluated.
CONCLUSIONS: SD-OCT is a useful tool to detect early glaucomatous damage to the ONH in dogs before vision loss. Loss in myelin peak height without inner retinal thinning was identified as an early clinical disease marker. This suggests that initial degenerative changes are mostly due to the loss of myelin.

The optic nerve head (ONH) is a complex structure wherein the axons of the retinal ganglion cells extrude from the eyeball through three openings: 1) the Bruch\'s membrane opening (BMO) in the retinal layer, 2) the anterior scleral canal opening in the anterior scleral layer, and 3) the lamina cribrosa (LC). Eyeball expansion during growth induces an offset among openings, since the expansion affects the inner retinal and outer scleral layers differently: the posterior polar retinal structure is preserved by the preferential growth in the equatorial region, whereas no such regional difference is observed in the scleral layer. The various modes and extents of eyeball expansion result in diverse directionality and amount of offset among openings, which causes diverse ONH morphology in adults, especially in myopia. In this review, we summarize the ONH changes that occur during myopic axial elongation. These changes were observed prospectively in our previous studies, wherein LC shift and subsequent offset from the BMO center could be predicted by tracing the central retinal vascular trunk position. This offset induces the formation of γ-zone parapapillary atrophy or externally oblique border tissue. As a presumptive site of glaucomatous damage, the LC/BMO offset may render the LC pores in the opposite direction more vulnerable. To support such speculation, we also summarize the relationship between LC/BMO offset and glaucomatous damage. Indeed, LC/BMO offset is not only the cause of diverse ONH morphology in adults, but is also, potentially, an important clinical marker for assessment of glaucoma.

OBJECTIVE: To investigate the diagnostic ability of retinal superficial vasculature evaluation by optic coherence tomography angiography (OCTA) combined with visual field (VF) testing for early primary open-angle glaucoma (POAG).
METHODS: In this cross-sectional study, 84 participants were included, including 11 in the ocular hypertension (OHT) group, 11 in the preperimetric POAG (pre-POAG) group, 29 in the early POAG group and 33 in the control group. All participants underwent 6 × 6 mm2 scans of macula and optic nerved head by optic coherence tomography (OCT) and OCTA, along with white-on-white and blue-on-yellow VF testing by static automated perimetry. The ability of diagnosing early glaucoma by either various examinations separately or combination of examinations in both terms of function and structure was studied using the receiver operating characteristic (ROC) curve and the area under the curve (AUC).
RESULTS: The superficial retinal vessel densities (VD) in peri-nasal, para-temporal, peri-temporal and peri-inferior regions around the macula, as well as vessel area densities (VAD) in all peripapillary regions, were significantly different among the four groups, with lower VD or VAD in the early POAG patients compared to the normal individuals. The diagnostic ability of peripapillary superficial retinal VAD alone or VF testing alone was limited for early POAG only. However, the combination of these two was more effective in distinguishing normal individuals from OHT subjects or pre-POAG patients without VF defects, with better performance than the combination of peripapillary retinal nerve fiber layer (RNFL) thickness and VF indicators.
CONCLUSIONS: Peripapillary retinal vessel densities were generally lower in early POAG patients compared to normal individuals. The combination of peripapillary superficial retinal VAD by OCTA with white-on-white VF testing improved the ability to distinguish POAG patients at early stage without function impairment, which may help in providing reference and guidance for the following-up and treatment of suspected POAG patients.