Five-year changes in retinal nerve fibre layer thickness in the adult population: a population-based cohort study.

CLINICAL RELEVANCE: Distinguishing between the pathological thinning of the retinal nerve fibre layer (RNFL) and age-related reduction requires a comprehensive understanding of the longitudinal changes in RNFL thickness within a healthy population. BACKGROUND: To determine five-year changes in RNFL thickness and associated factors in people aged 45-69 years. METHODS: This report pertains to the second and third phases of the Shahroud Eye Cohort Study. Participants were recruited by a multi-stage cluster sampling in Shahroud, Iran. Data on demographic details, visual acuity, non-cycloplegic refraction, and slit-lamp biomicroscopy were collected. High-definition optical coherence tomography was employed for retinal imaging. RESULTS: A total of 1,524 eyes from 908 participants were examined. The average RNFL thickness was 92.2 ± 8.5 (95% CI: 91.6 to 92.8) and 93.1 ± 8.7 µm (95% CI: 92.5 to 93.7) in the first and second phases with a five-year mean change of 0.95 ± 4.15 µm (95% CI: 0.70 to 1.20). The RNFL thickness mean changes in the superior, inferior, nasal, and temporal quadrants were 2.51 ± 7.86 (95% CI: 2.01 to 3.02), 2.93 ± 7.39 (95% CI: 2.56 to 3.29), -0.53 ± 6.15 (95% CI: -0.84 to -0.21), and -1.01 ± 4.67 µm (95% CI: -1.27 to -0.75), respectively. The five-year changes in average RNFL thickness were inversely correlated with axial length (ß = -0.69, p < 0.001), mean keratometry (ß = -0.37, p = 0.017), and baseline RNFL thickness (ß = -0.617, p < 0.001). In hyperopic individuals, the increase in average RNFL thickness (ß = 0.65, p = 0.012) was significantly greater than in those with emmetropia. Macular volume (ß = 1.65, p < 0.001) showed a direct association with five-year changes in average RNFL thickness. CONCLUSION: Over 5 years, RNFL thickness changes were clinically insignificant in the normal population. The mean RNFL thickness seems to remain stable unless there is ocular disease. However, increased axial length and steeper keratometric readings were linked to RNFL thinning. Those with thicker RNFL measurements were at higher risk of thinning over time.

Applicability of ISNT rule to retinal nerve fiber layer thickness by SD-OCT in normal subjects.

Aim: The usefulness of the Inferior>Superior>Nasal>Temporal (ISNT) rule for the neuroretinal rim (NRR) has been widely used in differentiating normal eyes from glaucoma, but only a few studies have assessed whether this classical ISNT rule applies to the retinal nerve fibre layer (RNFL). This study aimed to determine the applicability of the ISNT rule for the peripapillary RNFL thickness in normal eyes using Spectral Domain Optical Coherence Tomography (SD-OCT) and assess if variants of the ISNT rule apply. Methods: A cross-sectional study was conducted on 120 eyes of 62 healthy subjects who fulfilled the study criteria. Peripapillary RNFL thickness was measured by OCT scan and each eye's global, superior, temporal, nasal, and inferior quadrant thickness was noted. The values obtained were analyzed to determine the percentage of eyes obeying the ISNT rule and its variants. Results: The ISNT rule for RNFL thickness was applicable for normal subjects in only 53.33% of cases. Removing the nasal quadrant from analysis increased the number of eyes obeying the IST rule to 71.66%. Further exclusion of the temporal quadrant showed almost the same results (75%) for the IS rule. Conclusion: The ISNT rule for RNFL thickness could be validated in only 53.33% of normal individuals. Though documented as useful for NRR during ophthalmoscopy in glaucoma diagnosis, the ISNT rule did not apply to the quadrant values on RNFL on SD-OCT examination.

Nicotine acute impact on RNFL: a comparative analysis of smoking cessation aids including nicotine gum and electronic cigarettes.

PURPOSE: To investigate the immediate impact of nicotine consumption on Retinal Nerve Fiber Layer (RNFL) thickness in healthy young individuals, comparing nicotine gum and electronic cigarette (vaping) as delivery methods. MATERIALS AND METHODS: Twenty participants underwent RNFL measurements at baseline, 30, and 60 minutes after consuming 4 mg of nicotine, based on product labeling and specifications. Measurements were obtained using optical coherence tomography (OCT) (Topcon 3D OCT-1 Maestro System). Nicotine was delivered through either nicotine gum or vaping. RESULTS: Both nicotine gum and vaping led to a statistically significant increase in RNFL thickness, with no significant difference between the two methods. The analysis revealed that area, time, and visit factors significantly affected RNFL scores. Stratification by smoking type (tobacco, vaping, dual) demonstrated significant effects for area, time, and visit factors, with an interaction effect among these factors. CONCLUSIONS: The findings highlight the acute impact of nicotine intake on RNFL thickness in young healthy smokers. Researchers and clinicians should account for recent nicotine exposure when evaluating RNFL thickness, particularly within the first hour post-smoking. The observed significant effects warrant further research, especially in older or health-compromised populations, to improve clinical protocols and diagnostic evaluations across different demographics.

Clinical follow-up investigation on thickness changes in the peripapillary retinal nerve fibre layer of patients with Leber hereditary optic neuropathy.

BACKGROUND: To investigate the peripapillary retinal nerve fibre layer (RNFL) thickness changes and analyse factors associated with visual recovery of G11778A Leber hereditary optic neuropathy (LHON) patients. METHODS: Patients diagnosed with G11778A LHON between July 2017 and December 2020 in Tongji hospital were included in this follow-up study. Patients were grouped according to disease duration. Variations in the RNFL thickness in each quadrant at different disease stages were characterised using optical coherence tomography. According to the absence or presence of significant visual acuity improvements, LHON patients of disease duration ≥ 6 months were divided into two groups. A bivariate logistic regression model was constructed to analyse the potential factors associated with spontaneous visual recovery. RESULTS: This study included 56 G11778A LHON patients (112 eyes) and 25 healthy controls (50 eyes), with a mean follow-up of 5.25 ± 1.42 months. All quadrants and mean RNFL thicknesses of LHON patients first increased and then decreased, except for the temporal RNFL. As the disease progressed, RNFL thinning slowed; however, gradual RNFL thinning occurred. Logistic regression revealed that baseline best corrected visual acuity was related to spontaneous visual recovery of LHON patients with disease duration ≥ 6 months. CONCLUSION: The pattern of RNFL involvement could be helpful in the differential diagnosis of LHON and other optic neuropathies. LHON patients with better vision are more likely to experience some degree of spontaneous visual acuity recovery after the subacute phase.

[Ophthalmological traits in older adult and risk of Alzheimer's disease: results from a French geriatric cohort]. / Caractéristiques ophtalmologiques chez la personne âgée et risque de maladie d'Alzheimer : résultats d'une cohorte française gériatrique.

Ophthalmological changes have been reported in Alzheimer's patients. Our objectives were to determine whether: i) GCC (ganglion cell complex) and RNFL (retinal nerve fibre layer) thickness were associated with different stages of AD (i.e., no AD, prodromal AD, dementia-stage AD), and ii) GCC and RNFL thickness predicted disease progression in older non-demented patients with subjective memory complaints followed for four years. Ninety-one French older community-dwellers with memory complaint and without open-angle glaucoma or age-related macular degeneration (mean, 71.60 ± 4,73 years; 44% women) from the GAIT study underwent examination with HD-OCT, measuring the thickness of the macula, the macular GCC and the RNFL. They also had a complete cognitive diagnosis (i.e., cognitively healthy, prodromal AD, or dementia AD), and a cognitive follow-up 4 years later looking for a possible conversion. Age, sex, body mass index (BMI), number of comorbidities, and Instrumental activities of daily living (IADL) score were considered as potential confounders. At baseline, 37 (40.7%) patients were diagnosed as cognitively healthy, 47 (51.6%) as MCI, and 7 (7.7%) as AD. Mean GCC thickness was higher in cognitively healthy patients than in MCI patients (79.23 vs. 76.27 µm, p = 0.023), particularly in the inferior and nasal fields (p = 0.023 and p = 0.005, respectively). This difference was also found between cognitively healthy patients and others (MCI and AD) in the superior, inferior and nasal fields (p = 0.030, p = 0.014 and p = 0.002, respectively). There was no difference in RNFL thickness between the different cognitive statuses. After 4 years of follow-up, 12 patients (70.6%) of the 17 followed had not changed their cognitive status, while 5 (29.4%) had converted to a more advanced stage of AD. There were no significant differences between the two groups in either GCC thickness (p = 0.429) or RNFL thickness (p = 0.286). We found decreased CGG thicknesses in Alzheimer's patients at prodromal and dementia stages, compared with cognitively healthy participants. There was no association between RNFL thickness and cognitive status, nor between CCG or RNFL thicknesses and the risk of progressing to AD stages after 4 years of follow-up.

Correlation of pre-operative and post-operative retinal nerve fibre layer thickness with visual outcome following decompression of pituitary macroadenoma.

OBJECTIVE: To (i) correlate preoperative retinal nerve fibre layer (RNFL) thickness with visual parameters in patients with pituitary macroadenomas. (ii) study the predictive role of preoperative RNFL in visual outcome following surgery for pituitary macroadenomas (iii) correlate change in postoperative RNFL thickness (RNFLT) with visual outcome. METHODS: Preoperative and post-operative RNFL thickness of thirty-three consecutive patients operated for pituitary macro adenoma between June 2022 and May 2023 were measured using Optical Coherence Tomography (OCT) and compared with standard visual examination findings and Magnetic Resonance Imaging (MRI) measurements. RESULTS: A total of 66 eyes of 33 patients who underwent surgical excision of pituitary macro adenoma between June 2022 and May 2023 were studied. The mean age in years of the study group was 44.36 ± 13.77 and both sexes were equally represented (Male: Female = 16:17). RNFL thinning predominantly involved the temporal (51.21+/-15.19 µm) followed by nasal quadrants (62.67+/- 17.03 µm) and correlated well with the visual field (VF) deficit (p <0.001). Patients with severe disc pallor had extremely thin RNFL (less than 67 +/- 8.68 µm). Patients with moderate to severe visual acuity (VA) deficits had significantly thinner RNFLs (65.08±7.09) compared to patients with normal to mild impairment in vision. (83.185±1.2) (p<0.05). RNFL values were significantly thinner for patients with Wilson Grade C, D and E tumours (66.13 ±12.19 µm) compared to those in Grade A and B (77.67±22.12 µm). The mean preop RNFL of patients who showed post-operative improvement in vision was 87.025± 15.02 µm, of patients in whom vision remained static was 74.58 ±18.31 µm. The mean VA (Decimal) increased from a minimum of 0.60 at the pre-operative timepoint to a maximum of 0.68 at the post-operative timepoint. (Wilcoxon Test: V = 42.5, p = <0.001). The mean RNFLT (µm) increased from 77.14 µm at the pre-operative timepoint to 83.77 µm at the post-operative timepoint. (Wilcoxon Test: V = 218.0, p = <0.001). The mean change of RNFL in patients in whom vision improved was 3.6 µm and the mean change of RNFL in patients in whom vision remained static was 9.51 µm. Absence of postoperative visual improvement was noted despite postoperative RNFL thickness improvement in eyes which showed significant preoperative thinning of the nasal (<65 µm) and temporal (<52µm) quadrants. CONCLUSION: RNFL thinning corelates directly with visual acuity, visual field, and optic disc pallor. Patients with pituitary adenoma have preferential thinning of temporal and nasal quadrants. Visual outcome is better in patients with preserved RNFLT of values more than 82 +/- 5 µm. Reversal of RNFL thinning postoperatively need not necessarily correlate with visual improvement especially in patients who showed significant preoperative thinning of nasal and temporal quadrants.

Characteristic deviations of the optic disc and macula in optic nerve hypoplasia based on OCT.

PURPOSE: The purpose of this study was to evaluate the optic disc and macula in a large cohort of patients with different severity of optic nerve hypoplasia (ONH) using high-resolution spectral domain optical coherence tomography (SD-OCT). METHODS: In total, 36 patients (52 ONH eyes and 17 fellow eyes in unilateral cases) and 45 healthy right eyes from 45 controls were evaluated. All patients underwent an examination to confirm the diagnosis. SD-OCT images of the disc and macula were obtained and analysed both quantitatively and qualitatively. RESULTS: OCT in ONH eyes demonstrated a shorter disc diameter (1061 ± 375 µm vs. 1751 ± 221 µm, p < 0.001), shallower mean cup depth (427 ± 171 µm vs. 551 ± 152 µm, p = 0.01), thinner ganglion cell complex (GCC) perifoveally (47.3 ± 13.0 µm, 60.8 ± 6.0 µm, p < 0.001) and reduced foveal depth (61 ± 36 µm, 119 ± 19 µm, p < 0.001) compared to control eyes. Qualitative analysis showed that 1/3rd of ONH eyes lacked signs of an optic cup, and 2/3rd had reduced or no sign of a foveal pit. Fellow eyes had shorter disc diameter (1446 ± 404 µm vs. 1751 ± 221 µm, p = 0.004) and reduced foveal depth (93 ± 27 µm vs. 119 ± 19 µm, p < 0.001) but similar GCC thickness (60.8 ± 7.1 µm vs. 60.8 ± 6.0 µm, p = 0.738) compared to controls. Disc diameter showed the best correlation with visual acuity in ONH eyes (ρ = 0.517, p < 0.001). CONCLUSION: ONH eyes have reduced GCC thickness and reduced or no foveal pit. Fellow eyes in presumed unilateral cases have a smaller disc diameter and reduced foveal depth compared to controls, suggesting the possibility of subclinical/mild disease. However, GCC thickness was normal. The correlation between structure and visual function is not always straightforward.

The structure-function relationship between multifocal pupil perimetry and retinal nerve fibre layer in glaucoma.

BACKGROUND: Multifocal pupillographic objective perimetry (mfPOP) is a novel method for assessing functional change in diseases like glaucoma. Previous research has suggested that, in contrast to the pretectally-mediated melanopsin response of intrinsically photosensitive retinal ganglion cells, mfPOP responses to transient onset stimuli involve the extrastriate cortex, and thus the main visual pathway. We therefore investigate the correlation between peripapillary retinal nerve fibre layer (pRNFL) thickness and glaucomatous visual field changes detected using mfPOP. Parallel analyses are undertaken using white on white standard automated perimetry (SAP) for comparison. METHODS: Twenty-five glaucoma patients and 24 normal subjects were tested using SAP, 3 mfPOP variants, and optical coherence tomography (OCT). Arcuate clusters of the SAP and mfPOP deviations were weighted according to their contribution to published arcuate divisions of the retinal nerve fibre layer. Structure-function correlation coefficients (r) were computed between pRNFL clock-hour sector thickness measurements, and the local visual field sensitivities from both SAP and mfPOP. RESULTS: The strongest correlation was observed in the superior-superotemporal disc sector in patients with worst eye SAP MD < -12 dB: r = 0.93 for the mfPOP LumBal test (p < 0.001). Correlations across all disc-sectors were strongest in these same patients in both SAP and mfPOP: SAP r = 0.54, mfPOP LumBal r = 0.55 (p < 0.001). In patients with SAP MD ≥ -6 dB in both eyes, SAP correlations across all sectors were higher than mfPOP; mfPOP correlations however, were higher than SAP in more advanced disease, and in normal subjects. CONCLUSIONS: For both methods the largest correlations with pRNFL thickness corresponded to the inferior nasal field of more severely damaged eyes. Head-to-head comparison of mfPOP and SAP showed similar structure-function relationships. This agrees with our recent reports that mfPOP primarily stimulates the cortical drive to the pupils.

Changes in peripapillary retinal nerve fibre layer and ocular parameters in acute anterior uveitis.

CLINICAL RELEVANCE: Acute anterior uveitis (AAU) can lead to the thickening of the peripapillary retinal nerve fibre layer (pRNFL) and induce refractive changes during its active phase. BACKGROUND: AAU is a common form of uveitis characterised by inflammation in the anterior chamber. A notable prevalence of optical coherence tomography - defined pRNFL thickening was observed among patients with AAU. The alterations in pRNFL thickness and their associations with other relevant ocular parameters in patients with AAU were investigated. METHODS: A retrospective, consecutive case series was conducted at a specialised uveitis referral clinic in Taiwan. This study gathered data on various demographic characteristics and various ocular parameters, namely anterior chamber cell grading, refractive error, best-corrected visual acuity, intraocular pressure, and optical coherence tomography measurements. A comparative analysis of baseline and subsequent follow-up data was conducted. Additionally, this study examined the correlations between alterations in pRNFL thickness and various ocular parameters. Twenty-one patients with AAU (21 affected eyes/21 unaffected eyes) were examined. RESULTS: Initial measurements revealed pRNFL thickening in 20 patients. Treatment led to significant improvements in best-corrected visual acuity, intraocular pressure recovery, and pRNFL thickening (p < 0.01). The correlation between changes in pRNFL thickness and best-corrected visual acuity was weak (r = 0.20, p = 0.41). By contrast, a significant negative correlation was identified between changes in pRNFL thickness and refractive error alterations (r = -0.71, p = 0.01). CONCLUSION: This study demonstrated that AAU is associated with pRNFL thickening, which in turn is inversely correlated with changes in refractive error alterations throughout the disease course. Monitoring changes in pRNFL thickness can be effective in assessing ocular inflammation status.

Comparing Intraocular Pressure, Ocular Blood Flow, and Retinal Nerve Fiber Layer Thickness in Early and Chronic Hypertensives With Normotensives.

PURPOSE: To compare blood pressure (BP), intraocular pressure (IOP), ophthalmic artery flow (OAF) velocity, retinal nerve fiber layer (RNFL) thickness, and visual fields in newly diagnosed hypertension (HT) patients (before treatment), chronic HT (on antihypertensive medications >5 years) and normotensives. METHODS: A prospective, cross-sectional study at a tertiary care centre in India. Three groups of 45 patients each: group 1 - early HT, group 2 - chronic HT, and Group 3 - normotensives, underwent evaluation of BP, IOP by Goldmann applanation tonometry (GAT), OAF velocity by transcranial doppler (TCD), RNFL analysis by spectral-domain optical coherence tomography (SD-OCT), and visual fields. RESULTS: The BP was highest in early HT > chronic HT > normotensives (p < 0.001). The IOP of early HT, chronic HT, and normotensives were 15.87 ± 2.19 mmHg, 13.47 ± 1.92 mmHg, and 15.67 ± SD 1.75 mmHg (p < 0.001). The OAF velocity [peak systolic velocity (PSV), end-diastolic velocity (EDV) in cm/sec] was lowest in chronic HT (30.80 ± 7.05, 8.58 ± 1.58) < early HT (35.47 ± 5.34, 10.02 ± 1.74) < normotensives (36.29 ± 4.43, 10.44 ± 2.29), (p < 0.001). The average RNFL thickness was significantly lower in chronic HT (p = 0.022). The PSV, EDV, and MFV showed significant correlation with IOP (r = 0.247, p = 0.004; r = 0.206, p = 0.016; r = 0.266, p = 0.002) and average RNFL thickness (r = 0.309, p= <0.001; r = 0.277, p = 0.001; r = 0.341, p < 0.001). CONCLUSIONS: Patients with chronic HT demonstrated the lowest retrobulbar flows, IOP and lower RNFL measurements. Lower ocular perfusion may be associated with lower IOP and may be a risk factor for end-organ damage (RNFL) independent of IOP.

Impaired brachial flow-mediated dilation may predict choroidal and retinal nerve fibre layer thickness changes in people with obesity.

CLINICAL RELEVANCE: Choroidal thickness and peripapillary retinal nerve fibre layer (RNFL) changes are known to occur in obesity. Endothelial dysfunction and systemic atherosclerosis may play a role in the pathophysiology of these differences. BACKGROUND: Flow-mediated dilation (FMD) is reduced in patients with endothelial dysfunction, and the ankle-brachial index is a surrogate marker for atherosclerosis. This study was conducted to examine the relationship between systemic vascular parameters (FMD, and ankle-brachial index), subfoveal choroidal thickness, and peripapillary RNFL thickness in obese individuals. METHODS: This observational, cross-sectional study involved 108 total participants who were divided into two groups. One group consisted of 54 obese subjects who each had a body mass index of 30 kg/m2 or more. The other control group contained 54 participants who each had a body mass index of 25 kg/m2 or less but higher than 20 kg/m2 . For each participant, only one eye was examined in this study. Subfoveal choroidal thickness, RNFL thickness, ankle-brachial index, and ultrasound measurement of the brachial artery FMD were performed. FMD was categorised according to receiver operating characteristic analysis, and endothelial dysfunction was defined as an FMD ≤ 7.29%. RESULTS: Subfoveal choroidal and RNFL thicknesses in the temporal quadrant were significantly lower in the obese group (p < 0.05). Lower mean values of subfoveal choroidal and RNFL thicknesses in the temporal and inferior quadrants were observed in subjects with an FMD ≤ 7.29% (p < 0.05). In people with obesity, FMD was positively correlated with subfoveal choroidal thickness (r = 0.322, p = 0.001), inferior RNFL thickness (r = 0.259, p = 0.007), and temporal RNFL thickness (r = 0.297, p = 0.002). However, the ankle-brachial index was not correlated with obesity. CONCLUSIONS: Impaired FMD was associated with reduced subfoveal choroidal and RNFL thicknesses in the temporal and inferior quadrants of people with obesity.

Recent advances in the use of optical coherence tomography in neuro-ophthalmology: A review.

Optical coherence tomography (OCT) is an in vivo imaging modality that provides non-invasive, high resolution and fast cross-sectional images of the optic nerve head, retina and choroid. OCT angiography (OCTA) is an emerging tool. It is a non-invasive, dye-free imaging approach of visualising the microvasculature of the retina and choroid by employing motion contrast imaging for blood flow detection and is gradually receiving attention for its potential roles in various neuro-ophthalmic and retinal conditions. We will review the clinical utility of the OCT in the management of various common neuro-ophthalmic and neurological disorders. We also review some of the OCTA research findings in these conditions. Finally, we will discuss the limitations of OCT as well as introduce other emerging technologies.

Long-term functional and structural outcomes in patients with primary congenital glaucoma-A Danish nationwide study.

PURPOSE: Evaluation of long-term functional and structural outcomes in patients with primary congenital glaucoma (PCG) based on visual acuity (VA), visual field (VF) using standard automated perimetry, and peripapillary retinal nerve fibre layer thickness (pRNFL). METHODS: We retrospectively reviewed medical records of all patients diagnosed with PCG in Denmark from 1977 to 2016. Severe vision loss was defined as VA <6/60 and/or VF >20 decibels (dB). Prognostic factors were evaluated in a correlation matrix. RESULTS: The median age of the 94 patients (153 PCG eyes) was 12 years (IQR 9-16). In PCG eyes 62% had VA ≥6/18 but 22% had <6/60. VA in the better seeing eye was ≥6/18 in 90% and <6/60 in 5%. VF was measured in 59 PCG eyes and the median mean defect was 5.1 dB (IQR 2.1-9.6) with 52% better than 6 dB and 9% worse than 20 dB. Generalized pRNFL was reduced below the age-expected 1st percentile in 29% of the 58 PCG eyes where pRNFL was measured. Poor VA, poor VF and reduced pRNFL were all correlated (p = 0.0001). More surgeries (p < 0.0001) and longer diagnostic delay (p = 0.004) were associated with poorer vision and to a lesser degree with poor VF pRNFL. CONCLUSION: In Denmark, most patients with bilateral PCG retain VA ≥6/18 in the better seeing eye. Poor VA was associated with poor VF. Longer diagnostic delay and more surgeries were associated with a poorer prognosis.

Genetic risk of glaucoma is associated with vascular and retinal nerve fibre wedge defects.

PURPOSE: To evaluate the association between localised vascular and retinal nerve fibre layer (RNFL) loss and genetic risk for glaucoma and cardiovascular disease using polygenic risk scores (PRS). METHODS: 858 eyes were included from 455 individuals with suspect and early manifest primary open angle glaucoma. Eyes were characterised as having localised vascular and/or RNFL wedge-shaped defects by scrutiny of optical coherence tomography angiography (OCTA) and OCT images, respectively. Investigations included associations with pre-established scores for genetic risk of glaucoma and cardiovascular disease in the context of glaucoma risk factors and systemic vascular disease outcomes. RESULTS: Higher genetic risk for glaucoma was associated with both vascular wedge defects and RNFL defects (p < 0.001 and p = 0.020, respectively). A greater genetic risk of glaucoma was associated with the presence of multiple vascular wedges per eye (p = 0.005). Glaucoma progression based on global RNFL loss was associated with vascular and RNFL wedge defects (p ≤ 0.001 and p = 0.008, respectively). The glaucoma PRS was significantly associated with vascular, but not RNFL, wedge defects after controlling for disc haemorrhage (p = 0.007 and p = 0.070, respectively). Vascular wedge defects were not related to the cardiovascular PRS. CONCLUSION: Individuals with a higher genetic risk of glaucoma based on the PRS were more likely to have retinal vascular defects, as well as structural glaucomatous loss, but this did not relate to systemic cardiovascular risk. This possibly implies a local pathophysiology for the vascular defects in some cases, which may have clinical relevance in the early stages of glaucoma and in individuals at high genetic risk.

Retinal neural tissue and vascular calibres in migraine: the Northern Finland Birth Cohort Eye Study.

PURPOSE: To evaluate the possible effects of migraine on retinal nerve fibre layer (RNFL), ganglion cell-inner plexiform layer (GC-IPL), macular thickness and retinal arteriolar and venular diameters (CRAE, CRVE) in a population-based birth cohort. METHODS: 375 migraineurs and 1489 healthy controls were included in this cross-sectional cohort study. RNFL, GC-IPL and macular thickness parameters were measured by spectral domain optical coherence tomography (OCT), and vascular parameters were measured from fundus photographs. Migraine was determined by a questionnaire and specific features were selected as covariates (gender, smoking status, systolic blood pressure, refraction and diabetes). RESULTS: There were no statistically significant differences between healthy controls and migraineurs in average RNFL (p = 0.123), macular (p = 0.488) or GC-IPL (p = 0.437) thickness. Migraine did not have a significant effect on any of the macular or GC-IPL subfields. For RNFL subfields, only temporal inferior was borderline significantly increased in migraineurs (p = 0.039) in adjusted results. No statistically significant differences were found between study groups on retinal vascular calibres CRAE (p = 0.879), CRVE (p = 0.145) or AVR (p = 0.259). GC-IPL thickness was found to be positively correlated with CRAE and CRVE in both study groups as GC-IPL thickness increased together with the increase in CRAE and CRVE (p-trend < 0.001 in both), and a similar trend was detected with central macular subfield thickness and systolic (p-trend < 0.001) and diastolic (p-trend = 0.010) blood pressure, but only in the control group. CONCLUSION: There were no remarkable differences between migraineurs and healthy controls in retinal vascular or structural parameters in our study.

Evaluation of Retinal Nerve Fibre Layer Thickness and Choroidal Thickness in Parkinson Disease Patients.

To evaluate the retinal nerve fibre layer (RNFL) thickness and choroidal thickness (CT) in Parkinson disease (PD) patients. A comparative cross-sectional, hospital-based study. 39 PD and 39 controls were recruited, who were gender and age matched. Subjects that fulfilled the inclusion criteria underwent optical coherence tomography for evaluation of RNFL thickness and choroidal thickness (CT). There was significant reduction of RNFL thickness in average (adjusted mean 88.87 µm vs. 94.82 µm, P=0.001), superior (adjusted mean 110.08 µm vs. 119.10 µm, P=0.002) and temporal (adjusted mean 63.77 µm vs. 70.36 µm, P=0.004) in PD compared to controls. The central subfoveal CT was significantly thinner in PD compared to controls (adjusted mean 271.13 µm vs. 285.10 µm, P=0.003). In PD group, there was significant weak negative correlation between the duration of PD with average RNFL thickness (r=-0.354, P=0.027), moderate negative correlation between the duration of PD with central subfoveal CT (r=-0.493, P=0.001), and weak negative correlation between the stage of PD with central subfoveal CT (r=-0.380, P=0.017). PD group had significant thinner average, superior and temporal RNFL thickness and CT compared to controls.

Toxic Optic Neuropathy Due to Mercury in Skin Lightening Products.

Mercury has been described as been in daily household items such as soaps, skin-lightening creams (SLC), and topical disinfectants. Mercury exposure can reportedly cause damage to the optic nerve and retina. A 30-year-old Somali woman presented with decreased vision and was found to have bilateral optic atrophy. Neuroimaging and laboratory work-up for nutritional deficiencies, heavy metals, and syphilis were performed. Evaluation revealed normal neuroimaging and laboratory work-up except for elevated serum and urine mercury levels. Mercury levels at the initial blood test was 11.1 ug/L (normal limits < 10.0 ug/L) and was 15.7 ug/L on repeat testing. A 24-h urine test showed elevated mercury at 16 ug/24 h (normal limits < 2 ug/24 h). Evaluation of an unlabelled SLC that she was using showed the presence of mercury. It is worth testing for heavy metals in the work-up of bilateral optic atrophy. Clinicians should consider cosmetic products as a potential source of mercury exposure and recommend discontinuation if mercury is present.

Central macular morphology and optic nerve fibre layer thickness in young adults born premature and screened for retinopathy of prematurity.

PURPOSE: To investigate central retinal morphology and optic retinal nerve fibre layer (RNFL) in prematurely born young adults and compare to term born controls. MATERIALS AND METHODS: The participants were 59 prematurely born individuals, with a birthweight ≤1.500 g, and 44 term born controls, all 25-29 years of age. Visual acuity (VA) and contrast sensitivity (CS) were assessed. The retinal macular thickness, ganglion cell-inner plexiform layer (GC-IPL) thickness and RNFL thickness were assessed with Cirrus optical coherence tomography (OCT). RESULTS: Central macular thickness was increased (mean 26.7 µm) in prematurely born individuals compared to controls. The macular GC-IPL was thinner (mean 3.84 µm), also when excluding those with previous retinopathy of prematurity (ROP) and those with neurological complications. Gestational age at birth and previous treatment of ROP were risk factors for a thicker macula, however, not for reduced GC-IPL. The average peripapillary RNFL was thinner (mean 4.61 µm) in the prematurely born individuals, also when excluding those with previous ROP and/or neurological complications. Within the prematurely born group, treated ROP was correlated with increased average RNFL. Further, both better VA and CS were associated with thinner optic nerve RNFL and thicker average GC-IPL. CONCLUSION: Macular and optic nerve morphology were influenced by premature birth as assessed with OCT in adult individuals. Gestational age at birth and treatment for ROP seemed to affect central macular thickness, and treated ROP affected the peripapillary RNFL. Thus, retinal sequelae remained in adulthood.

Ocular hemodynamics in epileptic children treated with antiepileptic drugs.

PURPOSE: To evaluate the quantitative measurements obtained for vessel density (VD) of the optic nerve head, macula, peripapillary retinal nerve fibre layer (p-RNFL) and total retinal thicknesses (Trt) by optical coherence tomography angiography (OCT-A) and the choroidal vascular structure using an image binarization method in children with epilepsy using three different antiepileptic drugs (AEDs) and to compare these measurements with healthy participants. METHODS: This observational, cross-sectional study included 124 patients divided into 4 groups: Group-1: patients receiving carbamazepine(n = 30), group-2: patients receiving levetiracetam (n = 31), group-3: patients receiving valproic acid (n = 32), and group 4: healthy controls (n = 31).A fully automated microstructural analysis of the VD of the retinal superficial capillary plexus (SCP), deep capillary plexus (DCP), and the choriocapillaris (CC) layers and radial peripapillary capillary, and Trt, p-RNFL thickness were analyzed by using OCT-A. Enhanced depth imaging (EDI)-OCT scans of the macula were obtained and the images were binarized using the ImageJ software. RESULTS: The mean age, gender distribution and the duration of epilepsy were similar in all groups. Evaluation of the p-RNFL thickness and perifoveal Trt between the groups showed a statistically significant difference in all quadrants.The p-RNFL thickness was lower in patients receiving carbamazepine and valproic acid. The lowest values of the luminal area and choroidal vascular index (CVI) were found in patients receiving valproic acid; comparison with matched healthy controls showed statistically significant differences. CONCLUSION: Valproic acid and carbamazepine are associated with thinning of the p-RNFL in epilepsy patients, but the macular and radial peripapillary VD were not affected.However, a reduction of choroidal vascular blood flow was found in epilepsy patients taking valproic acid.

Quantification of retinal ganglion cell loss in patients with homonymous visual field defect due to stroke.

BACKGROUND: To quantify the degree of ganglion cell degeneration through spectral domain optical coherence tomography (SD-OCT) in adult patients with post-stroke homonymous visual field defect. METHODS: Fifty patients with acquired visual field defect due to stroke (mean age = 61 years) and thirty healthy controls (mean age = 58 years) were included. Mean deviation (MD) and pattern standard deviation (PSD), average peripapillary retinal nerve fibre layer thickness (pRNLF-AVG), average ganglion cell complex thickness (GCC-AVG), global loss volume (GLV) and focal loss volume (FLV) were measured. Patients were divided according to the damaged vascular territories (occipital vs. parieto-occipital) and stroke type (ischaemic vs. haemorrhagic). Group analysis was conducted with ANOVA and multiple regressions. RESULTS: pRNFL-AVG was significantly decreased among patients with lesions in parieto-occipital territories compared to controls and to patients with lesions in occipital territories (p = .04), with no differences with respect to stroke type. GCC-AVG, GLV and FLV differed in stroke patients and controls, regardless of stroke type and involved vascular territories. Age and elapsed time from stroke had a significant effect on pRNFL-AVG and GCC-AVG (p < .01), but not on MD and PSD. CONCLUSIONS: Reduction of SD-OCT parameters occurs following both ischaemic and haemorrhagic occipital stroke, but it is larger when the injury extends to parietal territories and increases as time since stroke increases. The size of visual field defect is unrelated to SD-OCT measurements. Macular GCC thinning appeared to be more sensitive than pRNFL in detecting retrograde retinal ganglion cell degeneration and its retinotopic pattern in stroke.