Optical Coherence Tomography Measurements Research Articles

Assessment of the Retinal Ganglion Cell Layer after Uncomplicated Cataract Surgery.

(1) Background: This research aimed to evaluate the changes in ganglion cell layer thickness (GCLT) after uncomplicated cataract surgery in patients without previous ocular pathology and the impact of the appearance of cystoid macular edema on the GCLT and visual acuity. (2) Methods: The evaluation of 174 patients was performed with the indication of uncomplicated cataract surgery. The variables analyzed were demographic data, best-corrected visual acuity (BCVA), cataract type and OCT (Optical Coherence Tomography) measurements of central macular thickness (CMT), and the presence of cysts and GCLT preoperatively and one day, one and three months after surgery. (3) Results: There was a relationship between the postoperative increase in retinal GCLT and BCVA after uncomplicated cataract surgery. The presence of microcysts reduced the thickness of the GCL, which is significantly related to the loss of BCVA. The appearance of cystoid macular edema one month after surgery was also related to the preoperative CMT. There was a statistically significant decrease in preoperative GCL but a statistically significant increase in preoperative CMT in patients with microcysts one-month post-surgery. (4) Conclusions: There is a relationship between postoperative retinal GCLT and BCVA after uncomplicated cataract surgery. The presence of microcysts significantly reduces the thickness of the GCL, which is significantly related to the loss of BCVA.

Optical Coherence Tomography Characteristics for Differentiating Scars in Type 1 (Polypoidal Choroidal Vasculopathy (PCV)) and Type 2 (Classical) Macular Neovascularization (MNV) in Age-Related Macular Degeneration (AMD).

This study aimed to assess the optical coherence tomography (OCT) characteristics for differentiating scars in the scarred stages of macular neovascularization (MNV) in age-related macular degeneration (AMD). Medical records of 20 patients, 10 in each group with type 1 and type 2 MNV, were selected for the study. Participants chosen were above 50 years of age and underwent comprehensive eye examination alongside indocyanine green angiography (ICGA), fundus fluorescence angiography (FFA), and Spectralis optical coherence tomography (SOCT) (Heidelberg Engineering, Germany), respectively. The qualitative and quantitative OCT measurements, such as the frequency of outer retinal tubulations, presence of cystoid spaces, scar area, choroid thickness, retinal thickness, presence of disorganization in retinal layers (DRIL), foveal contour, and involvement of retinal layers in the scar, were meticulously evaluated and compared between the two groups. Significant disparities between type 1 MNV and type 2 MNV in choroidal thickness were identified in the nasal and superior quadrants within 1 mm, in the superior quadrant within 3 mm, and in all quadrants except the inferior quadrant within 6 mm. Overall, type 2 MNV showed thinner choroid than type 1 MNV. Although there are several overlapping features noticed between the groups, the OCT was able to pick up characteristic features that aid in differentiating type 1 (polypoidal choroidal vasculopathy (PCV)) and type 2 (classic) MNV in AMD. This precise differentiation has the potential to assist ophthalmologists in making well-informed decisions, thereby enhancing patient care.

Optical coherence tomography angiography in patients with bipolar disorder and major depressive disorder

BackgroundCerebral microvascular dysfunction is a promising area for research into the pathogenesis of major depressive disorder (MDD) and bipolar disorder (BD). Despite the scientific and clinical potential of studying microvascular dysfunction, progress in this area has long been hampered by the lack of methods to study microvessels intravitally. AimsThe aim of the present study was to search for potential optical coherence tomography (OCT) and OCT-angiography (OCTA) biomarkers of BD and MDD. MethodsOne hundred and five consecutive patients with a current depressive episode were enrolled in the study (39 – BD and 66 – MDD). In addition, forty-one generally healthy subjects were enrolled as a control group. Only the right eye was examined in all subjects. Structural OCT and OCTA scans with signal strength ≥7 were included. ResultsStructural OCT measurements showed no significant differences between the groups. OCTA measurements of foveal avascular zone (FAZ), area and skeleton density showed a decrease in the retinal capillary bed in BD patients, whereas OCTA values in MDD patients did not differ from the control group. Several significant differences were found between the BD and control groups. In the BD group, the FAZ of the deep capillary plexus was increased, reflecting a reduction in capillary perfusion in the central subfield of this plexus. ConclusionsOCTA measurements of FAZ, area and skeleton density showed a decrease in the retinal capillary bed in BD patients, whereas OCTA values in MDD patients did not differ from the control group.

Macular OCT's Proficiency in Identifying Retrochiasmal Visual Pathway Lesions in Multiple Sclerosis-A Pilot Study.

Optical coherence tomography (OCT) is a non-invasive imaging technique based on the principle of low-coherence interferometry that captures detailed images of ocular structures. Multiple sclerosis (MS) is a neurodegenerative disease that can lead to damage of the optic nerve and retina, which can be depicted by OCT. The purpose of this pilot study is to determine whether macular OCT can be used as a biomarker in the detection of retrochiasmal lesions of the visual pathway in MS patients. We conducted a prospective study in which we included 52 MS patients and 27 healthy controls. All participants underwent brain MRI, visual field testing, and OCT evaluation of the thicknesses of the peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell layer (GCL), and macular inner plexiform layer (IPL). OCT measurements were adjusted for optic neuritis (ON). VF demonstrated poor capability to depict a retrochiasmal lesion identified by brain MRI (PPV 0.50). In conclusion, the OCT analysis of the macula appears to excel in identifying retrochiasmal MS lesions compared to VF changes. The alterations in the GCL and IPL demonstrate the most accurate detection of retrochiasmal visual pathway changes in MS patients.

Multiple scattering suppression for in vivo optical coherence tomography measurement using the B-scan-wise multi-focus averaging method.

We demonstrate a method that reduces the noise caused by multi-scattering (MS) photons in an in vivo optical coherence tomography image. This method combines a specially designed image acquisition (i.e., optical coherence tomography scan) scheme and subsequent complex signal processing. For the acquisition, multiple cross-sectional images (frames) are sequentially acquired while the depth position of the focus is altered for each frame by an electrically tunable lens. In the signal processing, the frames are numerically defocus-corrected, and complex averaged. Because of the inconsistency in the MS-photon trajectories among the different electrically tunable lens-induced defocus, this averaging reduces the MS signal. Unlike the previously demonstrated volume-wise multi-focus averaging method, our approach requires the sample to remain stable for only a brief period, approximately 70 ms, thus making it compatible with in vivo imaging. This method was validated using a scattering phantom and in vivo unanesthetized small fish samples, and was found to reduce MS noise even for unanesthetized in vivo measurement.

Artificial Intelligence-Based Disease Activity Monitoring to Personalized Neovascular Age-Related Macular Degeneration Treatment: A Feasibility Study

PurposeTo evaluate the performance of a disease activity (DA) model developed to detect DA in participants with neovascular age-related macular degeneration (nAMD). DesignPost-hoc analysis. ParticipantsPatient dataset from the phase III HAWK and HARRIER (H&H) studies. MethodsAn artificial intelligence (AI)-based DA model was developed to generate a DA score based on measurements of optical coherence tomography (OCT) images and other parameters collected from H&H study participants. DA assessments were classified into three categories based on the extent of agreement between the DA model’s scores and the H&H investigators’ decisions: agreement (“easy”), disagreement (“noisy”), and close to the decision boundary (“difficult”). Then, a panel of 10 international retina specialists (“panelists”) reviewed a sample of DA assessments of these three categories that contributed to the training of the final DA model. A panelists’ majority vote on the reviewed cases was used to evaluate the accuracy, sensitivity, and specificity of the DA model. Main Outcome MeasureThe DA model’s performance in detecting DA compared with the DA assessments made by the investigators and panelists’ majority vote. ResultsA total of 4472 OCT DA assessments were used to develop the model; of these, panelists reviewed 425, categorized as “easy” (17.2%), “noisy” (20.5%), and “difficult” (62.4%). False-positive and false-negative rates of the DA model’s assessments decreased after changing the assessment in some cases reviewed by the panelists and retraining the DA model. Overall, the DA model achieved 80% accuracy. For “easy” cases, the DA model reached 96% accuracy and performed as well as the investigators (96% accuracy) and panelists (90% accuracy). For “noisy” cases, the DA model performed similarly to panelists and outperformed the investigators (84%, 86%, and 16% accuracies, respectively). The DA model also outperformed the investigators for “difficult” cases (74% and 53% accuracies, respectively), but underperformed the panelists (86% accuracy) owing to lower specificity. Subretinal and intraretinal fluids were the main clinical parameters driving the DA assessments made by the panelists. ConclusionsThese results demonstrate the potential of using an AI-based DA model to optimize treatment decisions in the clinical setting and in detecting and monitoring DA in nAMD patients.

Anterior scleral thickness in Marfan syndrome: A quantitative analysis.

To investigate the anterior scleral thickness (AST) in patients with Marfan syndrome (MFS). A prospective, cross-sectional study was conducted at the Department of Ophthalmology, Ghent University Hospital, Ghent, including patients with a genetically confirmed clinical diagnosis of MFS and age-, gender- and axial length-matched controls. Subjects with known corneal, conjunctival or scleral pathology and a history of ocular surgery, including pars plana vitrectomy, recent contact lens use or high-grade astigmatism were excluded. Subjects underwent non-cycloplegic autorefraction, Scheimpflug-based corneal tomography, axial length measurement and spectral-domain optical coherence tomography (OCT). AST was manually measured at 1 mm (AST1), 2 mm (AST2) and 3 mm (AST3) from the scleral spur, temporally and nasally. A total of 56 subjects (28 subjects in the MFS group and 28 matched subjects in the control group) were included in this study. In patients with MFS, AST was significantly reduced compared to matched controls, both overall and at every analysed measuring point in the nasal and temporal areas (p < 0.001). Central corneal thickness (CCT) and mean keratometry (Kmean) values were significantly lower in patients with MFS (p < 0.05). A positive correlation was found between nasal AST and CCT in patients with MFS. No correlation was found between AST and Kmean or between AST and axial length. In patients with MFS with ectopia lentis, compared to those without, temporal AST3 was significantly lower (p < 0.05). AST was significantly lower in patients with MFS harbouring a variant predicted to cause haploinsufficiency compared to those with a variant expected to lead to a dominant negative effect for both nasal and temporal measurements. Based on anterior segment OCT measurements, AST of patients with MFS is significantly lower compared to matched controls.

Wavenumber-dependent dynamic light scattering optical coherence tomography measurements of collective and self-diffusion

We demonstrate wavenumber-dependent DLS-OCT measurements of collective and self-diffusion coefficients in concentrated silica suspensions across a broad q-range, utilizing a custom home-built OCT system. Depending on the sample polydispersity, either the collective or self-diffusion is measured. The measured collective-diffusion coefficient shows excellent agreement with hard-sphere theory and serves as an effective tool for accurately determining particle sizes. We employ the decoupling approximation for simultaneously measuring collective and self-diffusion coefficients, even in sufficiently monodisperse suspensions, using a high-speed Thorlabs OCT system. This enables particle size and volume fraction determination without the necessity of wavenumber-dependent measurements. We derive a relationship between the particle number-based polydispersity index and the ratio of self and collective mode amplitudes in the autocorrelation function and utilize it to measure the particle number-based polydispersity index. Notably, the polydispersity determined in this manner demonstrates improved sensitivity to smaller particle sizes compared to the standard intensity-based DLS cumulant analysis performed on dilute samples.

In-vivo characterization of scleral rigidity in myopic eyes using fundus-pulsation optical coherence elastography

The sclera plays an important role in the structural integrity of the eye. However, as myopia progresses, the elongation of the eyeball exerts stretching forces on the posterior sclera, which typically happens in conjunction with scleral remodeling that causes rigidity loss. These biomechanical alterations can cause localized eyeball deformation and vision impairment. Therefore, monitoring scleral rigidity is clinically important for the management and risk assessment of myopia. In this study, we propose fundus pulsation optical coherence elastography (FP-OCE) to characterize posterior scleral rigidity in living humans. This methodology is based on a choroidal pulsation model, where the scleral rigidity is inversely associated with the choroidal max strain obtained through phase-sensitive optical coherence tomography (PhS-OCT) measurement of choroidal deformation and thickness. Using FP-OCE, we conducted a pilot clinical study to explore the relationship between choroidal strain and myopia severity. The results revealed a significant increase in choroidal max strain in pathologic myopia, indicating a critical threshold beyond which scleral rigidity decreases significantly. Our findings offer a potential new method for monitoring myopia progression and evaluating therapies that alter scleral mechanical properties.

Effect of isoflurane anaesthetic time on ocular a-scan ultrasonography measures and their relationship to age and OCT measures in the Guinea pig

A-scan ultrasonography enables precise measurement of internal ocular structures. Historically, its use has underpinned fundamental studies of eye development and aberrant eye growth in animal models of myopia; however, the procedure typically requires anaesthesia. Since anaesthesia affects intra-ocular pressure (IOP), we investigated changes in internal ocular structures with isoflurane exposure and compared measurements with those taken in awake animals using optical coherence tomography (OCT). Continuous A-scan ultrasonography was undertaken in tri-coloured guinea pigs aged 21 (n = 5), 90 (n = 5) or 160 (n = 5) days while anaesthetised (up to 36 min) with isoflurane (5% in 1.5L/min O2). Peaks were selected from ultrasound traces corresponding to the boundaries of the cornea, crystalline lens, retina, choroid and sclera. OCT scans (Zeiss Cirrus Photo 800) of the posterior eye layers were taken in 28-day-old animals (n = 19) and compared with ultrasound traces, with choroid and scleral thickness adjusted for the duration of anaesthesia based on the changes modelled in 21-day-old animals. Ultrasound traces recorded sequentially in left and right eyes in 14-day-old animals (n = 30) were compared, with each adjusted for anaesthesia duration. The thickness of the cornea was measured in enucleated eyes (n = 5) using OCT following the application of ultrasound gel (up to 20 min). Retinal thickness was the only ultrasound internal measure unaffected by anaesthesia. All other internal distances rapidly changed and were well fitted by exponential functions (either rise-to-max or decay). After 10 and 20 min of anaesthesia, the thickness of the cornea, crystalline lens and sclera increased by 17.1% and 23.3%, 0.4% and 0.6%, and 5.2% and 6.5% respectively, whilst the anterior chamber, vitreous chamber and choroid decreased by 4.4% and 6.1%, 0.7% and 1.1%, and 10.7% and 11.8% respectively. In enucleated eyes, prolonged contact of the cornea with ultrasound gel resulted in an increase in thickness of 9.3% after 10 min, accounting for approximately half of the expansion observed in live animals. At the back of the eye, ultrasound measurements of the thickness of the retina, choroid and sclera were highly correlated with those from posterior segment OCT images (R2 = 0.92, p = 1.2 × 10−13, R2 = 0.55, p = 4.0 × 10−4, R2 = 0.72, p = 5.0 × 10−6 respectively). Furthermore, ultrasound measures for all ocular components were highly correlated in left and right eyes measured sequentially, when each was adjusted for anaesthetic depth. This study shows that the depth of ocular components can change dramatically with anaesthesia. Researchers should therefore be wary of these concomitant effects and should employ adjustments to better render ‘true’ values.

Does a Healthy Weight Body Mass Index at Onset of Idiopathic Intracranial Hypertension Change the Outcomes? A United Kingdom Prospective Cohort Study

ABSTRACT Idiopathic intracranial hypertension (IIH) predominantly affects reproductive-aged females with obesity. However, the prevalence and impact of a healthy weight body mass index (BMI) at disease presentation is not known. This study aimed to evaluate the visual and headache outcomes stratified by the presenting BMI. This was a longitudinal prospective cohort study (IIH Life) based on a tertiary neuro-ophthalmology IIH service, University Hospitals Birmingham NHS Trust, United Kingdom, recruiting consecutive patients living with IIH between 2012 and 2021. Those with a presenting BMI were included. The outcome measures included visual outcomes of LogMAR visual acuity, Humphrey visual field perimetric mean deviation (PMD), optical coherence tomography (OCT) measurements, and headache outcomes of frequency, severity, and Headache Impact Test-6 score. Three hundred seventy-five people with IIH and a documented baseline BMI. About 3.7% of the entire cohort had a healthy weight BMI at IIH presentation and 15.5% BMI < 30 kg/m2. The baseline PMD was worse in patients without obesity; however, OCT papilloedema measures were similar. The presence of obesity was associated with a small but significant greater worsening in visual acuity but slower macular ganglion cell layer loss. There was no impact on PMD or papilloedema prognosis related to baseline obesity. The headache outcomes showed heterogeneity, with worse baseline headache frequency in patients with obesity. No BMI group was associated with worse headache outcomes. Patients with a healthy weight BMI or those without obesity at baseline make up a small proportion of IIH patients. BMI at presentation does not appear to influence long-term visual or headache outcomes.

Histopathological and statistical study of corneal repair in rabbits. A new way to understand corneal recovery.

The study aims to evaluate corneal healing post amniotic membrane transplantation in controlled corneal defects, justifying its application in routine ophthalmology practice. The objective is to establish a reliable method for assessing the repair process. In three groups of six adult New Zealand rabbits, keratectomy and a monolayer transplant of dehydrated human amniotic membrane (AM) were conducted in the left eye (OS) with the right eye (OD) serving as the control eye. Clinical signs were assessed, and both eyes were enucleated at 1, 2, and 4 weeks for optical coherence tomography (OCT) measurements and histological analysis, collecting data from different epithelium, stroma, and limbus regions. This study was conducted using a formula that combines histologic data categorizing their presence and/or type as beneficial for corneal repair. No statistically significant differences were found between the experimental and control eyes regarding all clinical signs and OCT measurements. However, a linear model using histopathological results showed a period-implant mode interaction with statistical significance (p=0.010). The use of the single-layer amniotic membrane resulted in improved corneal recovery with the stromal side showing better performance in the first week and the epithelial side proving to be more effective than the stromal side in the long term. For the first time, a statistical formula employing histopathological data is introduced to determine corneal recovery, potentially offering a more accurate and reliable method compared with the observation of clinical signs and corneal measurements with OCT.

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

ABSTRACT 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.

Trans-Synaptic Degeneration in the Visual Pathway in Patients With Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease.

We aimed to assess the presence of retinal neurodegeneration independent of optic neuritis (ON) in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and to investigate the development of trans-synaptic anterograde degeneration in these patients after ON. Cross-sectional, retrospective study of 34 adult patients with MOGAD and 23 healthy controls (HC). Clinical, optical coherence tomography (OCT), and MRI data were collected. Peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell inner plexiform layer (GCIPL) were obtained using Heidelberg Spectralis. FreeSurfer7 was used to obtain the lateral geniculate nucleus (LGN), occipital volume fractions (to total estimated intracranial volume), and occipital cortical thickness. For the anterior visual pathway, the analysis was conducted using eyes, classified based on the history of ON (Eye-ON and Eye-NON) and compared with Eye-HC. The analysis of OCT and brain volumetric measures was conducted comparing MOGAD-ON, MOGAD-NON, and HC groups. The analysis of covariance with a Bonferroni-adjusted post hoc test was used to test differences between groups and linear regression analysis to evaluate OCT/MRI associations; age and sex were considered as covariates. 24 (70.5%) patients had a prior ON. Median pRNFL and GCIPL thickness (um) was significantly reduced in Eye-ON vs EyeNON and HC (pRNFL: 69.4 (17.3), 89.6 (13.7), 98.2 (11.7), p < 0.001; GCIPL: 55.8 (8.7), 67.39 (8.7), 72.6 (4.5), p < 0.001). pRNFL and GCIPL thickness had a negative correlation with the number of ON episodes (p = 0.025 and p = 0.031, respectively). LGN volume fraction was significantly lower in patients with MOGAD-ON than in HC (0.33 (0.05) vs 0.39 (0.04), p = 0.002). The occipital cortical thickness was lower in MOGAD-ON compared with MOGAD-NON and HC (p = 0.010). In patients with MOGAD-ON, pRNFL correlated with LGN volume (p = 0.006), occipital thickness (p = 0.002), and the medial occipital cortex (p = 0.002), but not the lateral occipital lobe. Compared with HC, MOGAD-ON exhibits reduced retinal thickness, primarily influenced by the presence and the number of prior ON episodes. Moreover, MOGAD-ON demonstrates significant atrophy in the retinal, subcortical, and cortical regions of the visual pathway, distinguishing them from MOGAD-NON and HC. These findings suggest that in patients with MOGAD neurodegeneration is tightly correlated with damage to the involved pathway.

Anatomical Features can Affect OCT Measures Used for Clinical Decisions and Clinical Trial Endpoints.

To understand the association between anatomical parameters of healthy eyes and optical coherence tomography (OCT) circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements. OCT cpRNFL thickness was obtained from 396 healthy eyes in a commercial reference database (RDB). The temporal quadrant (TQ), superior quadrant (SQ), inferior quadrant (IQ), and global (G) cpRNFL thicknesses were analyzed. The commercial OCT devices code these values based on percentiles (red, <1%; yellow, ≥1% and <5%), after taking age and disc area into consideration. Four anatomical parameters were assessed: fovea-to-disc distance, an estimate of axial length, and the locations of the superior and the inferior peaks of the cpRNFL thickness curve. Pearson correlation values were obtained for the parameters and the thickness measures of each of the four cpRNFL regions, and t-tests were performed between the cpRNFL thicknesses coded as abnormal (red or yellow, <5%) versus normal (≥5%). For each of the four anatomical parameters, the correlation with the thickness of one or more of the TQ, SQ, IQ, and G regions exceeded the correlation with age or disc area. All four parameters were significantly (P < 0.001) associated with the abnormal cpRNFL values. The significant parameters were not the same for the different regions; for example, a parameter could be negatively correlated for the TQ but positively correlated with the SQ or IQ. In addition to age and disc area, which are used for inferences in normative databases, four anatomical parameters are associated with cpRNFL thickness. Taking these additional anatomical parameters into consideration should aid diagnostic accuracy.

Comparison of Smartphone and internet addiction and Optical Coherence Tomography findings among University students

IntroductionInternet and smartphone use that reaches the level of addiction often leads to deterioration in the quality of life and functionality of individuals.ObjectivesIn our study, we aimed to investigate possible differences in retinal nerve fiber layer (RNFL) thickness and central macular thickness obtained by optical coherence tomography in internet and smartphone addiction.MethodsA total of 212 volunteer university students participated in our study. All participants were administered the Sociodemographic Information Form, Chen Internet Addiction Scale, Smartphone Addiction Scale-Short Form. Participants who completed the scales underwent routine eye examinations by experienced physicians in the ophthalmology outpatient clinic. Retinal nerve fiber layer (RNFL) thickness and central macular thickness were measured by optical coherence tomography (OCT).ResultsIn our study, internet addiction rate was 17% and smartphone addiction rate was 38.2%. RNFL thickness was found to be statistically significantly increased in the temporal superior and temporal inferior quadrants in those with internet addiction compared to healthy subjects (p&lt;0.05). In smartphone addiction, RNFL thickness was found to be statistically significantly increased in the temporal inferior quadrant compared to healthy subjects (p&lt;0.05). In the analyses comparing OCT measurements according to sex, it was found that nasal inferior (p&lt;0.01) and global (p&lt;0.05) quadrants in women and central macular thickness (p&lt;0.01) in men were statistically significantly increased.The correlation analyses in our study revealed statistically significant positive correlations between internet addiction scale scores (p&lt;0.01) and smartphone addiction scale scores (p&lt;0.01), RNFL temporal superior quadrant thickness (p&lt;0.01); smartphone addiction scale scores and RNFL temporal superior quadrant thickness (p&lt;0.05).ConclusionsInternet and smartphone addiction are seen considerable rates among university students. In OCT measurements, RNFL thickness was found to be increased in various quadrants in patients with addiction. In addition, RNFL thickness was found to be increased in all quadrants in female gender and central macular thickness was found to be increased in male gender. Correlation analysis revealed that internet addiction scale scores, smartphone addiction scale scores, and RNFL temporal superior quadrant thickness were positively correlated. In addition, there was a positive correlation between smartphone addiction scale scores, and RNFL temporal superior quadrant thicknessDisclosure of InterestNone Declared

Early Single-Examination Optical Coherence Tomography Biomarkers for Treatment-Requiring Retinopathy of Prematurity.

Optical coherence tomography (OCT) is an emerging adjunct imaging modality to evaluate retinopathy of prematurity (ROP). From an 11-year research database, we identify early OCT biomarkers that predict treatment-requiring ROP (TR-ROP). For preterm infants with acceptable OCT images at 32 ± 1weeks postmenstrual age (PMA), we extracted the following measures: total retina, inner retinal layer (IRL), and outer retinal layer (ORL) thicknesses at the fovea and the parafovea, inner nuclear layer (INL) and choroidal thickness, parafovea/fovea (P/F) ratio, and presence of macular edema. Using univariable and multivariable logistic regression models, we evaluated the association between retinal and choroidal OCT measurements at 32 ± 1weeks PMA and development of TR-ROP. Of 277 eyes (145 infants) with usable OCT images, 67 eyes had TR-ROP. Lower P/F ratio (P<0.0001), thicker foveal IRL (P=0.0001), and thinner choroid (P=0.03) were associated with TR-ROP in univariable analysis, but lost significance of association when adjusted for gestational age and race. Absence of macular edema was associated with TR-ROP when adjusted for gestational age and race (P=0.01). In 185 eyes without macular edema, P/F ratio was associated with TR-ROP in both univariable analysis (P<0.0001) and multivariable analysis (P=0.02) with adjustment for gestational age and race. Presence of macular edema at 32 ± 1weeks PMA in infants with lower gestational age may be protective against TR-ROP. In infants without macular edema, P/F ratio may be an early OCT biomarker for development of TR-ROP. Incorporation of early OCT biomarkers may be useful in prediction of TR-ROP.

A study of mydriatic effect on intraocular pressure and anterior chamber angle morphology by anterior segment optical coherence tomography

Context Pharmacological mydriasis possibly is associated with intraocular pressure (IOP) rise and anterior chamber angle changes. Hence, this study is focused on pressure analysis with anterior segment optical coherence tomography measurements of angle parameters during various dilation phases. Aims Purpose is to investigate IOP variations during dilation phases and to discover association of anterior segment optical coherence tomography measurements. Settings and design Observational study. Patients and methods Thirty-two participants were recruited and IOP measured by rebound tonometer in pre, mid, and full pupillary dilation phases. Lens vault (LV at horizontal and vertical), angle opening distance (AOD at 500 and 750 μm) and trabecular iris space area (TISA at 500 and 750 μm) in temporal and nasal scans were quantified. Paired t test performed to establish a statistical significance P value less than or equal to 0.05. Statistical analysis used MS Excel. Results A total of 32 participants with mean age of 47.5±10.94 years consisting of 17 (53.13%) males and 15 (46.87%) females with 20 (62.5%) right and 12 (37.5%) left eyes were investigated. Mean IOP in pre, mid, and full-dilation phases were 14.86±2.87, 15.94±2.72, and 15.63±2.69 mmHg. Predilation IOP with IOP in mid and full dilation showed statistical significance (P=0.0001, 95% confidence interval 0.56–1.56) and 0.88 and 0.85 Pearson’s coefficients, respectively. IOP analysis with LV, AOD, and TISA in pre, mid, and full-dilation phases exhibited a significant difference (P&lt;0.0001). Conclusion This research highlights an increase in IOP alongside a noteworthy decrease in the average LV by 30.94 μm during mid-dilation compared to the predilation phase. Likewise, the AOD at 750 μm demonstrated a significant reduction by 0.40 and 0.45 μm in temporal scans during mid and full dilation, respectively, while TISA remained unchanged.

Multispectral Fundus Photography of Choroidal Nevi With Trans-Palpebral Illumination.

The purpose of this study was to investigate the spectral characteristics of choroidal nevi and assess the feasibility of quantifying the basal diameter of choroidal nevi using multispectral fundus images captured with trans-palpebral illumination. The study used a widefield fundus camera with multispectral (625 nm, 780 nm, 850 nm, and 970 nm) trans-palpebral illumination to examine eight subjects diagnosed with choroidal nevi. Geometric features of nevi, including border clarity, overlying drusen, and lesion basal diameter, were characterized. Clinical imagers, including scanning laser ophthalmoscopy (SLO), autofluorescence (AF), and optical coherence tomography (OCT), were utilized for comparative assessment. Fundus images depicted nevi as dark regions with high contrast against the background. Near-infrared (NIR) fundus images provided enhanced visibility of lesion borders compared to visible fundus images and SLO images. Lesion-background contrast measurements revealed 635 nm SLO at 11% and 625 nm fundus at 42%. Significantly enhanced contrasts were observed in NIR fundus images at 780 nm (73%), 850 nm (63%), and 970 nm (67%). For quantifying the diameter of nevi, NIR fundus images at 780 nm and 850 nm yielded a deviation of less than 10% when compared to OCT measurements. NIR fundus photography with trans-palpebral illumination enhances nevi visibility and boundary definition compared to SLO. Agreement in diameter measurements with OCT validates the accuracy and reliability of this method for choroidal nevi assessment. Multispectral fundus imaging with trans-palpebral illumination improves choroidal nevi visibility and accurately measures basal diameter, promising to enhance clinical practices in screening, diagnosis, and monitoring of choroidal nevi.

Myelin Oligodendrocyte Glycoprotein Antibody Disease Optic Neuritis: A Structure-Function Paradox?

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a demyelinating disorder that most commonly presents with optic neuritis (ON) and affects children more often than adults. We report 8 pediatric patients with MOG-associated ON and characterize focal optical coherence tomography (OCT) abnormalities over time that help distinguish this condition from the trajectories of other demyelinating disorders. These OCT findings are examined in the context of longitudinal visual function testing. This is a retrospective case series of 8 pediatric patients with MOG-associated ON who were referred for neuro-ophthalmic evaluation. Longitudinal data for demographics, clinical history, physical examination, and OCT obtained in the course of clinical evaluations were collected through retrospective medical record review. Patients demonstrated acute peripapillary retinal nerve fiber layer (RNFL) thickening in one or both eyes, consistent with optic disc swelling. This was followed by steady patterns of average RNFL thinning, with 9 of 16 eyes reaching significantly low RNFL thickness using OCT platform reference databases ( P < 0.01), accompanied by paradoxical recovery of high-contrast visual acuity (HCVA) in every patient. There was no correlation between HCVA and any OCT measures, although contrast sensitivity (CS) was associated with global thickness, PMB thickness, and nasal/temporal (N/T) ratio, and color vision was associated with PMB thickness. There was a lower global and papillomacular bundle (PMB) thickness ( P < 0.01) in clinically affected eyes compared with unaffected eyes. There was also a significantly higher N:T ratio in clinically affected eyes compared with unaffected eyes in the acute MOG-ON setting ( P = 0.03), but not in the long-term setting. MOG shows a pattern of prominent retinal atrophy, as demonstrated by global RNFL thinning, with remarkable preservation of HCVA but remaining deficits in CS and color vision. These tests may be better clinical markers of vision changes secondary to MOG-ON. Of the OCT parameters measured, PMB thickness demonstrated the most consistent correlation between structural and functional measures. Thus, it may be a more sensitive marker of clinically significant retinal atrophy in MOG-ON. The N:T ratio in acute clinically affected MOG-ON eyes in our study was higher than the N:T ratio of neuromyelitis optica (NMO)-ON eyes and similar to the N:T ratio in multiple sclerosis (MS)-ON eyes as presented in the prior literature. Therefore, MOG may share a more similar pathophysiology to MS compared with NMO.