Decrease In Choroidal Thickness Research Articles

Peripapillary atrophy area predicts the decrease of macular choroidal thickness in young adults during myopia progression

ObjectiveThis study aimed to investigate the influence of peripapillary atrophy (PPA) area and axial elongation on the longitudinal changes in macular choroidal thickness (ChT) in young individuals with myopia.Methods and...

Choroidal thickness as a biomarker for axial length change

Aims/Purpose: Assessing axial eye growth is a key component in myopia management; however, access to biometry is limited in primary eye care settings. This study evaluated choroidal thickness, compared to spherical equivalent refraction, as a potential biomarker of axial elongation.Methods: The Myopia Outcome Study of Atropine in Children (MOSAIC) is a double‐blind, randomized controlled trial of 0.01% atropine eye drops. Irish myopic participants aged 6–16 years used either 0.01% atropine or placebo eye drops nightly for 2 years. Spherical equivalent refraction (SER) was measured by cycloplegic autorefraction, axial length (AL) by partial coherence interferometry and choroidal thickness (ChT) by Swept Source‐OCT. The respective 12‐month changes in both eyes were included in mixed linear regression analysis, while controlling for treatment group and within‐subject correlation. ROC analysis was conducted to assess the ability of ChT and/or SER to identify eyes in the top 25% (fast progressors) of AL change.Results: Of the 250 participants enrolled in MOSAIC (mean age 11.8 years, 62% female), 217 (87%) completed the 12‐month visit. Mean 12‐month change in AL, ChT and SER were 0.268 ± 0.19 mm, −3.62 ± 33.3 um and −0.437 ± 0.346 DS respectively. Analysis revealed a significant association between change in ChT and AL (−0.01 ± 0.002 mm per 10 μm; p < 0.001) and change in SER and AL (−0.28 ± 0.02 mm per 1D; p < 0.001). When both SER and ChT were combined in a single model, a 1D myopic change in SER and a 10um decrease in ChT were associated with a 0.27 mm (p < 0.001) and 0.007 mm increase in AL (p = 0.002), respectively. ROC analysis revealed that change in ChT was a stronger predictor of fast AL progression (AUC = 0.77) compared to SER change (AUC = 0.72), with the combined model performing better than either variable alone (AUC = 0.80).Conclusions: ChT change was significantly associated with AL change over 12 months and better than SER alone at identifying fast AL progressors, with a combined SER and ChT model achieving the best results.

Comparison of Chorioretinal Parameters in Diabetic Retinopathy with or without Pan-Retinal Photocoagulation Using Ultrawide-Field Swept-Source Optical Coherence Tomography Angiography

Introduction: To compare structural and vascular parameters in the central and peripheral retina and choroid of eyes diagnosed with severe nonproliferative diabetic retinopathy (NPDR) or proliferative diabetic retinopathy (PDR) with or without pan-retinal photocoagulation (PRP) using ultrawide-field swept-source optical coherence tomography angiography (SS-OCTA). Methods: All participants underwent SS-OCTA imaging centered on the fovea. Retinal and choroidal thickness, vessel density of the superficial capillary plexus (SCP), deep capillary plexus (DCP), choroidal capillary plexus (CCP), and choroidal Sattler’s and Haller’s layer (CSHL) were analyzed in nine grids using built-in angiography analysis software. Results: A total of 82 eyes from 82 participants were enrolled in this study, including 40 eyes diagnosed with severe NPDR or PDR without PRP and 42 eyes with PRP. Retinal thickness in part grids was higher in eyes with PRP than in eyes without PRP. Vessel density of the SCP in nasal-superior (p = 0.003) grid was lower in eyes with PRP than in eyes without PRP. No significant difference was found in the vessel density of the DCP between the two groups (all p > 0.05). The choroidal thickness and vessel density of the CSHL of all grids were significantly lower in eyes with PRP than in eyes without PRP (all p < 0.05). A statistically significant decrease in vessel density in CCP was found in the superior (p = 0.043), nasal-superior grid (p = 0.003), macular grid (p < 0.001), and optic disc grid (p = 0.001) of eyes with PRP, compared to eyes without PRP. A significant decrease in the vessel density of CSHL was observed in all grids of PDR eyes with PRP compared to PDR eyes without PRP (all p < 0.05). Significant decrease in choroidal thickness was observed in most grids of PDR eyes with PRP, except for macular grid (p = 0.090) and optic disc grid (p = 0.057). Conclusion: Structural and vascular parameters in the central and peripheral retinal and choroidal layers in eyes diagnosed with severe NPDR or PDR with or without PRP could be quantified using a ultrawide-field SS-OCTA. Eyes with PRP showed a significant decrease in choroidal thickness and vessel density of CCP and CSHL, compared with eyes without PRP. This trend was more obvious in eyes with PDR.

SubFoveal Choroidal Imaging in High Myopic Nepalese Cohort.

Evidence suggests that choroid is thinner in myopes as compared to nonmyopes. However, choroidal thickness varies with the refractive error, age, axial length, and ethnicity. The purpose of this study was to determine the subfoveal choroidal thickness (SFCT) in high myopic Nepalese subjects and to investigate its association with the mean spherical equivalent refractive error (MSE), axial length, and age. Ninety-two eyes of 92 high myopic subjects (MSE ≤ -6 diopters) and 83 eyes of 83 emmetropic subjects (MSE: 0.00 Diopters) were included in the study. SFCT was assessed using spectral domain optical coherence tomography, and the axial length was measured using partial coherence interferometry. SFCT was measured manually using the inbuilt tool within the imaging software. SFCT in the high myopic subjects was significantly thinner (mean ± SD: 224.17 ± 68.91 μm) as compared to the emmetropic subjects (353.24 ± 65.63 μm) (mean difference, 127.76 ± 130.80 μm, and p < 0.001). In high myopic subjects, there was a significant negative correlation of choroidal thickness with the axial length (rho = -0.75; p < 0.001) and MSE (rho = -0.404; p < 0.01). Regression analysis demonstrated a decrease of choroidal thickness by 40.32 μm (p < 0.001) for every 1 millimeter increase in the axial length and by 11.65 μm (p < 0.001) for every 1 diopter increase in the MSE. High myopic Nepalese subjects had significantly thinner choroid as compared to emmetropes. The MSE and axial length were inversely correlated with the SFCT. Age had no effect on SFCT in this study. These findings may have implications in interpreting choroidal thickness values in clinical and epidemiological studies in myopes, especially in the south Asian population.

Ultra-Widefield Swept-Source Optical Coherence Tomography Angiography in the Assessment of Choroidal Changes in Young Adults With Myopia.

To evaluate choroidal changes in young adults with myopia using ultra-widefield swept-source optical coherence tomography angiography (SS-OCTA). This study enrolled 105 eyes of 105 participants who underwent SS-OCTA imaging (24 mm × 20 mm) centered on the fovea. Eyes were categorized as low myopia, moderate myopia, or high myopia. Choroidal thickness, choroidal capillary plexus (CCP) vessel density, and choroidal Sattler's and Haller's layer (CSHL) vessel density were analyzed in nine grids using built-in angiography analysis software. A significant decrease in choroidal thickness was found in most grids (P < 0.01) in high myopia. The CSHL vessel density also showed a significant decrease in most grids (P < 0.05) in high myopia. Choroidal thickness was negatively correlated with axial length in most grids (P < 0.05). Choroidal thinning was most evident in the macular grid (β = -22.55, P < 0.001). CSHL vessel density was negatively correlated with axial length in most grids (P < 0.05). Choroidal changes could be quantified using ultra-widefield SS-OCTA. Choroidal thinning with increasing axial length indicated regional differences in eyes with myopia, which were most evident in the macular area. Decreased CSHL vessel density with increasing axial length also indicated regional differences in eyes with myopia. This study explored choroidal changes with a wider field of view than has been currently available.

Choroidal thickness in exudative age‐related macular degeneration and influence of intravitreal anti‐VEGF treatment

AbstractPurpose: To evaluate choroidal thickness progression over time in patients with exudative age‐related macular degeneration (AMD) and its relation with anti‐VEGF treatment.Methods: Retrospective observational case series. Study group included patients observed between January 2022 and April 2022 at Ophthalmology Department of Hospital de São João, Porto, Portugal, diagnosed with bilateral exudative AMD (eAMD) or unilateral eAMD and intermediate AMD (iAMD) in contralateral eye with a minimum follow up of 2 years. Subfoveal choroidal thickness was measured in each of the studied eyes using cross‐sectional spectral domain optical coherence tomography images, obtained every year during follow‐up period. Statistical analysis was performed to correlate choroidal thickness variation with number of intravitreal injections.Results: 66 eyes with eAMD and 20 eyes with iAMD from 43 patients (mean age, 81.15 ± 6.10 years) followed during 7.15 ± 2.65 years. eAMD eyes were treated with 54.83 (range 6–100 injections) anti‐VEGF intravitreal injections. Choroidal thickness of eyes with eAMD decreased 56.65 ± 11.66 μm over the follow up period (p &lt; 0.001) at a rate of 6.49 μm per year. Choroidal thickness of eyes with iAMD decreased 29.30 ± 22.07 μm over the follow up period (p &gt; 0.2) at a slower rate of 0.68 μm per year. In the subgroup of patients with unilateral eAMD and contralateral iAMD (n = 20), choroidal thickness changes were significantly different between the two eyes (p &lt; 0.001). Number of intravitreal injections correlated inversely with choroidal thickness in eyes with eAMD (r = −0.232; p &lt; 0.001).Conclusions: A significant thinning of choroid in eyes with eAMD and an inverse correlation with number of anti‐VEGF injections was observed, suggesting the influence of prolonged anti‐VEGF suppression on choroidal thickness decrease. Further studies with a higher number of eyes are needed to validate our results.

Optical Coherence Tomography Following Panretinal Photocoagulation Demonstrating Choroidal Detachment

Retinal laser therapy such as panretinal photocoagulation can be associated with complications, including rare cases of choroidal detachment. This report describes high-resolution optical coherence tomography (OCT) imaging after retinal laser panretinal photocoagulation (PRP) in patients with proliferative diabetic retinopathy (PDR) demonstrating choroidal detachment. A series of three sequential patients with high-risk proliferative diabetic retinopathy who were PRP laser naïve were examined with spectral-domain OCT immediately after green solid-state laser or PASCAL® PRP treatment. All three patients demonstrated a significant choroidal detachment immediately after PRP treatment. By one month after PRP, the choroidal detachment resolved spontaneously in all patients. OCT examinations were performed to detect and evaluate the severity and the change of choroidal detachment and thickness measurements were quantified and demonstrated a mean decrease in choroidal thickness of 122 µm (p &lt; 0.05 in all patients). Conventional green solid-state laser and PASCAL® laser both have the risk of developing complications such as choroidal detachment. While the rate of choroidal detachment has been reported to be quite low, this could be due to subclinical, self-limited, choroidal detachments. The risk could be larger than previously reported using modern high-resolution clinical optical imaging such as OCT.

SAUSAGING AND BULBOSITIES OF THE CHOROIDAL VEINS IN CENTRAL SEROUS CHORIORETINOPATHY.

To evaluate the caliber of the choroidal veins in central serous chorioretinopathy, a disease proposed to be associated with overloading of choroidal venous outflow. Widefield indocyanine green angiograms of eyes with central serous chorioretinopathy were graded for sausaging defined as three or more contiguous fusiform dilations that vary by at least 50% from the narrowest to largest diameters. A bulbosity was defined as a focal 2X dilation of a blood vessel as compared with the diameter of the surrounding host vessel. The data underwent statistical analysis including the use of generalized estimating equations. There were 73 eyes of 41 patients with a mean age of 53.5 years. Sausaging of vessels was seen in a mean and median of three quadrants per eye. Using generalized estimating equations, the only significant risk factor for sausaging was the use of corticosteroids. The two significant predictors of subfoveal choroidal thickness using generalized estimating equations were age ( P = 0.021) and proportion of quadrants involved by sausaging ( P < 0.001). The decrease in choroidal thickness per year of age was estimated to be 3.7 µ m, while the increase with four quadrant involvement with sausaging was estimated to be 236 µ m. There were a total of 39 bulbosities in 26 eyes (35.6%), preferentially involving intervortex venous anastomoses. Variations in the venous caliber are very common in eyes with central serous chorioretinopathy and seems to be associated with pathophysiologic alterations related to increased pressure within and remodeling of the larger choroidal veins. This may lead to overloading of the choriocapillaris with leakage as one manifestation.

Retinal and Choroidal Thinning—A Predictor of Coronary Artery Occlusion?

Introduction. Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) allowed visualization of retina and choroid to nearly the capillary level; however, the relationship between systemic macrovascular status and retinal microvascular changes is not yet known well. Aim. Our purpose was to assess the impact of retinal optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) parameters on prediction of coronary heart disease (CHD) in acute myocardial infarction (MI) and chronic three vessel disease (3VD) groups. Methods. This observational study included 184 patients—26 in 3VD, 76 in MI and 82 in healthy participants groups. Radial scans of the macula and OCTA scans of the central macula (superficial (SCP) and deep (DCP) capillary plexuses) were performed on all participants. All participants underwent coronary angiography. Results. Patients in MI groups showed decreased parafoveal total retinal thickness as well as GCL+ retinal thickness. Outer circle total retinal thickness and GCL+ retinal thickness were lowest in the 3VD group. The MI group had thinner, while 3VD the thinnest, choroid. A decrease in choroidal thickness and vascular density could predict 3VD. Conclusions. A decrease in retinal and choroidal thickness as well as decreased vascular density in the central retinal region may predict coronary artery disease. OCT and OCTA could be a significant, safe, and noninvasive tool for the prediction of coronary artery disease.

Choroidal Disorders in Staphyloma and Dome-Shaped Macula

Posterior staphyloma is described as an ectasia of the limited area of the eyewall mostly in highly myopic eyes. Dome-shaped macula (DSM), detected by optical coherence tomography (OCT) is a convex elevation of the eyewall mostly in the posterior staphyloma area. Both posterior staphyloma and DSM are also rarely seen in eyes without high myopia. The process that begins with the axial enlargement of the Bruch’s membrane (BM) in the equatorial region during axial elongation and breaks in BM play a role in the pathogenesis. It is thought that DSM may be a kind of compensation mechanism in eyes with high myopia and posterior staphyloma. The choroidal layer is relatively thinner in staphyloma and thicker in KŞM. Multimodal imaging is may be required for diagnosis. In OCT, it is important to evaluate the vertical and horizontal scans together and not to keep the scanning area within the lesion boundaries. Attention should be paid to the changes in the posterior eye wall curvature and choroidal thickness. The gradual decrease of choroidal thickness from the periphery to the staphyloma border is an important tip for diagnosis. The fact that the increase in choroidal thickness is limited to the convex elevation area in DSM with serous macular detachment should be considered in differential diagnosis with central serous chorioretinopathy. Studies on increasing the biomechanical power of the sclera in staphyloma are ongoing. It may be a good option to avoid overtreatment in the presence of complications, considering the benefit-risk ratio.

Accommodative movements of the choroid in the optic nerve head region of human eyes, and their relationship to the lens

The ciliary muscle (CM) powers the accommodative response, and during accommodation the CM pulls the choroid forward in the region of the ora serrata. Our goal was to elucidate the accommodative movements of the choroid in the optic nerve region in humans and to determine whether these movements are related to changes in the lens dimensions that occur with aging, in the unaccommodated and accommodated state.Both eyes of 12 human subjects (aged 18–51 yrs) were studied. Homatropine (1 drop/5%) was used to relax the ciliary muscle (unaccommodated or “resting” eye) and pilocarpine was used to induce the maximum accommodative response (2 drops/4%) (accommodated eye). Images of the fundus and choroid were collected in the region of the optic nerve (ON) via Spectralis OCT (infrared and EDI mode), and choroidal thickness was determined. Ultrasound biomicroscopy (UBM; 50 MHz, 35 MHz) images were collected in the region of the lens/capsule and ciliary body. OCT and UBM images were collected in the resting and accommodated state.The unaccommodated choroidal thickness declined significantly with age (p = 0.0073, r = 0.73) over the entire age range of the subjects studied (18–51 years old). The choroidal thickness was significantly negatively correlated with lens thickness in the accommodated (p = 0.01) and the unaccommodated states (p = 0.005); the thicker the lens the thinner the choroid.Choroid movements around the optic nerve during accommodation were statistically significant; during accommodation the choroid both thinned and moved centrifugally (outward/away from the optic nerve head). The accommodative choroid movements did not decline significantly with age and were not correlated with accommodative amplitude.Measurement of the choroidal thickness is possible with the Spectralis OCT instrument using EDI mode and can be used to determine the accommodative changes in choroidal thickness. The choroidal thickness decreased with age and during accommodation. It may be that age-related choroidal thinning is due to changes in the geometry of the accommodative apparatus to which it is attached (i.e., ciliary muscle/lens complex) such that when the lens is thicker, the choroid is thinner. Accommodative decrease in choroidal thickness and stretch of the retina/choroid may indicate stress/strain forces in the region of the optic nerve during accommodation and may have implications for glaucoma.

Uveal lymphoid hyperplasia: treatment with combination antibiotics and steroids

Background/aimsUveal lymphoid hyperplasia (formerly benign reactive hyperplasia of the choroid) spans histopatholological characteristics ranging from reactive hyperplasia to low-grade lymphoid neoplasm. There is strong evidence that other low-grade lymphoid neoplasms,...

Features of structural and microvascular changes of the choroid in angioretinopathy of various etiologies

To study structural and microvascular changes in the choroid in patients with chronic kidney disease (CKD), diabetic retinopathy (DR) and arterial hypertension (AH), and their relationship with the level of renal function, carbohydrate metabolism and blood pressure. The study involved 172 patients (325 eyes): 56 patients with CKD (109 eyes); 66 patients with DR (121 eyes); 50 patients with AH (95 eyes). All patients underwent comprehensive ophthalmological examination including visometry, biomicroscopy, ophthalmoscopy, optical coherence tomography (OCT) and OCT angiography. In patients with DR and CKD, a decrease in the thickness of the ganglion cell complex and the inner plexiform layer (GCL+IPL) was noted: in proliferative DR (PDR) - 62.45±4.25 µm, in stage 4-5 CKD - 75.23±6.43 µm; a decrease in choroidal thickness (CT) of minimal values in stage 4-5 CKD (179.9±37.72 µm) and PDR (211.0±40.7 µm). The decrease in choroidal vascularity index (CVI) depended on the stage of CKD and PDR (in PDR - 63.47±1.37, in stage 4-5 CKD - 65.93±2.01). Maximum decrease in perfusion density and vascular density was found in patients with DR (37.22±9.00% and 15.11±3.39 mm, respectively). An increase in the area, perimeter of the foveolar avascular zone (FAZ), and a decrease in the circularity index were noted in all groups, with most pronounced changes in PDR and stage 4-5 CKD. Patients with CKD were found to have strong correlations of CT and CVI with creatinine, urea, proteinuria and glomerular filtration rate (GFR). Patients with diabetes mellitus and PDR were revealed to have strong relations of CT, CVI, GCL+IPL, the area and perimeter of FAZ with creatinine levels and the duration of diabetes mellitus. Choroidal thickness and choroidal vascularity index are important diagnostic markers of disorders of chorioretinal microcirculation that allow stratifying individual assessment of risk factors for progression of both chronic kidney disease and diabetic retinopathy.

Choroidal thickness and choroidal vascularity index in diabetic retinopathy and diabetic macular edema – A clinical study

Purpose: To evaluate the choroidal thickness and choroidal vascularity index (CVI) in various stages of diabetic retinopathy and to assess its significance in diabetic macular edema. Materials and Methods: 166 eyes of 83 patients were evaluated in this study. 116 eyes were with various stages of diabetic retinopathy and 50 eyes were non-diabetic healthy controls. Spectral Domain Optical Coherence Tomography (SD OCT) was done for all patients. The choroidal thickness and the macular thickness at the fovea, 500 μm nasal, temporal, superior and inferior to the fovea were measured manually, and CVI was calculated as the ratio between the total choroidal area and the luminal area using ImageJ software. Results: The mean age of the study group was 55.95 ± 10.57 years and that of the control group was 53.33 ± 11.28 years. The choroidal thickness was significantly decreased in patients with proliferative diabetic retinopathy (p < 0.005). CVI was inversely proportional to the severity of diabetic retinopathy and was statistically significant (p < 0.01 to 0.005). In eyes with DR and macular edema a significant decrease in choroidal thickness (p = 0.019) was observed; however, the decrease in CVI was not significant (p = 0.056). Conclusion: In diabetic retinopathy, the choriodal thickness and CVI decreases as the severity of the retinopathy increases. Choroid plays an important role in disease progression. But in eyes with diabetic retinopathy associated with or without macular edema, there is no significant difference in CVI.

Effect of low-dose PDT on perfusion of the choriocapillaris in cCSCR : An OCT-angiography-based study

In patients with chronic central serous chorioretinopathy (cCSCR) it is assumed that low-dose photodynamic therapy (PDT) induces short-term hypoperfusion of the choriocapillaris, which leads to long-term choroidal vascular remodeling and subsequent reduction of vascular hyperpermeability and leakage; however, it remains unclear whether the hypoperfusion completely returns to normal. The main aim of the retrospective study was to analyze the choroidal flow signal after treatment with low-dose PDT by optical coherence tomography-angiography (OCT‑A). In this study 16eyes with atotal of 19treated areas were included. Aside from visual acuity and metamorphopsia checks, all patients underwent enhanced depth imaging-OCT (EDI-OCT) and OCT‑A in the areas treated with low-dose PDT. In the present study, the flow signal in the choriocapillaris and choroidal thickness were measured retrospectively both in the PDT-treated area and in anon-treated reference area located in close proximity with similar eccentricity to the center of the fovea. The study found amean reduction of 33% (p < 0.001) of the choroidal flow signal in the treated area compared to the reference area and an average decrease in choroidal thickness of 71 µm (p = 0.001). In the long term 7out of 10patients suffered from metamorphopsia despite the low-dose PDT; however, visual acuity was improved in almost half of the patients by the treatment. Using OCT‑A it could be shown that at the choriocapillaris level, hypoperfusion persists in spite of low-dose PDT. Thus, the choroidal vascular remodeling is not able to completely compensate for the hypoperfusion induced by thrombosis.

Short-Term Exposure to Blue Light Shows an Inhibitory Effect on Axial Elongation in Human Eyes Independent of Defocus.

PurposeGiven the potential role of light and its wavelength on ocular growth, we investigated the effect of short-term exposure to the red, green, and blue light on ocular biometry in the presence and absence of lens-induced defocus in humans.MethodsTwenty-five young adults were exposed to blue (460 nm), green (521 nm), red (623 nm), and white light conditions for 1-hour each on 4 separate experimental sessions conducted on 4 different days. In each light condition, hyperopic defocus (3D) was induced to the right eye with the fellow eye experiencing no defocus. Axial length and choroidal thickness were measured before and immediately after the light exposure with a non-contact biometer.ResultsAxial length increased from baseline after red light (mean difference ± standard error in the defocussed eye and non-defocussed eye = 11.2 ± 2 µm and 6.4 ± 2.3 µm, P < 0.001 and P < 0.01, respectively) and green light exposure (9.2 ± 3 µm and 7.0 ± 2.5 µm, P < 0.001 and P < 0.001) with a significant decrease in choroidal thickness (P < 0.05, both red and green light) after 1-hour of exposure. Blue light exposure resulted in a reduction in axial length in both the eyes (−8.0 ± 3 µm, P < 0.001 in the defocussed eye and −6.0 ± 3 µm, P = 0.11 in the non-defocused eye) with no significant changes in the choroidal thickness.ConclusionsExposure to red and green light resulted in axial elongation, and blue light resulted in inhibition of axial elongation in human eyes. Impact of such specific wavelength exposure on children and its application in myopia control need to be explored.

Einfluss der Akkommodation auf die Aderhautdicke: eine Pilotstudie

Purpose. The aim of this study is to characterise the changes in choroidal thickness during and after a prolonged accom­ modation period using optical coherence tomography (OCT). Subjects and Methods. This study used 24 test subjects (age 28.2 ± 2.6 years), with n = 18 assigned to the moderate myopic group (MSE: ­2.6 ± 1.76 D) and n = 6 to the emmetropic group (MSE: ­0.07 ± 0.24 D). The test subjects underwent an accommodation relaxation phase (ten minutes), an accom­ modation phase (twenty minutes of continuous accommoda­ tion), and another relaxation phase (ten minutes). Seven OCT scans (Topcon Corporation, Tokyo, Japan) were taken along a horizontal axis on each eye at five­minute intervals. For each tomogram, the subfoveal, temporal and nasal choroidal thick­ ness was determined manually at three measurement points (2 mm apart) using a measurement tool. To trigger the process of accommodation, a mobile phone was attached to the side of the OCT device and the display was projected into the measurement beam path of the OCT via a semi­transparent mirror (demand of accommodation = 5.0 D). Results. During accommodation, the choroidal thickness decreased significantly by an average of ­8.06 ± 7.33 µm in the subfoveal region, ­4.00 ± 11.00 µm in the nasal region, and ­5.29 ± 12.52 µm in the temporal region (each with p &lt; 0.01). Furthermore, emmetropic eyes showed a significantly strong­ er decrease in the subfoveal region (­13.08 ± 8.58 µm) than myopic eyes (­6.39 ± 6.06 µm). In the ten minutes following the accommodation phase, the choroid returned to its initial thickness, showing no significant difference (p = 0.80) in the degree of recovery between myopic and emmetropic eyes. Conclusion. The study shows that the process of accommo­ dation is associated with a decrease in choroidal thickness. The results further suggest that accommodation in myopic eyes entails a smaller decrease in choroidal thickness than in emmetropic eyes. The apparatus design developed spe­ cifically for this study to project a smartphone display into the measurement beam path of the OCT device is suitable for stimulating accommodation over a longer period while performing repeated OCT scans. Keywords myopia, accommodation, choroidal thickness

Wide-field choroidal thickness and vascularity index in myopes and emmetropes.

To study regional variations in choroidal thickness (CT), luminal thickness and stromal thickness of the choroid, and choroidal vascularity index (CVI) in low myopic and emmetropic eyes using wide-field optical coherence tomography (OCT). Sixty-nine healthy young adults between 20 and 38years of age participated in this study, including 40low myopes (mean ± SD spherical equivalent (MSE) refractive error: -3.00±1.39 D, range: -6.00 to -0.62 D) and 29 emmetropes (MSE: -0.05±0.09 D, range: -0.25 to +0.12 D). Wide-field CT, luminal thickness, stromal thickness and CVI were measured across five eccentricities (fovea, parafovea, perifovea; near-periphery and periphery) and four quadrants (nasal, temporal, inferior and superior), in vertical and horizontal meridians, while controlling for a range of extraneous factors potentially influencing the CT. Custom-written software was used to segment and binarize the OCT images. Wide-field CT, luminal thickness and stromal thickness, averaged across all participants, exhibited significant topographical variation, with the foveal (379±8µm, 200±4µm, 179±4µm, respectively) and peripheral (275±8µm, 161±4µm, 114±4µm, respectively) regions presenting the thickest and thinnest regions (all p<0.001). Wide-field CVI showed a progressively higher percentage (greater vascularity) with increasing eccentricity from the fovea towards the periphery (p<0.001). Macular CT and stromal choroidal thickness were significantly thinner in myopes compared to emmetropes (p<0.05). Myopes (55.7±0.3%) showed a slightly higher CVI compared with emmetropes (54.4±0.4%) (p<0.05). Low myopia in young adults was associated with significant choroidal thinning across the macular, but not extramacular regions, with this decrease in choroidal thickness mostly attributed to thinning in the stromal component of the choroid, rather than the luminal (vascular) component.

Prevention of Choroidal Thinning by 0.01% Atropine Administered 24 h Before Exposure to Hyperopic Blur in Young Myopes.

Purpose: To evaluate the persistence of atropine's effect upon choroidal thickness and ocular biometrics and its interaction with hyperopic blur in a population of young adult myopes. Methods: Twenty young (aged 18-35 years) myopic participants with spherical equivalent refractive error of -0.75 to -6.00 D (mean ± SD -2.85 ± 1.64 D) had subfoveal choroidal thickness (SFCT) measurements derived from scans collected from the right eye only with a SD-OCT instrument (Copernicus SOCT-HR) before, as well as 60 min following the introduction of 3 testing conditions: (1) placebo/hyperopic (-3 D) blur, (2) placebo/hyperopic blur one day after administration of 0.01% atropine, and (3) placebo/no blur. Each combination of blur and pharmacological agent was tested on a separate day at approximately the same time of day between 9 am and 2 pm. Results: Repeated measures ANOVA revealed that hyperopic blur and placebo were associated with a decrease in choroidal thickness (mean change: -10.7 ± 2.7 μm, P < 0.001 after 60 min), whereas administration of 0.01% atropine one day before the introduction of hyperopic blur prevented the thinning of the choroid (mean change of +1.1 ± 3.7 μm after 60 min) compared to baseline (both, P > 0.05). There was also no significant difference between the baseline choroidal thickness measurements for any of the conditions tested. Conclusion: Low dose atropine can inhibit signals associated with hyperopic defocus that cause thinning of the choroid for at least 24 h after initial instillation.

Assessment of the choroidal thickness, central macular vascular and optic disk perfusion in migraine patients with optical coherence tomography angiography

BackgroundComparing the central choroidal thickness (CCT) and the perfusion of the macula and optic disk in patients with migraine and control group participants using optical coherence tomography angiography (OCTA). MethodsA total of 38 patients diagnosed with migraine and 32 healthy controls were recruited. OCTA scans were performed on all participants. Optic disk, central macular vascular perfusions, and CCT were measured. ResultsThirty-eight eyes of 38 participants (34 female and 4 male) in the migraine group and 32 eyes of 32 participants (19 female and 13 male) in the healthy control (HC) group were evaluated. The mean age was 42.74 ± 8.14 and 43.09 ± 14.28 years in the migraine group and HC group, respectively. The mean CCT were 314 ± 103 μm and 301 ± 71 μm in the migraine and HC group, respectively (p = 0.54). The mean optic disk perfusions were 44.77 ± 1.93% and 45.25 ± 1.43% in migraine and HC group, respectively (p = 0.25). The mean central macular vascular perfusions were 20.50 ± 8.20% and 18.65 ± 7.46% in migraine and HC group, respectively (p = 0.32). There was a significant negative correlation between CCT and the duration of migraine history (p = 0.004). ConclusionsThe macular and peripapillary microvasculature were not significantly different in patients with migraine than in HC. As the duration of migraine prolonged, a significant decrease in choroidal thickness was observed.