Assessment of the anterior scleral thickness in central serous chorioretinopathy patients by optical coherence tomography

Influence of scleral thickness on photodynamic therapy outcomes in central serous chorioretinopathy

PURPOSE

To test the prognostic role of anterior scleral substantia propria (ASSP) thickness in predicting the 3-month response after half-dose photodynamic therapy (PDT) in central serous chorioretinopathy (CSCR) and to assess its clinical relevance of ASSP in different CSCR phenotypes.

METHODS

A prospective, exploratory, multi-centre cohort study conducted at IRCCS San Martino Hospital (Genoa, Italy) and Jules-Gonin Eye Hospital (Lausanne, Switzerland). Demographic and clinical data, and optical coherence tomography (OCT) were collected at baseline and 3 months after PDT. Based on OCT images, we categorized CSCR phenotypes and collected clinically relevant imaging metrics. ASSP thickness was obtained from four different measurements using anterior segment (AS) OCT. Multivariable regression models were performed to evaluate the distribution of ASSP thicknesses among different CSCR phenotypes and to test the prognostic role of ASSP thickness in discriminating between PDT responders (complete subretinal fluid reabsorption) and partial responders.

RESULTS

The study cohort comprised 109 Caucasian patients (82 males, 75.2%) with a total of 142 eyes: 84 eyes simple (59.1%) versus 58 eyes complex (40.9%) CSCR. A linear normal model confirmed a positive association between complex CSCR and higher ASSP thickness (β = 26.1, 95% CL = 12.1/40.1, p < 0.001), with a low prevalence of ciliochoroidal effusion loculations in AS-OCT (1/142 eyes, 0.7%). ASSP thickening was positively linked to the presence of posterior cystoid retinal degeneration (PCRD; p = 0.002), indicating a potential role in the pathogenesis of severe CSCR phenotypes. In the subgroup of treated patients (61 eyes), 63.9% had a complete response after PDT. In these patients a logistic binary model highlighted a significantly higher risk of PDT non-responsiveness (OR = 9.62, 95% CL = 2.44/37.9, p = 0.001) associated with a 60-unit increase in ASSP thickness levels. By contrast, other anatomical parameters (i.e., body surface area, age, gender, axial length) showed no remarkable prognostic roles.

CONCLUSION

This research highlighted the association of ASSP thickening with complex CSCR phenotype in Caucasian patients and its role in predicting PDT efficacy. These findings enhance our comprehension of the anatomical risk factors in patients affected with CSCR and potentially guide a better understanding of non-responsive cases to PDT treatment.

Relationship between Choroidal Thickness and Anterior Scleral Thickness in Patients with Keratoconus

PURPOSE

To evaluate the relationship between choroidal thickness (CT) and anterior scleral thickness (AST) in patients with subclinical keratoconus (SKC) and established keratoconus (KC).

METHODS

This single-center prospective case-control study included 97 eyes of 97 patients: 44 KC eyes, 14 SKC eyes, and 39 age- and axial length (AL)-matched healthy eyes. Using swept-source optical coherence tomography, the AST was manually measured in four directions and the CT was obtained automatically from the Early Treatment Diabetic Retinopathy Study (ETDRS) grid. Principal component analysis (PCA) was used to linearly reduce the dimensionality of nine CT inputs to one significant component, CT1. A multivariate model was created to evaluate the association between CT1, AST, and several ocular parameters in SKC and KC patients. Partial correlation was then performed to adjust the confounding factors and to examine the effect of AST on CT1.

RESULTS

The PCA showed that CT1 accounts for 86.54% of the total variance in the nine original CTs of the ETDRS grid. The CT1 model was associated with age, AL, and AST in the superior meridian in SKC eyes, whereas in KC eyes, it was correlated with gender, age, AL, and AST in the inferior meridian (p < 0.001). The partial correlation between CT1 and AST in the superior zone was found to be significant, positive, and strong in SKC eyes (r = 0.79, p = 0.019), whereas a significant, positive, and moderate correlation between CT1 and AST at the inferior zone (r = 0.41, p = 0.017) was observed in KC eyes.

CONCLUSIONS

Choroidal tissue was significantly correlated with the anterior sclera across the vertical meridian. This relationship was observed over the superior sclera in SKC eyes, whereas in established KC, it was over the inferior sclera. These results reveal new insights regarding the interactions between the anterior and posterior structures of the KC eyes and confirm the enigma of the pathophysiology of KC.

Central serous chorioretinopathy and the sclera: what we have learned so far

Central serous chorioretinopathy (CSC) is a common disorder characterized by serous retinal detachment. Several studies using indocyanine green angiography (ICGA) have revealed that choroidal filling delay, choroidal vascular dilation, and choroidal vascular hyperpermeability are the characteristic findings of CSC. These ICGA findings confirm that choroidal circulatory disturbances are the primary factors in the pathogenesis of CSC. With advancements in optical coherence tomography (OCT), choroidal thickness has been found to be significantly greater in eyes with CSC than in normal eyes. Dilated large choroidal vessels reportedly account for the thickened choroid in eyes with CSC. Although many possible mechanisms and risk factors have been suggested, the pathophysiologic features of choroidal circulatory disturbances and choroidal thickening in eyes with CSC have not yet been fully elucidated. Recently, using anterior segment OCT, we proposed that the sclera may induce choroidal circulatory disturbances since CSC eyes have significantly thicker sclera than do normal eyes. This review summarizes updated information on the close relationship between CSC pathogenesis and the sclera.

Pachychoroid disease: review and update

The pachychoroid disease spectrum is a phenotype characterized by alterations in choroidal vasculature which result in outer retinal and choriocapillaris damage and visual loss. The presence of pachyvessels is one of the key features of the pachychoroid phenotype. Recent imaging studies suggest that pachyvessels may form because of choroidal venous congestion in one or more quadrants. The formation of intervortex anastomosis may function as a compensatory mechanism to dissipate the increased venous pressure, while outflow obstruction has been hypothesized to occur at the site of the vortex vein exiting the sclera. This review aims to summarize recent imaging findings and discuss evolution in the understanding of pathogenesis of the pachychoroid disease spectrum. We have summarized notable treatment trials in central serous chorioretinopathy and polypoidal choroidal vasculopathy and included an update of the current diagnostic and management strategies of the entities that are part of the pachychoroid disease spectrum.

Central serous chorioretinopathy: An evidence-based treatment guideline

Central serous chorioretinopathy (CSC) is a relatively common disease that causes vision loss due to macular subretinal fluid leakage and it is often associated with reduced vision-related quality of life. In CSC, the leakage of subretinal fluid through defects in the retinal pigment epithelial layer's outer blood-retina barrier appears to occur secondary to choroidal abnormalities and dysfunction. The treatment of CSC is currently the subject of controversy, although recent data obtained from several large randomized controlled trials provide a wealth of new information that can be used to establish a treatment algorithm. Here, we provide a comprehensive overview of our current understanding regarding the pathogenesis of CSC, current therapeutic strategies, and an evidence-based treatment guideline for CSC. In acute CSC, treatment can often be deferred for up to 3-4 months after diagnosis; however, early treatment with either half-dose or half-fluence photodynamic therapy (PDT) with the photosensitive dye verteporfin may be beneficial in selected cases. In chronic CSC, half-dose or half-fluence PDT, which targets the abnormal choroid, should be considered the preferred treatment. If PDT is unavailable, chronic CSC with focal, non-central leakage on angiography may be treated using conventional laser photocoagulation. CSC with concurrent macular neovascularization should be treated with half-dose/half-fluence PDT and/or intravitreal injections of an anti-vascular endothelial growth factor compound. Given the current shortage of verteporfin and the paucity of evidence supporting the efficacy of other treatment options, future studies-ideally, well-designed randomized controlled trials-are needed in order to evaluate new treatment options for CSC.

Evaluation of scleral thickness in patients with pterygium

OBJECTIVES

To evaluate scleral thickness measurements of pterygium patients using anterior segment optical coherence tomography (AS-OCT) and to compare them with healthy individuals.

MATERIAL AND METHODS

Scleral thickness was measured from 2, 4, 6 mm posterior to the scleral spur with AS-OCT (Swept Source OCT Triton, Topcon, Japan) in 4 quadrants (superior, inferior, nasal and temporal).

RESULTS

Eyes with pterygium were determined as Group 1, and contralateral eyes without pterygium were determined as Group 2. Healthy controls were determined as Group 3. In the measurements made from 4 mm posterior, no significant difference was found between Group 1 and Group 2 in any quadrants (p > 0.05). In all measurements made from 4 mm posterior to the scleral spur, scleral thickness was found to be significantly higher in Group 1 compared to Group 3 (p < 0.05). Measurements made from 2 mm posterior to the scleral spur in Group 1 was found to be significantly higher in the superior and temporal quadrants compared to Group 3 (p = 0.05), while no significant difference was found in the nasal and inferior quadrants (p > 0.05). When Group 2 and Group 3 were compared, scleral thickness measurements made from 4 mm posterior to the scleral spur was significantly thicker in all quadrants in Group 2 (p > 0.05).

CONCLUSION

Scleral thickness was found to be higher in pterygium patients compared to healthy controls, especially when measured from 4 mm posterior to the scleral spur. It has been predicted that high scleral thickness may be associated with high fibroblast activity in subconjunctival structures, and this may predispose to pterygium.

Biomechanical properties measured with dynamic Scheimpflug analyzer in central serous chorioretinopathy

PURPOSE

Recent evidence suggests that venous congestion at the vortex vein significantly contributes to the development of central serous chorioretinopathy (CSCR), and sclera is observed to be thicker in affected eyes. This study aims to investigate whether eyes with CSCR exhibit stiff corneas, measured using Corneal Visualization Scheimflug Technology (Corvis ST), which may serve as an indicator of scleral stiffness.

METHODS

This retrospective case-control study comprises 52 eyes from 33 patients diagnosed with CSCR and 52 eyes from 32 normal controls without CSCR. We compared biomechanical parameters measured with Corvis ST and anterior scleral thickness measured using anterior segment swept-source optical coherence tomography between the two groups.

RESULTS

Age, sex, axial length, intraocular pressure, and central corneal thickness showed no significant differences between the two groups (p > 0.05, linear mixed model). Three biomechanical parameters-peak distance, maximum deflection amplitude, and integrated inverse radius-indicated less deformability in CSCR eyes compared to control eyes. The stress-strain index (SSI), a measure of stiffness, and anterior scleral thickness (AST) at temporal and nasal points were significantly higher in the CSCR eyes. SSI and AST were not correlated, yet both were significantly and independently associated with CSCR in a multivariate logistic regression model.

CONCLUSIONS

Eyes affected by CSCR have stiffer corneas, irrespective of thicker scleral thickness. This suggests that stiffer sclera may play a role in the pathogenesis of CSCR.

Scleral Thickness in Simple Versus Complex Central Serous Chorioretinopathy

PURPOSE

To evaluate the association between scleral thickness and a newly developed multimodal imaging-based classification of central serous chorioretinopathy (CSC).

DESIGN

Retrospective, cross-sectional study.

METHODS

This study included 217 eyes of 217 patients classified as simple or complex CSC based on the established protocols. Clinical and anatomical factors were compared between the 2 types. The scleral thickness was measured at 4 locations using anterior-segment optical coherence tomography.

RESULTS

Of the 217 eyes, 167 were classified as simple CSC and 50 as complex CSC. The complex CSC group showed older age (P = .011), higher male ratio (P = .001), more bilateral involvement (P < .001), poorer visual acuity (P < .001), greater subfoveal choroidal thickness (P = .025), and higher frequency of loculation of fluid (P < .001) and ciliochoroidal effusion (P < .001) than the simple CSC group. The complex CSC group had significantly greater scleral thicknesses in the superior, temporal, inferior, and nasal directions (all P < .001) than the simple CSC group. Multivariable analysis revealed that older age (odds ratio [OR] 1.054, 95% confidence interval [CI] 1.013-1.097, P < .001), male sex (OR 10.445, 95% CI 1.151-94.778, P < .001), bilateral involvement (OR 7.641, 95% CI 3.316-17.607, P < .001), and the mean value of scleral thicknesses in 4 directions (OR 1.022, 95% CI 1.012-1.032, P < .001) were significantly associated with the complex CSC.

CONCLUSIONS

Older age, male sex, bilateral involvement, and thick sclera were associated with the complex CSC. Scleral thickness seemed to determine the clinical manifestations of CSC.

Macular neovascularization and polypoidal choroidal vasculopathy: phenotypic variations, pathogenic mechanisms and implications in management

Advances in imaging have led to improved ability to characterize variations in clinical sub-phenotypes of macular neovascularization (MNV) in Age-related macular degeneration (AMD). Polypoidal choroidal vasculopathy (PCV) was initially described based on characteristic features observed in indocyanine green angiography (ICGA) and was thought to be a distinct entity from AMD. However, subsequent careful observations based on confocal scanning laser ophthalmoscopy-based ICGA, optical coherence tomography (OCT) and OCT angiography have led researchers to appreciate similarities between PCV lesion and type 1 MNV in typical neovascular AMD. Concurrently, clinical trials have shown that anti-VEGF monotherapy can achieve favourable visual outcome in the majority of eyes with PCV. These learnings have led to a shift in the way PCV is managed over the past decade. Recent studies have supported the use of non-ICGA based imaging modality to screen for PCV and the adoption of anti-VEGF monotherapy as initial therapy for PCV. A focus of recent research has been in the understanding of the role of choroidal alterations in the pathogenesis of PCV. The concept of pachychoroid in leading to outer retinal ischemia has garnered increasing support. Future research in this area should evaluate the potential of choroidal morphology in guiding personalized therapy in PCV.

Assessment of the ciliary muscle and scleral anterior thickness in high myopia by optical coherence tomography

PURPOSE

To assess ciliary muscle (CM) and anterior scleral thickness (AST) dimensions in vivo in high myopia using swept-source optical coherence tomography (SS-OCT) and to compare with emmetropic and hyperopic subjects.

METHODS

Cross-sectional study that included 34 high myopic patients (≥ -6 diopters [D]), 90 emmetropes (-1 to +1 D) and 38 hyperopic patients (≥ +3.5 D). CM thickness (CMT) and AST were measured in the temporal and nasal quadrants at 1, 2, and 3 mm from the scleral spur using SS-OCT. In addition, the length of the CM (CML) was evaluated.

RESULTS

The dimensions of the CML and the CMT at any of their measurement points were greater in high myopes and emmetropes than in hyperopes, both in the nasal and temporal quadrants (P < .001). However, there were no differences between high myopes and emmetropes for any of the parameters (P ≥ .076) except for the CMT at 3 mm in the temporal quadrant (P < .001). There were no differences in the AST between high myopes, emmetropes and hyperopes, in any of the measurement points or quadrants studied (P > .05).

CONCLUSIONS

The SS-OCT allows to measure the CM in vivo, not observing differences in its dimensions between high myopes and emmetropes, but they were smaller in hyperopes. In the measurement of the anterior sclera, no differences were observed between the three groups analyzed according to refraction.

Vortex Veins in Eyes With Pachychoroid Spectrum Disorders Evaluated by the Adjusted Reverse 3-Dimensional Projection Model

Purpose

To compare the distribution of vortex vein ampulla (VVA) between pachychoroid spectrum disorder (PSD) and controls.

Design

A single-center, case-control study.

Participants

This study included 75 PSD, 35 fellow, and 65 control eyes.

Methods

We quantified VVA distribution using a 3-dimensional reverse projection model corrected for image distortion. We investigated the distribution of major drainage veins (MDV), in which macular Haller's vessels directly influx.

Main Outcome Measures

The mean distances from the optic disc to VVAs and the mean angles between VVAs and the fovea-disc line.

Results

The PSD group had significantly fewer VVA in infranasal sector (PSD, fellow, control; 1.6 ± 0.6, 1.8 ± 0.6, 1.9 ± 0.6, respectively, P = 0.026). In supralateral sector, for PSD, fellows, and controls, the mean distances from the optic disc to VVAs were 14.1 ± 1.0 mm, 14.1 ± 1.1 mm, and 13.6 ± 1.4 mm, respectively, and were significantly farther in PSD than in controls (P = 0.023). The mean angles between VVAs and the fovea-disc line were 64.8 ± 5.9°, 66.4 ± 6.4°, and 61.7 ± 6.4°, respectively, and were significantly higher in PSD and fellows than in controls (P = 0.008). The mean distances from the optic disc to MDV in supratemporal sector were 14.1 ± 1.2 and 13.7 ± 1.2 in eyes whose Haller's vessels extended beyond the fovea-disc line (asymmetry), and those that did not, respectively, with the asymmetric eyes significantly farther (P = 0.016).

Conclusions

The VVA position in supralateral sector was farther and higher in PSD than in controls, suggesting that the distribution of VVA may be associated with the development of PSD.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Clinical update in nanophthalmos: Features, diseases and complications associated

Nanophthalmos is a rare congenital condition of the eyeball that is characterised by a smaller size of the anterior and posterior segments without associated ocular malformations. Typical features that have traditionally been described in these eyes are short axial length, thickened sclera, cornea with a smaller diameter, narrow anterior chamber, and an increased lens to globe volume ratio. However, at present, there is still a lack of recognised diagnostic criteria for nanophthalmos and a classification of its severity. Its clinical relevance stems from the increased risk of multiple ocular conditions, such as high hyperopia, amblyopia, angle-closure glaucoma, retinal detachment, and cataracts. Likewise, in relation to surgery in these eyes, there are particularities in cataract and glaucoma surgery and with a greater risk of associated intra- and postoperative complications. In this way, the treatment of nanophthalmos focuses on controlling the associated eye conditions and reducing and controlling surgical complications. This review aims to update what has been published in recent years regarding nanophthalmos.

Comparison in conjunctival-Tenon's capsule thickness, anterior scleral thickness and ciliary muscle dimensions between Caucasians and Hispanic by optical coherence tomography

PURPOSE

To investigate the differences in the dimensions of the anterior ocular segment, and specifically in conjunctival-Tenon's capsule thickness (CTT), anterior scleral thickness (AST) and ciliary muscle thickness (CMT), between Caucasian and Hispanic subjects using swept-source optical coherence tomography (SS-OCT).

METHODS

Cross-sectional study including 53 Hispanic and 60 Caucasian healthy participants, matched by age, sex and refractive error, who underwent a complete ophthalmological examination. CTT, AST and CMT were manually measured in the temporal and nasal quadrants at 0, 1, 2 and 3 mm from the scleral spur using SS-OCT.

RESULTS

Mean age and refractive error were 38.7 ± 12.3 years and -1.05 ± 2.6 diopters, and 41.8 ± 11.7 years and -0.50 ± 2.6 diopters for the Hispanic and Caucasians, respectively (p = 0.165 and p = 0.244). The CTT was increased in the temporal quadrant in the Hispanic group in the three studied regions (CTT1, CTT2 and CTT3; being the means 223.0 ± 68.4, 215.3 ± 66.4 and 203.8 ± 67.1 µm versus 190.8 ± 51.0, 189.4 ± 53.2 and 187.4 ± 55.3 µm respectively; p < 0.001). Larger AST values were observed in the temporal quadrant in the Hispanic group (AST2: 559.8 ± 80.8 µm and AST3: 591.6 ± 83.0 µm) compared to the Caucasian group (520.7 ± 50.1 and 558.9 ± 54.7 respectively; p ≤ 0.022). No differences were observed in the nasal quadrant for CTT, AST1 and AST3 (p ≥ 0.076). No differences emerged in the CM dimensions (p ≥ 0.055).

CONCLUSION

CTT and AST measurements were thicker in the temporal quadrant of Hispanic patients compared to Caucasians. This could have implications for the pathogenesis of different ocular diseases.

SCLERAL THICKNESS IN THE FELLOW EYES OF PATIENTS WITH UNILATERAL CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE

The sclera is reportedly thicker in eyes with central serous chorioretinopathy (CSC) than in healthy control eyes. We compared the scleral thicknesses of the affected and unaffected fellow eyes of patients with unilateral CSC.

METHODS

We retrospectively examined the findings of 115 patients with unilateral CSC. Comparisons of the spherical equivalent, axial length, anterior chamber depth, subfoveal choroidal thickness, scleral thickness, and presence of peripheral ciliochoroidal effusion of the affected and fellow eyes were made. Using anterior segment optical coherence tomography, scleral thickness was measured vertically, 6 mm posterior to the scleral spur in the superior, temporal, inferior, and nasal directions.

RESULTS

No significant differences in scleral thickness in all four directions, spherical equivalent, axial length, anterior chamber depth, and frequency of ciliochoroidal effusion were found between the affected and unaffected fellow eyes. The only significant difference between the affected and fellow eyes was observed in the subfoveal choroidal thickness (398.8 µ m vs. 346.6 µ m, P < 0.001).

CONCLUSION

A thickened choroid seems to have a direct effect on CSC development. By contrast, the affected and fellow eyes showed no significant difference in scleral thickness, indicating that scleral thickening may be a predisposing factor for the development of CSC.

Anterior Scleral Thickness and Other Dimensions in Nanophthalmos by Swept-Source Optical Coherence Tomography: A Comparative Study

PURPOSE

The purpose of this study is to assess the ocular dimensions of the anterior and posterior segment, including the anterior scleral thickness (AST) in nanophthalmos compared to control eyes.

METHODS

A cross-sectional comparative study was carried out in two groups: 46 eyes of 28 patients with nanophthalmos, defined as axial length (AXL) < 20.5 mm, and 60 eyes of 30 controls paired by age and sex. The AST and ocular wall thickness (OWT) were measured by optical coherence tomography in the temporal and nasal quadrants at 1, 2, and 3 mm from the scleral spur. Also, the anterior chamber depth (ACD), white-to-white (WTW), lens thickness (LT), subfoveal choroidal thickness (SFCT), and retinal thickness (RT) were evaluated.

RESULTS

The mean AXL was 19.3 ± 1.5 mm in the nanophthalmos group and 23.9 ± 1.1 mm in the control group (p < 0.001). The OWT was thicker in all measurement points in nanophthalmos (p < 0.001). There were no differences in the AST measurements between groups, except for the AST1 and the AST3 in the nasal quadrant. ACD was shallower and LT was thicker in nanophthalmos, with WTW being larger in controls (p < 0.001). SFCT and RT were thicker in nanophthalmos compared to healthy individuals (p < 0.001).

CONCLUSIONS

Significant anatomical differences are found in nanophthalmic eyes. They present a shallower ACD; thicker LT, OWT, choroid, and retina; and smaller WTW diameter-although no relevant differences in the AST were observed.

Clinical applications of anterior segment swept-source optical coherence tomography: A systematic review

Optical coherence tomography (OCT) is a non-invasive method that provides the opportunity to examine tissues by taking cross-sectional images. OCT is increasingly being used to evaluate anterior segment (AS) pathologies. Swept-source (SS) OCT allows greater penetration and achieves better visualization of the internal configuration of AS tissues due to the longer wavelength employed and high scan speeds. We reviewed the utilization of AS SS-OCT in various conditions including glaucoma, ocular surface pathologies, iris tumors, refractive surgery, cataract surgery, and scleral diseases. A systematic literature search was carried out on PubMed, Scopus, and Web of Science databases between January 1, 2008, and September 1, 2022 using the following keywords: AS SS-OCT; dry eye and SS-OCT; ocular surface and SS-OCT; cornea and SS-OCT; dystrophy and SS-OCT; glaucoma and SS-OCT; ocular surface tumors and SS-OCT; conjunctival tumors and SS-OCT; refractive surgery and SS-OCT; cataract and SS-OCT; biometry and SS-OCT; sclera and SS-OCT; iris and SS-OCT; ciliary body and SS-OCT; artificial intelligence and SS-OCT. A total of 221 studies were included in this review. Review of the existing literature shows that SS-OCT offers several advantages in the diagnosis of AS diseases. Exclusive features of SS-OCT including rapid scanning, deeper tissue penetration, and better image quality help improve our understanding of various AS pathologies.

Pathomechanisms in central serous chorioretinopathy: A recent update

BACKGROUND

Central serous chorioretinopathy (CSCR) is a potentially blinding choroidal disease. Despite decades of research, the pathological mechanisms of CSCR are still poorly understood. In recent years, there has been a strong emphasis on choroidal dysfunction as a primary cause of CSCR.

MAIN BODY

The concept of the pachychoroid disease spectrum and pachychoroid-driven processes are central to current theories regarding the pathophysiological underpinnings of CSCR. Choroidal hyperpermeability and subsequent leakage of fluid seen in CSCR may be due to several causes. Among them are venous congestion, inflammation, mineralocorticoid receptor activation, systemic factors including hemodynamic changes, obstructive sleep apnea, phosphodiesterase inhibitor use, pregnancy, and genetic predispositions. Congestion of vortex veins that drain blood from the choroid may contribute to the dilation of Haller vessels and cause fluid leakage. Vortex veins exit the eye through the sclera; thus, increased scleral thickness has been proposed to be a factor in venous congestion. Asymmetric vortex vein drainage may similarly result in congestion of the local venous system. Vortex vein anastomoses may overload the venous system and form secondary to venous congestion. Recent studies suggest inflammation and mineralocorticoid activation may factor into the development of CSCR, though more research in these areas is called for. Systemic conditions and genetics may predispose individuals to develop CSCR.

CONCLUSIONS

By striving to understand the molecular and physiological mechanisms of this disease, we can better diagnose and treat CSCR to improve outcomes for patients.

Relationship Between Scleral Thickness and Choroidal Structure in Central Serous Chorioretinopathy

Purpose

Central serous chorioretinopathy (CSC) is a retinal disorder characterized by serous retinal detachment with or without pigment epithelial detachment in the posterior pole of the eye. We aimed to elucidate the relationship between scleral thickness and choroidal structure in CSC eyes.

Methods

This single-center retrospective study included 111 eyes of 111 CSC patients. Using swept-source optical coherence tomography, the horizontal cross-sectional images of the posterior choroid were converted to binary images by semiautomated software. The luminal and stromal areas of the choroid were measured, and the luminal/stromal (L/S) ratios of the whole choroid (WC), inner choroid, and outer choroid (OC) at 1500 µm, 3000 µm, and 7500 µm ranges centered on the fovea were calculated. Correlations of L/S ratio and age, spherical equivalent, axial length, subfoveal choroidal thickness (SCT), and scleral thickness were determined. Scleral thickness was measured vertically, 6 mm posterior to the scleral spur in four directions.

Results

SCT and mean scleral thickness were significantly positively correlated with the L/S ratio in all ranges of WC and OC. Multiple regression analysis found that SCT and mean scleral thickness were significantly correlated with the L/S ratio, and the strength of correlation of mean scleral thickness (WC: 0.386, P < 0.001; OC: 0.391, P < 0.001) was greater than that of SCT (WC: 0.368, P < 0.001; OC: 0.383, P < 0.001) in 7500 µm range.

Conclusions

Thick sclera appeared to play a role in an increase in the luminal component of the posterior choroid in CSC eyes.

Choroidal arteriovenous anastomoses: a hypothesis for the pathogenesis of central serous chorioretinopathy and other pachychoroid disease spectrum abnormalities

The pachychoroid disease spectrum (PDS) includes several chorioretinal diseases that share specific choroidal abnormalities. Although their pathophysiological basis is poorly understood, diseases that are part of the PDS have been hypothesized to be the result of venous congestion. Within the PDS, central serous chorioretinopathy is the most common condition associated with vision loss, due to an accumulation of subretinal fluid in the macula. Central serous chorioretinopathy is characterized by distinct risk factors, most notably a high prevalence in males and exposure to corticosteroids. Interestingly, sex differences and corticosteroids are also strongly associated with specific types of arteriovenous anastomoses in the human body, including dural arteriovenous fistula and surgically created arteriovenous shunts. In this manuscript, we assess the potential of such arteriovenous anastomoses in the choroid as a causal mechanism of the PDS. We propose how this may provide a novel unifying concept on the pathophysiological basis of the PDS, and present cases in which this mechanism may play a role.

Prediction of the response to photodynamic therapy in patients with chronic central serous chorioretinopathy based on optical coherence tomography using deep learning

PURPOSE

To assess the prediction of the response to photodynamic therapy (PDT) in chronic central serous chorioretinopathy (CSCR) based on spectral-domain optical coherence tomography (SD-OCT) images using deep learning (DL).

METHODS

Retrospective study including 216 eyes of 175 patients with CSCR and persistent subretinal fluid (SRF) who underwent half-fluence PDT. SD-OCT macular examination was performed before (baseline) and 3 months after treatment. Patients were classified into groups by experts based on the response to PDT: Group 1, complete SRF resorption (n = 100); Group 2, partial SRF resorption (n = 66); and Group 3, absence of any SRF resorption (n = 50). This work proposes different computational approaches: 1st approach compares all groups; 2nd compares groups 1 vs. 2 and 3 together; 3rd compares groups 2 vs. 3.

RESULTS

The mean age was 55.6 ± 10.9 years and 70.3% were males. In the first approach, the algorithm showed a precision of up to 57% to detect the response to treatment in group 1 based on the initial scan, with a mean average accuracy of 0.529 ± 0.035. In the second model, the mean accuracy was higher (0.670 ± 0.046). In the third approach, the algorithm showed a precision of 0.74 ± 0.12 to detect the response to treatment in group 2 (partial SRF resolution) and 0.69 ± 0.15 in group 3 (absence of SRF resolution).

CONCLUSION

Despite the high clinical variability in the response of chronic CSCR to PDT, this DL algorithm offers an objective and promising tool to predict the response to PDT treatment in clinical practice.