Evaluation of changes in macular structures after subthreshold micropulse laser therapy on chronic central serous chorioretinopathy

PURPOSE

To evaluate the changes in macular structures following subthreshold micropulse laser (SHML) treatment for chronic central serous chorioretinopathy (cCSC).

METHODS

Data of 33 eyes from 31 cCSC patients treated with SHML and followed up for at least 6 months has been included in this retrospective study. Main outcome measurements include resolution of subretinal fluid (SRF) and pigment epithelial detachment (PED), the recovery of ellipsoid zone (EZ) continuity, and the foveal outer nuclear layer (ONL) thickness along with its ratio.

RESULTS

Mean observation period is 7.355 months (ranging from 6 to 24 months) and mean number of treatments administered is 1.839 (ranging from 1 to 5). 6 months after SHML treatment, there is a significant decrease in the area of SRF and PED (P < 0.001, P = 0.010, respectively). Additionally, the frequency of continuous EZ and the foveal ONL thickness reveal a significant increase (P<0.001, P = 0.005, respectively). The ratio of foveal ONL thickness is significantly higher after laser treatment, particularly in patients with a disease duration of ≤12 months (p = 0.022, P=0.036, respectively).

CONCLUSION

SHML treatment proves to be effective in cCSC eyes, leading to satisfactory recovery of macular structures, especially the photoreceptor layer.

Chronic Central Serous Chorioretinopathy in Elderly Subjects: Structure and Blood Flow Characteristics of Retina and Choroid

INTRODUCTION

With advancements in imaging technology, researchers have been able to identify more distinctive imaging features of central serous chorioretinopathy (CSC). However, existing research primarily concentrates on young patients aged 50 years and below, leaving a dearth of studies on elderly CSC patients. Previous studies indicate that elderly CSC patients may exhibit unique imaging characteristics and have a clinical prognosis that significantly differs from younger patients. This study aimed to evaluate the characteristics of retina, choroid structure, and blood flow in elderly patients with chronic CSC (cCSC) examined multimode imaging and try to find new pathogenesis information of it.

METHODS

Using a cut-off age of 50 years, patients with chronic central serous chorioretinopathy were divided into two groups: older and younger. The control group consisted of 40 healthy individuals, with their right eyes assigned. Various clinical features were recorded, including the incidence of ellipsoid zone rupture (EZ-), fibrin in the subretinal fluid (SRF), pachydrusen, subretinal drusenoid deposits (SDD), pigment epithelial detachment (PED), double-layer sign (DLS), and choroidal lipid globule cavern. Measurements were taken for the thickness of the outer nuclear layer (ONL), the length of the extended outer photoreceptor segment (POS), the height and width of SRF, the vascular density of each layer of the retinal capillary plexus, the central macular thickness (CMT), and the subfoveal choroidal thickness (SFCT).

RESULTS

The proportion of females in the elderly group (43.75%) was significantly higher than that in the youth group (22.41%) (p = 0.034). The degree of hyperopia in the elderly group (1.03 ± 0.73) was higher than that in the youth group (0.26 ± 1.06), with a significant difference in BCVA (p = 0.05). The thickness of SFCT, CMT, ONL in the elderly group, and the length of photoreceptor outer segment in the elderly group were thinner than those in the youth group (p < 0.05). Choroidal capillary perfusion area (CCPA), macular area, and paramacular area were lower in the elderly group than those in the youth group in the full scan range (p < 0.05). The blood flow densities of deep capillary plexus (DCP), intermediate capillary plexus (ICP), and superficial capillary plexus (SCP) in the whole scan range, macular area, and paramacular area were lower in the elderly group than in the youth group, but the differences were not statistically significant.

CONCLUSIONS

In conclusion, our data suggest that elderly patients with cCSC may experience different disease outcomes. Elderly cCSC patients exhibit less gender bias, poorer vision, more severe structural damage and ischemia in the choroid and retina, and have a higher risk of developing choroidal neovascularization.

Hyperreflective dots in the avascular outer retina in relapsing-remitting multiple sclerosis

BACKGROUND

Hyperreflective granular elements with a transient presence in the retina can be detected non-invasively by optical coherence tomography (OCT). Such foci or dots may represent aggregates of activated microglia. However, in multiple sclerosis an increased number of hyperreflective foci has so far not been demonstrated in the intrinsically hyporeflective and avascular outer nuclear layer of the retina where there are no fixed elements in healthy eyes. Therefore, the present study intended to investigate the presence of hyperreflective foci in the outer nuclear layer in patients with relapsing- remitting multiple sclerosis (RRMS) by using a high-resolution OCT scanning protocol.

METHODS

This cross-sectional exploratory study examined 88 eyes in 44 RRMS patients and 106 eyes in 53 age- and sex-matched healthy subjects. None of the patients had any sign of retinal disease. All patients and healthy subjects each underwent one session of spectral domain OCT imaging. A total of 23,200 B-scans extracted from 8 × 8 mm blocks of linear B-scans at 60 μm intervals were analysed for hyperreflective foci in the outer nuclear layer of the retina. Analyses were made of the total block scan and a circular 6-mm diameter fovea-centered field in each eye. Multivariate logistic regression analysis was used to assess associations between parameters.

RESULTS

Hyperreflective foci were observed in 31 out of 44 (70.5 %) multiple sclerosis patients compared to 1 out of 53 (1.8%) healthy subjects (p < 0.0001). From analyses of the total block scans, the median number of hyperreflective foci in the outer nuclear layer was 1 (range 0-13) in patients and 0 (range 0-2) in healthy subjects (p < 0.0001). In total, 66.2% of all hyperreflective foci were located within 6 mm of the center of the macula. There was no detectable association between the presence of hyperreflective foci and retinal nerve fiber layer or ganglion cell layer thickness.

CONCLUSION

Hyperreflective granular foci in the avascular outer nuclear layer of the retina seen by OCT were almost completely absent in healthy subjects, whereas they were found, albeit at low density, in the majority of patients with RRMS. Hyperreflective foci can be repeatedly examined by non-invasive means and without pupil dilation, which opens a new field of investigation of infiltrating elements in an unmyelinated part of the central nervous system.

LCM-Seq for Retinal Cell Layer-Specific Responses During Optic Nerve Regeneration

LCM-seq is a powerful tool for gene expression analysis from individual or groups of cells that can be spatially isolated. Within the visual system, retinal ganglion cells (RGCs), the cells that connect the eye to the brain through the optic nerve, reside in the retinal ganglion cell layer of the retina. This well-defined location provides a unique opportunity to harvest RNA by laser capture microdissection (LCM) from a highly enriched cell population. Using this method, it is possible to explore transcriptome-wide changes in gene expression following optic nerve injury. In the zebrafish model, this method can be used to identify molecular events driving successful optic nerve regeneration in contrast to mammals that fail to regenerate axons in the central nervous system. Here we provide a method for LCM from the different retinal layers of zebrafish following optic nerve injury and during the process of optic nerve regeneration. Purified RNA from this protocol is sufficient for RNA-seq or other downstream analysis.

Microstructural changes after half-dose photodynamic therapy in patients with chronic central serous chorioretinopathy

BACKGROUND

To evaluate the retinal and choroidal microstructural changes at fovea after half-dose photodynamic therapy (PDT) in patients with chronic central serous chorioretinopathy (CSC), using optical coherence tomography (OCT).

METHODS

The study included 35 eyes with unilateral chronic CSC treated with half-dose PDT. The foveal outer nuclear layer (ONL) and subfoveal choroidal thickness (SFCT) in the affected eyes were compared with baseline measurements at month 1, 3, and 6 after half-dose PDT, and those of the healthy contralateral eyes.

RESULTS

The mean baseline ONL thickness of the affected eyes was thinner compared to unaffected fellow eyes (66.9 ± 16.5 μm vs 111.5 ± 11.6 μm, p<0.001), and increased significantly to 68.6 ± 17.0 μm at month 3 and 68.9 ± 17.3 μm at month 6 after treatment (p = 0.025 and p = 0.014 respectively). The mean baseline SFCT of the affected eyes was thicker compared to unaffected fellow eyes (399.9 ± 87.0 μm vs 338.2 ± 75.4 μm, p<0.001), and decreased significantly after treatment at month 1, 3, and 6 (374.0 ± 84.8 μm, 369.7 ± 81.8 μm, 367.3 ± 80.8 μm respectively, p<0.001 for all). The responder group (n = 26), in which subretinal fluid was completely resorbed, showed a significant increase in ONL thickness and decrease in SFCT after treatment, whereas in the non-responder group (n = 9) ONL thickness and SFCT did not differ after treatment.

CONCLUSIONS

In CSC patients, significant changes are observed in foveal ONL thickness and SFCT after half-dose PDT. ONL thickness and SFCT are suggested to be considered in the OCT examinations of CSC patients.

Long term outer retinal changes in central serous chorioretinopathy submitted to half-dose photodynamic therapy

PURPOSE

To evaluate long-term changes in the foveal and parafoveal outer retina after half-dose photodynamic therapy (HD-PDT) in central serous chorioretinopathy (CSC).

METHODS

Retrospective study including CSC patients submitted to HD-PDT. Best corrected visual acuity (BCVA) was evaluated. Spectral-domain optical coherence tomography automatic segmentation algorithm was used and data on retinal, inner retinal, outer retinal and outer nuclear layers (ONL) in both foveal 1 mm (C) and parafoveal 3 mm ETDRS circles for the superior, nasal, inferior and temporal sectors, were obtained at baseline and 3, 12 and 24 months post-treatment. Subfoveal choroidal thickness, photoreceptors' outer segment thickness, subretinal fluid (SRF) height and width were also measured.

RESULTS

Twenty-one eyes of 15 patients were included. At baseline, the mean ONL thickness in the foveal area was significantly thinner in affected eyes compared to their fellow unaffected ones (55,50 ± 32,75 μm vs 93,00 ± 17,0 μm; p = 0,011), and was negatively correlated to logMAR BCVA (R=-0,601, p = 0,008) ONL thickness increased by 10,94 ± 11,88 μm at 24 months in the foveal area, and all the parafoveal sectors presented a similar increase. Baseline SRF width was significantly correlated with baseline BCVA (R1 = 0,483, p = 0,036), and with ONL thickness in all sectors.

CONCLUSION

In our study we found a significant long-term increase in foveal and parafoveal ONL thickness in CSC after HD-PDT, suggesting that this seems to be a safe treatment for the outer retina. This is the first study mapping the outer retinal changes in the macular area to 24 months follow up.

Correlation between tangential distortion of the outer retinal layer and metamorphopsia in patients with epiretinal membrane

PURPOSE

To evaluate tangential morphological changes in the outer retina and assess their correlation with the degree of metamorphopsia in patients with idiopathic epiretinal membrane (ERM).

METHODS

This retrospective study included patients with idiopathic ERM who underwent vitrectomy between January 2018 and December 2019. We evaluated the preoperative examination results. Using cross-sectional spectral-domain optical coherence tomography (OCT) images along the horizontal/vertical meridian through the fovea, we defined a new parameter, tangential displacement (TD), as the tangential component of the position vector of the distorted outer nuclear layer caused by ERM. Visual function measurements included M-CHARTS results (vertical/horizontal metamorphopsia score [MV/MH]) and best-corrected visual acuity (BCVA). The correlations among the OCT parameters including TD and central foveal thickness (CFT) with visual function measurements were determined.

RESULTS

Overall, 78 eyes of 76 patients (49 females; mean age, 67.9 [± standard deviation, 7.5 years]) were included. The mean horizontal TD was 24.0 ± 73.9 μm, which was significantly different from 0 (p = 0.005). The mean vertical TD was 6.0 ± 76.2 μm, which was not significantly different from 0. The absolute value of horizontal TD was significantly correlated with MV (r = 0.513, p < 0.01) and MH (r = 0.423, p < 0.01). The absolute value of vertical TD was also significantly correlated with MV (r = 0.274, p = 0.02) and MH (r = 0.413, p < 0.01). However, neither value was significantly correlated with BCVA. Multiple regression analysis showed that the horizontal absolute TD was an independent factor associated with both MV (β = 0.635, p < 0.001) and MH (β = 0.259, p = 0.048).

CONCLUSION

We found that ERM tended to distort the outer retinal layer toward the temporal side of the fovea. The tangential distortion of this layer was associated with the degree of metamorphopsia, suggesting that misalignment of parafoveal photoreceptors causes metamorphopsia in patients with ERM.

In-vivo longitudinal changes in thickness of the postnatal canine retina

The objectives of the present work were to assess by spectral domain optical coherence tomography (OCT) the changes in thickness of the outer nuclear layer (ONL), the ONL + photoreceptor inner segment (IS), and the retinal thickness, as a function of age in the normal canine retina. OCT retinal scans extending from the edge of the optic nerve head (ONH) along the superior and inferior meridians were captured in both eyes of 17 normal dogs at age ranging from 4 to 119 weeks. The different parameters along the superior and the inferior regions were determined following manual segmentation using the Heidelberg Eye Explorer software. Changes in thickness with age were modeled using one-phase exponential decay models. In vivo OCT imaging results showed no interocular statistically significant differences in ONL, ONL + IS, and retinal thickness at any age. All three parameters were however found to be statistically significantly thicker in the superior vs inferior retina. A rapid thinning of the three layers occurs in both the superior and inferior retina between 4 and 12 weeks of age, before reaching a plateau at around 20 weeks of age. In conclusion, the ONL, ONL + IS, and retinal thickness of the normal canine retina decrease significantly during the first three postnatal months, and is likely attributed to an overall increase in the eye volume and tangential dispersion of the photoreceptor since early photoreceptor developmental cell death is very limited at that age. Establishment of the natural history of ONL, ONL + IS, and retinal thinning will allow a more accurate assessment of the progression of a retinal degenerative condition as well as facilitate the detection of positive rescue effect of novel retinal therapies evaluated in this large animal model.

Assessment of the deformation of the outer nuclear layer in the Epiretinal membrane using spectral-domain optical coherence tomography

Background

We aimed to investigate the deformation of the outer nuclear layer using optical coherence tomography in patients with epiretinal membrane (ERM) and its relationship with metamorphopsia.

Methods

Thirty-nine eyes from 39 patients with ERM were included in the study. Patients with the subtypes of pseudo macula hole and lamellar hole were excluded. Twenty-one fellow eyes without macular disease were included as normal controls. Forty-nine B-scan images were obtained in the range of 20 degrees around the macula using SD-OCT. The outer nuclear layer (ONL) was evaluated as a three-dimensional image (3D-ONL) reconstructed using the distance between the ONL and retinal pigment epithelium (RPE) line. The deformation of the ONL was figured at the reference plane and evaluation plane (ONL-B). The characteristic parameters of the ONL-B were defined as circularity, area ratio, and axis ratio. The correlations between these parameters and visual acuity and MCHART score ratio (MH/MV) were then evaluated.

Results

ONL height was significantly higher in ERM patients than in normal controls (54.1 ± 5.3 μm and 84.1 ± 12.9 μm, respectively; P < 0.001). In ERM patients, the MV score was 0.53 ± 0.50, the MH score was 0.71 ± 0.61, and the distance from the RPE line to the ONL-B was 153.5 ± 13.5 μm. The axis of the ONL-B in normal controls and ERM patients was − 6.25 ± 21.8 and − 1.28 ± 29.1, respectively, which indicates that the ONL is horizontally long in both normal individuals and ERM patients. The circularity and area ratio were significantly smaller in ERM patients than in normal controls. In all ERM patients, MH/MV had a significant correlation with axis (r = − 0.29, p = 0.034), circularity (r = − 0.28, p = 0.044), and area ratio (r = − 0.47, p = 0.001). Moreover, we found that the correlation was more significant if the subjects had an axis of the ONL within ±10 degrees (n = 16); the correlations of MH/MV with axis (r = − 0.29, p = 0.034), circularity (r = − 0.53, p = 0.021), and area ratio were more significant (r = − 0.78, P < 0.0001).

Conclusion

The ONL is horizontally long in normal individuals and ERM patients. The direction of metamorphopsia is correlated with the direction of ONL deformation.

The relationship between foveal outer nuclear layer thickness in the active and resolved phases of central serous chorioretinopathy treated with half-dose photodynamic therapy

Background

To investigate the relationship between the foveal outer nuclear layer (ONL) thickness in the active and resolved phases of central serous chorioretinopathy (CSC), and its possible association with optical coherence tomography (OCT) parameters.

Methods

The medical records of CSC patients treated with half-dose photodynamic therapy (PDT) between August 2011 and October 2017 were reviewed. The difference between the foveal ONL thickness at 12 m after half-dose PDT and that before half-dose PDT was analyzed, and its association with OCT parameters was assessed using generalized linear models.

Results

Sixty-two patients were included. The mean difference in foveal ONL thickness was 9.15 ± 8.16 μm. The average ratios of the retinal detachment height to the subretinal space width on horizontal and vertical scans were 0.10 ± 0.04 and 0.12 ± 0.04, respectively. The ratio was independently associated with the degree of increase in the foveal ONL thickness difference on both the horizontal scans (β = 103.684, P = .000) and vertical scans (β = 67.569, P = .000), even after adjusting for potential confounders.

Conclusions

The majority of resolved CSC eyes showed some increase in foveal ONL thickness, and the degree of increase was related to the ratio of the retinal detachment height to the subretinal space width in their active phase. It suggested that the retina is stretched when it becomes detached, and recovers with resolution of the subretinal fluid. Therefore, besides photoreceptor cell death, retinal stretch may contribute to the reduction in foveal ONL thickness in eyes with active CSC.

Outer retinal layers as predictors of visual acuity in retinitis pigmentosa: a cross-sectional study

PURPOSE

To evaluate the integrity of the outer retinal layers-outer nuclear layer (ONL), external limiting membrane (ELM), ellipsoid (EZ), and interdigitation band (IZ)-using spectral-domain optical coherence tomography and estimate their effect on visual acuity in retinitis pigmentosa (RP).

METHODS

A cross-sectional study was performed in the Ophthalmology Department of Hospital de Braga, Portugal. Patients with RP followed in the Hospital de Braga during January to August 2017 were included. Exclusion criteria were lack of data, macular edema due to RP, and concomitant retinal, optic nerve, or corneal disease that could interfere with visual acuity. Age, sex, time from diagnosis, phakic status, ONL thickness, and presence or absence of foveal ELM, EZ, and IZ were correlated to the best-corrected visual acuity (BCVA).

RESULTS

Forty-eight eyes were analyzed. There was a strong and positive correlation in BCVA between both eyes (p < .001*). ONL thickness was decreased in 95.8%. The EZ was the most absent layer (79.2%), followed by IZ (70.8%) and ELM (45.8%). A positive family history (p = .04*) and increased time from diagnosis (p = .037*) correlated with worse BCVA. A thicker ONL (p = .001*) and the presence of subfoveal ELM (p < .001*), EZ (p < .001*), and IZ (p = .02*) are correlated with better BCVA. There was a strong and positive correlation between the number of layers affected and a lower BCVA (p < .001). The presence of EZ was a significant predictor of BCVA (p = .02*).

CONCLUSIONS

The status of the outer retinal layers seems to influence BCVA. The status of the EZ was the most important predictor of BCVA but the ONL, ELM, and IZ may have a cumulative effect in the progression of visual loss.

Quantification of retinal changes after resolution of submacular hemorrhage secondary to polypoidal choroidal vasculopathy

PURPOSE

To evaluate changes in the thickness of retinal layers after resolution of submacular hemorrhage secondary to polypoidal choroidal vasculopathy (PCV).

STUDY DESIGN

Retrospective, observational study.

METHODS

This study included 21 patients (21 eyes) who had been diagnosed with submacular hemorrhage secondary to PCV and treated using anti-vascular endothelial growth factor monotherapy. After the hemorrhage had resolved, the thicknesses of the retinal layers were measured on horizontal- and vertical-crosshair optical coherence tomography scan images. The thickness of each layer in the region affected by the hemorrhage was compared with the thickness of the layer in the corresponding region in the fellow eye, as well as between an unaffected region in the eye with the hemorrhage and the corresponding region in the fellow eye.

RESULTS

Optical coherence tomography (OCT) was performed 5.5±2.8 months after diagnosis. In the horizontal OCT images, the outer plexiform layer (OPL) and outer nuclear layer (ONL) + photoreceptor layer (PRL) were significantly thinner in the affected region than in the corresponding region (P = 0.019 and P <0.001, respectively). In the vertical OCT image, the ONL+PRL was significantly thinner in the affected region than in the corresponding region (P <0.001). The thickness of the retinal layer in the unaffected region did not differ from that in the corresponding region of the fellow eye.

CONCLUSIONS

The significant thinning of the outer retinal layers in the regions affected by submacular hemorrhage suggests that the hemorrhage induces marked damage in the outer retinal layers, explaining the poor visual prognosis of submacular hemorrhage.

Leber Congenital Amaurosis: Genotypes and Retinal Structure Phenotypes

Leber congenital amaurosis (LCA) patients of 10 known genotypes (n = 24; age range, 3-25 years) were studied clinically and by optical coherence tomography (OCT). Comparisons were made between OCT results across the horizontal meridian (central 60(o)) of the patients. Three patterns were identified. First, there were LCA genotypes with unusual and readily identifiable patterns, such as near normal outer nuclear layer (ONL) across the central retina or severely dysplastic retina. Second, there were genotypes with well-formed foveal architecture but only residual central islands of normal or reduced ONL thickness. Third, some genotypes showed central ONL losses or dysmorphology suggesting early macular disease or foveal maldevelopment. Objective in vivo morphological features could complement other phenotypic characteristics and help guide genetic testing of LCA patients or at least permit a differential diagnosis of genotypes to be made in the clinic.

Protective effect of light emitting diode phototherapy on fluorescent light induced retinal damage in Wistar strain albino rats

BACKGROUND

Artificial light at night alters retinal physiology. Several studies have shown that light emitting diode phototherapy protects the retina from the damaging effects of acute light exposure.

OBJECTIVE

The aim of this study has been to elucidate the protective effects of 670 nm LED light on retinal damage induced by chronic fluorescent light in Wistar rats.

METHODS

Male Wistar albino rats were divided into four groups: group 1 were control (CL), group 2, 3 and 4 were exposed to fluorescent light (FL), LED preexposure+fluorescent light exposure (LL) and only LED light exposure (OL) respectively. All animals were maintained in their specific exposure regime for 30 days. Fluorescent light of 1800 lx was exposed between 8 pm to 8 am. Rats were exposed to therapeutic LED light of 670 nm of 9 J/cm2 at 25 mW/cm2 for 6 min duration. Histopathological changes in the retina were studied.

RESULTS

Animals of the FL group showed a significant reduction in the outer nuclear layer thickness and cell count in addition to the total thickness of the retina. LL group which were exposed to 670 nm LED prior to exposure to fluorescent light showed a significant decrease in the degree of damage.

CONCLUSIONS

670 nm LED light preexposure is protective to retinal cells against fluorescent light-induced damage.