Factors Defining Density of Retinal Macrophage-like Cells Displayed with Optical Coherence Tomography.

PURPOSE: To study the factors which define the density of MLC of the inner retinal surface in healthy eyes. METHODS: Healthy individuals, including candidates for LASIK surgery, and post-LASIK patients were included. MLC density was calculated using structural en face projections of OCT angiography scans. The status of the vitreoretinal interface was assessed as the distance from the inner limiting membrane to the posterior hyaloid membrane on cross-sectional scans and as the area of tight posterior vitreous adhesion on en face projections. The correlation between MLC density and various demographic and anatomical parameters, including the status of the vitreoretinal interface was calculated. RESULTS: Fifty-four healthy individuals, 30 post-LASIK patients all without posterior vitreous detachment (PVD) as well as 20 patients with partial PVD were included. MLC density showed a statistically significant correlation with axial length, refractive error, age, subfoveal choroidal thickness, and the status of the vitreoretinal interface (p<0.05) in eyes without PVD. In multiple regression analysis the axial length was the main parameter independently correlated with MLC density (p=0.025). The status of the vitreoretinal interface had a statistically significant correlation with the axial length (p<0.001). Partial PVD was associated with almost complete loss of MLC (p<0.001). CONCLUSION: The status of the vitreoretinal interface is a characteristic directly defining the density of retinal MLC in healthy eyes. However, axial length appears to be a key anatomical parameter which correlates with MLC density due to its effects on the adhesion of the posterior hyaloid membrane to the retinal surface.

Topical bromfenac in VEGF-driven maculopathies: topical review and meta-analysis.

BACKGROUND: Topical non-steroidal anti-inflammatory drugs have the potential to reduce treatment burden and improve outcomes of anti-VEGF therapy for a number of retinal disorders, including neovascular age-related macular degeneration, diabetic macular edema, and retinal vein occlusions. In this review, we focused on the advantages of topical bromfenac as an adjunct to intravitreal anti-VEGF therapy in VEGF-driven maculopathies. METHODS: Cochrane Library, PubMed, and EMBASE were systematically reviewed to identify the relevant studies of neovascular age-related macular degeneration, diabetic macular edema, macular edema associated with retinal vein occlusion, myopic choroidal neovascularization, and radiation maculopathy which reported changes in central retinal thickness, visual acuity, and the number of anti-VEGF injections needed when anti-VEGF therapy was combined with topical bromfenac. RESULTS: In total, ten studies evaluating bromfenac as an adjunct to anti-VEGF therapy were identified. Five studies were included in meta-analysis of the number of injections and five studies were included in the analysis of changes in central retinal thickness. A statistically significantly lower number of intravitreal injections (p = 0.005) was required when bromfenac was used as an adjunct to anti-VEGF therapy compared to anti-VEGF monotherapy with pro re nata regimen. At the same time, eyes receiving bromfenac as an adjunct to anti-VEGF therapy demonstrated non-inferior outcomes in central retinal thickness (p = 0.07). Except for one study which reported better visual outcomes with combined treatment, no difference in visual acuity or clinically significant adverse effects were reported. CONCLUSIONS: This literature review and meta-analysis showed that topical bromfenac can be considered as a safe adjunct to anti-VEGF therapy with a potential to reduce the treatment burden with anti-VEGF drugs requiring frequent injections without compromising improvement of central retinal thickness or visual acuity.

Involvement of Sclera in Lattice Retinal Degeneration: An Optical Coherence Tomography Study.

The aim of the study was to evaluate the local status of the sclera in lattice retinal degeneration. Patients with lattice degeneration, snail-track degeneration, or horseshoe retinal breaks were included. One lesion of a single eye in each patient was captured with cross-sectional optical coherence tomography (OCT) along and across the greatest lesion dimension. The maximum height of scleral indentation was measured and compared between different lesion types and between lattice lesions with and without retinal breakage or local detachment. The correlation between the maximum height of the scleral indentation of lattice lesions and the age of the patients was calculated. Seventy-five eyes of 75 patients (44.4 ± 14.7 years; 35 males and 30 females) were included. OCT showed variable local scleral indentation in 52 out of 55 (94.5%) lattice lesions, in five out of nine (55.5%) snail-tack lesions, and in three out of eleven (27.3%) horseshoe breaks. The maximum scleral indentation within lattice lesions, snail-tack lesions, and horseshoe breaks was 227.2 ± 111.3, 22.0 ± 49.2, and 88.5 ± 48.4 µm, respectively (p < 0.001 for snail-tack lesions and horseshoe breaks compared to lattice lesions). Lattice lesions with retinal breaks and/or local retinal detachment had statistically significantly lower scleral indentation than those without (p = 0.01). The height of the scleral indentation of lattice lesions was positively correlated with patient age (r = 0.51, p = 0.03). In conclusion, scleral indentation is one of the hallmarks of lattice retinal degeneration and may be associated with a reduced risk of rhegmatogenous retinal detachment.

SAFETY AND EFFICACY OF PHOTODYNAMIC THERAPY WITH CHLORIN E6 IN CHRONIC CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To evaluate the efficacy and safety of photodynamic therapy (PDT) with chlorin E6 in chronic central serous chorioretinopathy. METHODS: In this single-center retrospective cohort study, all patients received standard PDT with 6 mg of chlorin E6 (Fotoran E6) for each m 2 of body surface area with 50 J/cm 2 fluence and a treatment time of 83 seconds. The changes in central retinal thickness, subfoveal choroidal thickness, and best-corrected visual acuity were evaluated at the end of the follow-up. The main outcome measure was the presence of subretinal fluid at 3 months after PDT. RESULTS: Thirty-nine eyes (32 men and 7 women, 43.7 ± 10.0 years) were included. In total, 50 PDT sessions were performed. At 3 months of follow-up, 31 of 39 (79.5%) study eyes showed complete resolution of subretinal fluid. The mean follow-up period after PDT was 15.3 ± 7.8 months. At the end of the follow-up, a complete resolution of subretinal fluid was observed in 32 of 39 (82.7%) eyes. The mean change in central retinal thickness, subfoveal choroidal thickness, and best-corrected visual acuity at the end of the follow-up was -139.7 ± 136.4 µ m, -66.8 ± 36.2 µ m, and -0.05 ± 0.08 logMAR, respectively ( P < 0.001). Neither systemic nor ocular adverse events were observed, nor were local reactions seen. CONCLUSION: Standard PDT with chlorin E6 is an effective and safe option in the management of chronic central serous chorioretinopathy and may be considered as an alternative to the standard PDT with Visudyne.

Spotlight on Lattice Degeneration Imaging Techniques.

Lattice degeneration (LD), routinely diagnosed with indirect ophthalmoscopy, is one of the most common and clinically significant peripheral retinal findings. In this review, we have summarized the data on currently available imaging techniques which help to improve diagnosis and our understanding of LD pathogenesis. Ultra-wide field imaging provides reliable color fundus capturing for the primary diagnosis of LD and may also be used as a screening tool. Wide-field imaging can be used for targeted documentation of LD lesions using true colors and with minimal optical distortions. Information on the status of the vitreoretinal interface, including detection of retinal holes, detachments, and vitreous tractions, can be obtained with peripheral structural optical coherence tomography (OCT) or scanning laser ophthalmoscopy in retro-mode. These techniques clarify the associated risks of rhegmatogenous retinal detachment. Fundus autofluorescence can provide details on atrophic changes. However, the risk of retinal detachment by means of this technique requires further investigation. OCT angiography may be successfully performed for some lesions. Taken together, OCT and OCT angiography demonstrate thinning of the choroid, alteration of local choroidal microcirculation, and, in severe lesions, involvement of the sclera. OCT angiography confirms loss of retinal microcirculation within LD lesion, which was previously shown with fluorescein angiography. In conclusion, despite relatively simple primary diagnosis, imaging of LD lesions remains challenging due to their peripheral localization. However, several new strategies, including ultra-wide field imaging, peripheral OCT, and scanning laser ophthalmoscopy, make LD imaging possible on a routine basis, improving diagnosis and understanding of LD pathogenesis.

Prevalence of choroidal nevi in patients with central serous chorioretinopathy.

Background: A number of articles report the association of polypoidal lesions and choroidal nevi; however, the relationship between choroidal nevi and pachychoroidal disorders has not been studied. Objectives: To study the prevalence of choroidal nevi in central serous chorioretinopathy (CSCR) patients and to elucidate potential differences in the clinical characteristics of CSCR in patients with and without choroidal nevi. Design: Case-control study. Methods: This study included a retrospective analysis of medical records and multimodal imaging data of CSCR patients and a prospective evaluation of the prevalence of the choroidal nevi in age- and sex-matched healthy controls. All participants received comprehensive ophthalmic examination and multimodal imaging including infrared scanning laser ophthalmoscopy in dark-field mode to detect choroidal nevi in the central 40° × 60° region. Results: A total of 199 CSCR patients (160 males and 39 females, 47.9 ± 9.4 years) and 184 age-matched healthy individuals (139 males and 45 females, 44.8 ± 12.5 years) were included. Choroidal nevi were detected in 24 (12.1%) CSCR patients and 10 (5.4%) healthy controls (p = 0.01). CSCR patients with choroidal nevi had statistically significantly higher subfoveal choroidal thickness, lower best-corrected visual acuity, and lower central retinal thickness (p < 0.05) than CSCR patients without choroidal nevi. The odds ratio for the presence of chronic CSCR in patients with choroidal nevi was 27.0 (95% CI: 3.1-231.9, p = 0.003). Conclusion: The prevalence of choroidal nevi among patients with CSCR is higher than in age- and sex-matched healthy population. Choroidal nevi may be associated with chronic CSCR.

MULTIMODAL IMAGING IN NONEXUDATIVE CHOROIDAL NEOVASCULARIZATION: A Pilot Study of Status of Retinal Pigment Epithelium.

PURPOSE: To study the status of retinal pigment epithelium in nonexudative and active choroidal neovascularization (CNV) in neovascular age-related macular degeneration. METHODS: Only treatment-naïve neovascular age-related macular degeneration patients were enrolled in this prospective case-control study, including 17 eyes with nonexudative CNV (6 males and 11 females, 74.9 ± 10.0 years) and 28 eyes with active CNV (8 males and 20 females, 69.3 ± 6.8 years). All patients received a comprehensive ophthalmic examination, optical coherence tomography, dark-field scanning laser ophthalmoscopy, and fundus autofluorescence. The status of the retinal pigment epithelium was assessed with ImageJ software as the brightness of the CNV region on transillumination optical coherence tomography, dark-field scanning laser ophthalmoscopy, and fundus autofluorescence images. Choroidal neovascularization vessel density was measured based on optical coherence tomography angiography. RESULTS: The brightness of CNV region in nonexudative CNV was statistically significantly lower than in active CNV with both optical coherence tomography transillumination ( P = 0.004) and dark-field scanning laser ophthalmoscopy ( P = 0.0015). No difference in brightness of the CNV region between nonexudative and active CNV was found based on fundus autofluorescence ( P = 0.44). The vessel density of nonexudative CNV was statistically significantly higher than that of active CNV with a median value of 64.5% (95% confidential interval [CI] 53.4-79.0%) and 55.3% (95% CI 52.2-60.0%), respectively ( P = 0.05). CONCLUSION: Multimodal imaging revealed substantial alteration of the retinal pigment epithelium in active CNV but not in nonexudative CNV which correlates with the higher vessel density of nonexudative CNV.

OPTICAL COHERENCE TOMOGRAPHY IMAGING OF RETINAL MACROPHAGE-LIKE CELLS IN PATIENTS WITH MULTIPLE EVANESCENT WHITE DOT SYNDROME.

PURPOSE: To analyze the changes of macrophage-like cells (MLCs) on the inner retinal surface associated with multiple evanescent white dot syndrome using optical coherence tomography. METHODS: Four eyes of four patients with multiple evanescent white dot syndrome were examined and followed with multimodal imaging, including optical coherence tomography angiography, to visualize MLC on en face structural projections. RESULTS: On en face structural optical coherence tomography angiography projection at presentation, all multiple evanescent white dot syndrome eyes showed a decrease of the nearest neighbor distance of MLC within the region of interest and an increase of MLC density in the perifovea compared with the fellow unaffected eye. Three eyes demonstrated protrusion of MLC into the vitreous. At 1 to 3 months of follow-up, nearest neighbor distance increased, and MLC density decreased to the level of the fellow unaffected eye along with regression of multiple evanescent white dot syndrome symptoms. CONCLUSION: Multiple evanescent white dot syndrome may be associated with increase of MLC population on the inner retinal surface, which can be tracked with clinical optical coherence tomography imaging.

Retinal Macrophage-Like Cells as a Biomarker of Inflammation in Retinal Vein Occlusions.

Aim: To study the macrophage-like cells (MLC) of the inner retinal surface in eyes with retinal vein occlusions (RVO) and the association of MLC with clinical characteristics of RVO. Methods: In this retrospective cross-sectional study, the medical records and multimodal imaging data of treatment-naïve patients with unilateral RVO and no abnormalities of vitreoretinal interface electronic were reviewed and analyzed. To visualize MLC, structural projections of optical coherence tomography (OCT) angiography scans within a slab between two inner limiting membrane segmentation lines (with 0 and −9 µm offset) were evaluated. The density of MLC was calculated and compared between affected and fellow eyes of each patient with regards to OCT and clinical characteristics of RVO. Results: Thirty-six eyes (twenty-eight branch RVO and eight central RVO) of 36 patients (21 males and 15 females, mean age 48.9 ± 9.8 years) were included. The density of MLC in affected eye was statistically significantly higher than that of the fellow eye, 8.5 ± 5.5 and 4.0 ± 3.6 cells/mm2, respectively (p < 0.001). The MLC density in the affected eye had a statistically significantly correlation with that of the fellow eye (r = 0.76, p = 0.0001), but with none of the OCT and clinical characteristics of the affected eye apart from the presence of subfoveal fluid. Eyes with subfoveal fluid had a statistically significantly higher mean number of MLC than that of eyes without subfoveal fluid, 12.6 ± 6.3 and 6.9 ± 4.0 cells/mm2, respectively (p = 0.009). Conclusion: The number of MLC on the inner retinal surface increases in RVO eyes which may reflect the activation of inflammatory pathways.

Reassessment of carbon emissions from fires and a new estimate of net carbon uptake in Russian forests in 2001-2021.

Russia has the largest forest area on earth. Its boreal forests officially store about 97 Pg C, which significantly affect the global carbon cycle. In recent years, forest fires have been intensifying on the planet, leading to increased carbon emissions. Here we review how differences in fire control management of Russian forests affect fire related emissions. Carbon emissions due to fire were estimated using satellite data and compared to official reports for 2001-2021. We found that the relative areas affected by fire did differ between different fire protection zones, and 89 % of the area burnt was in forests controlled by fire-fighting aircraft or areas without protection. As a result, 417.7 Mha of poor or unprotected Russian forests (42 % of total) account about a half of total carbon emissions. According to our estimates, the average area of burnt forests in Russia was about 8.3 Mha per year between 2016 and 2021, resulting in annual carbon emission of 193 million metric tons (Mt) C emissions, and 53 % of them were from unprotected forest. These estimated carbon emissions are significantly higher than official national reports (79 Mt C yr-1). We estimated that net carbon uptake for Russia for 2015-2021 was about 333 ± 37 Mt C, which is roughly double the official estimates. Our results highlight large spatial differences in fire protection and prevention strategies in fire related emissions. The so-called control zone which stretches across large parts of Eastern Russia has no fire control and is the region of major recent fires. Our study shows that to estimate the Russian forest carbon balance it is critical to include this area. Implementation of some forest management in the remote areas (i.e., control zone) would help to decrease forest loss and resulting carbon emissions.

Accommodation Is Decreased in Eyes with Acute Central Serous Chorioretinopathy.

SIGNIFICANCE: This is a case-control study showing changes in accommodation in eyes with acute central serous chorioretinopathy. We found that decreased accommodative amplitude in the affected eyes may indicate suppression of parasympathetic activity in those eyes as one of the pathophysiological mechanisms controlling choroidal thickness and perfusion. PURPOSE: This study aimed to evaluate the changes of accommodation in patients with acute central serous chorioretinopathy. METHODS: Patients with unilateral central serous chorioretinopathy, with and without foveal involvement, as well as patients after resolution of subretinal fluid and healthy age-matched controls were included. Accommodative amplitude was measured and compared between eyes with active or resolved central serous chorioretinopathy, fellow eyes of active central serous chorioretinopathy individuals, and eyes of controls. Correlation between accommodative amplitude and ocular and demographic parameters was calculated. RESULTS: Nineteen acute central serous chorioretinopathy patients (16 males and 3 females, 38.1 ± 5.1 years) and 17 age-matched controls (13 males and 4 females, 37.2 ± 5.4 years) were included. Accommodative amplitude in the study eyes of central serous chorioretinopathy patients was lower than that in the fellow unaffected eyes (1.25 ± 1.0 and 2.54 ± 0.94 D, respectively; P = .002) or in the eyes of healthy controls (2.41 ± 1.38 D, P = .002). In central serous chorioretinopathy eyes, after resolution of subretinal fluid or without foveal involvement, the median accommodative amplitude was lower than that in fellow eyes (1.6 [95% confidence interval, 0.83 to 1.75] and 2.7 D [95% confidence interval, 1.23 to 3.61], respectively; P = .004). No correlation was found between accommodative amplitude in affected central serous chorioretinopathy eyes and different parameters, except for age ( r = -0.47, P = .04). CONCLUSIONS: Acute central serous chorioretinopathy is associated with a substantial reduction of accommodative amplitude.

Catastrophic PM2.5 emissions from Siberian forest fires: Impacting factors analysis.

With increased forest fires due to climate change, PM2.5 emissions also intensified. Record PM2.5 emissions according to Copernicus Atmosphere Monitoring Service in Russia amounted to 8 megatons (Mt) in 2021, which is 78% higher than the average level of 2004-2021 (4.5 Mt). Seven federal subjects (the constituent entities) with vast forest areas without fire protection produced 86% of emissions (6.8 Mt) in 2021, the major losses (6.1 Mt) in Yakutia (Sakha Republic). The ambient temperature in Eastern Siberia is increasing, especially in months of winter and spring seasons (up to +3.6 °C) in 1990-2020 compared to 1901-2020 (CEDA Archive); climate change has affected meteorological conditions leading to increased forest fires. The results of the SARIMAX model study for PM2.5 emissions considering meteorological factors using ERA5 and burnt forest area using MODIS (MCD64A1), establishing a significant dependence of PM2.5 emissions on the lack of precipitation and the associated parameters of complete and potential evaporation. This influence long before the fire season (up to 9 months), as it affects the snow cover and the dryness of the fuel by the beginning of forest fires. In turn, high PM2.5 emission values are accompanied by a drop in 2 m air temperature and surface solar radiation downwards due to the aerosol saturation with suspended particles. The average COR for seven federal subjects was 0.79, with the highest forecast result in Yakutia (0.95), indicating the maximum propensity for record emissions due to weather conditions. In combination with forest management without fire protection, meteorological parameters have caused an increase in PM2.5 emissions in recent years in Siberia. The forest needs other ways to manage under the pressures of climate change to reduce environmental pollution associated with PM2.5 emissions from vast Siberian fires.

Interocular asymmetry in distribution of leaks in central serous chorioretinopathy.

PURPOSE: To study interocular asymmetry in distribution of leaks in central serous chorioretinopathy (CSC). MATERIAL AND METHODS: Patients with unilateral CSC were included in this retrospective multicenter study. All patients received multimodal imaging. The prevalence of leaks within 1 disk diameter (DD) peripapillary area and the mean shortest distance between a leak and the optic disk edge was analyzed for the right and left eyes separately based on FA images. Clinical and morphological characteristics were collected and compared between eyes with a peripapillary leak and eyes with a leak elsewhere. RESULTS: In total, 152 eyes (77 right eyes and 75 left eyes) of 152 patients (128 males and 24 females) with a mean age of 45.2 ± 9.8 years were included. The mean distance from the leak to the edge of the optic disk was statistically significantly lower (p = 0.0003), and the prevalence of the leaks within the 1 DD-peripapillary area was higher in the left eye than in the right eye (32.1% versus 10.7%, respectively, p = 0.0017). The eyes with a peripapillary leak had a longer duration of the disease (p < 0.05), a wider area of retinal pigment epithelium alteration (p < 0.001), and a higher prevalence of outer retinal atrophy (p < 0.001) compared to the eyes with a leak elsewhere. CONCLUSION: The left eye showed closer location of the leak to the optic disk edge and higher prevalence of leaks within the peripapillary area. The cases with peripapillary leak commonly demonstrated characteristics of chronic CSC despite relative preservation of visual acuity.

Effect of Topical Pilocarpine on Choroidal Thickness in Healthy Subjects.

SIGNIFICANCE: This is a proof-of-concept study showing the possibility of pharmacological control for choroidal thickness using pilocarpine as an agent that causes 2 to 5% choroidal thinning in healthy eyes after the instillation. PURPOSE: The purpose of this article was to study the effect of instillation of 1% pilocarpine on choroidal thickness in healthy subjects. METHODS: Sixteen healthy individuals (seven males and nine females; mean ± standard deviation age, 25.8 ± 3.3 years) were included. All participants received optical coherence tomography to evaluate subfoveal choroidal thickness (SCT) and choroidal area on cross-sectional scan within 4-mm central area. Axial length was measured using optical biometry. Optical coherence tomography was performed before and after pilocarpine was instilled six times for a 75-minute period in one eye; the fellow eye was used as the control. Subfoveal choroidal thickness and choroidal area were measured by two masked graders in random fashion and averaged for analysis. RESULTS: After instillation of 1% pilocarpine, percentage SCT change in study and control eye was -3.3 ± 3.8% and 0.4 ± 3.2%, respectively (P = .03). Percentage change choroidal area in study and control eye was -2.3 ± 2.5% and 0.8 ± 3.3%, respectively (P < .001). There was a correlation between percentage SCT change and axial length (r = -0.56, P < .001), as well as between percentage SCT change and baseline SCT (r = 0.72, P < .001). CONCLUSIONS: Instillation of 1% pilocarpine causes a decrease of choroidal thickness, which is more substantial in eyes with short axial length and thick choroid.