Choroidal Circulation Research Articles

Novel optical coherence tomography angiography biomarkers in the diagnosis and assessment of diabetic macular edema and diabetic macular ischemia in patients with non-proliferative diabetic retinopathy.

The present study aims to determine the macular and choroidal optical coherence tomography angiography (OCTA) biomarkers in the assessment and monitoring of diabetic macular edema (DME) and diabetic macular ischemia (DMI) in patients with non-proliferative diabetic retinopathy (NPDR). In this cohort study, a total of 176 eyes of 110 patients with NPDR were investigated at our institute over a period of 10 months. Eyes were divided into four groups based on the severity of NPDR. Each eye was subjected to OCTA (Topcon 3D OCT-1 Maestro2) macula 6 × 6 mm2 en face. It features IMAGEnet 6 software for dynamic viewing of OCTA and imaging data. Four OCTA biomarkers for the macula were identified: foveal avascular zone area (FAZ area), foveal avascular zone contour irregularity (FAZ-CI), capillary dropout areas (CDA), and perifoveal intercapillary areas (PICA). The choroidal OCTA biomarker was the number of choroidal circulation flow voids (CCFV). For all analyses, P < 0.05 was considered statistically significant. Increase in FAZ area and number of CDA were statistically significant (p < 0.0001) with an increase in central foveal thickness, suggesting a correlation of ischemic changes with an increase in DME. FAZ-CI, enlarged PICA, and CCFV were significantly associated with more severe NPDR patients. A correlation between DME and DMI in a patient of NPDR and its progression can be evaluated in a single visit. A unique feature of our study is it revealed novel diagnostic biomarkers of OCTA for DMI and DME.

Retinal and choroidal circulation in patients with lattice retinal degeneration: optical coherence tomography-angiography study

BACKGROUND: There are insufficient data covering retinal and choroidal microcirculation in eyes with lattice retinal degeneration.&#x0D; AIM: To investigate retinal and choroidal circulation in eyes with lattice retinal degeneration using optical coherence tomography-angiography (OCTA).&#x0D; MATERIALS AND METHODS: The study included 10 patients with lattice retinal degeneration and 12 healthy individuals. All subjects underwent OCTA examination of the macula. Additionally, in four patients, OCTA within the area of lattice retinal degeneration was performed.&#x0D; RESULTS: Retinal capillary non-perfusion, disorganization of retinal layers, a decrease of choriocapillaris perfusion, and choroidal thinning were found within the area of lattice degeneration in all cases. In the macula, the perfusion area in the choriocapillaris slab in the eyes with lattice degeneration and controls was 6.40 0.21 and 6.19 0.21 mm2 (p 0.05), respectively. The number of flow voids in the choriocapillaris in the eyes with lattice degeneration and controls eyes was 40.6 23.0 and 65.1 25.7 (p 0.05), respectively. The total area of flow voids in the choriocapillaris slab in the eyes with lattice degeneration and in controls eyes was 0.49 0.04 and 0.54 0.04 mm2 (p 0.05), respectively.&#x0D; CONCLUSIONS: The status the choroidal and choriocapillaris perfusion may play an important role in pathophysiology of the lattice retinal degeneration.

Protocol for Indocyanine Green Angiography.

Indocyanine green (ICG) angiography was first approved by the Food and Drug Administration for human use in the 1956. Prior to its use in chorioretinal angiograms, ICG was used to measure blood flow and track cardiac output. It was only in 1969 when two researchers, Kyuga Kogure and Earl Choromokos from the University of Miami, first used ICG to create more accurate angiograms. In the following years, researchers were able to hone the underlying science of this new form of angiography. As time passed and technology advanced, the application of ICG in clinical practice became widespread. Today ICG is used to diagnose and monitor the progression of retinal and choroidal diseases affecting millions of individuals across the globe. ICG utilizes the injection of indocyanine green dye into a patient's bloodstream to visualize abnormalities of the choroid and retina by evaluating choroidal circulation. ICG angiography is useful in the diagnosis and management of occult choroidal neovascularization in age-related macular degeneration and may be used in other inflammatory conditions with central serous chorioretinopathy. ICG angiography offers advanced imaging for improved monitoring and treatment of a wide variety of choroidal and retinal diseases.

Acquisition of optical coherence tomography angiography metrics during hemodialysis procedures: A pilot study.

The observation of optical microcirculation gives us an extraordinary way to directly assess in vivo the responses of human circulation to stress stimuli. We run a pilot study to analyze optical coherence tomography angiography (OCT-A) metrics at determined time-points during a hemodialysis (HD) session to understand how these metrics gradually change and to evaluate possible correlations with patients' characteristics. After the eligibility screening, 15 patients (23 eyes) were included in the study. OCT-A parameters were collected at established time-points: Before treatment (t0), at first hour (t1), at second hour (t2), at third hour (t3), and finally at the end of HD treatment (t4). Patients were finally shared in hypotensive group if they occurred in a hypotensive episode during subsequent month methods or no hypotensive group. The instrument software automatically segmented OCT-A scans into four en-face slabs: The superficial capillary plexus (SCP), the deep capillary plexus (DCP), the outer retinal plexus and the choriocapillaris plexus. In this study we focus on SCP, DCP plexuses. Overall, the majority of ophthalmic parameters remained unaffected and comparable at dialysis end; a significant reduction being observed at the end vs. starting of HD only for deep capillary plexus (DCP: Whole, fovea, and parafovea) and for central choroid thickness (CCT) (p < 0.05). An overall trend during the session showed in general a decrease with a significance in particular for DCP (whole, fovea, and parafovea) and for CCT (P = 0.006). In the hypotension group, Superficial capillary plexus (SCP: Fovea and parafovea) significantly increased comparing post vs. pre-dialysis values while CCT significantly decreased. Analyzing the trend during treatment only CCT maintained a significant trend (p for trend = 0.002). In the no-hypotension group, neither pre- vs. post-analysis and trend analysis showed a statistical significance. Main achievement of our study was to measure, for the first time in literature, single parameters at different time-points of a HD session. As a result of this process we did not notice a brusque decreasing or increasing of OCT-A metrics but we can characterize the different effect of HD on the two distinct areas distinguishing ocular vessels: Retinal and choroidal circulation. As interesting sub-analysis, Hypotensive group showed for CCT a decreasing trend with a difference statistically significant respect to the group with no-hypotension maintaining a constant trend. In our opinion, these results suggest the role of autonomic system on vessel control in patients affected by uremia.

Comparison of retinochoroidal microvascular circulation in menstrual and postmenopausal periods using swept-source optical coherence tomography angiography.

We aimed to examine the possible effects of the postmenopausal period on retinal and choroidal microvascular circulation using swept-source optical coherence tomography angiography (SS-OCTA). This cross-sectional study included 45 eyes of 45 subjects in menstrual group and 40 eyes of 40 subjects in postmenopausal group. SS-OCTA was used for the assessment of vessel density (VD), foveal avascular zone (FAZ), choroidal thickness (CT), choriocapillaris VD, central macular thickness (CMT), nerve fiber layer thickness (RNFL), and ganglion cell layer (GCL) measurements. The VDs of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) measurements were similar in both group. FAZ area was wider in postmenopausal group (0.305 mm2 (range, 0.212-0.498 mm2)) compared to menstrual group (0.271 mm2 (range, 0.131-0.464 mm2)) (p = 0.013). Choriocapillaris VD was significantly lower in postmenopausal group (p = 0.049). CT was thicker in the postmenopausal group, but with no statistically significant difference (p = 0.066). Central macular thickness, RNFL, and GCL were similar in both groups. This is the first study in the literature to evaluate the retinochoroidal microcirculation in the menstrual and postmenopausal periods with SS-OCTA. We observed an increase in both superficial and deep FAZ area and a decrease in choroidal blood flow in the postmenopausal period. We think that this enlargement in the FAZ area may be related to the decreased amount of estrogen.

Case Report: Improved Choroidal Circulation in a Patient with Unilateral Acute Idiopathic Maculopathy

Unilateral acute idiopathic maculopathy is a rare retinochoroidal disorder, the cause of which is unknown. Multimodal retinal imaging obtained in this case suggests that the cause of unilateral acute idiopathic maculopathy is impaired choroidal circulation. This study aimed to report a patient with unilateral acute idiopathic maculopathy who showed improvement of choroidal circulation over time in optical coherence tomography angiography images. A 33-year-old woman with a prodromal flu-like illness noticed a sudden central visual field abnormality in the right eye. Five days after the onset, best-corrected visual acuity was 0.15 in the right eye. Fundus photography showed a yellowish lesion at the macula in the right eye. Optical coherence tomography showed a blurred ellipsoid zone and a thickened retinal pigment epithelium at the fovea and a disrupted/blurred ellipsoid zone and retinal pigment epithelium at the parafovea. Optical coherence tomography angiography segmentation of the choriocapillaris revealed a hypointense region at the fovea with a hyperintense region surrounding it. One week after the onset, best-corrected visual acuity was improved from 0.15 to 2.0 in the right eye. Furthermore, the yellowish macula lesion shrank, and the outer retinal layers showed improvement in optical coherence tomography. Optical coherence tomography angiography showed reduction of the hypointense region and enlargement of the hyperintense region. Approximately 1 year after the onset, the yellowish lesion was faded. Optical coherence tomography revealed an almost normal ellipsoid zone but a thickened interdigitation zone. Optical coherence tomography angiography also revealed an apparent hyperintense instead of the hypointense region and increased choroidal blood flow. The current patient showed a gradual recovery of choroidal circulation and outer retinal layer morphology 1 year after the onset of unilateral acute idiopathic maculopathy. Optical coherence tomography angiography findings indicated that the primary cause of unilateral acute idiopathic maculopathy was impaired choroidal circulation, and choroidal vessels improved morphologically over the disease course.

Quantitative OCT angiography of the retinal and choroidal vascular circulation in pediatric patients with neurofibromatosis type 1

To investigate retinal and choroidal microvascular changes in neurofibromatosis type 1 (NF1) pediatric patients using optical coherence tomography angiography (OCTA). This study was performed on 21 eyes of 21 NF1 patients and 30 eyes of 30 healthy subjects. Foveal avascular zone (FAZ) parameters, including area, perimeter, acircularity index, and foveal density, were measured using OCTA. Superficial (SCP) and deep (DCP) capillary plexus and radial peripapillary capillary (RPC) vessel densities and choriocapillaris flow were also evaluated. Choroidal nodules and thickness were detected using infrared reflectance and enhanced-depth imaging OCT. No significant differences were observed for FAZ parameters or SCP and RPC vessel densities between groups. DCP vessel densities in the perifovea were significantly lower in the NF1 group than in the control group (P = 0.001). A significantly lower choriocapillaris flow area (P < 0.001) and increased subfoveal and nasal perifoveal choroidal thickness (P < 0.001) were observed in the NF1 group. Choriocapillaris flow area tended to be inversely related to the number of choroidal nodules in the NF1 group. Perifoveal DCP vessel density and choriocapillaris flow significantly differed between NF1 patients and controls, suggesting that retinal and choroidal vascular microcirculation is affected in the former, potentially by choroidal nodules. Further longitudinal studies are required to determine the effects of these differences on circulation in the posterior segment of the eye.

Acute and chronic occlusive disorders of the choroidal vasculature (ischemias)

Choroidal ischemia is a less common finding than retinal and optic nerve lesions due to difficulties in its evaluation, which may be caused by systemic diseases and/or local vascular disorders. Indocyanine green angiography is the most valuable imaging method for visualizing the choroidal circulation. Today, the use of optical coherence tomography angiography and enhanced depth optical coherence tomography has significantly improved the understanding of the choroid. In this way, it has been shown that the underlying cause in the pathogenesis of many retinal diseases may be choroidal circulatory disorders. The purpose of this review is to provide an overview of acute and chronic occlusive disorders (ischemias) of the choroidal vasculature.

Changes in choroidal circulation hemodynamics during the menstrual cycle in young, healthy women.

PurposeThe current study aimed to investigate the time course of changes in choroidal circulation hemodynamics and their relationship to systemic circulation dynamics during the normal menstrual cycle in young, healthy women using laser speckle flowgraphy (LSFG).MethodsThis prospective study included 26 eyes from 13 young, healthy women (21.3 ± 4.0 years) with a normal menstrual cycle and 24 eyes from 12 young, healthy men (21.8 ± 4.4 years) as a control group. The macular mean blur rate (MBR), a quantitative index of relative blood flow velocity in the choroid, was measured using LSFG. MBR, intraocular pressure (IOP), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), and ocular perfusion pressure (OPP) were evaluated in the late follicular phase and mid-luteal phase in women and at baseline and 10 days after baseline in men, respectively.ResultsIn the female group, IOP, SBP, DBP, MBP, and OPP values were significantly higher in the mid-luteal phase than those observed in the late follicular phase (P = 0.035, P < 0.001, P = 0.041, P = 0.001, P = 0.014, respectively). The average macular MBR values in the late follicular phase and mid-luteal phase were 12.7 ± 5.3 and 13.7 ± 6.6 (+7.7 ± 19.4%), representing a significant increase in the mid-luteal phase (P = 0.041). The rate of change in MBR exhibited a significant positive correlation with changes in DBP and MBP (R = 0.456, P = 0.019 and R = 0.474, P = 0.014). However, there were no significant changes in any of the factors in the male group during the study period.ConclusionsOur results suggest that in young, healthy women with a normal menstrual cycle, choroidal blood flow velocity decreases during the late follicular phase and increases during the mid-luteal phase, depending on systemic circulatory dynamics.

Spectrum of Mutations in NDP Resulting in Ocular Disease; a Systematic Review.

Aims and Rationale: The inner retina is supplied by three intraretinal capillary plexi whereas the outer retina is supplied by the choroidal circulation: NDP is essential for normal intraretinal vascularisation. Pathogenic variants in NDP (Xp11.3) may result in either a severe retinal phenotype associated with hearing loss (Norrie Disease) or a moderate retinal phenotype (Familial Exudative Vitreoretinopathy, FEVR). However, little is known about whether the nature or location of the NDP variant is predictive of severity. In this systematic review we summarise all reported NDP variants and draw conclusions about whether the nature of the NDP variant is predictive of the severity of the resulting ocular pathology and associated hearing loss and intellectual disability. Findings: 201 different variants in the NDP gene have been reported as disease-causing. The pathological phenotype that may result from a disease-causing NDP variant is quite diverse but generally comprises a consistent cluster of features (retinal hypovascularisation, exudation, persistent foetal vasculature, tractional/exudative retinal detachment, intellectual disability and hearing loss) that vary predictably with severity. Previous reviews have found no clear pattern in the nature of NDP mutations that cause either FEVR or Norrie disease, with the exception that mutations affecting cysteine residues have been associated with Norrie Disease and that visual loss amongst patients with Norrie disease tends to be more severe if the NDP mutation results in an early termination of translation as opposed to a missense related amino acid change. A key limitation of previous reviews has been variability in the case definition of Norrie disease and FEVR amongst authors. We thus reclassified patients into two groups based only on the severity of their retinal disease. Of the reported pathogenic variants that have been described in more than one patient, we found that any given variant caused an equivalent severity of retinopathy each time it was reported with very few exceptions. We therefore conclude that specific NDP mutations generally result in a consistent retinal phenotype each time they arise. Reports by different authors of the same variant causing either FEVR or Norrie disease conflict primarily due to variability in the authors’ respective case definitions rather than true differences in disease severity.

Monte-Carlo simulation and tissue-phantom model for validation of ocular oximetry.

Ocular oximetry, in which blood oxygen saturation is evaluated in retinal tissues, is a promising technique for the prevention, diagnosis and management of many diseases and conditions. However, the development of new tools for evaluating oxygen saturation in the eye fundus has often been limited by the lack of reference tools or techniques for such measurements. In this study, we describe a two-step validation method. The impact of scattering, blood volume fraction and lens yellowing on the oximetry model is investigated using a tissue phantom, while a Monte Carlo model of the light propagation in the eye fundus is used to study the effect of the fundus layered-structure. With this method, we were able to assess the performance of an ocular oximetry technique in the presence of confounding factors and to quantify the impact of the choroidal circulation on the accuracy of the measurements. The presented strategy will be useful to anyone involved in studies based on the eye fundus diffuse reflectance.

Quantitative evaluation of retinal and choroidal vascularity and retrobulbar blood flow in patients with myopic anisometropia by CDI and OCTA

AimsTo investigate the association between the myopic severity and retinal microvascular density, choroidal vascularity and retrobulbar blood flow in adult anisomyopes.MethodsThis study comprised 90 eyes of 45 myopic anisomyopes who...

A Modified Arrestin1 Increases Lactate Production in the Retina and Slows Retinal Degeneration.

Glucose metabolism in the retina is carefully orchestrated, with glucose being delivered to photoreceptors from the choroidal circulation through the retinal pigmented epithelium (RPE). In photoreceptors, glucose is processed principally by aerobic glycolysis, from which the lactate byproduct is provided to the RPE and Müller glia for their energetic needs. In this study, we utilize a modified arrestin1 protein to enhance the glycolytic output of lactate from rod photoreceptors through disinhibition of enolase1 activity with the goal being to use this increased lactate production as a gene-agnostic approach to slowing retinal degeneration. Mouse arrestin1 with E362G/D363G amino acid substitutions (referred to as “ArrGG”) was packaged into AAV and tested for safety and for efficacy in increasing retinal lactate production. Overexpression of ArrGG in C57BL/6J mice did not result in any detectable changes in either electroretinogram (ERG) function or photoreceptor survival as measured by outer nuclear layer (ONL) thickness. However, mouse retinas expressing ArrGG showed a ∼25% increase in the rate of lactate secretion.Therefore, AAV-ArrGG was delivered intravitreally to heterozygous P23H rhodopsin knockin mice (RhoP23H/+) to determine if enhancing glycolysis in photoreceptors can slow retinal degeneration in this animal model of retinitis pigmentosa. We found that the expression of ArrGG in these mice slowed the decline of both scotopic and photopic ERG function. Correspondingly, there was significant preservation of ONL thickness in RhoP23H/+ mice treated with ArrGG compared with controls. In conclusion, our studies show that expressing ArrGG in C57BL/6J mouse retina results in an increase in lactate production, consistent with an upregulation of glycolysis. In the P23H rhodopsin model of retinitis pigmentosa, the expression of ArrGG led to significant preservation of photoreceptor function and slowing of retinal degeneration. These findings suggest that enhancing glycolysis by targeting increased enolase1 activity with a modified arrestin1 in photoreceptors may offer a therapeutic approach to slowing retinal degeneration.

Assessment of the impact of N95 respirators or surgical masks use on the retinal microvasculature.

To determine the possible impact of wearing N95 respirator or surgical masks on retinal vessel diameters and choroidal thickness in healthy healthcare workers. Diameters of peripapillary retinal arteries and veins and choroidal thickness values at the foveal center and at 1000 μm distances from the foveal center in both nasal and temporal directions were measured before mask wearing using a spectral-domain optical coherence tomography. After four hours (h) of N95 or surgical mask wearing vessel diameter and choroidal thickness measurements were repeated. A total of 52 eyes from 52 participants (28 F [53.8%]; 24 M [46.2%]) were enrolled in this study. The mean age of patients was 34.58 ± 5.24 years (25-44 years). The diameters of all measured arteries [inferior temporal artery (p = 0.003), superior temporal artery (p < 0.001), inferior nasal artery (p = 0.003), and superior nasal artery (p = 0.004)] and veins,with the exception of superior nasal vein, (inferior temporal vein (p = 0.031), superior temporal vein (p = 0.027), inferior nasal vein (p < 0.001), and superior nasal vein (p = 0.063)] increased significantly after four hour use of N95 respirators and surgical maskswhen compared to baseline. There was also a significant diameter increase of the superior temporal (p < 0.001), inferior nasal veins (p < 0.001), and superior temporal artery (p = 0.037) for N95 respirators and surgical masks use, respectively. The differences in central subfoveal, temporal, and nasal choroidal thickness between baseline and after 4 h use of N95 respirators were statistically significant (From 366.73 ± 70.81 μm to 381.23 ± 69.29μm,p < 0.001 for the subfoveal; from 324.00 ± 64.13μm to 335.40 ± 61.35 μm, p = 0.007 for the temporal; from 297.40 ± 68.18 μm to 308.23 ± 74.51μm, p = 0.002 for the nasal thicknesses). Choroidal thickness values were also increased with surgical mask use. But only the increase in central subfoveal thickness was statistically significant (From 366.78 ± 71.00 μm to 372.58 ± 76.56 μm, p = 0.031 for the central subfoveal; from 297.42 ± 68.35 μmto 302.79 ± 73.05 μm, p = 0.068 for the nasal; from 324.01 ± 64.21μm to 330.33 ± 65.84, p = 0.117 for the temporal thicknesses). With four hours use of N95 respirators or surgical face masks, retinal vessel diameters and choroidal thicknesses showed an increase in comparison to baseline measurements. Hemodynamic changes seen secondary to hypercapnia due to prolonged use of N95 respirators or surgical masks may also be observed in the retinal and choroidal circulation. Furthermore, the use of face masks should be taken into account while assessing the retinal microvasculature.

Alterations of choroidal circulation and vascular morphology in a patient with chronic myeloid leukemia before and after chemotherapy

BackgroundChronic myeloid leukemia (CML) is known to cause leukemic retinopathy due to leukemia cell invasion into the choroid; however, details of the circulatory dynamics and morphological changes in the choroid are unknown. The aim of this study was to present a case of leukemic retinopathy and examine choroidal circulatory and structural analyses using laser speckle flowgraphy (LSFG) and optical coherence tomography with a binarization method, respectively.Case presentationA 15-year-old male diagnosed with CML complained of blurred vision in his right eye. He was ophthalmologically diagnosed with leukemic retinopathy due to retinal hemorrhage in both eyes. Tyrosine kinase inhibitors achieved complete cytogenetic remission and resolution of retinal hemorrhages at 6 months after treatment. After the treatment, the best-corrected visual acuity had recovered from 0.1 to 1.2 oculus dexter (OD) and remained at 1.5 oculus sinister (OS). The rate of change in macular blood flow assessed by the mean blur rate on LSFG was 18.3% increase OD and 25.2% decrease OS 19 months after treatment. The central choroidal thickness showed 0.4 and 3.1% reductions OD and OS, respectively. The binarization technique demonstrated that the rate of luminal areas in choroidal areas exhibited 3.2% increase OD but 4.8% decrease OS.ConclusionChoroidal blood flow improved OD after treatment for CML, while it deteriorated OS, together with choroidal thinning due to reduction of luminal areas. The degrees of leukemia cell invasion into the choroidal tissue and tissue destruction might be different between the eyes in this case.

Secondary Adverse Effects of Anti- Vascular Endothelial Growth Factor Therapy in Choroidal Circulation Case Report

Recent research has shown that abnormal production of vascular endothelial growth factor (VEGF) is an often finding in ocular pathologies involving neovascularization. The regulating factors that set the production of VEGF are not well understood, and only the presence of hypoxia in tissues is the most studied factor. But the regulation of oxygen levels in tissues is also not well elucidated, so therapies in this regard were not efficient. The availability of technology that allows to manufacture antibodies to the measure, allowed to design antibodies Anti VEGF. However, its therapeutic effects are far from what is expected because more is unknown than is known about VEGF. Therefore, its side effects as well as adverse effects are frequent, and even exceed its positive effects. The antiangiogenic effect of anti-VEGF antibodies is not selective, that is, it does not distinguish between normal vessels and neo-forming vessels. In this paper we report the adverse effects on the blood vessels of retinal and choroidal tissue of the intraocular application of anti-VEGF antibodies, and its impact on the form and function of these tissues.

Posterior ocular parameters following extraocular muscle surgery: an optical coherence tomography study

Background/Aim: Muscle trauma, vascular injury, and compensatory vasoconstriction during strabismus surgery may cause changes in the choroidal circulation in the early postoperative period. This study aims to evaluate the effect of extraocular muscle surgery on posterior ocular parameters, including central subfield thickness (CST), average retinal thickness (ART), choroidal thickness (CT), and macular volume (MV). Methods: This prospective cohort study included 26 eyes of 26 strabismic patients who underwent single medial or lateral rectus recession surgery using a fornix-based conjunctival incision. All participants underwent detailed ophthalmologic evaluation, including axial length (AL) and spherical equivalent (SE), uncorrected (UCVA), and best-corrected visual acuity (BCVA). Retinal and choroidal images were obtained using spectral-domain optical coherence tomography (OCT). All measurements were performed preoperatively and repeated 1 week and 1 month after surgery. Results: All patients received satisfactory results in terms of deviation. None of the patients showed changes in AL, SE, UCVA, and BCVA. No significant differences were noted in CST and MV values (P=0.472 and P=0.182, respectively). Although subfoveal CT and ART showed statistically significant decreases 1 week after surgery (P=0.012 and P=0.046, respectively), no significant differences in these values were observed 1 month after surgery (P>0.05). No significant differences exist in the measurements between the preoperative, postoperative first week, and first month in nasal and temporal CT (P>0.05). Conclusion: Extraocular muscle surgery performed with the fornix-based conjunctival incision is a safe procedure for posterior ocular parameters, including CST, ART, CT, and MV.

Associations Between Peripapillary Retinal Nerve Fiber Layer and Choroidal Thickness With the Development and Progression of Diabetic Retinopathy.

PurposeTo evaluate the role of the peripapillary retinal nerve fiber layer (pRNFL) and peripapillary choroidal thickness (pCT) in the development and progression of diabetic retinopathy (DR).MethodsThis is a cohort study based on the baseline and 2-year follow-up data of the Guangzhou Diabetic Eye Study. Patients with type 2 diabetes mellitus between the ages of 30 and 80 years were recruited from communities in Guangzhou. DR was graded by seven-field fundus photography after dilation of the pupil. pRNFL and pCT were measured via swept-source optical coherence tomography.ResultsA total of 895 patients were included in the study; of these, 748 did not have DR at baseline and 147 had DR at baseline. During the 2-year follow-up, 80 developed DR (10.7%), and 11 experienced DR progression (7.5%). After adjusting for confounding factors, a higher risk of incident DR was strongly associated with a lower average thickness of the pRNFL (risk ratio [RR] per 1 SD, 0.55; 95% confidence interval [CI], 0.42–0.72; P < 0.001) and average pCT (RR per 1 SD, 0.49; 95% CI, 0.34–0.70; P < 0.001). Adding both metrics to the DR prediction model significantly improved the discriminant ability of the model for incidences of DR (area under the curve increased by 15.38% from 0.673 to 0.777; P < 0.001).ConclusionsNeurodegeneration shown by the thinning of pRNFL and impaired choroidal circulation shown by the thinning of pCT are independently associated with DR onset, and assessing both metrics can improve the risk assessment for DR incidences.

THE PLACE OF PROGRESSIVE SPECTACLES CORRECTION IN AN INTEGRATED APPROACH TO THE THERAPY OF THE EARLY STAGES OF AGE-RELATED MACULAR DEGENERATION

The purpose: to determine the place of progressive spectacles correction in an integrated approach for the treatment of early stages of age-related macular degeneration (AMD) in hyperopic patients. Material and methods: 30 patients (60 eyes) aged 42-75 y.o., average age (58,8 ± 6,5) years, with early stages of AMD and hyperopia were under observation. The observation group was represented by 20 patients (40 eyes). After AMD revealing they applied progressive spectacles correction of «universal» type and received orally dietary supplement Retinorm® 3 capsules one time per day. The comparison group consisted of 10 patients (20 eyes). They received the same oral dietary supplement and used the previous monofocal correction. Methods of examination of patients included: checking of visual acuity with correction, refractometry, tonometry, computer static perimetry, ophthalmobiomicroscopy with Goldmann lens, optical coherence tomography of the central fundus area with measurement of retinal thickness in the fovea zone and choroid in manual mode. The duration of observation in both groups was 4 months. Results. The thickness of the retina in the fovea zone after the use of correction and prescribed treatment did not change either in the observation group (p &gt; 0,1) or in the comparison group (p &gt; 0,1). The thickness of the choroid after the prescribed therapeutic measures significantly increased in the observation group (p &lt; 0,05) and remained without changes in the comparison group (p &gt; 0,1). An increase of visual acuity was established, as well as a decrease in the number of relative scotomas in the central part of the visual field both in the observation group (p &lt; 0,02) and in the comparison group (p &lt; 0,05). Conclusion. The use of «universal» type of progressive spectacles correction in combination with taking dietary supplement Retinorm® increases the effectiveness of treatment of early stages of AMD in hyperopic patients due to both the activation of choroidal blood circulation, and the improvement of metabolic processes in the choroid and retina.

Acute macular neuroretinopathy and COVID-19 vaccination

Dear Editor, We read with interest the article by Vinzamuri et al.[1] The hyperreflective lesions seen on ganglion layer could represent sections across the vessels. It would be helpful if the optical coherence tomography images would be accompanied by section through which it was taken. Since acute macular neuroretinopathy (AMN) and paracentral middle maculopathy (PAMM) are possibly related to vascular occlusion either a fundus fluorescein angiography or optical coherence tomography angiography can add value to their case. In AMN, changes occur due to reduced retinal perfusion at the level of deep capillary plexus, which provides retinal perfusion to the zone between the retinal and choroidal circulations.[23] AMN multimodal imaging findings described could be dark lesions on red-free imaging, hypo-autofluorescence on fundus autofluorescence, and early and late hypofluorescence on fluorescein angiography. Infrared imaging also detected the lesions with a darkened outline.[4] Despite complete visual recovery, there is a possibility of persisting scotoma which may be as a result of thinning of the affected retinal layers.[5] We agree with the authors that AMN and PAMM following COVID-19 vaccine may not be causal and may have to be explored further. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.