Dual polarization Fourier transform processor using geometric-phase lenses.

This work presents a novel optical system for polarization image processing using geometric-phase (Pancharatnam-Berry) lenses. Such lenses are half-wave plates where the orientation of the fast (slow) axis follows a quadratic relation with the radial coordinate, and they present the same focal length but opposite sign for left and right circular polarizations. Therefore, they split an input collimated beam in a converging beam and a diverging beam with opposite circular polarizations. This coaxial polarization selectivity introduces a new degree of freedom in optical processing systems and makes it interesting for imaging and filtering applications that require polarization sensitivity. Here we profit from these properties to build an optical Fourier filter system with polarization sensitivity. A telescopic system is used to have access to two real Fourier transform planes, one for each circular polarization. A second symmetric optical system is used to recombine the two beams onto a single final image. As a result, polarization sensitive optical Fourier filtering can be applied, as demonstrated with simple bandpass filters.

Retrieving the phase of diffraction orders generated with tailored gratings.

A technique is performed to quantitatively evaluate the intensity and phase of the diffraction orders generated by tailored phase gratings displayed onto a liquid-crystal spatial light modulator (LC-SLM). The SLM displays the grating together with a lens to obtain the Fourier transform. The setup is converted into a polarization common-path interferometer by simply rotating a polarizer. This configuration allows a phase-shifting interferometry algorithm to be applied to retrieve the phase of the diffraction orders. The quadratic phase arising in the system, which must be subtracted, is calibrated using triplicator gratings of varying periods. Various tailored designs with controlled phase shift between diffraction orders are experimentally tested to prove the advantage and simplicity of the technique.

OPHTHALMOLOGIC INVOLVEMENT IN PATIENTS WITH HEREDITARY TRANSTHYRETIN AMYLOIDOSIS.

PURPOSE: The aim of this study was to determine the ophthalmologic involvement in patients with hereditary transthyretin amyloidosis and its correlation with the mutations described in the literature. METHODS: Cross-sectional, noninterventional study. Fifty-two eyes of 26 consecutive patients diagnosed with hereditary transthyretin amyloidosis who visited the Puerta de Hierro-Majadahonda University Hospital from September 2019 to March 2022. All patients underwent complete ophthalmologic examination and multimodal imaging. Cardiologic, neurologic, digestive, and renal examinations were also recorded. RESULTS: Eighteen eyes of the total (34.61%) showed amyloid-related ocular involvement, vitreous amyloid deposits being the most common ocular manifestation (18/52). Statistically significant differences were found for the presence of vitreous amyloid deposits ( P < 0.01), crystalline amyloid deposits ( P < 0.05), parenchymal amyloid deposits ( P < 0.01), and vascular alterations ( P < 0.01) when comparing affected and unaffected eyes. Moreover, affected eyes showed worse best-corrected visual acuity ( P < 0.01). CONCLUSION: Ocular manifestations are present in a substantial number of patients with ATTR that could potentially lead to devastating consequences to patients' best-corrected visual acuity and quality of life. Therefore, it is important to emphasize the importance of multidisciplinary management and ophthalmologic assessment, follow-up and surgical treatment when necessary. To the best of our knowledge, this represents the largest series in Spain of amyloidosis' ophthalmologic involvement.

ASSESSMENT AND ROLE OF ARTERY-VEIN COMPLEX IN MYOPIC CHOROIDAL NEOVASCULARIZATION USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To analyze the presence of an artery-vein complex (AVC) underneath myopic choroidal neovascularization (mCNV) and to determine its relationship with neovascular activity. METHODS: Retrospective analysis of 681 eyes from 362 patients with high myopia defined by an axial length of >26 mm using optical coherence tomography (OCT) and OCT angiography imaging. Patients with clinical diagnosis of mCNV and good quality OCT angiography images were then selected. An AVC was defined by the identification of both perforating scleral vessels and dilated choroidal veins under or in contact with the mCNV in the same case. Swept source OCT (SS-OCT) and SS-OCT angiography images (TRITON; Topcon Corporation, Tokyo, Japan) were reviewed to detect AVC in the mCNV area. RESULTS: Fifty eyes of 49 highly myopic patients with mCNV were analyzed. Eyes with AVC were statistically older (69.95 ± 13.53 vs. 60.83 ± 10.47 years old; P < 0.01), needed less intravitreal injections/year along the follow-up period (0.80 ± 0.62 vs. 1.92 ± 0.17; P < 0.01), and showed less relapses/year (0.58 ± 0.75 vs. 0.46 ± 0.42; P < 0.05) when compared with eyes without AVC. Moreover, eyes with AVC were less likely to relapse during the first year from mCNV activation (n = 5/14 vs. n = 14/16; P < 0.01; P < 0.01). No significant differences were found regarding either axial length (30.55 ± 2.31 vs. 29.65 ± 2.24, P > 0.05) or best-corrected visual acuity (0.4 ± 0.5 vs. 0.4 ± 0.5 Logarithm of the Minimum Angle of Resolution (logMAR), P > 0.05) between groups. CONCLUSION: AVC complex has an influence over myopic choroidal neovascularization activity resulting in less aggressive neovascular lesions than those with perforating scleral vessels only.

Atrophic, Tractional, and Neovascular Grading System in a Dome-Shaped Macula and Ridge-Shaped Macula Highly Myopic Cohort.

INTRODUCTION: The aim of this study was to analyze the atrophic, tractional, and neovascular (ATN) components grading in highly myopic patients with dome-shaped macula (DSM) and ridge-shaped macula (RSM). METHODS: This was a cross-sectional, noninterventional study. 57 eyes of 38 different patients were included. They were classified as DSM or RSM based on the number of radial scans that showed an inward protrusion ≥50 µm in the swept-source optical coherence tomography (SS-OCT) (12 = DSM; <12 = RSM). All patients underwent a complete ophthalmological examination in addition to SS-OCT. They were graded using the ATN system for myopic maculopathy by 2 masked retina specialists that assessed the atrophic (A), tractional (T), and neovascular (N) components in order to analyze the differences between the groups. As complementary measurements, age, axial length, and best-corrected visual acuity were collected. Height and orientation of the macular bulge and the presence of Bruch's membrane defects, scleral perforating vessels, and staphyloma were recorded. RESULTS: Out of total 57 eyes, 13 eyes (22.8%) were classified as DSM. Regarding the atrophic component (A), there were statistically significant differences between groups, with DSM group showing a greater stage of atrophy (predominantly stage A3 in 69.2% of the sample) compared to the RSM group (predominantly stage A2 in 61.3% of the sample) (p < 0.05). For the T and N components, there were no significant differences between groups. The presence of Bruch's membrane defects was more frequently seen in DSM (p < 0.05). CONCLUSIONS: DSM group showed more Bruch's membrane defects and a greater stage of the atrophy component, based on the ATN grading system, compared with RSM group. As Bruch's membrane may have biomechanical properties in terms of strength, the defects found around the macula, added to the major atrophic component, may be a cause of a local relaxation that induce a central bulge forming the dome.

Pathologic myopia and severe pathologic myopia: correlation with axial length.

PURPOSE: This study had three aims: (1) correlate axial length (AL), age and best-corrected visual acuity in high myopic patients scored on the ATN grading system; (2) determine AL cut-off values to distinguish between pathologic myopia (PM) and severe PM; and (3) identify clinical differences between PM and severe PM. METHODS: This is a cross-sectional, non-interventional study. All patients underwent complete ophthalmologic examination, ATN grading and multimodal imaging (colour fundus photography, swept-source OCT, fundus autofluorescence, OCT angiography and fluorescein angiography). RESULTS: Six hundred forty-four eyes from 345 high myopic patients were included. The eyes were graded on the ATN system and classified as PM (≥ A2) or severe PM (≥ A3, ≥ T3 and/or N2). Significant between-group (PM vs. severe PM) differences (p < 0.05) were observed on the individual ATN components (atrophic [A], tractional [T] and neovascular [N]), age, BCVA and AL. AL was also linearly correlated with the A, T and N components (r = 0.53, p < 0.01; r = 0.24, p < 0.01; r = 0.20, p < 0.01; respectively). ROC curve analysis showed the optimal AL cut-off value to distinguish between PM at 28 mm (AUC ROC curve: 0.813, specificity: 75%, sensitivity: 75%) and severe PM at 29.50 mm (AUC ROC curve: 0.760, specificity: 75%, sensitivity: 70%). CONCLUSION: AL is the main variable associated with myopic maculopathy. Due to the clinical differences found between PM and severe PM, there is need to create an objective cut-off point to distinguish these two different entities being the optimal cut-off points for AL 28 mm and 29.5 mm, respectively. These objective AL cut-off values should be taken into account for determining a correct follow-up, ophthalmic management and treatment.

RELATIONSHIP BETWEEN MYOPIC CHOROIDAL NEOVASCULARIZATION ACTIVITY AND PERFORATING SCLERAL VESSELS IN HIGH MYOPIA.

PURPOSE: To study perforating scleral vessels (PSVs) in patients with high myopia using swept-source optical coherence tomography and to determine their relationship with myopic choroidal neovascularization (mCNV) and its activity. METHODS: Retrospective analysis of patients with high myopia (≥-6 D or ≥26 mm of axial length) using multimodal imaging. The presence of PSVs and mCNV was assessed using swept-source optical coherence tomography images (TRITON; Topcon Corporation, Japan). RESULTS: Five hundred sixty-four eyes from 297 highly myopic patients were studied. One hundred fifty-five eyes (27.5%) showed signs of mCNV while PSVs were found in 500 eyes (88.6%). Perforating scleral vessels were found in 93.5% (145/155) of eyes with mCNV, and they were under or in contact with the mCNV in 80.6% (117/145). The mean number of intravitreal injections received by patients with mCNV was 4.06 ± 4.17 along 66.9 ± 4.1 months of follow-up. The number of injections per year was 1.32 ± 1.56, the mean number of relapses was 1.11 ± 1.83, and the mean number of relapses per year was 0.25 ± 0.41. CONCLUSION: Perforating scleral vessels are more common among highly myopic patients suffering from neovascular complications. Myopic CNV complexes that are coincident with PSVs on optical coherence tomography show higher rates of activity, needing more injections to control them and being more prone to relapses.

The economic burden of pulmonary arterial hypertension in Spain.

BACKGROUND: Pulmonary Arterial Hypertension (PAH) is a rare, debilitating, and potentially fatal disease. This study aims to quantify the economic burden of PAH in Spain. METHODS: The study was conducted from a societal perspective, including direct and indirect costs associated with incident and prevalent patients. Average annual costs per patient were estimated by multiplying the number of resources consumed by their unit cost, differentiating the functional class (FC) of the patient. Total annual costs per FC were also calculated, taking the 2020 prevalence and incidence ranges into account. An expert committee validated the information on resource consumption and provided primary information on pharmacological consumption. Unit costs were estimated using official tariffs and salaries in Spain. A deterministic sensitivity analysis was conducted to test the uncertainty of the model. RESULTS: The average annual total cost was estimated at €98,839 per prevalent patient (FC I-II: €65,233; FC III: €103,736; FC IV: €208,821), being €42,110 for incident patients (FC I-II: €25,666; FC III: €44,667; FC IV: €95,188). The total annual cost of PAH in Spain, taking into account a prevalence between 16.0 and 25.9 cases per million adult inhabitants (FC I-II 31.8%; FC III 61.3%; FC IV 6.9%) and an incidence of 3.7, was estimated at €67,891,405 to €106,131,626, depending on the prevalence considered. Direct healthcare costs accounted for 64% of the total cost, followed by indirect costs (24%), and direct non-healthcare costs (12%). The total costs associated with patients in FC I-II ranged between €14,161,651 and €22,193,954, while for patients in FC III costs ranged between €43,763,019 and €68,391,651, and for patients in FC IV between €9,966,735 and €15,546,021. In global terms, patients with the worst functional status (FC IV) account for only 6.9% of the adults suffering from PAH in Spain, but are responsible for 14.7% of the total costs. CONCLUSIONS: PAH places a considerable economic burden on patients and their families, the healthcare system, and society as a whole. Efforts must be made to improve the health and management of these patients since the early stages of the disease.

Organic mulching modulated native populations of entomopathogenic nematode in vineyard soils differently depending on its potential to control outgrowth of their natural enemies.

The entomopathogenic nematodes (EPNs) are biological control agents that are widespread in crop soils. However, traditional agricultural management practices such as cultivation and agrochemical usage can alter the soil balance that enables their occurrence and activity. Alternative strategies like mulching are commonly employed to prevent weed growth, enhance below-ground biodiversity by improving soil, organic matter content, fertility, and moisture. We hypothesized that organic mulches would favor biotic conditions for nematofauna development in crop soil, including EPNs, compared to herbicide application or tillage. Traditional (insect baits) and molecular (qPCR analysis) tools were used in this study to assess the abundance and activity of native EPNs, and the abundance of potential natural enemies, such as free-living nematode (FLN) competitors, nematophagous fungi (NF), and ectoparasitic bacteria, in soils managed with different organic mulches or traditional practices. As a model agroecosystem, we selected the vineyard, one of the most intensively managed crop systems. We compared mulches of grape pruning debris (GPD-M), straw (Str-M), and spent mushroom compost (SMC-M) in two commercial vineyards, which employed either integrated or organic pest and disease management. Following a completely randomized design, we retrieved two composite samples per plot (n = 3 per treatment in each vineyard) in April, June, and October 2020. Numbers of EPNs and selected members of their soil food web were higher in the organic than the integrated managed vineyard. Supporting our hypothesis, organic mulching overall favored nematode occurrence in both vineyards. We found higher NF abundance for Str-M, and GPD-M in the organic vineyard, which plausibly explained the lower EPN activity and occurrence compared to SMC-M in both vineyards. We conclude that the organic mulches can provide appropriate conditions for increasing nematofauna numbers but, depending on the mulch type, may also adversely affect EPNs by increasing their natural enemies. Our findings highlight the need to explore alternative farming practices to unravel complex biotic interactions that affect beneficial soil organisms in agroecosystems.

Head adaptation for sound production and feeding strategy in dolphins (Odontoceti: Delphinida).

Head morphology in toothed whales evolved under selective pressures on feeding strategy and sound production. The postnatal development of the skull (n = 207) and mandible (n = 219) of six Delphinida species which differ in feeding strategy but exhibit similar sound emission patterns, including two narrow-band high-frequency species, were investigated through 3D morphometrics. Morphological changes throughout ontogeny were demonstrated based on the main source of variation (i.e., prediction lines) and the common allometric component. Multivariate trajectory analysis with pairwise comparisons between all species was performed to evaluate specific differences on the postnatal development of skulls and mandibles. Changes in the rostrum formation contributed to the variation (skull: 49%; mandible: 90%) of the entire data set and might not only reflect the feeding strategy adopted by each lineage but also represents an adaptation for sound production and reception. As an important structure for directionality of sound emissions, this may increase directionality in raptorial feeders. Phylogenetic generalized least squares analyses indicated that shape of the anterior portion of the skull is strongly dependent on phylogeny and might not only reflect feeding mode, but also morphological adaptations for sound production, particularly in raptorial species. Thus, postnatal development seems to represent a crucial stage for biosonar maturation in some raptorial species such as Pontoporia blainvillei and Sousa plumbea. The ontogeny of their main tool for navigation and hunting might reflect their natural history peculiarities and thus potentially define their main vulnerabilities to anthropogenic changes in the environment.

Unraveling the physical information of depolarizers.

The link between depolarization measures and physical nature and structure of material media inducing depolarization is nowadays an open question. This article shows how the joint use of two complementary sets of depolarizing metrics, namely the Indices of polarimetric purity and the Components of purity, are sufficient to completely describe the integral depolarizing properties of a sample. Based on a collection of illustrative and representative polarimetric configurations, a clear and meaningful physical interpretation of such metrics is provided, thus extending the current tools and comprehension for the study and analysis of the depolarizing properties of material media. This study could be of interest to those users dealing with depolarization or depolarizing samples.

Seascape Genetics of the Atlantic Spotted Dolphin (Stenella frontalis) Based on Mitochondrial DNA.

The Atlantic spotted dolphin (Stenella frontalis) is endemic to tropical, subtropical, and warm temperate waters of the Atlantic Ocean. Throughout its distribution, both geographic distance and environmental variation may contribute to population structure of the species. In this study, we follow a seascape genetics approach to investigate population differentiation of Atlantic spotted dolphins based on a large worldwide dataset and the relationship with marine environmental variables. The results revealed that the Atlantic spotted dolphin exhibits population genetic structure across its distribution based on mitochondrial DNA control region (mtDNA-CR) data. Analyses based on the contemporary landscape suggested, at both the individual and population level, that the population genetic structure is consistent with the isolation-by-distance model. However, because geography and environmental matrices were correlated, and because in some, but not all analyses, we found a significant effect for the environment, we cannot rule out the addition contribution of environmental factors in structuring genetic variation. Future analyses based on nuclear data are needed to evaluate whether local processes, such as social structure and some level of philopatry within populations, may be contributing to the associations among genetic structure, geographic, and environmental distance.

Remote screening of retinal and optic disc diseases using handheld nonmydriatic cameras in programmed routine occupational health checkups onsite at work centers.

PURPOSE: To evaluate the first year outcomes of a remote screening program for detection of retinal diseases using handheld nonmydriatic cameras in occupational routine checkups performed onsite at work centers. METHODS: Cross-sectional, first year screening program outcomes audit. Participants were volunteers recruited from staff within work centers. Retinal fundus images were captured by technicians, and images and data were anonymized and sent securely to a remote server. A team of ophthalmologists, all retinal specialists, remotely read the images using a custom-made software and sent telematic reports of findings within 24-48 h. The main items evaluated were the detection of retinal abnormalities and the relationship between retinal findings and demographic data such as age and sex. RESULTS: A total of 19,881 workers were evaluated in 52 centers. Mean age was 41.1 years old, 43.9% men and 56.1% women. Mean duration of the test was around 2 min. Of the workers, 7.8% presented abnormalities in retinal fundus images, being the main findings choroidal nevus (2.4%), macular pigment abnormalities (1.5%), glaucomatous optic disc (1.2%), and macular signs of high myopia (1.1%). The presence of abnormalities was associated with greater age, being 5%, 7.9%, 12.6%, and 19.7% in workers less than 40 years, from 40 to 49, 50-59, and ≥ 60 years (p < 0.05), respectively. Men had more abnormalities in retinal fundus images than women (8.6 vs. 7.2; p < 0.05 RR: 1.2; CI 1092-1322). CONCLUSIONS: Mass screening of retinal and optic disc abnormalities during occupational health routine checkups is a feasible, quick, and efficient tool for early detection of potential vision-threatening disease markers.

CORRELATION BETWEEN ATROPHY-TRACTION-NEOVASCULARIZATION GRADE FOR MYOPIC MACULOPATHY AND CLINICAL SEVERITY.

PURPOSE: To assess the reliability of the atrophy-traction-neovascularization (ATN) classification in patients with pathologic myopia (PM) and its correlation with best-corrected visual acuity (BCVA). METHODS: Cross-sectional study. Hundred highly myopic eyes with a spherical equivalent of >-6.0 diopters or axial length of >26 mm and a total ATN score of ≥3 underwent a complete ophthalmological examination, including fundus photography and swept-source optical coherence tomography. Five observers graded each eye using the ATN system. Mean A, T, and N scores were calculated and correlated with age, BCVA (in logarithm of the minimum angle of resolution), and axial length. Patients were considered to present severe PM if either A or T components were ≥3 and/or N was ≥2. RESULTS: Hundred eyes (53 left) from 91 patients (78 women) were classified. Mean age, BCVA, and axial length values were, respectively, 65.1 ± 11.7 years (range, 36-97 years), -0.63 ± 0.62 (-3.00 to 0.00), and 29.26 ± 2.7 mm (26.01-37.66 mm). Mean ATN grades for each component were as follows: A = 2.51 ± 0.78 (0.6-4.0), T = 0.88 ± 1.14 (0.0-5.0), and N = 1.31 ± 1.40 (0.0-3.0). Weighted interobserver agreement was 98.1%, 98.7%, and 94.6%, for A, T and N, respectively. In eyes with severe PM, BCVA was significantly lower and axial length was significantly longer. CONCLUSION: The excellent interobserver rate in this study demonstrates that the updated ATN grading system is an accurate and reliable tool to classify patients with PM. These findings show that BCVA is more compromised in eyes with severe PM, particularly those graded ≥A3 and/or T3.

Evolution of Macular Bruch Membrane Defects of Patchy Chorioretinal Atrophy in Pathologic Myopia Based on a Recent Classification System.

PURPOSE: The purpose of this study was to analyze the progression of macular Bruch membrane defects (BMD) in highly myopic patients with patchy atrophy (PA); and study its correlation with the enlargement of PA and ATN grading. Setting/Venue: Puerta de Hierro-Majadahonda University Hospital, Madrid, Spain. PATIENTS AND METHODS: This was a cross-sectional, noninterventional study. A series of 451 highly myopic eyes with spherical equivalent > -6.0 D and/or >26 mm of axial length (AL) were included. All patients underwent a complete ophthalmological examination and swept-source optical coherence tomography (SS-OCT), and were graded using the ATN system by 2 masked retina experts that assessed the atrophic (A), tractional (T), and neovascular (N) components. SS-OCT b-scans were employed to study PA and macular BMD at baseline and at a 1-year follow-up, in patients with good foveal fixation. RESULTS: Out of total 451 eyes, 126 eyes (27.9%) had PA (53 patients; 75.4% women). Mean T and N in eyes with PA were 1.1 ± 1.3 and 0.08 ± 0.2, respectively. Sixty-eight of them had >1-year follow-up with a good foveal fixation and enough image quality. From them, BMD were found in 44 eyes (64.7%) at baseline and increased to 59 eyes (86.7%) at a 1-year follow-up. The mean great linear dimension of PA and macular BMD increased with a median of 384.5 ± 462.5 µm (IR 68.0-660.2) and 265.6 ± 418.1 µm (IR 0-331.7), respectively. At 1-year, PA and BMD sizes increase, and were statistically significant (p < 0.001). There was a positive correlation between the growth of macular BMD and the growth of PA (r = 0.490, p < 0.00). T grading correlated significantly with PA growth (p < 0.05). CONCLUSIONS: Macular BMD increase its prevalence and its size over time in highly myopic patients with PA. There is a positive correlation between BMD and PA area growth. New studies with a larger sample size, longer follow-up, and AL elongation correlation are necessary to corroborate our findings.

Measuring the spatial deformation of a liquid-crystal on silicon display with a self-interference effect.

We present a simple technique to characterize the spatial non-uniformity of a liquid-crystal on silicon (LCOS) spatial light modulator (SLM). It is based on illuminating the display with a wavelength out of the operation range, so there is a significant reflection at the output surface. As a consequence, a Gires-Tournois interferometer is directly created, without any alignment requirement and insensitive to vibrations. The beam reflected at the output surface is the reference beam, while the beam reflected at the silicon backplane is modulated with the addressed gray level in order to quantitatively derive its deformation. We provide an experimental demonstration using a LCOS-SLM designed to operate in the near-infrared range but illuminated with visible light.

In-phase sub-Nyquist lenslet arrays encoded onto spatial light modulators.

When encoding diffractive lenses onto a spatial light modulator (SLM), there is a Nyquist limit to the smallest focal length that can be formed. When this limit is surpassed, a two-dimensional array of lenslets is formed. There have been very few discussions on the performance of these lenslets. In this work, we focus on the phase distribution of these lenses in the array. We show that, for certain values of the focal length, the lenslets are all in perfect phase. We show that this situation happens for a total number of N/4 different discrete equidistant sub-Nyquist focal lengths, where N×N is the number of pixels in the SLM. We find other distances in between where the array is composed of two sets of lenslets with a relative π phase among them. Finally, we illustrate these phase distributions in the application to generate an array of vortex producing lenses. We expect that these results might be useful for high-accuracy interferometric or multiple imaging where this phase must be exactly the same for each replica.

VALIDATION OF THE RECENTLY DEVELOPED ATN CLASSIFICATION AND GRADING SYSTEM FOR MYOPIC MACULOPATHY.

PURPOSE: To validate the recently developed ATN grading system for myopic maculopathy to classify eyes with pathologic myopia. METHODS: Cross-sectional study. A series of consecutive eyes diagnosed with pathologic myopia and signs of myopic maculopathy (grade ≥1 for atrophic, tractional, or neovascular components of the ATN), with a refractive error > -6.0 diopters (D), were included. All patients underwent complete ophthalmological examination including fundus photography and swept-source optical coherence tomography. Six observers graded each eye twice using the ATN system (≥15 days between assessments) based only on the aforementioned data. RESULTS: Sixty eyes from 47 patients (61.7% female) were graded. Mean patient age was 63.2 ± 11.7 years. The mean spherical equivalent was -13.8 ± 6.5 D. Mean axial length was 28.6 ± 2.16 mm. Overall, the mean intraobserver agreement (%) for the same image was 92.0%, and the mean interobserver agreement for the second image was 77.5%. The weighted Fleiss k showed excellent correlation (k > 0.8) for the traction and neovascularization components and good correlation (0.75) for atrophy. Interobserver agreement for each of these three components was 95.2%, 98.4%, 95.0%, respectively. CONCLUSION: Application of the ATN resulted in high intraobserver and interobserver correlation, underscoring the reproducibility of the system.

CHANGES IN CHORIOCAPILLARIS, SATTLER, AND HALLER LAYER THICKNESSES IN CENTRAL SEROUS CHORIORETINOPATHY AFTER HALF-FLUENCE PHOTODYNAMIC THERAPY.

PURPOSE: To determinate the variation in thickness of the individual choroidal layers in patients with central serous chorioretinopathy treated with half-fluence photodynamic therapy. METHODS: Twenty-two eyes were evaluated with spectral-domain optical coherence tomography. The images were taken before photodynamic therapy, 3 months, and 6 months after the treatment. Two investigators performed these measurements: 1) choroidal thickness (CT), 2) Haller layer thickness, defined as the most external layer containing a 100-µm vessel, and 3) choriocapillaris + Sattler layer (C&S). Nine measurements were taken in the macular region. RESULTS: Choroidal thickness before photodynamic therapy was 471.8 µm ± 145.8. The Haller layer was 358.4 µm ± 122.6, and C&S was 114.3 µm ± 27.8. At 3-month follow-up, CT was 441.1 µm ± 150.7, Haller layer 348.8 µm ± 127.6, and C&S 92.4 µm ± 27.9. At 6-month follow-up, CT was 420.4 µm ± 118.4, Haller layer 331.8 µm ± 97.2, and C&S 89.5 µm ± 28.0. Using a multilevel mixed-effects linear regression, CT was found to be reduced at both 3 months (P < 0.03) and at 6 months (P < 0.001), Haller layer showed no significant reduction at 3 months (P = 0.483) or at 6 months (P = 0.055), and C&S showed reduction at 3 months (P < 0.001) and at 6 months (P < 0.001). Fellow nonaffected eyes showed no statistical variation at 3-month and 6-month follow-up. CONCLUSION: Reduction in CT in patients affected by central serous chorioretinopathy after half-fluence photodynamic therapy occurs primarily in the choriocapillaris and medium diameter vessel layers of the choroid in a short- and medium-term follow-up.

INTERNAL LIMITING MEMBRANE PEELING VERSUS NONPEELING TO PREVENT EPIRETINAL MEMBRANE DEVELOPMENT IN PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT: A Swept-Source Optical Coherence Tomography Study With a New Postoperative Classification System.

PURPOSE: To determine whether internal limiting membrane peeling in primary rhegmatogenous retinal detachment prevents epiretinal membrane (ERM) development. Secondarily, we propose a classification system for postoperative ERMs. METHODS: Retrospective, interventional, comparative case series. Consecutive eyes with primary rhegmatogenous retinal detachment (n = 140) treated by a single surgeon. The presence of postoperative ERMs was assessed with swept-source optical coherence tomography. RESULTS: An ERM was detected in 26 eyes (46.4%) in the nonpeeling group and in one eye (1.8%) in the internal limiting membrane peeling group (P ≤ 0.001). The median visual acuity significantly improved in both groups (P ≤ 0.001). Inner retinal dimples were observed in 41.1% of eyes in the internal limiting membrane peeling group versus 0% in the nonpeeling group (P ≤ 0.001), and they were not correlated with visual acuity (r = 0.011; P = 0.941). Based on swept-source optical coherence tomography findings, we identified three different types of ERMs: 7 (26.9%) were classified as Type 1, 12 (46.1%) as Type 2, and 7 (26.9%) as Type 3. Superficial retinal plexus deformations observed on optical coherence tomography angiography and en face images were detected in 100% of Type 3 ERMs, 41.6% of Type 2, and 0% of Type 1 (χ = 14.3; P = 0.001). Interestingly, all of the patients who presented these alterations also had metamorphopsia. CONCLUSION: Internal limiting membrane peeling in primary rhegmatogenous retinal detachment seems to prevent postoperative ERM development. Swept-source optical coherence tomography analysis is helpful to define and classify different types of ERMs and to establish the surgical indication for their removal.