New Insights into Calcite Dissolution Mechanisms under Water, Proton, or Carbonic Acid-Dominated Conditions.

Carbonate minerals are ubiquitous in nature, and their dissolution impacts many environmentally relevant processes including preferential flow during geological carbon sequestration, pH buffering with climate-change induced ocean acidification, and organic carbon bioavailability in melting permafrost. In this study, we advance the atomic level understanding of calcite dissolution mechanisms to improve our ability to predict this complex process. We performed high pressure and temperature (1300 psi and 50 °C) batch experiments to measure transient dissolution of freshly cleaved calcite under H2O, H+, and H2CO3-dominated conditions, without and with an inhibitory anionic surfactant present. Before and after dissolution experiments, we measured dissolution etch-pit geometries using laser profilometry, and we used density functional theory to investigate relative adsorption energies of competing species that affect dissolution. Our results support the hypothesis that calcite dissolution is controlled by the ability of H2O to preferentially adsorb to surface Ca atoms over competing species, even when dissolution is dominated by H+ or H2CO3. More importantly, we identify for the first time that adsorbed H+ enhances the role of water by weakening surface Ca-O bonds. We also identify that H2CO3 undergoes dissociative adsorption resulting in adsorbed HCO3- and H+. Adsorbed HCO3- that competes with H2O for Ca acute edge sites inhibits dissolution, while adsorbed H+ at the neighboring surface of CO3 enhances dissolution. The net effect of the dissociative adsorption of H2CO3 is enhanced dissolution. These results will impact future efforts to more accurately model the impact of solutes in complex water matrices on carbonate mineral dissolution.

CHOROIDAL VASCULARITY AND VISUAL OUTCOMES IN MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To investigate the association between visual outcomes and choroidal changes in patients with macula-off rhegmatogenous retinal detachment. METHODS: This study retrospectively reviewed 63 eyes of patients with macula-off rhegmatogenous retinal detachment who underwent vitrectomy. Their fellow eyes were analyzed as a control group. The choroidal vascularity index (CVI), ellipsoid zone/external limiting membrane integrity, central foveal thickness, and subfoveal choroidal thickness were documented and analyzed. Linear regression analyses were performed to identify factors affecting the final best-corrected visual acuity. RESULTS: Eyes with rhegmatogenous retinal detachment showed increased CVI (68.8 ± 4.1) compared with the control group (66.1 ± 8.8, P = 0.028). Multivariate linear regression analysis revealed that patients with a poor final best-corrected visual acuity had a longer detachment duration ( P = 0.002), worse baseline best-corrected visual acuity ( P = 0.034), thinner central foveal thickness ( P = 0.005), and greater CVI ( P = 0.001) and were more likely to be tamponated with silicone oil ( P = 0.001). Choroidal vascularity index was particularly increased in eyes with poor ellipsoid zone/external limiting membrane integrity, prolonged detachment duration, thin central foveal thickness, and worse best-corrected visual acuity. CONCLUSION: Increased CVI could indicate poor visual outcomes in patients with macula-off rhegmatogenous retinal detachment. Choroidal remodeling could be associated with the disruption of the ellipsoid zone/external limiting membrane integrity.

Noninvasive Ventilation for Acute Respiratory Failure in Pediatric Patients: A Systematic Review and Meta-Analysis.

OBJECTIVE: To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) on the use of noninvasive ventilation (NIV) for acute respiratory failure (ARF) in pediatric patients. DATA SOURCES: We searched PubMed, EMBASE, the Cochrane Central Register of Clinical Trials, and Clinicaltrials.gov with a last update on July 31, 2022. STUDY SELECTION: We included RCTs comparing NIV with any comparator (standard oxygen therapy and high-flow nasal cannula [HFNC]) in pediatric patients with ARF. We excluded studies performed on neonates and on chronic respiratory failure patients. DATA EXTRACTION: Baseline characteristics, intubation rate, mortality, and hospital and ICU length of stays were extracted by trained investigators. DATA SYNTHESIS: We identified 15 RCTs (2,679 patients) for the final analyses. The intubation rate was 109 of 945 (11.5%) in the NIV group, and 158 of 1,086 (14.5%) in the control group (risk ratio, 0.791; 95% CI, 0.629-0.996; p = 0.046; I2 = 0%; number needed to treat = 31). Findings were strengthened after removing studies with intervention duration shorter than an hour and after excluding studies with cross-over as rescue treatment. There was no difference in mortality, and ICU and hospital length of stays. CONCLUSIONS: In pediatric patients, NIV applied for ARF might reduce the intubation rate compared with standard oxygen therapy or HFNC. No difference in mortality was observed.

Machine learning algorithm for early-stage prediction of severe morbidity in COVID-19 pneumonia patients based on bio-signals.

BACKGROUND: Paralysis of medical systems has emerged as a major problem not only in Korea but also globally because of the COVID-19 pandemic. Therefore, early identification and treatment of COVID-19 are crucial. This study aims to develop a machine-learning algorithm based on bio-signals that predicts the infection three days in advance before it progresses from mild to severe, which may necessitate high-flow oxygen therapy or mechanical ventilation. METHODS: The study included 2758 hospitalized patients with mild severity COVID-19 between July 2020 and October 2021. Bio-signals, clinical information, and laboratory findings were retrospectively collected from the electronic medical records of patients. Machine learning methods included random forest, random forest ranger, gradient boosting machine, and support vector machine (SVM). RESULTS: SVM showed the best performance in terms of accuracy, kappa, sensitivity, detection rate, balanced accuracy, and run-time; the area under the receiver operating characteristic curve was also quite high at 0.96. Body temperature and SpO2 three and four days before discharge or exacerbation were ranked high among SVM features. CONCLUSIONS: The proposed algorithm can predict the exacerbation of severity three days in advance in patients with mild COVID-19. This prediction can help effectively manage the reallocation of appropriate medical resources in clinical settings. Therefore, this algorithm can facilitate adequate oxygen therapy and mechanical ventilator preparation, thereby improving patient prognosis, increasing the efficiency of medical systems, and mitigating the damage caused by a global pandemic.

Reconstruction of Range-Doppler Map Corrupted by FMCW Radar Asynchronization.

Frequency-modulated continuous wave (FMCW) radar system synchronization using external clock signals can cause repeated Range-Doppler (R-D) map corruption when clock signal asynchronization problems occur between the transmitter and receiver. In this paper, we propose a signal processing method for the reconstruction of the corrupted R-D map owing to the FMCW radar's asynchronization. After calculating the image entropy for each R-D map, the corrupted ones are extracted and reconstructed using the normal R-D maps acquired before and after the individual maps. To verify the effectiveness of the proposed method, three target detection experiments were conducted: a human target detection in an indoor environment and a wide place and a moving bike-rider target detection in an outdoor environment. The corrupted R-D map sequence of observed targets in each case was reconstructed properly and showed the validity by comparing the map-by-map range and speed changes in the detected target with the ground-truth information of the target.

Effect of citric acid and heat treatment on the content of less-polar ginsenosides in flower buds of Panax ginseng.

Ginseng flower bud (GFB), as an inexpensive part of Panax ginseng, attracted significant attention as a beneficial functional food with medicinal potentials due to its high content of ginsenosides. A few studies focused on the utilization of heat treatment and citric acid treatment to process ginseng flowers, converting its polar ginsenosides into rare ginsenosides to improve its biological activities. Thus, in this study, we compared the changes of ginsenosides in GFB after citric acid and heat treatment by HPLC method. The results revealed that less-polar ginsenoside, Rg6 and F4, increased to 1.01 and 0.27% by heat treatment, respectively. Further, ginsenoside F2 increased to 1.13% with 1 M citric acid treatment. Furthermore, based on the combination of these two processing methods for the first time, the conversion rate of less-polar ginsenosides surged to 80%. The content of ginsenoside Rg3(s) and Rg5 increased to 1.509 and 1.871%, respectively, by simultaneous heat and citric acid treatment. Therefore, a processing approach that simultaneously performs heat and citric acid treatments has been proposed, and this considerably inexpensive and convenient processing method could be applied to the processing of GFBs and produce less-polar ginsenosides.

Analyses of the effects of persistent subretinal fluid on visual/anatomic outcomes according to the type of macular neovascularization during the relaxed treat-and-extend protocol in age-related macular degeneration patients.

BACKGROUND: To analyze the long-term effects of persistent subretinal fluid (SRF) on visual/anatomic outcomes according to the type of macular neovascularization (MNV) during relaxed treat-and-extend regimen with anti-vascular endothelial growth factor (anti-VEGF) agents in age-related macular degeneration (AMD) patients. METHODS: Patients with fovea-involving type 1 or type 2 MNV, treated with a relaxed treat-and-extend regimen for 2 years were retrospectively reviewed. Eyes with SRF observed more than three times per year were defined as the 'persistent SRF (+) group'. To exclude the effects of IRF as much as possible, the eyes with persistent IRF were excluded. The effects of persistent SRF on the best-corrected visual acuity (BCVA), central subfield retinal thickness (CST), and changes in the photoreceptor layer (PRL) thickness and outer retinal bands (external limiting membrane, ellipsoid zone, and cone outer segment tip line) after anti-VEGF injection were analyzed for each MNV type. RESULTS: Seventy-seven eyes with type 1 MNV (44 eyes with persistent SRF) and 53 eyes with type 2 MNV (18 eyes with persistent SRF) were enrolled. Following a relaxed treat-and-extend regimen with anti-VEGF agents, BCVA and CST improved for each MNV type. In comparison between persistent SRF (+) and persistent SRF (-) group, there were no differences in the amount of change in BCVA and CST between the two groups for each MNV type during 2-year follow-up periods. In addition, there were no differences in the amount of reduction in PRL thickness and state of the outer retinal bands between the two groups for each MNV type. CONCLUSIONS: Using a relaxed treat-and-extend regimen with anti-VEGF agents, persistent SRF did not have additional effects on visual and anatomic outcomes by 2 years, regardless of the MNV type.

EN-FACE OPTICAL COHERENCE TOMOGRAPHY IN PATIENTS WITH EPIRETINAL MEMBRANE: Intuitive Method for Predicting Functional Outcomes.

PURPOSE: To evaluate the correlation between en-face optical coherence tomography (OCT) parameters and functional outcomes before and after idiopathic epiretinal membrane (ERM) surgery. METHODS: This retrospective cohort study involved 80 eyes from 80 patients who underwent surgery for idiopathic ERM. Best-corrected visual acuity, metamorphopsia assessment (M-score), and OCT were assessed before surgery and six months after. The adhesive zone (A-zone) and retinal fold, a novel en-face OCT parameter reflecting inner retinal layer changes, were evaluated. Correlations between the area of A-zone and the number of retinal folds on en-face OCT images and other B-scan OCT parameters were evaluated regarding visual outcomes before and after ERM surgery. RESULTS: The defect size of the ellipsoid zone, interdigitation zone, and external limiting membrane were significantly correlated with preoperative and postoperative 6-month best-corrected visual acuity (all P < 0.05). The central foveal thickness, A-zone area, number of marginal retinal folds, and fovea involvement in the A-zone were correlated with the preoperative and postoperative 6-month M-score (all P < 0.05). The A-zone area was significantly associated with the preoperative and postoperative 6-month M-score in a multiple linear regression model (P < 0.001, P = 0.008, respectively), and the number of marginal retinal folds was significantly associated with the preoperative M-score (P < 0.001) and marginally significantly with the postoperative 6-month M-score (P = 0.106). CONCLUSION: The A-zone area and the number of marginal retinal folds were significantly associated with the M-score before and after ERM surgery. These novel en-face OCT parameters can serve as a novel surrogate tool for predicting the functional outcomes in idiopathic ERM.

FLAT IRREGULAR PIGMENT EPITHELIUM DETACHMENT IN CENTRAL SEROUS CHORIORETINOPATHY: A Form of Pachychoroid Neovasculopathy?

PURPOSE: To investigate the differences in natural course, intravitreal bevacizumab injection (IVB) responsiveness, and optical coherence tomography angiography findings according to the type of pigment epithelial detachment (PED) in patients with central serous chorioretinopathy (CSC). METHODS: A retrospective review of angiographically proven CSC patients was conducted. Pigment epithelium detachment was classified as flat irregular or focal. To identify the natural course of CSC, we had observed whether subretinal fluid was improved without any treatment until symptom duration was >3 months. When CSC symptom duration was >3 months, IVB injection was performed. Symptom duration, central subfield thickness, subfoveal choroidal thickness, presence of subretinal fluid, natural course, optical coherence tomography angiography findings, and IVB responsiveness were compared between the PED types. RESULTS: One hundred eyes were included (64 flat irregular PED vs. 34 focal PED). Flat irregular PED had a longer symptom duration than focal PED (7.20 ± 11.52 vs. 3.69 ± 3.98 months, P = 0.03). In untreated cases, the rate of complete resolution of subretinal fluid was significantly lower in flat irregular PED than in focal PED (34.78% vs. 65.22%, P = 0.017). In contrast to the natural course, responsiveness to IVB was significantly better in flat irregular PED (72.41% vs. 31.58%, P = 0.005). Optical coherence tomography angiography revealed more CNV in flat irregular PED (42.90% vs. 10.00%, P = 0.014). Subfoveal choroidal thickness in flat irregular PED was significantly thicker. CONCLUSION: In CSC patients with flat irregular PED, the natural course was poor, but treatment response to IVB was favorable. Flat irregular PED patients showed longer symptom duration and thicker subfoveal choroidal thickness than those with focal PED. Optical coherence tomography angiography revealed more choroidal neovascularization in flat irregular PED. These findings suggest that CSC with flat irregular PED could be considered a form of pachychoroid neovasculopathy.

DEVELOPMENT OF IDIOPATHIC MACULAR HOLE IN FELLOW EYES: Spectral Domain Optical Coherence Tomography Features.

PURPOSE: To investigate the long-term incidence and risk factors of macular hole (MH) development in the fellow eyes of patients with unilateral idiopathic MH. METHODS: The retrospective case-control study involved the fellow eyes of 215 consecutive patients with idiopathic MH. The patients were classified into two groups according to the presence or development of MH in the fellow eye. The spectral domain optical coherence tomography features and clinical characteristics of each group were compared. RESULTS: Twelve (5.6%) patients presented with bilateral MH at the initial visit, whereas 20 (9.3%) initially unilateral patients developed MH in the fellow eye over a median interval of 44 months. Vitreomacular traction and inner foveal cyst were noted more frequently in the baseline spectral domain optical coherence tomography scans of fellow eyes of the bilateral group (P < 0.01). An outer foveal defect was found in five patients (35.7%) of the bilateral MH group (P < 0.01). CONCLUSION: The incidence of MH in fellow eyes was approximately 10%. The presence of outer foveal defect, inner foveal cyst, and vitreomacular adhesion or traction on spectral domain optical coherence tomography in the fellow eye was the risk factor for MH.

Visual Prognostic Factors of Epiretinal Membrane Surgery in Patients with Pseudophakia.

PURPOSE: To evaluate the visual prognostic factors in patients with pseudophakic epiretinal membrane (ERM) after vitrectomy using spectral domain optical coherence tomography (SD-OCT). METHOD: A retrospective review of patients with pseudophakic ERM having undergone vitrectomy was conducted. Best corrected visual acuity (BCVA) and SD-OCT were conducted before and 1, 3, and 6 months after vitrectomy. Known visual prognostic factors, such as inner-retina irregularity index, central foveal thickness (CFT), central inner retinal layer thickness (CIRLT), cone outer segment tip defect length, and photoreceptor outer segment length, were reviewed and their correlation with BCVA was analyzed. RESULTS: Forty-three patients (mean age: 64.88 ± 10.46 years) with pseudophakic ERM were included. BCVA significantly improved after vitrectomy (logMAR 0.30 ± 0.24 vs. 0.11 ± 0.14, p < 0.001). The preoperative high inner-retina irregularity index significantly correlated with poor postoperative BCVA in patients with pseudophakic ERM (correlation coefficient 0.583, p < 0.001). Postoperative improvements of inner retinal SD-OCT findings, such as inner-retina irregularity index, CFT, and CIRLT, were significantly associated with the amount of BCVA improvement after ERM surgery (correlation coefficients were as follows: inner-retina irregularity index - 0.711, p < 0.001; CFT - 0.462, p = 0.002; CIRLT - 0.596, p < 0.001). However, preoperative outer retinal SD-OCT findings were not associated with postoperative visual prognosis. CONCLUSION: From this study, we determined the visual prognostic factors of ERM surgery without confounding factors, such as visual acuity improvement following combined cataract surgery, and inner retinal SD-OCT findings more significantly associated with the visual prognosis of ERM surgery compared to outer retinal SD-OCT findings.

IgG Seroprevalence of COVID-19 among Individuals without a History of the Coronavirus Disease Infection in Daegu, Korea.

BACKGROUND: Seroprevalence studies of coronavirus disease 2019 (COVID-19) from many countries have shown that the number of undiagnosed missing cases is much larger than that of confirmed cases, irrespective of seroprevalence levels. Considering the strategy of Korea entailing massive testing and contact tracing from the beginning of epidemic, the number of undiagnosed missing cases in Korea may be negligible. This study was conducted to estimate the seroprevalence of COVID-19 among individuals who were never diagnosed with COVID-19 in Daegu, the epicenter of COVID-19 epidemic in Korea. METHODS: Serologic testing for immunoglobulin G antibody based on immunochromatographic assay was conducted in 103 patients and 95 guardians aged 18 to 82 years without any history of COVID-19 diagnosis, who visited outpatient clinics of a single university-affiliated hospital from May 25 to June 5, 2020. RESULTS: The estimated seroprevalence was 7.6% (95% confidence interval, 4.3%-12.2%) with 15 positive cases. Among them, only one had a polymerase chain reaction (PCR)-confirmed case among their close contacts and 13 did not experience COVID-19-related symptoms. Seroprevalence was similar between patients and guardians. Based on this figure, the number of undiagnosed missing cases in Daegu was estimated to be a dozen times more than the number of confirmed cases based on PCR testing. CONCLUSION: Despite the limitation of a small and unrepresentative sample, this is the first study on seroprevalence of COVID-19 in Korea. Our study suggested that the number of undiagnosed missing cases was substantial even with the stringent strategy adopted in Korea, similar to that of other countries.

Near reading speed changes after panretinal photocoagulation in diabetic retinopathy patients: a prospective study using an iPad application for the measurement of reading speed.

PURPOSE: To investigate the changes in the near reading speed after panretinal photocoagulation (PRP) in diabetic retinopathy patients. METHODS: This non-randomized, prospective, clinical study enrolled diabetic retinopathy patients who underwent PRP from January 2016 to June 2017. The near reading speed was measured before and 1 week, 1 month, and 4 months after PRP by using an iPad application for the assessment of reading speed; near best-corrected visual acuity (BCVA) and subfoveal choroidal thickness (SFCT) were also analyzed. The reading speed of age-matched healthy individuals was compared with that of diabetic retinopathy patients. RESULTS: Forty-seven patients were enrolled in this study. The baseline near reading speed of diabetic retinopathy patients was significantly slower than that of age-matched healthy controls. The near reading speed was reduced at 1 week after PRP, but recovered at 1 and 4 months after PRP. Near BCVA showed a similar pattern after PRP. SFCT increased at 1 week after PRP and significantly decreased at both 1 and 4 months after PRP. CONCLUSION: The near reading speed of diabetic patients was significantly slower than that of age-matched healthy controls. The speed was temporarily reduced at 1 week after PRP, potentially due to short-term impairment of parasympathetic nerve innervation.

Central serous chorioretinopathy in elderly subjects: angiographic and tomographic characteristics.

PURPOSE: To investigate the angiographic, tomographic, and clinical characteristics of idiopathic central serous chorioretinopathy (CSC) in elderly patients. METHODS: The patients were divided into two groups according to a cutoff age of 60 years at baseline. Patients underwent spectral domain optical coherence tomography, fluorescein angiography, and indocyanine green angiography. Angiographic and tomographic features were compared between the two groups (young vs. elderly group). RESULTS: Of 176 patients, 26 patients (15.1%) were 60 years or older. Complete resolution of subretinal fluid after treatment was noted in 72.0% of the elderly group and 90.8% of the young group (P = 0.021). The elderly group showed worse baseline and final vision, more bilateral involvement, and lower male preponderance than the young group (P < 0.05, respectively). The elderly group was also associated with a higher frequency of retinal pigment epithelium depigmentation, foveal thinning, and double-layer sign compared with the young group (P < 0.05, respectively). CONCLUSION: CSC in elderly patients was associated with a lower resolution of serous detachment, increased impairment of retinal pigment epithelial layers, foveal thinning, and worse visual outcome, suggesting a chronic insult to the choroidal vessels involving more severe damage to the outer retinal layers.

Fabrication of an Aluminum-Based Thermoelectric Module Substrate via Anodization and Nickel Plating.

In this study, a thermoelectric module substrate was fabricated by subjecting an aluminum plate to a surface treatment process. To achieve this, the aluminum-based substrate was carried out to electrolytic etching, anodization, and Ni plating. The anodization of aluminum created an oxide film, which served as an insulation layer, while the Ni plating formed a conductive circuit layer. The substrate fabricated in this study exhibited excellent insulation performance, demonstrating its potential for future use in thermoelectric module substrates. Its adhesion properties were verified using a cross-cut adhesion test; microstructures of the surface and cross-section revealed the successful formation of the oxide film and Ni circuit layers on the aluminum base. From the results of these, it is clearly confirmed that the anodized aluminum substrate developed in this study provides suitable insulating performances and bonding nature with Ni electrode.

Wet Etching Method for Electroless Ni-P Plating of Bi-Te Thermoelectric Element.

In this study, a method for electroless Ni-P plating with excellent adhesion via chemical wet etching to fabricate Bi-Te thermoelectric modules is proposed. The electroless Ni-P plating formed through the proposed method showed excellent adherence without peeling, even under heat treatment of 200 °C for 24 h. Wet etching and electroless Ni-P plating was performed on a Bi-Te thermoelectric module, which showed the excellent bond strength of approximately 10 MPa. The surface roughness of the Bi-Te thermoelectric element was increased significantly by the wet etching process, which secured the adherence of the Ni-P plating by anchoring to this induced surface roughness.

Fabrication of a Bi2Te3-Based Thermoelectric Module Using Tin Electroplating and Thermocompression Bonding.

A method for directly bonding thermoelectric elements onto copper electrodes without applying a solder paste was developed in this study. A tin coating of thickness approximately 50 µm was deposited via electroplating onto the surface of a Bi2Te3-based thermoelectric element, which had a nickel diffusion barrier layer. The resulting structure was subsequently subjected to direct thermocompression bonding at 250 °C on a hotplate for 3 min at a pressure of 1.1 kPa. Scanning electron microscopy imaging confirmed that a strong and uniform bond was formed at the copper electrode-thermoelectric element interface, and the melted or solidified tin layer remained defect-free. The thermoelectric module fabricated using tin plating had an average bonding strength similar to that fabricated using soldering.

Fabrication of Silver-Doped (Bi,Sb)2Te3 Thermoelectric Film Prepared from Ag Nanoparticles/Bi-Sb-Te Pastes.

Film-type thermoelectric generator (TEG) utilizing Bi-Te based paste has been highly considered as advanced power sources for the wearable electronic devices due to its light, thin and flexible characteristics when producing electricity from certain thermal resources such as human body heat. However, the application of the film-typed TEG has been often limited due to its low TE conversion efficiency caused by low electrical conductivity resulting from severe porosity. Thus, it is crucial to increase electrical properties via densification of the TE film. Here, we synthesized silver nanoparticle (AgNP)-dispersed (Bi,Sb)2Te3 (BSbT) powders to fabricate AgNP-BSbT pastes by adding organic binder. The synthesized AgNP-BSbT pastes were printed through a hand-painting process and were consolidated into Ag-doped BSbT (Ag-BSbT) thick film with a few hundreds µm with controlled 2-step heat treatment. The microstructures of Ag-BSbT films show abnormally elongated grains but also the amount of porosities in the film significantly decreased by addition of AgNP. As a result, it is confirmed that the 0.072 at% Ag-BSbT thick film exhibits power factor of 2.93 × 10-3 W/mK² at room temperature, which is comparable to that of practically utilized bulk materials. It is elucidated that the increase in power factor originates from the modulation between electrical conductivity and Seebeck coefficients due to increased hole carrier density at room temperature.

PHOTODYNAMIC THERAPY FOR SYMPTOMATIC SUBFOVEAL RETINAL PIGMENT EPITHELIAL DETACHMENT IN CENTRAL SEROUS CHORIORETINOPATHY: Outcomes and Prognostic Factors.

PURPOSE: To report the clinical outcomes of reduced-fluence photodynamic therapy (PDT) for symptomatic subfoveal retinal pigment epithelial detachment (RPED) in central serous chorioretinopathy and identify prognostic factors affecting treatment outcome. METHODS: This retrospective interventional study included 35 eyes of 35 patients with serous subfoveal RPED with choroidal hyperpermeability. Cases with evidence of age-related macular degeneration were excluded from the study. Reduced-fluence PDT was applied to each patient. Best-corrected visual acuity, anatomical resolution of RPED, subjective symptom improvement, and complications were analyzed. RESULTS: One month after reduced-fluence PDT, 28 eyes (80.0%) manifested complete resolution of subfoveal RPED. Among the patients whose eyes manifested complete resolution, 19 (67.9%) reported subjective vision improvement. This subjective improvement was significantly associated with the presence of dysmorphopsia at baseline. Logarithm of the minimal angle of resolution visual acuity improved from 0.15 (Snellen equivalent of 20/28) to 0.09 (20/25) between baseline and 3 months after PDT (P = 0.008). Older age and increased RPED height were independent risk factors of poor resolution of RPED after PDT. The mean follow-up period after treatment was 10.4 ± 13.6 months; recurrence of RPED did not occur in any case. CONCLUSION: Subfoveal RPED in central serous chorioretinopathy responded well to reduced-fluence PDT, especially in younger patients with less RPED. Dysmorphopsia, rather than decreased visual acuity, is a main symptomatic presentation in subfoveal RPED.

TYPICAL POLYPOIDAL CHOROIDAL VASCULOPATHY AND POLYPOIDAL CHOROIDAL NEOVASCULARIZATION.

PURPOSE: To compare typical polypoidal choroidal vasculopathy (T-PCV) and polypoidal choroidal neovascularization (P-CNV), which can be defined as two subtypes of PCV, and to elucidate the significance of the classification. METHODS: Seventy-seven patients diagnosed with PCV and followed up for more than 12 months were reviewed. The PCV cases were divided into a T-PCV group (n = 36) and a P-CNV group (n = 41) according to the presence of features of pachychoroid or age-related macular degeneration. Angiographic and tomographic characteristics and changes in vision during the follow-up period were compared between the two groups. RESULTS: Logarithm of the minimum angle of resolution visual acuity of T-PCV and P-CNV was 0.27 ± 0.31 and 0.62 ± 0.47 at baseline (P < 0.001) and 0.28 ± 0.41 and 0.54 ± 0.52 at the final visit (P = 0.006), respectively. A marginally higher rate of complete response to anti-vascular endothelial growth factor treatment was noted in the T-PCV group (47.2%) compared with the P-CNV group (26.8%) (P = 0.05). At the final visit, subfoveal fibrosis was noted in 11.1% of the T-PCV group and 39.0% of the P-CNV group (P = 0.009). CONCLUSION: The two subtypes of PCV, P-CNV and T-PCV, behave differently in terms of angiographic and tomographic manifestations and visual outcomes. Classifying PCVs would be helpful not only for pathogenic implications, but also for prognostic significance.