Enhancing foveal avascular zone analysis for Alzheimer's diagnosis with AI segmentation and machine learning using multiple radiomic features.

We propose a hybrid technique that employs artificial intelligence (AI)-based segmentation and machine learning classification using multiple features extracted from the foveal avascular zone (FAZ)-a retinal biomarker for Alzheimer's disease-to improve the disease diagnostic performance. Imaging data of optical coherence tomography angiography from 37 patients with Alzheimer's disease and 48 healthy controls were investigated. The presence or absence of brain amyloids was confirmed using amyloid positron emission tomography. In the superficial capillary plexus of the angiography scans, the FAZ was automatically segmented using an AI method to extract multiple biomarkers (area, solidity, compactness, roundness, and eccentricity), which were paired with clinical data (age and sex) as common correction variables. We used a light-gradient boosting machine (a light-gradient boosting machine is a machine learning algorithm based on trees utilizing gradient boosting) to diagnose Alzheimer's disease by integrating the corresponding multiple radiomic biomarkers. Fivefold cross-validation was applied for analysis, and the diagnostic performance for Alzheimer's disease was determined by the area under the curve. The proposed hybrid technique achieved an area under the curve of [Formula: see text]%, outperforming the existing single-feature (area) criteria by over 13%. Furthermore, in the holdout test set, the proposed technique exhibited a 14% improvement compared to single features, achieving an area under the curve of 72.0± 4.8%. Based on these facts, we have demonstrated the effectiveness of our technology in achieving significant performance improvements in FAZ-based Alzheimer's diagnosis research through the use of multiple radiomic biomarkers (area, solidity, compactness, roundness, and eccentricity).

Microperimetric analysis of eyes after macular hole surgery with indocyanine green staining: a retrospective study.

BACKGROUND: Indocyanine green (ICG) aids in the visualization of the internal limiting membrane (ILM). Retinal damage from ICG dye toxicity has been reported through in vitro and in vivo studies. However, the clinical toxic effect of ICG during macular surgery has not been functionally evaluated. In this study, we evaluated functional and structural changes in retinal sensitivity and retinal thickness associated with ICG toxicity using microperimetry before and after ICG-assisted ILM peeling in patients with macular holes. METHODS: ICG staining was performed only on the macular area below the horizontal line connecting the fovea and optic disc. ILM peeling was performed over the entire macular area inside the vascular arcade. Visual acuity assessment, spectral domain optical coherence tomography, and microperimetry were performed at baseline and one, three, and six months postoperatively. The mean retinal sensitivity of four macular areas was calculated and analyzed. RESULTS: Eleven eyes were included. Macular holes were successfully closed in all patients. Six months postoperatively, retinal sensitivity improved insignificantly in Area 1 (ICG-/ILM-) and Area 2 (ICG-/ILM+) but decreased in Area 4 (ICG+/ILM-). Three months postoperatively, retinal sensitivity significantly decreased in Area 3 (ICG+/ILM+; 26.63 ± 1.80 vs. 25.52 ± 2.08 dB, p = 0.036). However, the statistical significance of this result was lost six months after the surgery (p = 0.059). The change of Gc-IPL thickness in Area 3 was significantly different compared to Area 2 at post-operative 3- and 6-months (p = 0.01, 0.05). CONCLUSIONS: Retinal sensitivity decreased three months after ICG-assisted ILM peeling. However, the statistical significance was lost six months after surgery. ICG staining can be performed with caution during macular hole surgery.

Short-term effect of intravitreal brolucizumab injections in patients with neovascular age-related macular degeneration on retinal nerve fiber layer thickness.

This study reported the short-term effects of intravitreal brolucizumab (IVB) on peripapillary retinal nerve fiber layer (RNFL) thickness in patients with neovascular age-related macular degeneration (nAMD). This retrospective observational case series included patients with nAMD treated with other anti-vascular endothelial growth factor (anti-VEGF) agents and subsequently switched to IVB because of poor response to those other agents on spectral domain optical coherence tomography (SD-OCT). Best-corrected visual acuity (BCVA), intraocular pressure, funduscopy, and SD-OCT were assessed at baseline, 2 weeks, 1 month, and 3 months after injection. Twenty-two patients were included in the study. In the IVB group, BCVA significantly improved 3 months after injection compared with baseline (0.45 ± 0.25 vs. 0.38 ± 0.25, p = 0.012). During the 3-month follow-up, compared with baseline, RNFL thicknesses of the global, superior temporal, inferior temporal, inferior nasal, nasal, and superior nasal sectors did not change substantially in the IVB group. However, temporal RNFL thickness significantly decreased at 1 month (p = 0.045), and the significance was lost at 3 months (p = 0.378). The central macular thickness of treated eyes significantly decreased compared with the baseline at every follow-up visit. IVB in patients with nAMD had morphological and functional visual gain effects without RNFL thinning during the short-term follow-up.

Pound-shape Silicone Oil Retention Suture in Aphakic Eyes With Intact Iris.

PURPOSE: To introduce a surgical technique, "pound-shape silicone oil retention suture in aphakic eye with intact iris." METHODS: A retrospective analysis of medical records was performed. Each patient had an aphakic eye with intact iris and received the pound-shape silicone oil retention suture during vitrectomy combined with silicone oil injection. RESULTS: In the four patients who received the pound-shape silicone oil retention suture, the silicone oil was confined behind the suture for 3 months to 7 months without prolapse into the anterior chamber. Increased intraocular pressure was not observed in any patient, although peripheral iridectomy was not performed. CONCLUSION: Pound-shape silicone oil retention suture is a simple and effective surgical technique to prevent silicone oil prolapse into the anterior chamber.

Effect of vitrectomy with silicone oil tamponade and internal limiting membrane peeling on eyes with proliferative diabetic retinopathy.

We investigated the combined effect of silicone tamponade and the internal limiting membrane (ILM) peeling and investigated whether timing of peeling of the ILM affects the outcomes of vitrectomy with silicone oil tamponade in eyes with proliferative diabetic retinopathy (PDR). Here, we examined 63 eyes (58 patients) with PDR, which underwent vitrectomy with silicone oil tamponade and stepwise removal of silicone oil. ILM peeling was performed just before oil injection (group 1; 33 eyes, 30 patients) or after oil removal (group 2; 30 eyes, 28 patients). Visual acuity and retinal and choroidal thicknesses were compared between the groups. Thinning of the inner retina, including the ganglion cell-inner plexiform layer and macular retinal nerve fiber layer, was evident at 1 year after surgery in both groups. Thinning of the total retina (P = 0.019) and inner retina (P = 0.008) was significantly correlated with final visual acuity. There was no considerable between-group difference observed in final visual acuity, intraocular pressure, or retinal or choroidal thickness at 1 year after surgery. The incidence of epiretinal membrane was higher during silicone endo-tamponade in group 2 (P = 0.033). Visual recovery and macular configuration in eyes with PDR are not affected by whether the ILM is peeled before or after silicone oil tamponade.

Clinical characteristics of Demodex-associated recurrent hordeola: an observational, comparative study.

Our study evaluated the association between Demodex infestation and recurrent hordeola and examined the clinical features associated with these eyelid lesions. This was an observational, comparative study. We reviewed 250 patients and divided them into the recurrent hordeolum (n = 153) and control (n = 97) groups. Demodex infestation was detected by epilating eyelashes around the lesion/s and viewing them under a light microscope. Patient medical records and photographs were retrospectively analyzed to identify the clinical characteristics of Demodex-associated recurrent hordeola. Demodex was detected in 91 (59.5%) and 17 (17.5%) patients in the recurrent hordeolum and control groups (p < 0.001), respectively. In the recurrent hordeolum group, Demodex mites were found in 74 (68.5%) and 17 (37.8%) of the adult and pediatric patients (p < 0.001), respectively. Among patients with recurrent hordeola, patients in their 20s were most likely to have concomitant Demodex infestation. Patients with Demodex infestations were also more likely to develop recurrent lesions within a shorter period of time from the primary incision and curettage. The most common presentation of Demodex-associated recurrent lesions was external hordeola (67%) (p = 0.002). Demodex infestation may cause recurrent hordeola in adults and children. These mites may play a greater role in the development of lesions in adult patients. The strongest association between Demodex infestation and recurrent lesions was seen in patients in their 20s. Our results suggest that if the hordeola recur within a short period of time with the clinical characteristics of external location of eyelid, multiple numbers of lesions, or anterior blepharitis, eyelash epilation should be performed to identify the presence of Demodex mites.

Common Illnesses in Tropical Asia and Significance of Medical Volunteering.

This study was conducted to provide practical information for actual preparation of medical volunteering in tropical Asia, mainly the distribution of common illnesses encountered during mission. From 2012 to 2017, we visited two rural areas of Eastern Cambodia for medical volunteering missions, Cham Lak and Khsoem. Neither area has electricity or public water. We classified the common cases encountered during missions into six groups (upper respiratory infection, gastroenteritis, vaginitis and/or cystitis, dermatitis, work-related pain and parasite prevention) and assessed the distribution. In Cham Lak and Khsoem, 558 and 371 people were treated, respectively. The most commonly encountered cases in children under age of 18 were upper respiratory infection, followed by parasite control and dermatitis, in both areas. There was no significant difference in distribution between the two areas. For adults, the most common illnesses in Cham Lak area were vaginitis and/or cystitis, followed by gastroenteritis and work-related pain. In Khsoem area, the common illnesses were work-related pain followed by gastroenteritis, and upper respiratory infection. The distribution between the two areas differed significantly (p <0.001). The difference might be due to the water source and main crops of agriculture. Successful preparation of a medical volunteering needs deep understanding of the destination community.