Image quality assessment of retinal fundus photographs for diabetic retinopathy in the machine learning era: a review.

This study aimed to evaluate the image quality assessment (IQA) and quality criteria employed in publicly available datasets for diabetic retinopathy (DR). A literature search strategy was used to identify relevant datasets, and 20 datasets were included in the analysis. Out of these, 12 datasets mentioned performing IQA, but only eight specified the quality criteria used. The reported quality criteria varied widely across datasets, and accessing the information was often challenging. The findings highlight the importance of IQA for AI model development while emphasizing the need for clear and accessible reporting of IQA information. The study suggests that automated quality assessments can be a valid alternative to manual labeling and emphasizes the importance of establishing quality standards based on population characteristics, clinical use, and research purposes. In conclusion, image quality assessment is important for AI model development; however, strict data quality standards must not limit data sharing. Given the importance of IQA for developing, validating, and implementing deep learning (DL) algorithms, it's recommended that this information be reported in a clear, specific, and accessible way whenever possible. Automated quality assessments are a valid alternative to the traditional manual labeling process, and quality standards should be determined according to population characteristics, clinical use, and research purpose.

Multitask Learning for Activity Detection in Neovascular Age-Related Macular Degeneration.

Purpose: The purpose of this study was to provide a comparison of performance and explainability of a multitask convolutional deep neuronal network to single-task networks for activity detection in neovascular age-related macular degeneration (nAMD). Methods: From 70 patients (46 women and 24 men) who attended the University Eye Hospital Tübingen, 3762 optical coherence tomography B-scans (right eye = 2011 and left eye = 1751) were acquired with Heidelberg Spectralis, Heidelberg, Germany. B-scans were graded by a retina specialist and an ophthalmology resident, and then used to develop a multitask deep learning model to predict disease activity in neovascular age-related macular degeneration along with the presence of sub- and intraretinal fluid. We used performance metrics for comparison to single-task networks and visualized the deep neural network (DNN)-based decision with t-distributed stochastic neighbor embedding and clinically validated saliency mapping techniques. Results: The multitask model surpassed single-task networks in accuracy for activity detection (94.2% vs. 91.2%). The area under the curve of the receiver operating curve was 0.984 for the multitask model versus 0.974 for the single-task model. Furthermore, compared to single-task networks, visualizations via t-distributed stochastic neighbor embedding and saliency maps highlighted that multitask networks' decisions for activity detection in neovascular age-related macular degeneration were highly consistent with the presence of both sub- and intraretinal fluid. Conclusions: Multitask learning increases the performance of neuronal networks for predicting disease activity, while providing clinicians with an easily accessible decision control, which resembles human reasoning. Translational Relevance: By improving nAMD activity detection performance and transparency of automated decisions, multitask DNNs can support the translation of machine learning research into clinical decision support systems for nAMD activity detection.

[Ocular changes as a diagnostic tool for malaria]. / Okuläre Veränderungen als Hilfsmittel in der Malariadiagnostik.

BACKGROUND: According to the WHO Malaria Report 2019 a total of 229 million people fall ill with malaria each year and two thirds of deaths involve children under 5 years of age. AIM: To review the fundus changes in the context of malaria and the importance of ophthalmoscopy in the diagnosis. MATERIAL AND METHODS: Summary of changes in cerebral malaria visible on fundus examination, possible underlying pathomechanisms and the value of ophthalmoscopy in practice. RESULTS: Retinal findings in malaria include white or gray staining of the retina (retinal whitening), color change of retinal vessels (orange or white staining), hemorrhages often with a white center, such as Roth's spot and papilledema. DISCUSSION: The retinal changes in malaria are specific and may help to differentiate malaria from other causes of coma and fever. Smartphone-based fundus photography and artificial intelligence could support malaria diagnostics particularly in resource-poor regions.

XEN45 Gelstent Implantation in the Treatment of Glaucoma Secondary to Fuchs Uveitis Syndrome.

PURPOSE: Evaluation of treatment efficacy of XEN45 gelstent for glaucoma secondary to Fuchs uveitis syndrome (FUS). METHODS: This retrospective case series evaluated patients with glaucoma secondary to FUS, who underwent XEN45 implantation. Complete success was defined as IOP lowering of ≥ 20% and cutoff IOP at ≤18 mmHg. Success was qualified if additional glaucoma medication was necessary. Additional glaucoma surgery except for needling and open bleb revision was regarded as failure. RESULTS: Twelve eyes of 12 patients were included. Qualified and complete success rates were 50% after one year (n = 10). Qualified success was achieved in 66.6% of patients with 33.3% of patients achieving complete success after two years (n = 6). CONCLUSIONS: XEN45 implantation had some success in the treatment of glaucoma secondary to FUS, but needling was frequently necessary to improve outcome.

CT Assessment of Intraorbital Cable Movement of Electronic Subretinal Prosthesis in Three Different Surgical Approaches.

Purpose: Electronic retinal implants restore some visual perception in patients blind from retinitis pigmentosa. Eye movements cause mechanical stress in intraorbital power supply cables leading to cable breaks. By using computer tomography (CT) scans at the extreme positions of the four cardinal gaze directions, this study determined in vivo, which of three surgical routing techniques results in minimal bending radius variation and favors durability. Methods: Nine patients received the first-generation subretinal implant Alpha IMS (Retina Implant AG, Reutlingen, Germany) in one eye. Three techniques for intraorbital cable routing were used (straight cable route (A), parabulbar loop (B), and encircling band (C)), each in three patients. All patients underwent computer tomography of the orbital region. The bending radius of the intraorbital cable was measured with the DICOM viewer Osirix v4.1.2 (Pixmeo SARL, Bernex, Switzerland) and served as indicator for mechanical stress. Results: Average bending radius variation was 87% for method A, 11% for method B, and 16% for method C. Methods A and B (P = 0.005) and methods A and C (P = 0.007) differed significantly, while method B and C showed no statistical difference (P = 0.07). Conclusions: Compared to straight routes, arcuated cable routes significantly reduce cable movement and bending. Due to an easier surgical procedure, a parabulbar loop is the preferred method to minimize bending radius variation and prolong survival time of electronic subretinal implants. Translational Relevance: CT analysis of cable bending of implanted medical devices allows to determine which surgical routing technique favors durability in vivo.

Identification of a New Genetic Mutation Associated With Peters Anomaly.

PURPOSE: To report a new genetic mutation in the COL4A1 gene, which was identified in a baby girl with Peters anomaly (PA), a rare anterior segment mesenchymal dysgenesis, which is characterized by unilateral or bilateral corneal opacities often accompanied by glaucoma, cataract, and systemic malformations and associated with various genetic mutations. METHODS: Ophthalmologic examination of one baby girl and whole exome sequencing and Sanger sequencing of blood samples of the child and her biological parents were performed. RESULTS: Ophthalmologic examination led to the diagnosis of PA type I in the baby girl. Whole exome sequencing and Sanger sequencing identified the de novo mutation c.181_189delinsAGGTTTCCG; p.Gly61Arg in the COL4A1 gene in the child, whereas no other putatively causative variants in established genes associated with anterior segment dysgenesis were present. CONCLUSIONS: PA might be associated with the mutation c.181_189delinsAGGTTTCCG; p.Gly61Arg in the COL4A1 gene. The COL4A1 gene encodes for collagen IVα1, an essential component of basal membranes, and mutations are associated with an increased risk for renal and cerebrovascular disorders and stroke. This should be considered when advising and monitoring patients.

Restriction of eye motility in patients with RETINA IMPLANT Alpha AMS.

PURPOSE: To evaluate the motility of the eye in patients with the RETINA IMPLANT Alpha AMS. METHODS: Eye motility was determined in eight gaze directions in ten blind retinitis pigmentosa patients, who had received the RETINA IMPLANT Alpha AMS, before implantation of the subretinal implant and at six time-points up to one year after. RESULTS: The analysis of eye motility showed a restriction in the upgaze and gaze to the temporal side directly after surgery in eight of the nine patients included. The degree of motility restriction decreased continuously with recovery during the observation time. One year after surgery, eye motility was still restricted in the majority of patients, especially in the upgaze to the temporal side at 20° (five of seven patients). CONCLUSION: Retinal implants with intraorbital parts (e.g. connecting cables) caused restriction in the temporal and superior viewing directions in the majority of patients. Although this restriction might be cosmetically visible, this limitation in eye motility has no effects on the monocular vision and the implant's efficacy for daily use.

[Electronic Retina Implants - an Abandoned Dream?] / Elektronische Netzhautimplantate ­ ein aufgegebener Traum?

Between 2005 and 2016, over 30,000 cochlear implants were implanted in Germany, while the number of retinal implants remained less than 1% of this number. The two types of retina implants that reached the market did not survive economically. The present review article discusses the impact and future of electronic retina implants in ophthalmology.

[Acute loss of visual acuity after pregnancy]. / Akute Visusminderung nach Schwangerschaft.

A 28-year-old female patient presented with acute loss of visual acuity after pre-eclampsia. Funduscopy revealed minor alterations of the posterior pole of the macula. Optical coherence tomography displayed a bilateral neurosensory detachment. Fluorescence angiography showed filling defects of the choroid in both eyes. These findings were in line with choroidal ischemia following a hypertensive episode. The symptoms disappeared completely after 3 months without additional treatment. To clarify ambiguous pathologies the ophthalmologist should always initiate a comprehensive evaluation in internal medicine to find the right diagnosis and treatment.

Polarity-independent effects of tDCS on paired associative stimulation-induced plasticity.

BACKGROUND: Transcranial direct current stimulation (tDCS) can polarize the cortex of the human brain. OBJECTIVE/HYPOTHESIS: We sought to verify the hypothesis that posterior-anterior (PA) but not anterior-posterior (AP) tDCS of primary motor cortex (M1) produces cooperative effects with corticospinal plasticity induced by paired associative stimulation of the supplementary motor area (SMA) to M1 projection (PASSMA→M1) in a highly controlled experimental design. METHODS: Three experimental conditions were tested in a double-blinded, randomized crossover design in 15 healthy adults: Navigated PASSMA→M1 during PA-tDCS (35 cm2 electrodes, anode 3 cm posterior to M1 hand area, cathode over contralateral frontopolar cortex, 1 mA, 2 × 5 min) or AP-tDCS (reversed polarity), or sham-tDCS. Effects were analyzed over 120 min post-intervention by changes of motor evoked potential (MEP) amplitude in a hand muscle. RESULTS: There was no significant effect of tDCS on PASSMA→M1 induced plasticity in the repeated-measures ANOVA. However, post-hoc within-subject contrasts revealed a significant tDCS with PASSMA→M1 interaction. This was explained by PA-tDCS and AP-tDCS modifying the PASSMA→M1 effect into the same direction in 13/15 subjects (87%, p = 0.004 for deviation from equality). Sizes of the PA-tDCS and AP-tDCS effects were correlated (rs = 0.53, p = 0.044). A control experiment demonstrated that PA-tDCS and AP-tDCS alone (without PASSMA→M1) had no effect on MEP amplitude. CONCLUSIONS: Data point to unidirectional tDCS effects on PASSMA→M1 induced plasticity irrespective of tDCS polarity, in contrast to our hypothesis. We propose that radial symmetry of cortical columns, gyral geometry of motor cortex, and cooperativity of plasticity induction can explain the findings.