Relevance-Based Compression of Cataract Surgery Videos

In the last decade, the need for storing videos from cataract surgery has increased significantly. Hospitals continue to improve their imaging and recording devices (e.g., microscopes and cameras used in microscopic surgery, such as ophthalmology) to enhance their post-surgical processing efficiency. The video recordings enable a lot of user-cases after the actual surgery, for example, teaching, documentation, and forensics. However, videos recorded from operations are typically stored in the internal archive without any domain-specific compression, leading to a massive storage space consumption. In this work, we propose a relevance-based compression scheme for videos from cataract surgery, which is based on content specifics of particular cataract surgery phases. We evaluate our compression scheme with three state-of-the-art video codecs, namely H.264/AVC, H.265/HEVC, and AV1, and ask medical experts to evaluate the visual quality of encoded videos. Our results show significant savings, in particular up to 95.94% when using H.264/AVC, up to 98.71% when using H.265/HEVC, and up to 98.82% when using AV1.Comment: 11 pages, 5 figures, 3 table

Ocular toxicity due to Trametinib and Dabrafenib

Abstract Background To report a case of uveitis and neuroretinal detachment in a patient treated with Trametinib and Dabrafenib due to metastatic cutaneous melanoma stage IV. Case presentation We evaluated slit lamp examination, fundoscopy, optical coherence tomography, fluorescein and indocyanine green angiography in a 66 years old man suffering visual loss. Fundoscopy showed serous neuroretinal detachment of the fovea accompanied with white spots surrounding the fovea in both eyes. Although therapy with Trametinib and Dabrafenib was stopped uveitis anterior was seen 2 weeks later. After a year, the therapy was started again and the serous neuroretinal detachment appeared once more, however without inflammatory reaction of the anterior chamber. Conclusion Patients treated with Trametinib and Dabrafenib should undergo consecutive eye examinations from the beginning of the therapy

Analysis of a Functional IL-6 Gene Polymorphism in HLAB27 Associated and Intermediate Uveitis Gives New Insight in Disease Pathogenesis and Commonality with Other Autoimmune Diseases

Purpose. Interleukin 6 (IL-6) plays a crucial role in both adaptive and innate immunity. The rs1800795 gene polymorphism of IL-6 is associated with various autoimmune diseases, like multiple sclerosis. Methods. 134 patients with HLAB27 positive iridocyclitis, 84 patients with intermediate uveitis, 132 controls, and 65 HLAB27 positive controls were recruited for the present case-control study. Main outcome measures were genotype distribution and allelic frequencies determined by polymerase chain reaction. Results. The frequency of carriers of the minor allele for rs1800795 was significantly higher in patients with intermediate uveitis compared to controls (p=0.04; OR: 1.46; CI: 1.02–2.11). Frequencies of the minor allele for rs1800795 did not differ significantly in patients with HLAB27 associated uveitis when compared to controls (p>0.05). Conclusion. These findings further deepen our understanding of the commonality between multiple sclerosis and intermediate uveitis. Given the functionality of the investigated polymorphism, new pathophysiological insights are gained that help to evaluate possible therapeutic targets

Predicting Postoperative Intraocular Lens Dislocation in Cataract Surgery via Deep Learning

A critical yet unpredictable complication following cataract surgery is intraocular lens dislocation. Postoperative stability is imperative, as even a tiny decentration of multifocal lenses or inadequate alignment of the torus in toric lenses due to postoperative rotation can lead to a significant drop in visual acuity. Investigating possible intraoperative indicators that can predict post-surgical instabilities of intraocular lenses can help prevent this complication. In this paper, we develop and evaluate the first fully automatic framework for the computation of lens unfolding delay, rotation, and instability during surgery. Adopting a combination of three types of CNNs, namely recurrent, region-based, and pixel-based, the proposed framework is employed to assess the possibility of predicting postoperative lens dislocation during cataract surgery. This is achieved via performing a large-scale study on the statistical differences between the behavior of different brands of intraocular lenses and aligning the results with expert surgeons’ hypotheses and observations about the lenses. We exploit a large-scale dataset of cataract surgery videos featuring four intraocular lens brands. Experimental results confirm the reliability of the proposed framework in evaluating the lens’ statistics during the surgery. The Pearson correlation and t-test results reveal significant correlations between lens unfolding delay and lens rotation and significant differences between the intra-operative rotations stability of four groups of lenses. These results suggest that the proposed framework can help surgeons select the lenses based on the patient’s eye conditions and predict post-surgical lens dislocation

Automatic detection of pupil reactions in cataract surgery videos.

In the light of an increased use of premium intraocular lenses (IOL), such as EDOF IOLs, multifocal IOLs or toric IOLs even minor intraoperative complications such as decentrations or an IOL tilt, will hamper the visual performance of these IOLs. Thus, the post-operative analysis of cataract surgeries to detect even minor intraoperative deviations that might explain a lack of a post-operative success becomes more and more important. Up-to-now surgical videos are evaluated by just looking at a very limited number of intraoperative data sets, or as done in studies evaluating the pupil changes that occur during surgeries, in a small number intraoperative picture only. A continuous measurement of pupil changes over the whole surgery, that would achieve clinically more relevant data, has not yet been described. Therefore, the automatic retrieval of such events may be a great support for a post-operative analysis. This would be especially true if large data files could be evaluated automatically. In this work, we automatically detect pupil reactions in cataract surgery videos. We employ a Mask R-CNN architecture as a segmentation algorithm to segment the pupil and iris with pixel-based accuracy and then track their sizes across the entire video. We can detect pupil reactions with a harmonic mean (H) of Recall, Precision, and Ground Truth Coverage Rate (GTCR) of 60.9% and average prediction length (PL) of 18.93 seconds. However, we consider the best configuration for practical use the one with the H value of 59.4% and PL of 10.2 seconds, which is much shorter. We further investigate the generalization ability of this method on a slightly different dataset without retraining the model. In this evaluation, we achieve the H value of 49.3% with the PL of 18.15 seconds

Effects of Type 2 Diabetes Mellitus and Smoking on Changes in Corneal Endothelial Morphology and Cell Density

Purpose:The purpose of this study was to compare the corneal endothelial morphology and cell density of diabetic smokers and nonsmokers with 50 to 70 age-matched healthy subjects and to determine whether smoking increases the effects of type 2 diabetes mellitus (DM) on these corneal parameters.Methods:This prospective cohort study included 200 patients who were assigned to 4 groups, including smokers with type 2 DM (group 1), nonsmokers with type 2 DM (group 2), healthy smokers (group 3), and healthy nonsmokers (control group, group 4). Noncontact specular microscopy was used to measure central endothelial cell density (ECD), coefficient of variation of cell area, percentage of hexagonal cells, and central corneal pachymetry (CCT).Results:According to the ECD and CCT values (P < 0.001 and P = 0.013, respectively), a significant difference was observed between the groups. The mean ECD was lowest in diabetic smokers (1917 ± 399 cells/mm2). Healthy smokers and diabetic smokers had significantly lower ECD compared with the control group (P = 0.03 and P < 0.001, respectively). Healthy smokers and diabetic smokers had significantly lower ECD compared with diabetic nonsmokers (P = 0.012 and P < 0.001, respectively). The cornea was significantly thicker in the diabetic smokers than in the control group (P = 0.013).Conclusions:The coexistence of DM and smoking causes a significant decrease in ECD and an increase in CCT. Cigarette smoking is more harmful to corneal endothelial cells than DM alone

Glaucoma Medication and Quality of Life after Phacoemulsification Combined with a Xen Gel Stent

Glaucoma has a significant impact on quality of life. Here, we aimed to evaluate the influence of a reduction in glaucoma medications on quality of life and patient satisfaction after phacoemulsification combined with the Xen gel stent. We carried out a cross-sectional survey of patients who underwent phacoemulsification with the Xen gel stent at the Medical University of Graz, Austria. Quality of life was assessed using the German version of the Glaucoma Symptoms Scale (GSS)&mdash;questionnaire. Patients were also asked whether the operation reduced glaucoma medications and to indicate their overall satisfaction from 1 (totally discontented) up to 10 (totally contented). Questionnaires of 80 patients were evaluated. A total of 36 patients (45.0%) reported a reduction in glaucoma medications. Three items of the GSS were significantly better in patients who needed fewer glaucoma medications after the operation (&ldquo;hard to see in daylight&rdquo;, 75.0 &plusmn; 31.1 vs. 57.7 &plusmn; 39.1, p = 0.035; &ldquo;hard to see in dark places&rdquo;, 81.1 &plusmn; 28.7 vs. 54.9 &plusmn; 41.2, p = 0.002; and &ldquo;halos around lights&rdquo;, 88.3 &plusmn; 25.9 vs. 68.8 &plusmn; 38.6, p = 0.002). Patient satisfaction was significantly higher when the procedure led to a reduction in glaucoma medication (8.3 &plusmn; 2.0 vs. 6.8 &plusmn; 3.1; p = 0.034). The reported quality of life and patient satisfaction were significantly better when phacoemulsification with the Xen gel stent reduced the number of glaucoma medications needed