Impaired Visual Function in Posterior Vitreous Detachment Assessed With the Active-Learning Quantitative Contrast Sensitivity Function Test.

Introduction: To investigate whether there is visual function impairment in patients with posterior vitreous detachment (PVD) using the active-learning quantitative contrast sensitivity function test. Methods: In this cross-sectional study, contrast sensitivity was measured in eyes with PVD and eyes without PVD using the quantitative contrast sensitivity function algorithm on the Adaptive Sensory Technology platform. Outcomes included the area under the log contrast sensitivity function curve, contrast acuity, and contrast sensitivity thresholds at 1 to 18 cycles per degree (cpd). Snellen visual acuity (VA) was also measured. Mixed-effects multiple linear regression analyses were performed to evaluate the association between the presence of PVD and visual function, controlling for age and lens status. Results: The cohort comprised 232 healthy eyes of 205 participants; of these, 80 eyes of 69 patients had PVD. There was no significant association between VA and PVD presence. However, PVD was significantly associated with decreased contrast sensitivity thresholds at 1.5 cpd (ß, -0.058; P = .003) and 3 cpd (ß, -0.067; P = .004). Contrast sensitivity thresholds at lower (1 cpd) or higher (6, 12, 18 cpd) spatial frequencies did not significantly correlate with PVD presence. Even in the subgroup of symptomatic PVD eyes, VA was not significantly decreased, while quantitative contrast sensitivity function outcomes showed visual function deficits at low spatial frequencies (1.5 cpd and 3 cpd). Conclusions: Contrast sensitivity measured with the quantitative contrast sensitivity function test showed visual function deficits in eyes with PVD that would have been missed with VA testing alone. Incorporating this test in the retina clinic might offer a more comprehensive functional assessment of eyes with PVD, serving as an adjunct outcome metric in clinical decision-making.

Combined high rates of alternative breeding strategies unexpectedly found among populations of a solitary nesting raptor.

Social monogamy is the prevalent mating system in birds, but alternative strategies of extra-pair paternity (EPP) and conspecific brood parasitism (CBP) occur in many species. Raptors are virtually absent in discussions of broad taxonomic reviews regarding EPP and CBP likely because these strategies are mostly absent or at low frequency; CBP is unreported in solitary nesting raptors. In contrast, we found high frequencies of EPP (16%-31%) and CBP (15%-26%) nests among three populations of Cooper's Hawks (Accipiter cooperii) across the northern breeding range of this solitary nesting, socially monogamous species. EPP and CBP combined occurred in 42%-46% of all nests among populations and hence unexpectedly were nearly equivalent to proportions of genetically monogamous nests. Select covariates failed to predict presence of EPP and CBP in part because virtually all extra-pair adults were uncaught and likely were floaters. We found no support for the hypothesis that territorial females traded copulations for food to maximize energy intake for increased production. Our unique discoveries enhance knowledge of the extent and diversity of alternative breeding strategies among groups of avian and other animal species.

The role of ultra-widefield imaging with navigated central and peripheral cross-sectional and three-dimensional swept source optical coherence tomography in ophthalmology: Clinical applications.

PURPOSE: To assess central and peripheral retinal and choroidal diseases using ultra-widefield (UWF) fundus imaging in combination with navigated central and peripheral cross-sectional and three-dimensional (3D) swept source optical coherence tomography (SS-OCT) scans. METHODS: Retrospective study involving 332 consecutive patients, with a nearly equal distribution of males and females. The mean age of patients was 52 years (range 18-92 years). Average refractive error was -3.80 D (range +7.75 to -20.75 D). RESULTS: The observations in this study demonstrate the efficacy of peripheral navigated SS-OCT in assessing various ocular conditions. The technology provides high-quality images of the peripheral vitreous, vitreoretinal interface, retina, and choroid, enabling visualization of vitreous floaters and opacities, retinal holes and tears, pigmented lesions, and peripheral retinal degenerations. 3D OCT scans enhance the visualization of these abnormalities and improve diagnostic and therapeutic decisions. CONCLUSION: Navigated central and peripheral cross-sectional and 3D SS-OCT scans offer significant complementary benefits in the assessment and management of retinal diseases. Their addition to UWF imaging provides a comprehensive view of central and peripheral ocular structures, aiding in early detection, precise anatomical measurements, and objective monitoring of disease progression. In addition, this technology serves as a valuable tool for patient education, a teaching tool for trainees, and documentation for medico-legal purposes.

The Importance of Posterior Hyaloid Removal in a Case of Vitrectomy for Floaters in High Myopia.

A 61-year-old Malaysian Chinese man who has high myopia complained of both eye floaters. Spectral-domain optical coherence tomography (SD-OCT) of the macula showed bilateral posterior staphyloma with right eye (RE) foveoschisis without macula detachment, which had been stable for a seven-year follow-up. When bilateral YAG laser vitreolysis could not alleviate his symptoms, he underwent pars plana vitrectomy with the inducement of posterior vitreous detachment, first in the left eye, followed by the RE one month later. The best-corrected visual acuity for both eyes was 6/6, N5 two months postoperatively, and he was asymptomatic for floaters. However, six months postoperatively, he complained of metamorphopsia and worsening RE vision. Repeat OCT showed worsening of the foveoschisis bilaterally with left foveal detachment. The patient had to undergo a repeat vitrectomy with peeling of the internal limiting membrane (ILM) in bilateral eyes, which successfully restored his foveal architecture and alleviated his symptoms. This article highlights theimportance of preoperative OCT assessment of the fovea in patients undergoing vitrectomy for floaters, as staining and complete removal of posterior hyaloid with ILM peeling during vitrectomy may mitigate the progression of foveoschisis after core vitrectomy for floaters in myopic patients.

Floater Stories: Assessing the Potential Benefits of Vitrectomy.

Symptomatic vitreous opacities (SVO, "floaters") in the mobile, aging vitreous that substantially interfere with daily visual activities (DVA) constitute degenerative vitreous syndrome (DVS). DVS is best distinguished from common "nuisance" floaters by use of "floater stories" written by presenting patients describing their symptoms. Here I discuss why vitreous opacity vitrectomy, though curative, has been adopted only belatedly and is still controversial, and I describe my long-term experience with its use for this disease.

The association of symptomatic vitreous floaters with depression and anxiety.

PURPOSE: To evaluate the levels of anxiety and depression in patients with symptomatic vitreous floaters and to determine the possible correlations of psychological implications with the symptoms duration and possible improvement, the degree of posterior vitreous detachment, and the discomfort severity. METHODS: Ninety patients complaining for floaters and fifty-seven age- and gender-matched healthy-control subjects were recruited. Every participant underwent a complete ophthalmological examination, including funduscopy and optical coherence tomography scans, while clinical and demographic data were also gathered. The Patient Health Questionnaire-9 (PHQ-9), the Zung Depression Inventory-Self-Rating Depression Scale (Zung SDS), and the Hospital Anxiety and Depression Scale (HADS) were completed by everyone. RESULTS: Between the studied groups, no significant differences were detected regarding the clinical and demographic data (p > 0.05). The patients with floaters had significantly higher scores of PHQ-9, Zung SDS, HADS Anxiety, and HADS Depression (p < 0.001). After adjustment for several confounders, PHQ-9 (p = 0.041), Zung SDS (p = 0.003), and HADS Anxiety (p = 0.036) values remained significantly impaired. Among the patients, PHQ-9 and Zung SDS scores were significantly elevated in the patients with floaters duration less than 4 weeks (p < 0.05). Finally, anxiety and depression were significantly correlated with the symptoms duration and intensity, with the floater-associated discomfort, and with the stage of posterior vitreous detachment. CONCLUSION: Vitreous floaters have a negative impact on patients' psychological status, by the terms of enhanced depressive and anxiety levels. To the best of our knowledge, our study is the first in the literature to elaborate the aforementioned association, by assessing three different questionnaires simultaneously.

No side effects on rabbit retina or vitreous microenvironment by nd:YAG laser vitreolysis.

BACKGROUND: To explore the safety of Neodymium:Yttrium-aluminum-garnet (Nd:YAG) laser vitreolysis based on the histological examination of the retina and the alteration of vitreous cytokines in the rabbits. METHODS: Nine male New Zealand rabbits underwent Nd:YAG laser vitreolysis of 10 mJ x 500 pulses in the left eyes, while the right eyes were used as controls. Intraocular pressure, color fundus photography, and ultrasound B scan were measured before, as well as 1 day, 4 weeks, and 12 weeks after Nd:YAG laser vitreolysis. Three rabbits were euthanized 1 day, 4 weeks, and 12 weeks after treatment, respectively. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and hematoxylin-eosin (H&E) staining were used to look for pathological changes in the retina. An enzyme-linked immunosorbent assay (ELISA) was utilized to detect the expression of vascular endothelial growth factor (VEGF) and some inflammatory cytokines, including interferon inducible protein 10 (IP-10), monocyte chemoattractant protein 1 (MCP-1) and interlenkin 6 (IL-6) in the vitreous humor. The ascorbic acid (AsA) and total reactive antioxidant potential (TRAP) in the vitreous humor were also measured. RESULTS: Following Nd:YAG laser vitreolysis, the levels of VEGF, IP-10, MCP-1, IL6, AsA, and TRAP in the vitreous humor did not change substantially (P > 0.05). There were no detectable pathological changes in the retinal tissues, and no apoptotic signal was found. CONCLUSIONS: Rabbits tolerate Nd:YAG laser vitreolysis without observable impact on retinal tissue or the microenvironment of the vitreous.

Male starling floaters preferentially visit nests of males with reduced resource holding potential.

Floaters are sexually mature individuals that are not able to reproduce by defending breeding resources. Floaters often visit active nests, probably to gather public information or to compete for a nesting site. We tested the hypothesis that floaters preferentially prospect nests in which they have a better chance of taking over, and that they do so by assessing the owners' resource holding potential (RHP). We manipulated the flight capacity of male and female breeders in a population of spotless starlings (Sturnus unicolor) by clipping two flight feathers per wing before egg laying, thus increasing their wing-load and likely impairing their condition. We subsequently monitored breeder and floater activity by means of transponder readers during the nestling period. We found that nests owned by wing-clipped males were visited by a greater number of male floaters than control nests. This effect was absent in the case of wing-clipped females. The number of male floaters also increased with increasing nestling age and number of parental visits. The experiment shows that male floaters preferentially prospect nests in which the owner shows a reduced RHP, a strategy that likely allows them to evict weak owners and take over their nests for future reproductive attempts.

Evaluating referrals of flashing lights and floaters coming into secondary care from primary care.

CLINICAL RELEVANCE: Optometrists should look to take every opportunity to expand their knowledge, understanding and skills pertaining to vitreoretinal conditions. BACKGROUND: Despite the existence of acute eye care schemes and the up-skilling of optometrists, many units are still noticing large numbers of poor-quality referrals with high false positive rates. The authors pondered whether these schemes are effective. METHODS: At two different time points, a prospective analysis of patients took place, of all the flashing lights and floaters referrals coming into secondary care at the Royal Glamorgan Hospital, Wales, UK. The following data was captured: the exact source of the primary care referral, the diagnosis being queried, the secondary care diagnoses made and the secondary care management decisions. The accuracy of retinal break and Shafer's sign detection were also directly compared between primary care and secondary care using Cohen's Kappa Coefficient. RESULTS: For the 2018 period, n = 51 patients were included. For the 2022-23 period n = 100 patients were included. The majority of referrals during both periods were from optometrists (>80%) via the WECS pathway. The most common diagnoses being queried were retinal breaks (~50%), followed by retinal detachments (~20%). Interestingly up to 20% of patients seen in secondary care were diagnosed as normal examinations and ~ 20%. Over 1/3 of patients were discharged after their first visit to the EEC. Statistically significant differences were found between the accuracy of retinal tear and Shafer's identification between the primary and secondary care settings. CONCLUSION: A high number of false positive referrals are coming into secondary care from the WECS pathway and clear training and education needs have been identified.

Patients with floaters: Answers from virtual assistants and large language models.

Objectives: "Floaters," a common complaint among patients of all ages, was used as a query term because it affects 30% of all people searching for eye care. The American Academy of Ophthalmology website's "floaters" section was used as a source for questions and answers (www.aao.org). Floaters is a visual obstruction that moves with the movement of the eye. They can be associated with retinal detachment, which can lead to vision loss. With the advent of large language model (LLM) chatbots ChatGPT, Bard versus virtual assistants (VA), Google Assistant, and Alexa, we analyzed their responses to "floaters." Methods: Using AAO.org, "Public & Patients," and its related subsection, "EyeHealth A-Z": Floaters and Flashes link, we asked four questions: (1) What are floaters? (2) What are flashes? (3) Flashes and Migraines? (4) Floaters and Flashes Treatment? to ChatGPT, Bard, Google Assistant, and Alexa. The American Academy of Ophthalmology (AAO) keywords were identified if they were highlighted. The "Flesch-Kincaid Grade Level" formula approved by the U.S. Department of Education, was used to evaluate the reading comprehension level for the responses. Results: Of the chatbots and virtual assistants, Google Assistant is the only one that uses the term "ophthalmologist." There is no mention of the urgency or emergency nature of floaters. AAO.org shows a lower reading level vs the LLMs and VA (p = .11). The reading comprehension levels of ChatGPT, Bard, Google Assistant, and Alexa are higher (12.3, 9.7, 13.1, 8.1 grade) vs the AAO.org (7.3 grade). There is a higher word count for LLMs vs VA (p < .0286). Conclusion: Currently, ChatGPT, Bard, Google Assistant, and Alexa are similar. Factual information is present but all miss the urgency of the diagnosis of a retinal detachment. Translational relevance: Both the LLM and virtual assistants are free and our patients will use them to obtain "floaters" information. There may be errors of omission with ChatGPT and a lack of urgency to seek a physician's care.

Efficacy and safety of early YAG laser vitreolysis for symptomatic vitreous floaters: the study protocol for a randomized clinical trial.

BACKGROUND: Vitreous floaters are a common ocular condition that affects individuals of all ages. Although vitreous floaters are typically benign, they can significantly impair visual acuity and quality of life. Laser vitreolysis, which uses an Nd: YAG laser to vaporize collagenous vitreous opacities, is increasingly being used as a treatment option. However, there is currently a lack of evidence regarding its efficacy and the appropriate timing of its application. This study aims to evaluate the efficacy and safety of early intervention with YAG laser vitreolysis in treating symptomatic vitreous floaters. METHODS: The present study is a randomized, controlled, double-blind clinical trial. A total of 70 participants with symptomatic floaters for 1 month were prospectively recruited. These participants will be randomly assigned to two groups, with 35 individuals in each group: the early treatment group and the delayed treatment group. Participants assigned to the early treatment group will undergo YAG laser vitreolysis immediately, followed by a sham laser treatment 3 months later. On the other hand, participants assigned to the delayed treatment group will receive a sham laser treatment and then undergo YAG laser vitreolysis 3 months later. The follow-up time points will be 1, 3, 6, and 12 months from randomization. Primary outcomes will be participants' self-reported improvement in visual disturbance on a scale of 1 to 10 and their scores on the National Eye Institute Visual Functioning Questionnaire 25 (NEI VFQ-25). Secondary outcomes will be an objective evaluation of the effectiveness of the treatment in reducing vitreous floaters through OCT and fundus photography and tracking any adverse events related to the eyes or overall health. DISCUSSION: This clinical trial aims to evaluate the effectiveness of YAG laser vitreolysis in treating symptomatic vitreous floaters and assess the safety of performing early intervention with YAG laser vitreolysis. TRIAL REGISTRATION: ClinicalTrials.gov NCT05800353 . Registered on 10 March 2023.

Long-term efficacy and safety of YAG laser vitreolysis for vision degrading myodesopsia.

AIM: To assess the long-term efficacy and safety of yttrium-aluminum garnet (YAG) laser vitreolysis for vision degrading myodesopsia (VDM) caused by posterior vitreous detachment (PVD). METHODS: This retrospective study reviewed VDM patients of PVD type undergoing YAG laser vitreolysis. The baseline demographic information, the patterns of floaters, the number of floaters, and the subjective improvement of floater sympotoms (ranging from 0 to 100%) from medical records were collected. Significant improvement was defined as a relief of floater symptoms of ≥50% at the final visit. The long-term efficacy and safety of YAG laser vitreolysis were analyzed. The risk factors linked to significant improvement of floater symptoms were defined using univariate and multivariate logistic regression analyses. RESULTS: The final analysis included 221 patients with VDM. The mean age of patients was 61.08±7.74y, and the mean length of follow-up was 21.38±5.61mo. Totally 57.01% of patients experienced a significant improvement in their floater symptoms after YAG laser therapy, and none of them developed delayed retinal abnormalities such as retinal tears or detachments. Age (OR=1.049, 95%CI=1.007-1.092, P=0.021) was identified as a significant risk factor for significant improvement in VDM. CONCLUSION: YAG laser vitreolysis is an effective and secure treatment for PVD-type VDM, and patients of advanced age are more likely to get favorable outcomes.

Vision degrading myodesopsia assessed with optos ultra-widefield scanning laser ophthalmoscope.

BACKGROUND: To investigate the diagnostic sensitivity of Optos imaging for vision degrading myodesopsia (VDM). METHODS: A total of 420 eyes from 345 patients with VDM were collected in this cross-sectional study. All eyes were classified as having posterior vitreous detachment (PVD) or not having PVD. The sensitivity of Optos imaging for the visibility of vitreous floaters was evaluated. The associated factors with the visibility of vitreous floaters on Optos images were analyzed in univariate and multivariate logistic regression analyses. RESULTS: The mean age of all patients was 56.19 ± 13.89 years old, and 66.67% of patients were female. The vitreous floaters were visible on the ultrasound B scan in all eyes, but only in 47.62% of Optos images (55.29% in eyes with PVD and 15% in eyes without PVD). In the multiple binary logistic regression analysis, age (OR = 1.094, 95%CI = 1.063-1.125, P < 0.001), spherical equivalent (OR = 0.869, 95%CI = 0.791-0.955, P = 0.004) and the distance of the floaters from the retina (OR = 1.191, 95%CI = 1.059-1.339, P = 0.003) were significantly correlated with the visibility of vitreous floaters on Optos images. On Optos images, 25.71% of VDM eyes presented additional retinal abnormalities. CONCLUSIONS: Optos imaging has a low sensitivity for vitreous floaters, particularly in eyes without PVD. On Optos imaging, floaters were more visible in older patients, eyes with greater myopia, and floaters that were further from the retina.

Safety of YAG laser vitreolysis for intraocular tissues: analysis of postoperative complications.

PURPOSE: To evaluate the safety of yttrium-aluminum-garnet (YAG) laser vitreolysis for intraocular tissues. METHODS: Thirty-six New Zealand rabbits were divided as follows: Group 1000 (n = 12) treated with YAG laser of 1000 mJ (5 mJ × 200 shots), Group 2000 (n = 12) treated with YAG laser of 2000 mJ (5 mJ × 400 shots), Group 3000 (n = 12) treated with YAG laser of 3000 mJ (5 mJ × 600 shots). Either a single eye was chosen as the study eye in study groups while the other was untreated as the control group. Intraocular pressure (IOP), slit-lamp, optical coherence tomography (OCT), transmission electron microscopy (TEM), and inflammatory cytokines of aqueous humor (interleukin-1α (IL-1α), interleukin-1ß (IL-1ß), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α)) were performed to examine the rabbits. RESULTS: There were no abnormalities in the study groups of IOP, slit-lamp, and OCT examinations. Group 3000 of TEM showed: neutrophils and mitochondrial swelling on day 1, and fibroblasts and neocollagen on day 14. No abnormalities were observed in Group 1000 and 2000 of TEM. Levels of IL-1α and TNF-α increased at 12 h and decreased to baseline on day 3. Levels of IL-1ß increased at 12 h and decreased to baseline on day 7. Levels of IL-8 increased on day 1 and decreased to baseline on day 3. CONCLUSION: YAG laser vitreolysis is safe when the distance is more than 2 mm from ablation point to the lens and the retina, and the total energy is less than 2000 mJ for one treatment procedure.

Practical applications of vitreous imaging for the treatment of vitreous opacities with YAG vitreolysis.

PURPOSE: To demonstrate the methodology and efficacy of using scanning laser ophthalmoscopy (SLO) and dynamic optical coherence tomography (OCT) to identify and treat symptomatic vitreous floaters using yttrium-aluminum garnet laser vitreolysis (YLV). METHODS: This is a case series highlighted from a cross sectional retrospective study conducted at the Vitreous Retina Macula Specialists of Toronto. Forty eyes from thirty-five patients were treated with YLV between November 2018 and December 2020 for symptomatic floaters and imaged with SLO and dynamic OCT. Patients were re-treated with YLV if they reported ongoing significant vision symptoms during follow-up which correlated to visible opacities on exam and or imaging. Three cases will be highlighted to present the practical applications of SLO and dynamic OCT imaging for YLV treatment. RESULTS: Forty treated eyes were enrolled in this study, with twenty-six eyes (65%) requiring at least one repeat YLV treatment following the first treatment due to ongoing symptomatic floaters. Following the first YLV, there was a significant improvement in overall mean best corrected visual acuity compared to before treatment (0.11 ± 0.20 LogMAR units vs. 0.14 ± 0.20 LogMAR units, p = 0.02 (paired t test)). Case 1 demonstrates a dense, solitary vitreous opacity that has been localized with dynamic OCT imaging to track its movements and retinal shadowing with the patient's eye movements. Case 2 shows the utility of adjusting the fixation target to monitor the movement of vitreous opacities in real-time. Case 3 exhibits an association between decreased symptom burden and vitreous opacity density after YLV. CONCLUSION: Image-guided YLV facilitates the localization and confirmation of vitreous opacities. SLO and dynamic OCT of the vitreous can provide a real-time evaluation of floater size, movement, and morphology, to help clinicians target treatment and monitoring of symptomatic floaters.

Patient-reported outcomes in patients with vitreous floaters: A systematic literature review.

Seeking treatment for bothersome vitreous floaters is patient driven. To measure the impact of floaters and treatment on an individual's quality of life, patient-reported outcome measurements (PROMs) are essential. We review all studies using a PROM for patients with floaters. We evaluated content coverage against quality-of-life domains previously identified in other ophthalmic disorders, and against a qualitative study investigating quality-of-life issues in patients with floaters. We assessed measurement properties of PROMs using an extensive range of psychometric quality criteria. We identified 59 studies using 28 different PROMs. Many PROMs were not specifically developed for patients with floaters. Floater-specific PROMs were mostly based on content validation from an ophthalmologist or researcher perspective; two included a patient perspective. Using the outcomes of the qualitative study, we found that the floater-specific PROMs were narrow in their content coverage, with most items relating to visual symptoms and activity limitations. Testing the psychometric quality of PROMs was rare, and when employed mostly limited to responsiveness and known group validity. The remarkable high number of floater-specific PROMs reveals a need for such measurements in ophthalmology. Unfortunately, reporting on psychometric quality is limited, and content development is most often done without patient involvement.

Dynamic Infrared Imaging of Vitreous Floaters.

Background and Objective: To evaluate the use of dynamic infrared (IR) imaging as a tool for the objective evaluation of symptomatic vitreous floaters and to correlate it with the patient symptomatology. Study Design/Materials and Methods: Retrospective study that examined 66 eyes of 44 patients with symptomatic and asymptomatic vitreous opacities. Patients were imaged using the Heidelberg Spectralis dynamic infrared (IR) image in video mode to record the vitreous movements and shadow artifacts within 30 degrees of the center of the macula. Patients were also asked how symptomatic their vitreous floaters were from absent to severe. After reviewing IR videos and OCT, a grading system was created to evaluate the floaters and a masked reader was asked to evaluate the videos and OCT based on the grading system created. Results: A total of 66 eyes were identified and examined with the IR videos, 50 were symptomatic, and 16 were asymptomatic. After masked review and analysis of the IR videos, there were 4 characteristics that correlated with the patient's symptoms: size, location, movement, and density of obscuration of the OCT B Scan by the vitreous opacity. A table with grading of these characteristics was created to analyze how symptomatic patients were. A masked grader was asked to grade the videos and OCT using the grading system created. A positive correlation was found between the masked grader and the symptoms of patients. (0.70039; p < 0.00001). Conclusion: Dynamic IR video capture of vitreous opacities is a new imaging technique that can qualitatively assess vitreous opacities in a way that correlates to a patient's symptoms. This imaging modality can provide a qualitative assessment of the patient's severity of symptoms based on the location, density, and movement of the visualized vitreous opacities in the imaged video.

A Simple Approach to Estimate the Drag Coefficients of a Submerged Floater.

The calculation of the drag force is a fundamental requirement in the design of any submerged system intended for marine exploration. The calculation can be performed by analytic analysis, numerical modeling, or by a direct calculation performed in a designated testing facility. However, for complex structures and especially those with a non-rigid design, the analytic and numerical analyses are not sufficiently accurate, while the direct calculation is a costly operation. In this paper, we propose a simple approach for how to calculate the drag coefficient in-situ. Aimed specifically at the complex case of elastic objects whose modeling via Computer-Aided Design (CAD) is challenging, our approach evaluates the relation between the object's speed at steady-state and its mass to extract the drag coefficient in any desired direction, the hydro-static force, and, when relevant, also the thruster's force. We demonstrate our approach for the special case of a highly complex elastic-shaped floater that profiles the water column. The analysis of two such floaters in two different sea environments shows accurate evaluation results and supports our claim for robustness. In particular, the simplicity of the approach makes it appealing for any arbitrary shaped object.

Presentations to eye emergency departments with flashes and floaters differ dependent on incident solar radiation.

AIM: The aim of this retrospective review was to analyse the frequency of patients presenting with flashes and/or floaters (F/F) on bright versus dark days to the eye emergency department of a tertiary referral hospital (the Mater Misericordiae University Hospital) over a 3-year period. The diagnostic and clinical outcomes of F/F presentations were also analysed. METHODS: This retrospective study assessed eye casualty attendances between January 2018 and December 2020. Solar irradiation (j/cm2) at ground level was retrieved from the records of Met Eireann (Irish National Meteorological Service) via their open access records. A review of electronic patient medical records using the in-house database patient centre was carried out of all patients who attended EED of during the study timeline on the 5 'brightest' and 5 'darkest' days of each year. RESULTS: Seven hundred forty patient presentations were analysed in total. Overall, 16% (n = 119) of all patients that attended EED during the timeframe of the study presented with F/F. One hundred six patients (89%) presented with floaters, 40 patients (34%) presented with flashing lights/photopsia, and 35 patients (29%) presented with both F/F. More patients presented to EED with F/F on bright days when compared with dark days (74 vs 45, p < 0.05). Eighty-nine percent of all patients with F/F presented with monocular floaters. There were more floater presentations during bright when compared with dark days (70 vs 36, p < 0.05). More patients were diagnosed with PVD on bright days when compared with those diagnosed with PVD on dark days (43vs 15, p < 0.05). More RDs were diagnosed on dark days compared with bright days (7 vs 3, p < 0.05). CONCLUSION: This study established that F/F presentations were more likely to present during bright days when compared with dark days. The diagnosis of PVD was more common during bright days, and RDs were diagnosed significantly more frequently on dark days. Although incident solar radiation was correlated with greater floaters/PVD presentation, causation is unlikely, and the duration of PVD may have been longer in patients presenting on bright days (i.e. pseudo-sudden symptoms).

Spontaneous remission of vision degrading myodesopsia of posterior vitreous detachment type.

PURPOSE: The study aims to observe the spontaneous remission of posterior vitreous detachment (PVD)-type vision degrading myodesopsia (VDM) during long-term follow-up. METHODS: We retrospectively reviewed VDM patients with PVD type that refused any treatment. The ratio and time of significant spontaneous remission of floater symptoms occurring were described. The associated factors with significant remission of floater symptoms were analyzed in the univariate and multivariate logistic regression analyses. RESULTS: In total, 179 patients with VDM were assessed. The mean age of all patients was 60.56 ± 0.47 years old, and the mean duration of follow-up was 23.89 ± 6.63 months. Of the patients, 40.78% have significant improvement in their floater symptoms after mean 16.55 ± 10.63-month follow-up. Myopia (OR = 0.280, 95% CI = 0.084-0.932, P = 0.038), the number of floaters > 3 (OR = 0.343, 95% CI = 0.172-0.683, P = 0.002), and floaters with string-like pattern (OR = 0.370, 95% CI = 0.166-0.824, P = 0.015) and blocky pattern (OR = 0.299, 95% CI = 0.090-0.993, P = 0.049) were negatively correlated with the significant spontaneous remission of VDM symptoms in the multiple binary logistic regression analysis. CONCLUSIONS: Approximately 40% of VDM patients with PVD may experience significant spontaneous remission during long-term follow-up. Patients that are non-myopic and with fewer floaters are more likely to feel relief from VDM symptoms. Floaters with string-like or blocky patterns are less likely to undergo spontaneous remission.