Advancements in Wearable and Implantable Intraocular Pressure Biosensors for Ophthalmology: A Comprehensive Review.

Glaucoma, marked by its intricate association with intraocular pressure (IOP), stands as a predominant cause of non-reversible vision loss. In this review, the physiological relevance of IOP is detailed, alongside its potential pathological consequences. The review further delves into innovative engineering solutions for IOP monitoring, highlighting the latest advancements in wearable and implantable sensors and their potential in enhancing glaucoma management. These technological innovations are interwoven with clinical practice, underscoring their real-world applications, patient-centered strategies, and the prospects for future development in IOP control. By synthesizing theoretical concepts, technological innovations, and practical clinical insights, this review contributes a cohesive and comprehensive perspective on the IOP biosensor's role in glaucoma, serving as a reference for ophthalmological researchers, clinicians, and professionals.

Breaking Barriers in Eye Treatment: Polymeric Nano-Based Drug-Delivery System for Anterior Segment Diseases and Glaucoma.

The eye has anatomical structures that function as robust static and dynamic barriers, limiting the penetration, residence time, and bioavailability of medications administered topically. The development of polymeric nano-based drug-delivery systems (DDS) could be the solution to these challenges: it can pass through ocular barriers, offering higher bioavailability of administered drugs to targeted tissues that are otherwise inaccessible; it can stay in ocular tissues for longer periods of time, requiring fewer drug administrations; and it can be made up of polymers that are biodegradable and nano-sized, minimizing the undesirable effects of the administered molecules. Therefore, therapeutic innovations in polymeric nano-based DDS have been widely explored for ophthalmic drug-delivery applications. In this review, we will give a comprehensive overview of polymeric nano-based drug-delivery systems (DDS) used in the treatment of ocular diseases. We will then examine the current therapeutic challenges of various ocular diseases and analyze how different types of biopolymers can potentially enhance our therapeutic options. A literature review of the preclinical and clinical studies published between 2017 and 2022 was conducted. Thanks to the advances in polymer science, the ocular DDS has rapidly evolved, showing great promise to help clinicians better manage patients.

Fasting/refeeding: an experimental model to study the impact of early thermal manipulation on hepatic metabolism in mule ducks.

An increase in egg incubation temperature was previously shown to enhance the metabolism of mule ducks and increase liver fattening after overfeeding, through a metabolic programming mechanism. Here, we examined whether fasting (F) followed by refeeding (RF) in 11-wk-old mule ducks could become an accelerated model to study the mechanisms of metabolic programming following embryonic thermal manipulation. This study investigated the hepatic response of mule ducks subjected to 23 h of fasting and 1 h of refeeding, in control or thermally programmed animals (with an increase of 1°C, 16 h per day from days 13 to 27 of embryogenesis). Liver weight and energy composition, hepatocyte structure, plasma parameters, and gene expression levels were measured at 1, 2, and 4 h after RF. All these parameters were strongly affected by RF, whereas significant impacts of embryonic programming were measured in cell size (+1 µm on average), lipid composition (+4.2% of saturated fatty acids 4 h after the meal), and relative gene expressions (including HK1, SCD1, ELOVL6, and FASN). In addition to confirming previously identified molecular targets of thermal manipulation, this study revealed new ones, thanks to kinetic sampling after RF. Finally, the detailed description of the impact of the F/RF challenge on the liver structure, composition, and gene expression, but also on plasma parameters allowed us to draw a parallel with these same traits measured during overfeeding. This comparative analysis suggests that this protocol could become a pertinent model to study the mechanisms involved in embryonic liver thermal programming, without overfeeding.

Assessment of the Role and Timing of Glaucoma Surgery in Boston Keratoprosthesis Type 1 Patients.

PURPOSE: To determine the role and optimal timing of glaucoma surgery in relation to Boston keratoprosthesis type 1 (KPro) implantation. DESIGN: Retrospective, comparative, nonrandomized clinical study. METHODS: Single-center study of a total of 100 eyes (100 patients) implanted with a KPro between 2008 and 2017, and diagnosed with glaucoma before or after KPro. Patients were separated into 2 groups: those with preexisting glaucoma and those who developed de novo glaucoma after KPro. Groups were then divided based on whether patients were medically or surgically managed. Glaucoma surgery included glaucoma drainage device (GDD) implantation, trabeculectomy, and cyclophotocoagulation (CPC). Primary outcomes included best-corrected visual acuity (BCVA), glaucoma progression, and complications. Differences in outcomes were compared using parametric and nonparametric tests, as well as log-rank test to compare time-to-outcome events. RESULTS: Among 72 eyes with preexisting glaucoma, 27 (38%) had glaucoma surgery before KPro (18 GDD), whereas 45 (62%) were medically managed only. Among the latter, 19 (42%) needed glaucoma surgery post-KPro (16 GDD). Among 28 eyes with de novo glaucoma, 12 (43%) had glaucoma surgery post-KPro (9 GDD). For eyes with preexisting glaucoma, glaucoma progression was greater with glaucoma surgery performed post-KPro (100%) compared with pre-KPro (74%, P = .016) and to medical management (54%, P = .002). No increase in complications were observed with glaucoma surgery compared to medications only (P > .05), whereas fewer eyes maintained a BCVA of 20/200 or better over time with medical management (P = .013). Eyes with de novo glaucoma had similar progression, BCVA, and complications between medical and surgical care (P > .05). CONCLUSIONS: Glaucoma surgery should be performed before or at the same time as KPro implantation in eyes with preexisting glaucoma. Complication rates are not increased when glaucoma surgery is performed in KPro eyes with either preexisting or de novo glaucoma. To ensure optimal glaucoma control, glaucoma surgery should be performed as early as possible in KPro eyes with good visual potential.

Effects of Low Stocking Densities on Zootechnical Parameters and Physiological Responses of Rainbow Trout (Oncorhynchus mykiss) Juveniles.

The present study investigated the effect of low stocking density on growth, survival, feed parameters and physiological responses (blood metabolites, welfare indicators, immune biomarkers, and transcriptomic responses of stress and immune-related genes) on juvenile rainbow trout (Oncorhynchus mykiss) reared under a recirculating aquaculture system during 12 weeks. Fish (average weight 29.64 g) were reared in triplicate under four initial densities: nine fish per tank (D9, 3.76 ± 0.06 kg/m3), 18 fish per tank (D18, 7.66 ± 0.18 kg/m3), 27 fish per tank (D27, 9.67 ± 0.01 kg/m3) and 36 fish per tank (D36, 12.94 ± 0.14 kg/m3). Results showed that lower stocking density D9 significantly altered survival with several fish dying during the experiment and an alteration of growth and feed efficiency for the remaining fish. In parallel, the study revealed that low stocking density induced a chronic stress altering the physiological responses of trout by dysregulation of the inflammatory, immune system, and indolamine/catecholamine brain levels. In conclusion, regarding all the variables observed, low stocking density (D9) alters survival, growth and feed efficiency of rainbow trout with alteration of their physiological responses. Selecting appropriate fish density relating to rearing conditions proved to be an essential concern to improve welfare in an aquaculture context.

Short-Term Effect of a Low-Protein High-Carbohydrate Diet on Mature Female and Male, and Neomale Rainbow Trout.

Rainbow trout are considered as a poor user of dietary carbohydrates, displaying persistent postprandial hyperglycaemia when fed a diet containing high amounts of carbohydrates. While this phenotype is well-described in juveniles, less attention was given to broodstock. Our objective was to assess for the first time the short-term consequences of feeding mature female and male, and neomale trout with a low-protein high-carbohydrate diet on glucose and lipid metabolism. Fish were fed for two days with a diet containing either no or 32% of carbohydrates. We analysed plasma metabolites, mRNA levels and enzymatic activities of glycolysis, gluconeogenesis, de novo lipogenesis and ß-oxidation in the liver. Results demonstrated that the glucose and lipid metabolism were regulated by the nutritional status in all sexes, irrespective of the carbohydrate intake. These data point out that carbohydrate intake during a short period (5 meals) at 8 °C did not induce specific metabolic changes in broodstock. Finally, we demonstrated, for the first time, sex differences regarding the consequences of two days of feeding on glucose and lipid metabolism.

Enophthalmos as the Initial Systemic Finding of Undiagnosed Metastatic Breast Carcinoma.

PURPOSE: To report on the importance of detecting and investigating non-traumatic enophthalmos, which occurred as the first presenting sign of an undiagnosed metastatic breast carcinoma in two patients with no prior history of neoplasia. DESIGN: Case series. OBSERVATIONS: The first case consists of a 74-year-old woman with no significant past medical history, who presented with a non-traumatic enophthalmos and ptosis of her left eye, and horizontal diplopia on right-gaze. Imaging revealed an intraconal lesion of her left orbit, with orbital fat atrophy. Transcutaneous anterior orbitotomy was performed for tumor biopsy, and the histopathology study concluded on a diagnosis of orbital metastasis consistent with infiltrative breast carcinoma. Thorough breast imaging and multiple breast biopsies were not able to localize the primary tumor. The second case consists of a 76-year-old woman, with no prior relevant medical history, who presented for progressive enophthalmos and ptosis of her right eye. Imaging revealed an osteolytic lesion of her right frontal bone, and multiple infiltrative lesions implicating both orbits. A biopsy was performed through a transcutaneous anterior orbitotomy and histopathology study lead to a diagnosis of metastatic lobular breast carcinoma. The primary breast tumor was localized using positron emission tomography, and further biopsy confirmed the diagnosis. CONCLUSION: Although uncommon, non-traumatic enophthalmos has a broad differential diagnosis. In some rare instances, it may be the initial presentation of orbital metastases in patients with no prior history of cancer, and in the absence of other systemic symptoms. Clinicians must be thorough when assessing and investigating this clinical entity. A comprehensive eye exam, systemic evaluation, orbit imaging, biopsy and immunohistochemistry analysis are essential to promptly diagnose orbital metastases and plan the appropriate treatment.

Micropulse trans-scleral laser therapy outcomes for uncontrolled glaucoma: a prospective 18-month study.

OBJECTIVE: To evaluate the efficacy and safety of micropulse trans-scleral laser therapy (mTLT) in glaucomatous patients. DESIGN: Prospective, interventional study in a university hospital setting. PARTICIPANTS: Fifty-two eyes of 52 adult patients with uncontrolled glaucoma despite maximal tolerated medical treatment, and/or poor candidates for filtering surgery. METHODS: Participants received a 360-degree mTLT diode laser treatment (2000mW, 31.33% duty cycle), with duration adjusted to iris pigmentation and glaucoma severity (160-320 seconds). They were followed for 18 months to assess intraocular pressure (IOP), number of medications, corrected distance visual acuity (CDVA), glaucoma progression based on Humphrey Sita 24-2 perimetry and Cirrus high-definition optical coherence tomography, and complications. The primary outcome measure was the absolute success at 18 months. Absolute success was defined as an IOP 6-21 mm Hg and at least 25% IOP reduction, with equal or less number of IOP medications. Qualified success allowed for an increased number of IOP medications. Failure was defined as an inability to meet the criteria for success or the need for incisional glaucoma surgery. RESULTS: Treatment absolute success was 61.5% at 12 months and 59.6% at 18 months. Mean IOP was reduced by 35.6% at 18 months (23.6 ± 6.5 mm Hg at baseline; 15.2 ± 4.1 mm Hg at 18 months, p < 0.001). mTLT did not significantly reduce the number of topical glaucoma medications (p = 0.075); however, 15 eyes (29%) had systemic oral glaucoma treatment at baseline and 10 eyes (20%) at 18 months. Eight patients (15%) experienced vision loss of ≥2 lines after the procedure. Three patients (6%) regained their preoperative CDVA by 1 month, and 3 patients (6%) by 3 months, while 2 patients (4%) sustained persistent visual loss. No ocular complications were noted in 84.6%. Incisional surgery was required in 25% of eyes owing to inadequately controlled glaucoma despite mTLT. CONCLUSIONS: mTLT is a good therapeutic option for moderate IOP reduction, while being safe and predictable. This improved safety profile makes mTLT a treatment to be considered earlier in the management of glaucoma.

Nutritional regulation of glucose metabolism-related genes in the emerging teleost model Mexican tetra surface fish: a first exploration.

Astyanax mexicanus has gained importance as a laboratory model organism for evolutionary biology. However, little is known about its intermediary metabolism, and feeding regimes remain variable between laboratories holding this species. We thus aimed to evaluate the intermediary metabolism response to nutritional status and to low (NC) or high (HC) carbohydrate diets in various organs of the surface-dwelling form of the species. As expected, glycaemia increased after feeding. Fish fed the HC diet had higher glycaemia than fish fed the NC diet, but without displaying hyperglycaemia, suggesting that carbohydrates are efficiently used as an energy source. At molecular level, only fasn (Fatty Acid Synthase) transcripts increased in tissues after refeeding, suggesting an activation of lipogenesis. On the other hand, we monitored only moderate changes in glucose-related transcripts. Most changes observed were related to the nutritional status, but not to the NC versus HC diet. Such a metabolic pattern is suggestive of an omnivorous-related metabolism, and this species, at least at adult stage, may adapt to a fish meal-substituted diet with high carbohydrate content and low protein supply. Investigation to identify molecular actors explaining the efficient use of such a diet should be pursued to deepen our knowledge on this species.

Serum drops for ocular surface disease: national survey of Canadian cornea specialists.

OBJECTIVE: To review the use and preparation of serum drops for the treatment of ocular surface disease in Canada and to assess the need for an improved access to this therapy. DESIGN: Cross-sectional study. PARTICIPANTS: Cornea specialist members of the Canadian Ophthalmological Society and Canadian laboratories preparing serum tears. METHODS: A confidential survey was emailed to participants in April 2016 and continued through September 2016. Descriptive statistics on serum drops accessibility, production, and use are reported. RESULTS: Thirty-four cornea specialists (out of 93) and 8 laboratories completed the survey. Half of respondents (47%) described serum drops as inaccessible in their practice setting, mainly because of financial (75%) and logistic (66%) barriers. The use of allogeneic serum was perceived as a potential solution to poor accessibility by 62% of ophthalmologists. A private laboratory or pharmacy produced serum drops for 52% of respondents, whereas 32% coordinated serum drop procurement through a hospital laboratory. No serological tests were routinely performed, and sterility checks were done by one laboratory. Over the last year, each laboratory prepared serum tears for 49 ± 32 patients, representing a median of 15 patients per ophthalmologist. CONCLUSIONS: Although most cornea specialists agree that serum drops are indicated in several refractory ocular surface disorders, there is significant discrepancy in accessibility to this treatment across Canada. This study confirms the need for an improved access to serum drops. Use of autologous serum is limited by logistic and financial barriers, which could be reduced by the introduction of an allogeneic serum drop.

Increased systolic blood pressure in rats induced by a maternal low-protein diet is reversed by dietary supplementation with glycine.

When rat dams consume a diet low in protein during pregnancy, their offspring develop high blood pressure. On a low-protein diet, the endogenous formation of the amino acid glycine is thought to become constrained. Glycine may become conditionally essential, as its rate of endogenous formation is inadequate to meet metabolic needs, and may be limiting for the normal development of the fetus. In the present study, five groups of Wistar rats were provided during pregnancy with one of five diets: a control diet containing 18% (w/w) casein (CON), a low-protein diet containing 9% casein (MLP), or the low-protein diet supplemented with 3% glycine (MLPG), alanine (MLPA) or urea (MLPU). The offspring were weaned on to standard laboratory chow, and blood pressure was measured at 4 weeks of age. Blood pressure was significantly increased in the MLP, MLPA and MLPU groups compared with the CON group, but for the MLPG group blood pressure was not significantly different from CON. Compared with the CON group, body weight was significantly reduced for the MLP, MLPA and MLPG groups, but for the MLPU group body weight was not different from CON. These data show that different forms of non-essential dietary nitrogen, when consumed during pregnancy, exert different effects upon the growth and function of the offspring. The availability of glycine appears to be of critical importance for normal cardiovascular development.