2021

The hippocampus is thought to guide navigation by forming a cognitive map of space. Different environments differ in geometry and the availability of cues that can be used for navigation. Although several spatial coding mechanisms are known to coexist in the hippocampus, how they are influenced by various environmental features is not well understood. To address this issue, we examined the spatial coding characteristics of hippocampal neurons in mice and rats navigating in different environments. We found that CA1 place cells located in the superficial sublayer were more active in cue-poor environments and preferentially used a firing rate code driven by intra-hippocampal inputs. In contrast, place cells located in the deep sublayer were more active in cue-rich environments and used a phase code driven by entorhinal inputs. Switching between these two spatial coding modes was supported by the interaction between excitatory gamma inputs and local inhibition.

Gelatin methacryloyl (GelMA) is one of the most widely used photo-crosslinkable biopolymers in tissue engineering. In in presence of an appropriate photoinitiator, the light activation triggers the crosslinking process, which provides shape fidelity and stability at physiological temperature. Although ultraviolet (UV) has been extensively explored for photo-crosslinking, its application has been linked to numerous biosafety concerns, originated from UV phototoxicity. Eosin Y, in combination with TEOA and VC, is a biosafe photoinitiation system that can be activated via visible light instead of UV and bypasses those biosafety concerns; however, the crosslinking system needs fine-tuning and optimization. In order to systematically optimize the crosslinking conditions, we herein independently varied the concentrations of Eosin Y [(EY)], triethanolamine (TEOA), vinyl caprolactam (VC), GelMA precursor, and crosslinking times and assessed the effect of those parameters on the properties the hydrogel. Our data showed that except EY, which exhibited an optimal concentration (~ 0.05 mM), increasing [TEOA], [VA], [GelMA], or crosslinking time improved mechanical (tensile strength/modulus and compressive modulus), adhesion (lap shear strength), swelling, biodegradation properties of the hydrogel. However, increasing the concentrations of crosslinking reagents ([TEOA], [VA], [GelMA]) reduced cell viability in 3-dimensional (3D) cell culture. This study enabled us to optimize the crosslinking conditions to improve the properties of the GelMA hydrogel and to generate a library of hydrogels with defined properties essential for different biomedical applications.

Electron beam (E-beam) irradiation is an attractive and efficient method for sterilizing clinically implantable medical devices made of natural and/or synthetic materials such as poly(methyl methacrylate) (PMMA). As ionizing irradiation can affect the physicochemical properties of PMMA, understanding the consequences of E-beam sterilization on the intrinsic properties of PMMA is vital for clinical implementation. A detailed assessment of the chemical, optical, mechanical, morphological, and biological properties of medical-grade PMMA after E-beam sterilization at 25 and 50 kiloGray (kGy) is reported. Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry studies indicate that E-beam irradiation has minimal effect on the chemical properties of the PMMA at these doses. While 25 kGy irradiation does not alter the mechanical and optical properties of the PMMA, 50 kGy reduces the flexural strength and transparency by 10% and 2%, respectively. Atomic force microscopy demonstrates that E-beam irradiation reduces the surface roughness of PMMA in a dose dependent manner. Live-Dead, AlamarBlue, immunocytochemistry, and complement activation studies show that E-beam irradiation up to 50 kGy has no adverse effect on the biocompatibility of the PMMA. These findings suggest that E-beam irradiation at 25 kGy may be a safe and efficient alternative for PMMA sterilization.

Gelatin based adhesives have been used in the last decades in different biomedical applications due to the excellent biocompatibility, easy processability, transparency, non-toxicity, and reasonable mechanical properties to mimic the extracellular matrix (ECM). Gelatin adhesives can be easily tuned to gain different viscoelastic and mechanical properties that facilitate its ocular application. We herein grafted glycidyl methacrylate on the gelatin backbone with a simple chemical modification of the precursor, utilizing epoxide ring-opening reactions and visible light-crosslinking. This chemical modification allows the obtaining of an elastic protein-based hydrogel (GELGYM) with excellent biomimetic properties, approaching those of the native tissue. GELGYM can be modulated to be stretched up to 4 times its initial length and withstand high tensile stresses up to 1.95 MPa with compressive strains as high as 80% compared to Gelatin-methacryloyl (GeIMA), the most studied derivative of gelatin used as a bioadhesive. GELGYM is also highly biocompatible and supports cellular adhesion, proliferation, and migration in both 2 and 3-dimensional cell-cultures. These characteristics along with its super adhesion to biological tissues such as cornea, aorta, heart, muscle, kidney, liver, and spleen suggest widespread applications of this hydrogel in many biomedical areas such as transplantation, tissue adhesive, wound dressing, bioprinting, and drug and cell delivery.

PURPOSE: To evaluate the effects of electron-beam (E-beam) irradiation on the human cornea and the potential for E-beam sterilization of Boston keratoprosthesis (BK) devices when pre-assembled with a donor cornea prior to sterilization. METHODS: Human donor corneas and corneas pre-assembled in BK devices were immersed in recombinant human serum albumin (rHSA) media and E-beam irradiated at 25 kGy. Mechanical (tensile strength and modulus, and compression modulus), chemical, optical, structural, and degradation properties of the corneal tissue after irradiation and after 6 months of preservation were evaluated. RESULTS: The mechanical evaluation showed that E-beam irradiation enhanced the tensile and compression moduli of human donor corneas, with no impact on their tensile strength. By chemical and mechanical analysis, E-beam irradiation caused a minor degree of crosslinking between collagen fibrils. No ultrastructural changes due to E-beam irradiation were observed. E-beam irradiation slightly increased the stability of the cornea against collagenase-induced degradation and had no impact on glucose diffusion. The optical evaluation showed transparency of the cornea was maintained. E-beam irradiated corneal tissues and BK-cornea pre-assembled devices were stable for 6 months after room-temperature preservation. CONCLUSIONS: E-beam irradiation generated no detrimental effects on the corneal tissues or BK-cornea pre-assembled devices and improved native properties of the corneal tissue, enabling prolonged preservation at room temperature. The pre-assembly of BK in a donor cornea, followed by E-beam irradiation, offers the potential for an off-the-shelf, ready to implant keratoprosthesis device.

Therapeutic angiogenesis would be clinically valuable in situations such as peripheral vascular disease in diabetic patients and tissue reperfusion following ischemia or injury, but approaches using traditional isoforms of vascular endothelial growth factor-A (VEGF) have had little success. The isoform VEGF165 is both soluble and matrix-associated, but can cause pathologic vascular changes. Freely diffusible VEGF121 is not associated with pathologic angiogenesis, but its failure to remain in the vicinity of the targeted area presents therapeutic challenges. In this study, we evaluate the cellular effects of engineered VEGF variants that tether extracellular VEGF121 to the cell membrane with the goal of activating VEGF receptor 2 (VEGFR2) in a sustained, autologous fashion in endothelial cells. When expressed by primary human retinal endothelial cells (hRECs), the engineered, membrane-tethered variants eVEGF-38 and eVEGF-53 provide a lasting VEGF signal that induces cell proliferation and survival, increases endothelial permeability, promotes the formation of a cord/tube network, and stimulates the formation of elongated filopodia on the endothelial cells. The engineered VEGF variants activate VEGFR2, MAPK/ERK, and the Rho GTPase mediators CDC42 and ROCK, activities that are required for the formation of the elongated filopodia. The sustained, pro-angiogenic activities induced by eVEGF-38 and eVEGF-53 support the potential of engineered VEGF variants-overexpressing endothelial cells as a novel combination of gene and cell-based therapeutic strategy for stimulating endothelial cell-autologous therapeutic angiogenesis.

Neuroscientific studies on the function of the basal ganglia often examine the behavioral performance of patients with movement disorders, such as Parkinson's disease (PD) and dystonia (DT), while simultaneously examining the underlying electrophysiological activity during deep brain stimulation surgery. Nevertheless, to date, there have been no studies comparing the cognitive performance of PD and DT patients during surgery. In this study, we assessed the memory function of PD and DT patients with the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE). We also tested their cognitive performance during the surgery using a continuous recognition memory test. The results of the MoCA and MMSE failed to reveal significant differences between the PD and DT patients. Additionally, no significant difference was detected by the intraoperative memory test between the PD and DT patients. The intraoperative memory test scores were highly correlated with the MMSE scores and MoCA scores. Our data suggest that DT patients perform similarly to PD patients in cognitive tests during surgery, and intraoperative memory tests can be used as a quick memory assessment tool during surgery.

Purpose: To assess microvascular beds in the optic nerve head (ONH), peripapillary tissue, and the nailfold in patients with primary open-angle glaucoma (POAG) versus controls. Methods: Patients with POAG (n = 22) and controls (n = 12) underwent swept-source optical coherence tomography angiography of ophthalmic microvasculature and nailfold video capillaroscopy of the hand. The main outcomes were vessel density (VD) and blood flow of the ONH, the peripapillary and the nailfold microvasculatures. Results: Patients with POAG were younger than controls (63.5 ± 9.4 vs. 69.9 ± 6.5 years, P = 0.03). Deep ONH VD and blood flow were lower in patients with POAG than controls (39.1% ± 3.5% vs. 43.8% ± 5.7%; 37.8% ± 5.3% vs. 46.0% ± 7.8%, respectively, P < 0.02 for both); similar results were observed with peripapillary VD (37.9 ± 2.6%, 43.4 ± 7.6%, respectively, P = 0.03). Nailfold capillary density and blood flow were lower in patients with POAG than controls (8.8 ± 1.0 vs. 9.8 ± 0.9 capillaries/mm; 19.9 ± 9.4 vs. 33.7 ± 9.8 pL/s, respectively; P < 0.009 for both). After adjusting for age and gender, deep ONH VD and blood flow, peripapillary VD, and nailfold capillary blood flow were lower in POAG than controls (β = -0.04, -0.07, -0.05, -13.19, respectively, P ≤ 0.046 for all). Among all participants, there were positive correlations between deep ONH and nailfold capillary blood flow (Pearson's correlation coefficient r = 0.42, P = 0.02), peripapillary and nailfold capillary density (r = 0.43, P = 0.03), and peripapillary and nailfold capillary blood flow (r = 0.49, P = 0.01). Conclusions: Patients with POAG demonstrated morphologic and hemodynamic alterations in both ophthalmic and nailfold microvascular beds compared to controls. Translational Relevance: The concomitant abnormalities in nailfold capillaries and relevant ocular vascular beds in POAG suggest that the microvasculature may be a target for POAG treatment.

PURPOSE: To identify demographic and disease-related characteristics predictive of LTFU status in amblyopia treatment and create a risk model for predicting LTFU status. DESIGN: Retrospective cohort study METHODS: Setting: Single center, ophthalmology department at Boston Children's Hospital (BCH). PATIENTS: 2037 patients treated for amblyopia at BCH between 2010-2014. OBSERVATION PROCEDURE: LTFU was defined as patients who did not return after initial visit, excluding those who came for second opinion. Multiple variables were tested for association with LTFU status. OUTCOME MEASURE: Odds ratio of LTFU risk associated with each variable. Multivariate logistic regression was used to create a risk score for predicting LTFU status. RESULTS: A large proportion of patients (23%) were LTFU after first visit. Older age, non-white race, lack of insurance, previous glasses or atropine treatment, and longer requested follow-up intervals were independent predictors of LTFU status. A multivariable risk score was created to predict probability of LTFU (AUC 0.68). CONCLUSIONS: Our comprehensive amblyopia database allows us to predict which patients are more likely to be LTFU after baseline visit, and develop strategies to mitigate these effects. These findings may help with practice efficiency and improve patient outcomes in the future by transitioning these analyses to an electronic medical record that could be programmed to provide continually updated decision support for individual patients based on large datasets.

PURPOSE: To report the results of a glaucoma screening campaign targeting first-degree relatives of glaucoma patients in South India. METHODS: 1598 glaucoma patients were contacted via letter or letter and phone call and asked to bring their siblings and children to a glaucoma screening. Participants underwent standardised eye examinations and completed questionnaires that assessed barriers to participation and awareness of glaucoma risk. Two-proportion z-tests were used to compare categorical data. Costs associated with the screening were recorded. RESULTS: 206 probands (12.9%) attended the screening along with 50 siblings and children. Probands were nearly twice as likely to attend if they had been contacted via both letter and phone call rather than letter only. Over half of probands reported that their relatives could not participate because they did not live in the region, and one-fifth reported that their relatives had other commitments. Fifty-eight per cent of the siblings and children who attended did not know that they were at increased risk for glaucoma due to their family history, and 32.0% did not know that the relative who had invited them to the screening had glaucoma. Thirteen siblings and children (26.0% of those who attended) were found to have findings concerning for glaucoma. The average cost per first-degree relative who was screened was INR2422 (£26). CONCLUSION: Participation in this glaucoma screening campaign was poor. The major barrier to participation was distance from the screening site and associated indirect costs. Better strategies for bringing first-degree relatives in for examinations are needed.

OBJECTIVE: To assess whether machine learning algorithms (MLA) can predict eyes that will undergo rapid glaucoma progression based on an initial visual field (VF) test. DESIGN: Retrospective analysis of longitudinal data. SUBJECTS: 175,786 VFs (22,925 initial VFs) from 14,217 patients who completed ≥5 reliable VFs at academic glaucoma centers were included. METHODS: Summary measures and reliability metrics from the initial VF and age were used to train MLA designed to predict the likelihood of rapid progression. Additionally, the neural network model was trained with point-wise threshold data in addition to summary measures, reliability metrics and age. 80% of eyes were used for a training set and 20% were used as a test set. MLA test set performance was assessed using the area under the receiver operating curve (AUC). Performance of models trained on initial VF data alone was compared to performance of models trained on data from the first two VFs. MAIN OUTCOME MEASURES: Accuracy in predicting future rapid progression defined as MD worsening more than 1 dB/year. RESULTS: 1,968 eyes (8.6%) underwent rapid progression. The support vector machine model (AUC 0.72 [95% CI 0.70-0.75]) most accurately predicted rapid progression when trained on initial VF data. Artificial neural network, random forest, logistic regression and naïve Bayes classifiers produced AUC of 0.72, 0.70, 0.69, 0.68 respectively. Models trained on data from the first two VFs performed no better than top models trained on the initial VF alone. Based on the odds ratio (OR) from logistic regression and variable importance plots from the random forest model, older age (OR: 1.41 per 10 year increment [95% CI: 1.34 to 1.08]) and higher pattern standard deviation (OR: 1.31 per 5-dB increment [95% CI: 1.18 to 1.46]) were the variables in the initial VF most strongly associated with rapid progression. CONCLUSIONS: MLA can be used to predict eyes at risk for rapid progression with modest accuracy based on an initial VF test. Incorporating additional clinical data to the current model may offer opportunities to predict patients most likely to rapidly progress with even greater accuracy.

PURPOSE: To study the epidemiology of inpatient open globe injuries (OGI) in the United States (US). METHODS: This was a retrospective cohort study of patients with a primary diagnosis of OGI in the National Inpatient Sample (NIS) from 2009 to 2015. Sociodemographic characteristics, including age, gender, race, ethnicity, insurance, and income were stratified for comparison. Annual prevalence rates were calculated using 2010 US Census data. Statistical analysis included Chi-square tests, ANCOVA, and Tukey tests. RESULTS: A total of 6,821 US inpatient hospital discharge records met inclusion/exclusion criteria. The estimated national prevalence of OGI during the 5-year period from 2009 to 2015 was 34,061 (95% confidence interval [CI] 31,445-36,677). The overall annual prevalence rate was 1.58 per 100,000 per year (CI 1.56-1.59). Overall, average annual prevalence rates were highest among patients 85 years or older (7.72, CI 6.95-8.49), on Medicare (3.92, CI 3.84-4.00), males (2.28, CI 2.25-2.30), African Americans (2.38, CI 2.32-2.44), and Native Americans (1.80, CI 1.62-2.00). OGI rates were lowest among Whites (1.21, CI 1.19-1.22), females (0.89, CI 0.87-0.91), those with private insurance (0.84, CI 0.82-0.86), and Asians (0.69, CI 0.64-0.74). Being in the lowest income quartile was a risk factor for OGI (p < .05). CONCLUSIONS: Inpatient OGIs disproportionately affected those over 85, young males, elderly females, patients of African-American descent, on Medicare, and in the lowest income quartile. Additionally, children and young children had lower rates of OGI compared to adolescents. Further studies should delineate causes for socioeconomic differences in OGI rates to guide future public health measures.

Purpose: To demonstrate changes in three-dimensional choroidal volume with enhanced depth imaging optical coherence tomography (EDI-OCT) in patients with recurrent stage of Vogt-Koyanagi-Harada disease (VKH).Materials and Methods: This prospective comparative case series included 9 patients with recurrent VKH, 10 patients with quiet VKH, and 15 healthy controls after sample size was calculated. All VKH cases with recurrences underwent raster scanning with EDI-OCT at active and inactive stages of the disease.Results: All choroidal parameters in the active stage significantly reduced when the inflammation subsided: total choroidal volume (P = .02), central choroidal volume (P = .01), central choroidal thickness (P = .03). The changes in central choroidal volume over the resolution phase were more pronounced than the changes in central choroidal thickness in 56% of cases. Two cases presenting with only subclinical posterior segment recurrence had their choroidal parameters recovered after prompt treatment.Conclusions: In the recurrent stage of VKH, alteration in choroidal volume was evident by EDI-OCT even in an absence of anterior segment inflammation. Central choroidal volume may serve as a biomarker for detecting choroidal morphological change.

PURPOSE: To quantify abnormalities in the peripapillary microvasculature in eyes with primary open-angle glaucoma (POAG) and paracentral visual field (VF) loss. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: Thirty-three POAG patients, including 15 with paracentral VF loss and 18 with peripheral VF loss, and 31 control participants underwent swept-source OCT angiography (OCTA) of the peripapillary region. METHODS: The POAG groups were matched by VF mean deviation (MD). The peripapillary microvasculature from the internal limiting membrane to the retinal nerve fiber layer (RNFL) interface was quantified within a 0.70-mm annulus around Bruch's membrane opening after removal of large vessels. Both vessel density (VD) and the integrated OCTA by ratio analysis signal (IOS) suggestive of flow were measured. Regional VD and IOS were measured from the affected hemisphere corresponding to the VF hemifield of more severe loss, which was used to calculate the paracentral total deviation (PaTD), or total deviation within the central 10°. One eye per participant was included. MAIN OUTCOME MEASURES: Difference in peripapillary OCTA measurements between paracentral and peripheral VF loss groups and correlation of peripapillary VD and IOS with PaTD. RESULTS: The POAG groups had matched VF MD (-3.1 ± 2.5 dB paracentral vs. -2.3 ± 2.0 dB peripheral; P = 0.31), did not differ in average RNFL thickness (71.1 ± 14.7 μm vs. 78.1 ± 15.0 μm; P = 0.55), but differed in age (59.2 ± 9.6 years paracentral vs. 67.4 ± 6.6 years peripheral; P = 0.02). Compared with control participants, both paracentral and peripheral VF loss groups showed reduced VD (P < 0.001 and P = 0.009, respectively) and IOS (P < 0.001 and P = 0.01, respectively) in the affected hemisphere. Compared with POAG eyes with peripheral VF loss, the paracentral group showed reduced peripapillary VD (38.0 ± 2.0%, 35.0 ± 2.2%, respectively; P = 0.001) and IOS (44.3 ± 3.1%, 40.4 ± 4.0%, respectively; P = 0.02) in the affected hemisphere. Among all POAG eyes, peripapillary VD and IOS of the affected hemisphere correlated significantly with functional measurement of paracentral loss (PaTD, r = 0.40, P = 0.02; r = 0.45, P = 0.008; respectively). These correlations remained significant after adjusting for age (r = 0.41, P = 0.02; r = 0.47, P = 0.01; respectively). CONCLUSIONS: Regional peripapillary microvasculature showed decreased VD and flow in POAG with paracentral loss, supporting its importance in this glaucoma subtype.

The long-term survival of biomaterial implants is often hampered by surgery-induced inflammation that can lead to graft failure. Considering that most corneas receiving grafts are either pathological or inflamed before implantation, the risk of rejection is heightened. Here, we show that bioengineered, fully synthetic, and robust corneal implants can be manufactured from a collagen analog (collagen-like peptide-polyethylene glycol hybrid, CLP-PEG) and inflammation-suppressing polymeric 2-methacryloyloxyethyl phosphorylcholine (MPC) when stabilized with the triazine-based crosslinker 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The resulting CLP-PEG-MPC implants led to reduced corneal swelling, haze, and neovascularization in comparison to CLP-PEG only implants when grafted into a mini-pig cornea alkali burn model of inflammation over 12 months. Implants incorporating MPC allowed for faster nerve regeneration and recovery of corneal sensation. CLP-PEG-MPC implants appear to be at a more advanced stage of regeneration than the CLP-PEG only implants, as evidenced by the presence of higher amounts of cornea-specific type V collagen, and a corresponding decrease in the presence of extracellular vesicles and exosomes in the corneal stroma, in keeping with the amounts present in healthy, unoperated corneas.

Pigment epithelium-derived factor (PEDF) is a widely expressed 50-kDa glycoprotein belonging to the serine protease inhibitor family, with well-established anti-inflammatory functions. Recently, we demonstrated the immunoregulatory role played by PEDF in dry eye disease (DED) by suppressing the maturation of antigen-presenting cells at the ocular surface following exposure to the desiccating stress. In this study, we evaluated the effect of PEDF on the immunosuppressive characteristics of regulatory T cells (Tregs), which are functionally impaired in DED. In the presence of PEDF, the in vitro cultures prevented proinflammatory cytokine (associated with type 17 helper T cells)-induced loss of frequency and suppressive phenotype of Tregs derived from normal mice. Similarly, PEDF maintained the in vitro frequency and enhanced the suppressive phenotype of Tregs derived from DED mice. On systemically treating DED mice with PEDF, moderately higher frequencies and significantly enhanced suppressive function of Tregs were observed in the draining lymphoid tissues, leading to the efficacious amelioration of the disease. Our results demonstrate that PEDF promotes the suppressive capability of Tregs and attenuates their type 17 helper T-cell-mediated dysfunction in DED, thereby playing a role in the suppression of DED.

PURPOSE: To estimate point prevalence of uveal melanoma in the patients with germline BAP1 pathogenic variant. DESIGN: Cohort study with risk assessment using Bayesian analysis. METHODS: The point prevalence estimate was obtained by Bayes's rule of reverse conditional probabilities. The probability of uveal melanoma given that BAP1 mutation exists was derived from the prevalence of uveal melanoma, prevalence of germline BAP1 pathogenic variants, and the probability of germline BAP1 pathogenic variant given that uveal melanoma is present. Confidence intervals (CIs) for each variable were calculated as the mean of Bernoulli random variables and for the risk estimate, by the delta method. The age at diagnosis and the gender of the uveal melanoma patients with BAP1 germline pathogenic variants obtained from previous publications or from authors' unpublished cohort was compared with those in the Surveillance, Epidemiology, and End Results (SEER) database. RESULTS: The point prevalence of uveal melanoma in patients with the germline BAP1 pathogenic variants in the US population was estimated to be 2.8% (95% CI, 0.88%-4.81%). In the SEER database, the median age at diagnosis of uveal melanomas was 63 (range 3-99 years) with a male-to-female ratio of 1.01:1. In comparison, uveal melanoma cases with BAP1 germline pathogenic variants from the US population (n = 27) had a median age at diagnosis of 50.5 years (range 16-71). CONCLUSIONS: Quantification of the risk of developing uveal melanoma can enhance counseling regarding surveillance in patients with germline BAP1 pathogenic variant.

Conjunctival hyperemia is one of the most common causes for visits to primary care physicians, optometrists, ophthalmologists, and emergency rooms. Despite its high incidence, the treatment options for patients with conjunctival hyperemia are restricted to over-the-counter drugs that provide symptomatic relief due to short duration of action, tachyphylaxis and rebound redness. As our understanding of the immunopathological pathways causing conjunctival hyperemia expands, newer therapeutic targets are being discovered. These insights have also contributed to the development of animal models for mimicking the pathogenic changes in microvasculature causing hyperemia. Furthermore, this progress has catalyzed the development of novel therapeutics that provide efficacious, long-term relief from conjunctival hyperemia with minimal adverse effects.

Ocular complications associated with anesthesia in ocular and non-ocular surgeries are rare adverse events which may present with clinical presentations vacillating between easily treatable corneal abrasions to more serious complication such as irreversible bilateral vision loss. In this review, we outline the different techniques of anesthetic delivery in ocular surgeries and highlight the incidence and etiologies of associated injuries. The changes in vision in non-ocular surgeries are mistaken for residual sedation or anesthetics, therefore require high clinical suspicion on part of the treating ophthalmologists, to ensure early diagnosis, adequate and swift management especially in surgeries such as cardiac, spine, head and neck, and some orthopedic procedures, that have a comparatively higher incidence of ocular complications. In this article, we review the literature for reports on the clinical incidence of different ocular complications associated with anesthesia in non-ocular surgeries and outline the current understanding of pathophysiological processes associated with these adverse events.

Neuronal ceroid lipofuscinoses (NCLs) are a group of rare neurodegenerative storage disorders associated with devastating visual prognosis, with an incidence of 1/1,000,000 in the United States and comparatively higher incidence in European countries. The pathophysiological mechanisms causing NCLs occur due to enzymatic or transmembrane defects in various sub-cellular organelles including lysosomes, endoplasmic reticulum, and cytoplasmic vesicles. NCLs are categorized into different types depending upon the underlying cause i.e., soluble lysosomal enzyme deficiencies or non-enzymatic deficiencies (functions of identified proteins), which are sub-divided based on an axial classification system. In this review, we have evaluated the current evidence in the literature and reported the incidence rates, underlying mechanisms and currently available management protocols for these rare set of neuroophthalmological disorders. Additionally, we also highlighted the potential therapies under development that can expand the treatment of these rare disorders beyond symptomatic relief.