Unveiling the therapeutic potential of Dl-3-n-butylphthalide in NTG-induced migraine mouse: activating the Nrf2 pathway to alleviate oxidative stress and neuroinflammation.

BACKGROUND: Migraine stands as a prevalent primary headache disorder, with prior research highlighting the significant involvement of oxidative stress and inflammatory pathways in its pathogenesis and chronicity. Existing evidence indicates the capacity of Dl-3-n-butylphthalide (NBP) to mitigate oxidative stress and inflammation, thereby conferring neuroprotective benefits in many central nervous system diseases. However, the specific therapeutic implications of NBP in the context of migraine remain to be elucidated. METHODS: We established a C57BL/6 mouse model of chronic migraine (CM) using recurrent intraperitoneal injections of nitroglycerin (NTG, 10 mg/kg), and prophylactic treatment was simulated by administering NBP (30 mg/kg, 60 mg/kg, 120 mg/kg) by gavage prior to each NTG injection. Mechanical threshold was assessed using von Frey fibers, and photophobia and anxious behaviours were assessed using a light/dark box and elevated plus maze. Expression of c-Fos, calcitonin gene-related peptide (CGRP), Nucleus factor erythroid 2-related factor 2 (Nrf2) and related pathway proteins in the spinal trigeminal nucleus caudalis (SP5C) were detected by Western blotting (WB) or immunofluorescence (IF). The expression of IL-1ß, IL-6, TNF-α, Superoxide dismutase (SOD) and malondialdehyde (MDA) in SP5C and CGRP in plasma were detected by ELISA. A reactive oxygen species (ROS) probe was used to detect the expression of ROS in the SP5C. RESULTS: At the end of the modelling period, chronic migraine mice showed significantly reduced mechanical nociceptive thresholds, as well as photophobic and anxious behaviours. Pretreatment with NBP attenuated nociceptive sensitization, photophobia, and anxiety in the model mice, reduced expression levels of c-Fos and CGRP in the SP5C and activated Nrf2 and its downstream proteins HO-1 and NQO-1. By measuring the associated cytokines, we also found that NBP reduced levels of oxidative stress and inflammation. Most importantly, the therapeutic effect of NBP was significantly reduced after the administration of ML385 to inhibit Nrf2. CONCLUSIONS: Our data suggest that NBP may alleviate migraine by activating the Nrf2 pathway to reduce oxidative stress and inflammation in migraine mouse models, confirming that it may be a potential drug for the treatment of migraine.

Photophobia is associated with lower sleep quality in individuals with migraine: results from the American Registry for Migraine Research (ARMR).

BACKGROUND: Patients with migraine often have poor sleep quality between and during migraine attacks. Furthermore, extensive research has identified photophobia as the most common and most bothersome symptom in individuals with migraine, second only to headache. Seeking the comfort of darkness is a common strategy for managing pain during an attack and preventing its recurrence between episodes. Given the well-established effects of daily light exposure on circadian activity rhythms and sleep quality, this study aimed to investigate the relationship between photophobia symptoms and sleep quality in a cohort of patients with migraine. METHODS: A cross-sectional observational study was conducted using existing data extracted from the American Registry for Migraine Research (ARMR). Participants with a migraine diagnosis who had completed the baseline questionnaires (Photosensitivity Assessment Questionnaire (PAQ), Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-2 (PHQ-2)), and selected questions of the ARMR Sleep questionnaire were included. Models were created to describe the relationship of photophobia and photophilia with various sleep facets, including sleep quality (SQ), sleep disturbance (SDis), sleep onset latency (SOL), sleep-related impairments (SRI), and insomnia. Each model was controlled for age, sex, headache frequency, anxiety, and depression. RESULTS: A total of 852 patients meeting the inclusion criteria were included in the analysis (mean age (SD) = 49.8 (13.9), 86.6% (n = 738) female). Those with photophobia exhibited significantly poorer sleep quality compared to patients without photophobia (p < 0.001). Photophobia scores were associated with SQ (p < 0.001), SDis (p < 0.001), SOL (p = 0.011), SRI (p = 0.020), and insomnia (p = 0.005) after controlling for age, sex, headache frequency, depression, and anxiety, signifying that higher levels of photophobia were associated with worse sleep-related outcomes. Conversely, photophilia scores were associated with better sleep-related outcomes for SQ (p < 0.007), SOL (p = 0.010), and insomnia (p = 0.014). CONCLUSION: Results suggest that photophobia is a significant predictor of poor sleep quality and sleep disturbances in migraine. These results underscore the necessity for comprehensive and systematic investigations into the intricate interplay between photophobia and sleep to enhance our understanding and develop tailored solutions for individuals with migraine.

Cataract surgery and artificial iris implantation in patient with oculocutaneous albinism: a case report.

We present a case report detailing the successful phacoemulsification surgery with artificial iris implantation for two individuals with oculocutaneous albinism. These women suffered from cataracts, resulting in reduced visual acuity and heightened photophobia due to iris pigmentary epithelium deficiency. The patients underwent phacoemulsification along with prosthetic artificial iris implantation into the posterior chamber. This intervention resulted in improved visual acuity, reduced photophobia and glare, and an overall enhanced quality of life. Our report highlights two cases of successful phacoemulsification and artificial iris implantation in patients with oculocutaneous albinism and cataracts, leading to improved visual acuity, reduced photophobia, and enhanced quality of life. Notably, there are no prior records in South American literature of cataract surgery combined with artificial iris implantation for oculocutaneous albinism patients up to the time of this publication.

Muscae volitantes: A 19th-century precursor of visual snow syndrome?

PURPOSE: Visual snow syndrome comprises a whole-field static-like visual disturbance, with increased awareness of entopic phenomena, an inability to suppress the 'just seen' and photophobia. Visual snow syndrome is often associated with other problems such as headache, tinnitus, and anxiety. The earliest reported case of a patient experiencing symptoms consistent with visual snow syndrome dates only to 1995. This paper seeks to find patterns of experience in the medical literature of the past that are reminiscent of visual snow syndrome, to challenge the view that it is in any sense a novel disorder. Descriptions of subjective visual sensations such as experienced by patients suffering from visual snow syndrome were sought in treatises, textbooks and other literature generated by leading figures in 19th-century ophthalmology, physiology and physics. CONCLUSION: While retrospective diagnosis of modern illness categories in historical medical literature is an enterprise fraught with pitfalls, it is nonetheless possible to see patterns of experience in the 19th-century medical literature that are strongly reminiscent of visual snow syndrome.

Individualized spectral filters alleviate persistent photophobia, headaches and migraines in active duty military and Veterans following brain trauma.

PURPOSE: Consistent with association between photophobia and headache, growing evidence suggests an underlying causal relationship between light sensitivity and central pain. We investigated whether an intervention to regulate light sensitivity by filtering only wavelengths causing difficulties for the specific individual could alleviate headaches/migraines resulting from traumatic brain injury (TBI). METHODS: Secondary data analysis of a clinical database including N = 392 military personnel (97% men, 3% women), ranging in age from 20 to 51 years, diagnosed with TBI, persistent headaches/migraines, and light sensitivity. The average elapsed time from TBI diagnosis to intervention was 3 years. Headache/migraine severity, frequency, medication use, and difficulties related to daily functioning were assessed pre and 4-12 weeks post-intervention with individualized spectral filters. RESULTS: Monthly migraine frequency decreased significantly from an average of 14.8 to 1.9, with 74% reporting no migraines post-intervention. Prescription and over-the-counter medication use decreased by more than 70%. Individuals also reported significant improvement in light sensitivity, headaches/migraine severity, and physical and perceptual symptoms. CONCLUSIONS: Wearing individualized spectral filters was associated with symptom relief, increased subjective quality of reported health and well-being, and decreased objective medication use for TBI-related persistent headaches/migraines. These results support a suggested relationship between dysregulated light sensitivity and central regulation of pain.

Contribution of chemical and electrical transmission to the low delta-like intrinsic retinal oscillation in mice: A role for daylight-activated neuromodulators.

Basal electroretinogram (ERG) oscillations have shown predictive value for modifiable risk factors for type 2 diabetes. However, their origin remains unknown. Here, we seek to establish the pharmacological profile of the low delta-like (δ1) wave in the mouse because it shows light sensitivity in the form of a decreased peak frequency upon photopic exposure. Applying neuropharmacological drugs by intravitreal injection, we eliminated the δ1 wave using lidocaine or by blocking all chemical and electrical synapses. The δ1 wave was insensitive to the blockade of photoreceptor input, but was accelerated when all inhibitory or ionotropic inhibitory receptors in the retina were antagonized. The sole blockade of GABAA, GABAB, GABAC, and glycine receptors also accelerated the δ1 wave. In contrast, the gap junction blockade slowed the δ1 wave. Both GABAA receptors and gap junctions contribute to the light sensitivity of the δ1 wave. We further found that the day light-activated neuromodulators dopamine and nitric oxide donors mimicked the effect of photopic exposure on the δ1 wave. All drug effects were validated through light flash-evoked ERG responses. Our data indicate that the low δ-like intrinsic wave detected by the non-photic ERG arises from an inner retinal circuit regulated by inhibitory neurotransmission and nitric oxide/dopamine-sensitive gap junction-mediated communication.

Mathematical Analysis of Light-sensitivity Related Challenges in Assessment of the Intrinsic Period of the Human Circadian Pacemaker.

Accurate assessment of the intrinsic period of the human circadian pacemaker is essential for a quantitative understanding of how our circadian rhythms are synchronized to exposure to natural and man-made light-dark (LD) cycles. The gold standard method for assessing intrinsic period in humans is forced desynchrony (FD) which assumes that the confounding effect of lights-on assessment of intrinsic period is removed by scheduling sleep-wake and associated dim LD cycles to periods outside the range of entrainment of the circadian pacemaker. However, the observation that the mean period of free-running blind people is longer than the mean period of sighted people assessed by FD (24.50 ± 0.17 h vs 24.15 ± 0.20 h, p <0.001) appears inconsistent with this assertion. Here, we present a mathematical analysis using a simple parametric model of the circadian pacemaker with a sinusoidal velocity response curve (VRC) describing the effect of light on the speed of the oscillator. The analysis shows that the shorter period in FD may be explained by exquisite sensitivity of the human circadian pacemaker to low light intensities and a VRC with a larger advance region than delay region. The main implication of this analysis, which generates new and testable predictions, is that current quantitative models for predicting how light exposure affects entrainment of the human circadian system may not accurately capture the effect of dim light. The mathematical analysis generates new predictions which can be tested in laboratory experiments. These findings have implications for managing healthy entrainment of human circadian clocks in societies with abundant access to light sources with powerful biological effects.

Novel ATF6 homozygous variant in a Chinese patient with achromatopsia.

BACKGROUND: ATF6-associated Achromatopsia (ACHM) is a rare autosomal recessive disorder characterized by reduction of visual acuity, photophobia, nystagmus, and poor color vision. METHODS: Detailed ophthalmological examinations were performed in a Chinese patient with ACHM. Whole exome sequencing and Sanger sequencing were performed to detect the disease-causing gene in the patient. RESULTS: A 6-year-old girl presented photophobia, low vision and reduced color discrimination. Small yellow lesion in the macula of both eyes was observed. FAF demonstrated hypofluorescence in the macular fovea. OCT images revealed interruption of ellipsoid and interdigitation zone in the foveal area and a loss of the foveal pit. ERG showed relatively normal rod responses and unrecordable cone responses. Sequencing result identified a novel splicing variant c.354 + 6T>C in the ATF6 gene (NM_007348.4). CONCLUSIONS: We reported detailed clinical features and genetic analysis of a new Chinese ATF6-associated patient with ACHM.

Premonitory symptoms in migraine: A REFORM Study.

BACKGROUND: Estimates of proportions of people with migraine who report premonitory symptoms vary greatly among previous studies. Our aims were to establish the proportion of patients reporting premonitory symptoms and its dependency on the enquiry method. Additionally, we investigated the impact of premonitory symptoms on disease burden using Headache Impact Test (HIT-6), Migraine Disability Assessment (MIDAS) and World Health Organization Disability Assessment 2.0 (WHODAS 2.0), whilst investigating how various clinical factors influenced the likelihood of reporting premonitory symptoms. METHODS: In a cross-sectional study, premonitory symptoms were assessed among 632 patients with migraine. Unprompted enquiry was used first, followed by a list of 17 items (prompted). Additionally, we obtained clinical characteristics through a semi-structured interview. RESULTS: Prompted enquiry resulted in a greater proportion reporting premonitory symptoms than unprompted (69.9% vs. 43.0%; p < 0.001) and with higher symptom counts (medians 2, interquartile range = 0-6 vs. 1, interquartile range = 0-1; p < 0.001). The number of symptoms correlated weakly with HIT-6 (ρ = 0.14; p < 0.001) and WHODAS scores (ρ = 0.09; p = 0.041). Reporting postdromal symptoms or triggers increased the probability of reporting premonitory symptoms, whereas monthly migraine days decreased it. CONCLUSIONS: The use of a standardized and optimized method for assessing premonitory symptoms is necessary to estimate their prevalence and to understand whether and how they contribute to disease burden.

Quantitative Assessment of Subjective Symptoms and Corneal Sensitivity in Chronic Orbital Pain Patients.

PURPOSE: To objectively evaluate the subjective symptoms and characteristics of chronic orbital pain as well as to quantify sensitization of peripheral trigeminal nerves. METHODS: In this prospective cohort study, patients who previously showed a response to peripheral trigeminal nerve blocks for unilateral, idiopathic chronic orbital pain and healthy subjects completed validated questionnaires assessing headaches, neuropathic signs and symptoms, photophobia, and pain qualities. Corneal sensitivity was measured in both eyes for all subjects with a Cochet-Bonnet aesthesiometer. For pain patients, the full assessment protocol was repeated 2-4 weeks after the study injection, and corneal sensitivity was also measured 30 minutes postinjection. Outcomes assessed were headache, neuropathic pain, and photophobia scores; pain qualities; and corneal sensitivity. RESULTS: Six female chronic orbital pain patients (mean age 48.2 years) and 11 female controls (mean age 47.5) were included. The mean headache, neuropathic pain, and photophobia questionnaire scores were significantly higher for pain patients than for controls (p < 0.001). On sensory testing, 5 pain patients (83.3%) endorsed allodynia, and all 6 (100%) had hyperalgesia in the ipsilateral frontal nerve dermatome. No controls had allodynia or hyperalgesia. Corneal sensitivity was similar between eyes in pain patients and between groups. Questionnaire scores and corneal sensitivity did not change significantly after the injection. CONCLUSIONS: Chronic orbital pain patients have a measurable reduction in quality of life due to headaches and photophobia. The supraorbital and supratrochlear nerves are sensitized, resulting in cutaneous hypersensitivity in the corresponding dermatome, but corneal nerves have normal sensitivity.

Unstable environmental conditions constrain the fine-tune between opsin sensitivity and underwater light in an Amazon forest stream fish.

Visual adaptations can stem from variations in amino acid composition, chromophore utilization, and differential opsin gene expression levels, enabling individuals to adjust their light sensitivity to environmental lighting conditions. In stable environments, adaptations often involve amino acid substitutions, whereas in unstable conditions, differential gene expression may be a more relevant mechanism. Amazon forest streams present diverse underwater lighting conditions and experience short-term water colour fluctuations. In these environments, it is less likely for genetic and amino acid sequences to undergo modifications that tailor opsin proteins to the prevailing lighting conditions, particularly in species having several copies of the same gene. The sailfin tetra, Crenuchus spilurus, inhabits black and clear water Amazon forest streams. The long-wavelength sensitivity (LWS) is an important component for foraging and courtship. Here, we investigated LWS opsin genes in the sailfin tetra. Three copies of LWS1 and two copies of LWS2 genes were found. The maximum absorbance wavelength (λmax) estimated from the amino acid sequences of LWS1 genes exhibited variation among the different copies. In contrast, the copies of LWS2 genes showed identical expected λmax values. Although the amino acid positions affecting λmax varied among LWS genes, they remained consistent among populations living in different water colours. The relative expression levels of LWS genes differed between gene copies. While not formally tested, our results suggest that in fluctuating environments, visual adaptations may primarily stem from alterations in gene expression profiles and/or chromophore usage rather than precise genetic tuning of protein light sensitivity to environmental lighting conditions.

Utilizing visual symptoms to distinguish dry eye from glaucoma, cataract, and suspect glaucoma patients: a cross-sectional study.

BACKGROUND: The diagnosis of dry eye and other common ophthalmological conditions can be supported using patient reported symptoms, which is increasingly useful in contexts such as telemedicine. We aim to ascertain visual symptoms that differentiate dry eye from cataract, glaucoma, or glaucoma suspects. METHODS: Adults with dry eye, glaucoma, cataract, and suspected glaucoma (controls) completed a questionnaire to rate the frequency and severity of 28 visual symptoms. Univariate, followed by multivariable logistic regression with backward stepwise selection (p < 0.05), determined the individual symptoms and set of symptoms best distinguishing dry eye from each of the other conditions. RESULTS: Mean age of 353 patients (94 glaucoma suspect controls, 79 glaucoma, 84 cataract, and 96 dry eye) was 64.1 years (SD = 14.1); 67% were female and 68% White. Dry eye patients reported more frequent light sensitivity (OR = 15.0, 95% CI = 6.3-35.7) and spots in vision (OR = 2.8, 95% CI = 1.2-6.3) compared to glaucoma suspect controls. Compared to glaucoma patients, dry eye patients experienced more frequent light sensitivity (OR = 9.2, 95% CI = 2.0-41.7), but less frequent poor peripheral vision (OR = 0.2, 95% CI = 0.06-0.7), difference in vision between eyes (OR = 0.09, 95% CI = 0.01-0.7), and missing patches of vision (OR = 0.06, 95% CI = 0.009-0.3). Compared to cataract patients, dry eye patients reported more frequent spots in vision (OR = 4.5, 95% CI = 1.5-13.4) and vision variability across the week (OR = 4.7, 95% CI = 1.2-17.7) and were less likely to report worsening vision (OR = 0.1, 95% CI = 0.03-0.4) and blindness (OR = 0.1, 95% CI = 0.02-0.8). CONCLUSION: Visual symptoms may serve as a complementary tool to distinguish dry eye from various ocular conditions, though the symptoms that best distinguish dry eye differ across comparisons. Differentiating how patients visually perceive common eye diseases may be used in a variety of clinical settings to rule out specific conditions.

Sutureless intrascleral intraocular lens fixation and modified iris cerclage pupilloplasty for aphakia and traumatic mydriasis.

PURPOSE: To evaluate the safety and efficacy of sutureless intrascleral intraocular lens (IOL) fixation combined with modified iris cerclage pupilloplasty for treating aphakia and traumatic mydriasis. METHODS: Five patients with aphakia and traumatic mydriasis were operated on by the same surgeon. All patients underwent sutureless intrascleral IOL fixation combined with modified iris cerclage pupilloplasty and were followed up for ≥6 months. Best-corrected visual acuity (BCVA) was measured using the logarithm of the minimum angle of resolution (logMAR). BCVA, intraocular pressure (IOP), pupil diameter, and corneal endothelial cell count (CECC) preoperatively and postoperatively were statistically analyzed. The pupil shape, photophobia, IOL position, and surgical complications were evaluated. RESULTS: The mean BCVA was significantly improved 6 months postoperatively (0.26 ± 0.17 logMAR, P = 0.042) than preoperatively (0.50 ± 0.30 logMAR). No significant difference was observed between the preoperative and postoperative IOP (P = 0.138). The mean pupil diameter significantly reduced postoperatively than preoperatively (3.44 ± 0.35 mm vs. 7.28 ± 0.35 mm, P = 0.043). There was no significant decrease in CECC postoperatively (P = 0.225). The pupil shape was round-like, and photophobia disappeared in all patients. No intraoperative or postoperative complications occurred. CONCLUSION: Sutureless intrascleral IOL fixation combined with modified iris cerclage pupilloplasty is a safe and efficient procedure for treating aphakia traumatic mydriasis patients without sufficient capsular support.

Recognising and managing migraine.

Migraine is a common neurological disorder characterised by a severe, pulsating headache, sometimes accompanied with photophobia or phonophobia and nausea and/or vomiting. The symptoms of migraine can have a significant adverse effect on a person's ability to undertake normal activities. Nurses have an important role in assisting patients in identifying migraine triggers and in supporting them to manage the symptoms of migraines through lifestyle changes and pharmacological treatments. This article describes different types of migraines and some differential diagnoses and 'red flag' symptoms that could indicate a more serious condition. The author also discusses non-pharmacological and pharmacological management strategies and treatments.

Custom Iris Prosthesis for Subtotal Traumatic Aniridia From Combat Ocular Trauma.

Traumatic aniridia from combat ocular trauma can cause visual disability. A 41-year-old male Army Veteran was referred for evaluation of light sensitivity and glare secondary to subtotal traumatic aniridia of his left eye from an improvised explosive device blast. A custom-made artificial iris prosthesis was implanted in the ciliary sulcus and secured using Gore-Tex sutures. After surgery, the patient reported improvement of his light sensitivity and quality of life. The custom iris prosthesis is a surgical option for visual disability resulting from traumatic aniridia from combat ocular trauma.

Clinicopathologic and trichoscopic features of keratosis follicularis spinulosa decalvans: A case series study.

Keratosis follicularis spinulosa decalvans (KFSD) is a rare X-linked hereditary disorder characterized by the triad of follicular hyperkeratosis-photophobia-alopecia. The clinical heterogeneity makes the diagnosis difficult. To investigate the clinicopathologic and trichoscopic features of KFSD and to further clarify the essential requisites for the diagnosis, we conducted a retrospective study of patients with KFSD. The clinical information, histologic features, and trichoscopic findings were evaluated. Eight patients were from seven separate families. Two females were mother and daughter from the same family and the other six patients were male and represented sporadic cases. The average age of onset of alopecia was 21.25 years. Involvement of the scalp hairs leading to progressive scarring alopecia on the midline of the scalp with variable degrees of inflammation was the pathognomonic feature. It typically began after puberty. Vellus hair-associated follicular hyperkeratosis affected all of the patients. However, photophobia was not a constant feature. Histopathologic examination revealed disorders of the hair follicle with an acute-chronic inflammatory response. Follicular changes including fused infundibulum, the protrusion of the outer root sheath into the follicular canal, and a dilatation of the follicles at the isthmus level caused by the occlusion of keratin were observed. The trichoscopic features included perifollicular scaling, tufted hairs, and loss of follicular openings. In conclusion, terminal hair involvement, either scalp hairs, eyebrows, or eyelashes, and the hyperkeratosis of the follicle of vellus hairs is the diagnostic basis of KFSD. We hypothesize that follicular changes in histopathology are the primary event that trigger variable inflammation and further follicular destruction.

FL-41 Tint Reduces Activation of Neural Pathways of Photophobia in Patients with Chronic Ocular Pain.

PURPOSE: To assess the therapeutic effect of tinted lenses (FL-41) on photophobia and light-evoked brain activity using functional magnetic resonance imaging (fMRI) in individuals with chronic ocular surface pain. DESIGN: Prospective case series. METHODS: 25 subjects from the Miami veterans affairs (VA) eye clinic were recruited based on the presence of chronic ocular pain, dry eye symptoms, and photophobia. Using a 3T MRI scanner, subjects underwent 2 fMRI scans using an event-related design based on light stimuli: one scan while wearing FL-41 lenses and one without. Unpleasantness ratings evoked by the light stimuli were collected after each scan. RESULTS: With FL-41 lenses, subjects reported decreased (n = 19), maintained (n = 2), or increased (n = 4) light-evoked unpleasantness ratings. Group analysis at baseline (no lens) revealed significant light evoked responses in bilateral primary somatosensory (S1), bilateral secondary somatosensory (S2), bilateral insula, bilateral frontal pole, visual, precuneus, paracingulate, and anterior cingulate cortices (ACC) as well as cerebellar vermis, bilateral cerebellar hemispheric lobule VI, and bilateral cerebellar crus I and II. With FL-41 lenses, light-evoked responses were significantly decreased in bilateral S1, bilateral S2, bilateral insular, right temporal pole, precuneus, ACC, and paracingulate cortices as well as bilateral cerebellar hemispheric lobule VI. CONCLUSION: FL-41 lenses modulated photophobia symptoms in some individuals with chronic ocular pain. In conjunction, FL-41 lenses decreased activation in cortical areas involved in processing affective and sensory-discriminative dimensions of pain. Further research into these relationships will advance the ability to provide precision therapy for individuals with ocular pain.

Understanding visual snow syndrome: A retrospective study from a tertiary eye care center.

PURPOSE: Visual snow syndrome is a debilitating neurological condition. A comprehensive eye examination may not detect any abnormalities in this condition. Presently the condition is recognized only through the history elicited. Hence, it becomes important to understand the presenting complaints and profile of these patients. A retrospective study at a tertiary eye care center was undertaken to achieve this goal. METHODS: Electronic medical records of patients presenting to a Binocular Vision and Orthoptics clinic were reviewed. Records of the patients containing keywords such as "light sensitivity, shadowing, visual snow, multiple images, and night vision" were retrieved and inspected. Those matching the diagnostic criteria of visual snow syndrome were included in the study. RESULTS: A total of 33 patients (average age ± standard deviation: 29.7 ± 9.8 years) were identified. Majority of the patients were males (69%). All the patients had logMAR visual acuity 0 or better in each eye. The most prominent (84.4%) presenting symptom was palinopsia (or afterimage or trailing). About 34.4% complained of floaters (including snow-like appearance). More than half (54.6%) of the patients also had binocular dysfunction. CONCLUSION: Visual snow syndrome is a relatively new condition on the rise, with unclear pathology. The symptoms of this condition can easily be confused with regular floaters or black spots seen in vitreous and retinal pathologies. In the absence of such pathology, an elaborate history should be elicited, and the distress of the patient should be acknowledged. The patient should also be reassured that this is not a blinding condition.

Comparison of pupil size in patients of migraine with photophobia versus normal subjects and correlation of the pupil size to severity of headache.

PURPOSE: To compare the pupil size of patients having migraine with photophobia versus normal subjects and to correlate the pupil size to the severity of headache. METHODS: This was a prospective case-control study. One hundred eyes of 50 patients who had migraine with photophobia were compared with same number of control subjects who had no history of headache. Pupil size was measured using the IOL Master 700 in all cases. Severity of headache was evaluated by the Migraine Disability Assessment (MIDAS) test questionnaire, and MIDAS grades from 1 to 4 ranging from minimal disability to severe disability were obtained in all cases. The pupil sizes in all grades were compared. RESULTS: The mean pupil size was 4.89 ± 0.9 mm (95% confidence interval [CI]) in patients of migraine with photophobia compared to 3.8 ± 0.49 mm (95% CI) in normal subjects, with a P value of <0.0001, which was statistically significant. Among the 50 patients with migraine, according to MIDAS grades, 20 had Grade 4 or severe disability, 15 had Grade 3 or moderate disability, 10 had Grade 2 or mild disability, and five had Grade 1 or minimal disability. Pupil size in Grade 4 category was the largest with a mean value of 5.6 ± 0.79 mm (95% CI). CONCLUSION: The pupil size in patients of migraine with photophobia is larger than in normal subjects and could be a trigger for the migraine attacks. The larger the pupil size, the more severe is the migraine disability.

Multiple rod layers increase the speed and sensitivity of vision in nocturnal reef fishes.

Most vertebrates have one layer of the dim-light active rod photoreceptors. However, multiple rod layers, known as a multibank retina, can be found in over 100 species of fish, including several deep-sea species and one family of nocturnally active reef fish, the Holocentridae. Although seemingly associated with increased photon catch, the function of multibank retinas remained unknown. We used an integrative approach, combining histology, electrophysiology and amino acid sequence analysis, applied to three species of nocturnal reef fishes, two holocentrids with a multibank retina (Neoniphon sammara and Myripristis violacea) and an apogonid with a single rod bank (Ostorhinchus compressus), to determine the sensory advantage of multiple rod layers. Our results showed that fish with multibank retinas have both faster vision and enhanced responses to bright- and dim-light intensities. Faster vision was indicated by higher flicker fusion frequencies during temporal resolution electroretinography as well as faster retinal release rates estimated from their rhodopsin proteins. Enhanced sensitivity was demonstrated by broadened intensity-response curves derived from luminous sensitivity electroretinography. Overall, our findings provide the first functional evidence for enhanced dim-light sensitivity using a multibank retina while also suggesting novel roles for the adaptation in enhancing bright-light sensitivity and the speed of vision.