Circadian rhythm dysfunction in glaucoma: A hypothesis

The absence of circadian zeitgebers in the social environment causes circadian misalignment, which is often associated with sleep disturbances. Circadian misalignment, defined as a mismatch between the sleep-wake cycle and the timing of the circadian system, can occur either because of inadequate exposure to the light-dark cycle, the most important synchronizer of the circadian system, or reduction in light transmission resulting from ophthalmic diseases (e.g., senile miosis, cataract, diabetic retinopathy, macular degeneration, retinitis pigmentosa, and glaucoma). We propose that glaucoma may be the primary ocular disease that directly compromises photic input to the circadian time-keeping system because of inherent ganglion cell death. Glaucomatous damage to the ganglion cell layer might be particularly harmful to melanopsin. According to histologic and circadian data, a subset of intrinsically photoresponsive retinal ganglion cells, expressing melanopsin and cryptochromes, entrain the endogenous circadian system via transduction of photic input to the thalamus, projecting either to the suprachiasmatic nucleus or the lateral geniculate nucleus. Glaucoma provides a unique opportunity to explore whether in fact light transmission to the circadian system is compromised as a result of ganglion cell loss

Daily illumination exposure and melatonin: influence of ophthalmic dysfunction and sleep duration

BACKGROUND: Ocular pathology lessens light's efficacy to maintain optimal circadian entrainment. We examined whether ophthalmic dysfunction explains unique variance in melatonin excretion of older adults over and above the variance explained by daily illumination, medical, and sociodemographic factors. We also examined whether ophthalmic dysfunction influences relationships between ambient illumination and melatonin. METHODS: Thirty older adults (mean age = 69 years; Blacks = 42% and Whites = 58%) of both genders participated in the study. Demographic and health data were collected at baseline. Participants underwent eye exams at SUNY Downstate Medical Center, wore an actigraph to monitor illumination and sleep, and collected urine specimens to estimate aMT6s concentrations. RESULTS: Hierarchical regression analysis showed that illumination factors explained 29% of the variance in aMT6s mesor. The proportion of variance explained by ophthalmic factors, sleep duration, and race was 10%, 2%, and 2%, respectively. Illumination factors explained 19% of the variance in aMT6s acrophase. The proportion of variance explained by ophthalmic factors, sleep duration, and race was 11%; 17%; and 2%, respectively. Controlling for sleep duration and race reduced the correlations between illumination and melatonin, whereas controlling for ophthalmic factors did not. CONCLUSION: Ophthalmic exams showed that elevated intraocular pressure and large cup-to-disk ratios were independently associated with earlier melatonin timing. Lower illumination exposure also had independent associations with earlier melatonin timing. Conceivably, ophthalmic and illumination factors might have an additive effect on the timing of melatonin excretion, which in turn might predispose individuals to experience early morning awakenings

Pseudo Pseudotumor Cerebri

Headache; Visual obscuration with reduced acuityA 29-year old female with a 1-month history of worsening headaches, transient visual obscurations and reduced visual acuity.VA: best-corrected, 20/30 OD, 20/100 OS; RAPD OSCT; MRIThrombosis of left jugular bulb; Eosionphilic granulomaSurgery; XRT; DiureticsAttache

There is More Than Meets the Eye

Peri-ocular painA 78 year-old woman with acute left peri-ocular painVA: 20/25 OD later declining to 20/30 OD, 20/200 OSSoft tissue mass of the left superior orbit with bone erosion.ChemotherapyAttache

Common Radiological Pitfalls in Ophthalmology and Neuro-Ophthalmology Practice

During a two year period, we collected a series of cases demonstrating common errors in the use of neuro-imaging for neuro-ophthalmologic disorders. These errors can be divided into four categories

Serum and Cerebrospinal Fluid Enzymes in Cerebrovascular Disease

THE clinical significance of enzymology in neurological disorders is as yet uncertain. A number of enzymes have been studied both in serum and in cerebrospinal fluid (CSF). In general, these studies have been limited to a single enzyme and have not included a comparison of the serum and CSF activities of the same enzymes.1-12 Much more needs to be known about the levels of different enzymes in CSF, their relation with one another, and their relation to the serum levels of the same enzymes. In the present study, we compare the CSF and serum activities of the enzymes creatine phosphokinase (CPK), lactic dehydrogenase (LDH), and aldolase (ALD) in a series of patients suffering from acute vascular disorders of the brain. These enzymes are well-known in clinical enzymology and have been studied to some extent in the CSF. CPK in particular is an attractive enzyme because it is foun

Associations of ambient illumination with mood: Contribution of ophthalmic dysfunctions

Evidence suggests that ocular pathology could reduce light-stimulated neuronal signaling to the suprachiasmatic nuclei. This study investigated associations of ambient illumination with moods, while considering the contribution of ophthalmic dysfunctions. Seventy Black (59%) and White (41%) Americans participated in the study. Their average age was 68.27±5.97 years; 73% were women. Baseline data included: physical health, mood, and sociodemographics. Ophthalmic factors including visual acuity, visual field defects, intraocular pressure, vertical and horizontal cup-to-disk ratios, and nerve-fiber-layer thickness were assessed at SUNY Downstate's eye clinic. The following week, participants wore the Actiwatch-L at home to monitor ambient illumination and sleep. Cosine analyses were performed on the logarithm of measured illumination, yielding the mesor and acrophase of daily illumination exposure. Sleep was estimated with an automatic scoring algorithm. Of the sample, 25% reported visual impairment and 85% reported good to excellent health; 27% were visually impaired according to American criteria. Partial correlation analyses showed an inverse correlation of daily illumination levels to depressed mood [ r p=−0.33, P<0.05], when age, sex, ethnicity, income, BMI, diabetes, hypertension, respiratory disease, and habitual sleep duration were controlled. With further control for ophthalmic factors, the magnitude and significance of the correlation diminished [ r p=−0.26, NS]. Individuals receiving daily illumination later in the day reported more depressed moods [ r p=0.36, P<0.01]; of note, this correlation was not significant after control for the covariates [ r p=0.18, NS]. Regression analysis indicated that the ophthalmic factors explained 13% of the variance in depression. Our results show that both the level and timing of ambient illumination are associated with mood. Furthermore, they suggest that visual impairment has a mediating effect on the associations of ambient illumination with depression, supporting the notion that ocular pathology lessens the efficacy of daily illumination in promoting positive moods

Sleep complaints and visual impairment among older Americans: a community-based study

BACKGROUNDThis report describes the associations between sleep complaints and reported visual impairment in an urban community-residing older adult sample.METHODSA total of 1118 volunteers from a biracial cohort participated in the study (mean age = 74 +/- 6; mean body mass index = 28 +/- 10). Volunteers were recruited using a stratified, cluster sampling technique. In a standard order, several questionnaires were administered, soliciting information on socioeconomic status, physical health, social support, and emotional experience. The physical health questionnaire included questions on whether or not the volunteer experienced sleep disorder, visual impairment, heart disease, respiratory disease, arthritis, and hypertension. In this report, we present data on the prevalence of reported sleep problems and visual impairment among older adults.RESULTSOf the total sample, 9% used sleep medicine, 25% reported difficulty falling asleep, 52% indicated experiencing difficulty maintaining sleep, 28% reported waking up early in the morning, and 12% reported daytime sleep longer than 2 hours. Chi-square results showed greater sleep complaints for volunteers with visual impairment. Consistent with these results, analysis of variance revealed that visually impaired volunteers had a higher index rate of sleep disturbance (F((1, 1110)) = 35.32, p <.0001).CONCLUSIONSThese data provide evidence that older adults reporting visual impairment are also likely to report sleep complaints. This verifies laboratory findings of an association of ophthalmic diseases with sleep-wake problems and with circadian rhythm abnormalities