Photophobia in primary headaches, in essential blepharospasm and in major depression

The pattern glare and visual memory are disrupted in patients with major depressive disorder

BACKGROUND

Visual memory impairment is one of the most commonly complained symptoms in patients with major depressive disorder (MDD). Pattern glare is also a distorted visual phenomenon that puzzles patients with MDD. Nevertheless, how these two phenomena interact in MDD remains unknown. This study investigated the association between pattern glare and visual memory in MDD patients.

METHODS

Sixty-two patients with MDD and forty-nine age-, sex- and education level-matched healthy controls (HCs) were included in this study. The Pattern Recognition Memory (PRM) test and the Brief Visual Memory Test-Revised (BVMT-R) were applied to measure visual memory. The pattern glare test including three patterns with different spatial frequencies (SFs) was used to explore pattern glare levels.

RESULTS

Patients with MDD scored lower on the PRM-PCi, BVMT-R1, BVMT-R2, BVMT-R3, and BVMT-Rt and higher on the PRM-MCLd than HCs (all p < 0.05). Pattern glare scores for MDD patients were higher with mid-SF (p < 0.001), high-SF (p = 0.006) and mid-high SF differences (p = 0.01) than for HCs. A positive correlation between mid-SF and PRM-MCLd scores in all participants was observed (p = 0.01, r = 0.246). A negative correlation between mid-high difference scores and BVMT-R2 scores (p = 0.032, r = -0.317) was observed in HCs, but no significant correlation was observed in MDD patients.

CONCLUSIONS

The present study showed that visual memory and pattern glare are disrupted in MDD. Visual memory may be associated with pattern glare and needs to be studied in future work.

Differential diagnosis and theories of pathophysiology of post-traumatic photophobia: A review

BACKGROUND: Photophobia is a common sensory symptom after traumatic brain injury (TBI) that may have a grave impact on a patient’s functional independence, neurorehabilitation, and activities of daily living. Post-TBI photophobia can be difficult to treat and the majority of patients can suffer chronically up to and beyond one year after their injury. OBJECTIVES: This review evaluates the current theories of the pathophysiology of photophobia and the most-common co-morbid etiologies of light sensitivity in TBI to help guide the differential diagnosis and individualized management of post-TBI photophobia. METHODS: Primary articles were found via PubMed and Google Scholar search of key terms including “photophobia” “light sensitivity” “photosensitivity” “photo-oculodynia” “intrinsically photosensitive retinal ganglion cells” “ipRGC” and “concussion” “brain injury” “dry eye”. Due to paucity of literature papers were reviewed from 1900 to present in English. RESULTS: Recent advances in understanding the pathophysiology of photophobia in dry eye and migraine and their connection to intrinsically photosensitive retinal ganglion cells (ipRGC) have revealed complex and multifaceted trigeminovascular and trigeminoautonomic pathways underlying photophobia. Patients who suffer a TBI often have co-morbidities like dry eye and migraine that may influence the patient’s photophobia. CONCLUSION: Post-traumatic photophobia is a complex multi-disciplinary complaint that can severely impact a patient’s quality of life. Exploration of underlying etiology may allow for improved treatment and symptomatic relief for these patients beyond tinted lenses alone.

Photophobia in headache disorders: characteristics and potential mechanisms

Photophobia is present in multiple types of headache disorders. The coexistence of photophobia and headache suggested the potential reciprocal interactions between visual and pain pathways. In this review, we summarized the photophobic characteristics in different types of headache disorders in the context of the three diagnostic categories of headache disorders: (1) primary headaches: migraine, tension-type headache, and trigeminal autonomic cephalalgias; (2) secondary headaches: headaches attributed to traumatic brain injury, meningitis, non-traumatic subarachnoid hemorrhage and disorder of the eyes; (3) painful cranial neuropathies: trigeminal neuralgia and painful optic neuritis. We then discussed potential mechanisms for the coexistence of photophobia and headache. In conclusion, the characteristics of photophobia are different among these headache disorders. The coexistence of photophobia and headache is associated with the interactions between visual and pain pathway at retina, midbrain, thalamus, hypothalamus and visual cortex. The communication between these pathways may depend on calcitonin gene-related peptide and pituitary cyclase-activating polypeptide transmission. Moreover, cortical spreading depression, an upstream trigger of headache, also plays an important role in photophobia by increased nociceptive input to the thalamus.

Altered Visual Cortical Excitability Is Associated With Psychopathological Symptoms in Major Depressive Disorder

Previous studies suggest that in people with major depressive disorder (MDD), there exists a perturbation of the normal balance between the excitatory and inhibitory neurotransmitter systems in the visual cortex, indicating the possibility of altered visual cortical excitability. However, investigations into the neural activities of the visual cortex in MDD patients yielded inconsistent findings. The present study aimed to evaluate the visual cortical excitability utilizing a paired-pulse stimulation paradigm in patients with MDD and to access the paired-pulse behavior of recording visual evoked potentials (VEPs) as a marker of MDD. We analyzed the amplitudes of VEPs and paired-pulse suppression (PPS) at four different stimulus onset asynchronies (SOAs) spanning 93 ms to 133 ms. Further, the relationship between PPS and the symptom severity of depression was investigated using Spearman's correlation. We found that, whereas the first VEP amplitude remained unchanged, the second VEP amplitude was significantly higher in the MDD group compared to the healthy controls. As a result, the amplitude ratio (second VEP amplitude/first VEP amplitude) increased, indicating reduced PPS and thus increased excitability in the visual cortex. Moreover, we found the amplitude ratios had a significantly positive correlation with the symptom severity of depression in MDD, indicating a clinically useful biomarker for MDD. Our findings provide new insights into the changes in the excitation-inhibition balance of visual cortex in MDD, which could pave the way for specific clinical interventions.

Photoaversion in inherited retinal diseases: clinical phenotypes, biological basis, and qualitative and quantitative assessment

Severe light sensitivity is a feature common to a range of ophthalmological and neurological diseases. In inherited retinal diseases (IRDs) particularly, this may be accompanied by significant visual disruption. These symptoms are extremely debilitating for affected individuals and have significant implications in terms of day-to-day activities. Underlying mechanisms remain to be fully elucidated. Currently, there are many assessments of photoaversion (PA), however, all have limitations, with quantitative measurement in particular needing further evaluation. To understand the complexities associated with photoaversion from different pathologies, qualitative and quantitative assessments of the light aversion response must be standardized. There is no treatment to date, and strategies to alleviate symptoms focus on light avoidance. With respect to IRDs, however, gene therapy is currently being investigated in clinical trials and promising and further treatments may be on the horizon. The better characterization of these symptoms is an important end point measure in IRD gene therapy trials.

High level of pattern glare in major depressive disorder

BACKGROUND

Visual deficits have been reported in abundance by recent studies on major depressive disorder. Pattern glare manifests as visual distortions, such as the symptoms of headache, glare, eyestrain, illusions of shapes, colors, and motion when viewing repetitive striped patterns, of which some can be observed in major depressive disorder. Inspired by what mentioned, the present study aims to explore whether there exists association between pattern glare and major depressive disorder and further attempts to explore possible clinical diagnostic value of pattern glare in major depressive disorder.

METHODS

Twenty-four patients diagnosed with major depressive disorder (MDDs group) were compared with 30 age-, gender- and education level-matched healthy control subjects (HCs group) on their visual stress with black-and-white gratings of different spatial frequencies-0.3 (low-SF), 2.3 (mid-SF), and 9.4 (high-SF) cycles per degree (c/deg)-which was named pattern glare test. The MDDs group divided into first episode medication-free group (fMDD) and recurrent medicated group (rMDD), comparisons of pattern glare scores (PGS) were performed within the MDDs group. We used Pearson and Spearman analysis to explore the relationship between some clinical indexes and pattern glare scores. ROC (receiver operating characteristic) curve was used to evaluate whether pattern glare test was able to discriminate patients and healthy controls.

RESULTS

The mid-SF pattern glare score significantly elevated in patients with major depressive disorder compared to control subjects. No differences of pattern glare scores were found between fMDD and rMDD. A significant negative correlation between mid-high difference and age in HCs group was found. There were no correlations between other variables and pattern glare scores. The mid-SF score has limited value in the diagnosis of major depressive disorder.

CONCLUSIONS

We observed an increased level of pattern glare in patients with major depressive disorder, reflecting the existence of cortical hyper-excitability in major depressive disorder. The mid-SF score may have a value in understanding cortical excitability in major depressive disorder.

Psychiatric comorbidities and photophobia in patients with migraine

BACKGROUND

Based on recent findings and our own impressions we took a closer look at the relationship between (inter)ictal photophobia and psychometric variables in migraine patients with photophobia.

FINDINGS

For this study we included 29 (27 female) migraine patients and 31 (18 female) controls with a mean age of 31.6 ± 12.5 years and 24.0 ± 4.1 years, respectively. All participants filled out the Depression Anxiety Stress Scale (DASS). Interictal photophobia in patients was significantly higher than photophobia in controls (p = .001). Patients showed statistically significantly higher levels of depressive symptoms (p < .001), anxiety symptoms (p < .001) and stress (p < .001) than controls. Among all participants, (interictal) photophobia correlated positively with age (rho = .318, p = .013) as well as with the levels of depressive symptoms (rho = .459, p < .001), anxiety symptoms (rho = .346, p = .008) and stress (rho = .368, p = .005), but not with gender. In the patients, ictal photophobia correlated positively with age (rho = .473, p = .01) and interictal photophobia (rho = .423, p = .022). Linear regression analysis revealed only a trend towards statistical significance for (interictal) photophobia as a predictor for the level of depressive symptoms (rho = .457, p = 0.056) in the whole sample.

CONCLUSIONS

Considering higher levels of photophobia in depression and the comorbidity of migraine and depression, it might be possible that depression contributes to interictal photophobia in patients with migraine. The same may be true for anxiety and stress. Both are also related to migraine and their possible impact on photophobia in migraine may be explained by pupillary dysfunction.