Intraocular pressure and ocular biometric parameters changes in migraine

Using optical coherence tomography and optical coherence tomography angiography to delineate neurovascular homeostasis in migraine: a review

Migraine is one of the world's most debilitating disorders, and it has recently been shown that changes in the retina can be a potential biomarker for the disease. These changes can be detected by optical coherence tomography (OCT), which measures retinal thickness, and optical coherence tomography angiography (OCTA), which measures vessel density. We searched the databases Google Scholar, ProQuest, Scopus, and Web of Science for studies in English using OCT and OCTA in migraineurs, using the search terms "optical coherence tomography," "OCT," "optical coherence tomography angiography," "OCTA" and "migraine." We found 73 primary studies, 11 reviews, and 8 meta-analyses pertaining to OCT and OCTA findings in migraineurs. They showed that migraineurs had reduced retinal thickness (via OCT), retinal vessel density, and greater foveal avascular zone area (via OCTA) than controls. OCTA changes reflect a perfusion compromise occurring in migraineurs as opposed to in healthy controls. OCT and OCTA deficits were worse in migraine-with-aura and chronic migraine than in migraine-without-aura and episodic migraine. Certain areas of the eye, such as the fovea, may be more vulnerable to these perfusion changes than other parts. Direct comparison between study findings is difficult because of the heterogeneity between the studies in terms of both methodology and analysis. Moreover, as almost all case-control studies were cross-sectional, more longitudinal cohort studies are needed to determine cause and effect between migraine pathophysiology and OCT/OCTA findings. Current evidence suggests both OCT and OCTA may serve as retinal markers for migraineurs, and further research in this field will hopefully enable us to better understand the vascular changes associated with migraine, perhaps also providing a new diagnostic and therapeutic biomarker.

Ocular biometry, anterior chamber morphometry, and their relationship with serum ferritin levels in children with beta thalassemia major

Background

Ocular biometry and anterior segment evaluations are important to determine ocular development and pathological changes, especially in thalassemia patients in Mediterranean countries such as Turkey.

Objectives

The objectives of this study were to compare ocular biometry and anterior segment parameters in children with thalassemia major and healthy controls and to examine the relationship between ferritin levels, anthropometric measurements, and ocular parameters.

Design

This is a prospective case-control study.

Methods

The height, weight, body mass index, and occipitofrontal circumference values of the participants were recorded. Anterior and vitreous chamber depth, lens thickness, axial length, central corneal thickness, anterior chamber volume, iridocorneal angle, pupil diameter, and mean keratometry were measured. Measurements were compared between patients and healthy children, and between patients with ferritin levels above and below 1000 ng/mL.

Results

This study included 40 patients and 45 controls. Height, weight, and body mass index were significantly lower while ferritin level and occipitofrontal circumference were significantly higher in patients compared with the controls (p < 0.001 for all). There were no statistically significant differences in the other ocular parameters (p > 0.05). In comparisons between patients with ferritin levels below (n = 15) and above 1000 ng/mL (n = 25), there were no significant differences in age, height, weight, body mass index, occipitofrontal circumference, or ocular parameters (p > 0.05). Occipitofrontal circumference and mean keratometry value were positively correlated in patients with ferritin levels below 1000 ng/mL (r = 0.573, p = 0.025), while body mass index was negatively correlated with pupil diameter in patients with ferritin levels above 1000 ng/mL (r = -0.469, p = 0.018).

Conclusion

Children with thalassemia showed significant growth retardation and large occipitofrontal circumference but did not differ from controls in terms of biometrics and anterior segment morphology. Our results demonstrated a positive correlation between the occipitofrontal circumference and mean keratometry value in children with ferritin levels below 1000 ng/mL and a negative correlation between body mass index and pupil diameter in children with ferritin levels above 1000 ng/mL.

Choroidal thickness in eyes of migraine patients measured using spectral domain-optical coherence tomography: A meta-analysis

Recent developments in high-resolution optical coherence tomography allow evaluation of even the slightest changes of choroidal thickness in various disorders, including migraine. In this review, we analyze the choroidal thickness measurements reported in various studies that compare results between migraineurs and healthy individuals. We searched PubMed, Scopus, and EMBASE to identify relevant literature reporting choroidal thickness in the migraineurs' different macular regions compared with healthy controls. A fixed-effects or random-effects model was applied for the meta-analysis based on the heterogeneity level. Moreover, subgroup analyses, meta-regression, publication bias, and quality assessment were also performed. We identified ten studies involving 580 migraineurs (173 with aura, 128 without aura, and 279 without specification for the presence of aura) and 407 healthy controls to be included in this meta-analysis. Results indicated that average choroidal thickness was significantly decreased in the migraine cases (SMD, -1.28; 95% CI, -2.47 to -0.08; P = 0.04) compared to healthy individuals. Furthermore, both with aura (SMD, -1.16; 95% CI, -1.39 to -0.92; P < 0.0001) and without aura migraine patients (SMD, -0.81; 95% CI, -1.28 to -0.34; P < 0.001) had significantly thinner subfoveal choroid compared to healthy controls. Moreover, subfoveal choroidal thickness in the migraineurs with aura was significantly lower than those without aura (SMD, -0.45; 95% CI, -0.84 to -0.05; P = 0.03). The alterations in choroidal thickness, suggestive of migraine's neurovascular pathophysiology, were tentatively confirmed by this study's findings. Further longitudinal studies with more diverse settings are required to derive more definitive conclusions.

Oküler biyometrik ölçümler ile pediatrik migren arasında ilişki

Amaç: Bu çalışmada pediatrik migren hastalarında biyometri ölçümlerinin ve ön segment parametrelerinin değerlendirilmesi ve sağlıklı çocuklarla karşılaştırılması amaçlanmıştır. Gereç ve Yöntem: Bu prospektif vaka-kontrol çalışmasına yaş ve cinsiyeti uyumlu 40 pediatrik migren hastası ve 45 sağlıklı çocuk dahil edildi. Ölçümlerden önce tüm katılımcılar tam bir oftalmolojik muayeneden geçirildi. Ön kamara derinliği (ÖKD), vitreus uzunluğu (VU), lens kalınlığı (LK), aksiyel uzunluk (AU), merkezi kornea kalınlığı (MKK), kornea hacmi (KH), ön kamara hacmi (ÖKH), iridokorneal açı (İKA), pupil çapı (PÇ) ve ortalama kornea kırıcılığı (Km) değerlendirildi. Tüm değerlendirmeler ataksız dönemde yapıldı. Fotofobisi olan ve olmayan migrenli hastalarda pupil çapı karşılaştırıldı. Diürnal varyasyondan en az oranda etkilenmek açısından göz içi basınç ölçümleri ve biyometri değerlendirmeleri günün aynı saatlerinde (10:00–12:00) yapıldı. Tüm katılımcıların sağ gözü çalışmaya dahil edildi. Bulgular: Pediatrik migren grubuyla (27 kız, 13 erkek) kontrol grubu (30 kız, 15 erkek) arasında ÖKD, VU, LK, AU, MKK, KH, ÖKH, İKA, PÇ, göz içi basıncı, sferik eşdeğer ve Km ölçümleri bakımından istatistiksel olarak anlamlı farklılık görülmedi. Migren grubu içerisinde fotofobisi olan hastalar ile olmayanların pupil çapları arasında anlamlı farklılık görülmedi. Sonuç: Pediatrik migren hastalarında biyometri, korneal topografi ve keratometri ölçümlerinde sağlıklı çocuklara göre farklılık görülmemektedir. Pediatrik migren ile oküler biyometrik ölçümler arasındaki ilişkiyi incelemek için daha geniş hasta popülasyonlu çalışmalara ihtiyaç vardır.

Effect of migraine attack on pupil size, accommodation and ocular aberrations

PURPOSE

To evaluate the pupil size, accommodation, and ocular higher-order aberrations (HOAs) in patients with migraine during migraine attacks and compare them with interictal period and healthy controls.

METHODS

This prospective, case-control study included 48 eyes of 24 patients with migraine and 48 eyes of 24 age and sex-matched healthy controls. Measurements were performed using a Hartmann Shack aberrometer. Accommodative responses to accommodative stimulus ranging from 0 to 5 diopters (D) in increments of 0.5 D were recorded. Spherical, coma, trefoil aberration, and root mean square (RMS) of total HOAs were assessed. Patients with migraine were measured twice during the interictal phase and during migraine attack.

RESULTS

The mean pupil size significantly decreased during migraine attack (5.85 ± 0.19 mm) compared with the interictal phase (6.05 ± 0.19 mm) in the patients with migraine (p = 0.012). There was a significant increase in the accommodative response to accommodative stimulus of 1.5 to 5 D during migraine attack. No significant change was observed in HOAs during migraine attack. In addition, no ictal or interictal period measurements were statistically significantly different from the controls. Comparing symptomatic and non-symptomatic sides in 17 migraine patients with unilateral headache, no significant difference was found in any of the measurements in both ictal and interictal periods.

CONCLUSION

Our results suggest the presence of a subtle oculosympathetic hypofunction in patients with migraine during the ictal period compared to the interictal period. The accommodation status of the eye seems to be affected by this autonomic dysfunction.

Topographic changes measured by the swept source optical coherence tomography in retinal nerve fiber layer, optic nerve head and macula in children with migraine

As a vascular-inflammatory disease, migraine affects the brain and some other organs, such as the eye. The aim of this study was to measure and compare the peripapillary retinal nerve fiber layer (RNFL) thickness, macular ganglion cell layer thickness and optic nerve head parameters to detect structural damage in children with migraine using swept-source optical coherence tomography. Twenty-four children with migraine in the painless period and 26 controls were included in the study. The vast majority of the groups consisted of females (75% for patients and 77% for controls). Certain RNFL quadrants and optic disc parameters revealed significant differences between the patients and controls. In the right and left eyes of children with migraine, nasal quadrant RNFL was significantly thicker than that in healthy subjects (88.82 ± 11.03 vs 77.80 ± 13.77, P = 0.004 for right eyes and 87.71 ± 11.79 vs 77.80 ± 13.77, P = 0.01 for left eyes). Temporal quadrant RNFL in the left eyes was thinner (78.67 ± 9.57 vs 84.44 ± 9.68, P = 0.04). Disc area in the left eyes of the patients was greater (2.29 ± 0.46 vs 1.94 ± 0.28, P = 0.003). There were significant expansions in cup volumes in favor of the patients for right and left eyes (0.15 ± .0.19 vs 0.05 ± 0.05, P = 0.03 and 0.17 ± 0.14 vs 0.05 ± 0.05, P = 0.001, respectively). The only significant difference between the left and right eyes of the migraineurs was the RNFL thickness in the superior quadrant. Ganglion cell layer thickness did not differ between the right eyes, left eyes and controls. In conclusion, children with migraine showed significant variations in specific RNFL and optic disc parameters compared to control subjects.

Migraine as a risk factor for primary open angle glaucoma: A systematic review and meta-analysis

Migraine is increasingly being reported as a risk factor for primary open angle glaucoma (POAG). However, studies aimed to investigate this association yielded conflicting results. To assess the consistency of the data on the topic, we performed a systematic review and meta-analysis. A systematic literature search from Embase, Web of Science, and PubMed was performed to identify relevant studies on the relationship between migraine and POAG. Random effects models were used to estimate the pooled relative risks (RRs) with 95% confidence intervals (95% CIs) in this meta-analysis. A total of 11 studies meeting the inclusion criteria were included in this meta-analysis. Our findings showed an RR of developing POAG of 1.24 (95% CI = 1.12-1.37) in migraine patients. No evidence of significant heterogeneity was detected across studies (P = .071; I = 41.7%). This association was not modified by the glaucoma type of the included patients. A significant association was observed in case-control design studies, but not in cohort design studies. Little evidence of publication bias was found. The findings of this meta-analysis suggest that migraine can significantly increase the risk of the development of POAG. However, the cohort study design failed to identify this association. Whether migraines can significantly increase the risk of developing POAG is still controversial.

Optical Coherence Tomography in Patients with Chronic Migraine: Literature Review and Update

Migraine is a chronic disease characterized by unilateral, pulsating, and often moderate-to-severe recurrent episodes of headache with nausea and vomiting. It affects approximately 15% of the general population, yet the underlying pathophysiological mechanisms are not fully understood. Optical coherence tomography (OCT) is a safe and reproducible diagnostic technique that utilizes infrared wavelengths and has a sensitivity of 8–10 μm. It can be used to measure thinning of the retinal nerve fiber layer (RNFL) in some neurological disorders. Although ophthalmologists are often the first specialists to examine patients with migraine, few studies have addressed the involvement of the optic nerve and retino-choroidal structures in this group. We reviewed the literature on the etiological and pathological mechanisms of migraine and the relationship between recurrent constriction of cerebral and retrobulbar vessels and ischemic damage to the optic nerve, retina, and choroid. We also assessed the role of OCT for measuring peripapillary RNFL thickness and macular and choroidal changes in migraine patients. There is considerable evidence of cerebral and retrobulbar vascular involvement in the etiology of migraine. Transitory and recurrent constriction of the retinal and ciliary arteries may cause ischemic damage to the optic nerve, retina, and choroid in patients with migraine. OCT to assess the thickness of the peripapillary RNFL, macula, and choroid might increase our understanding of the pathophysiology of migraine and facilitate diagnosis of retino-choroidal compromise and follow-up of therapy in migraine patients. Future studies should determine the usefulness of OCT findings as a biomarker of migraine.