Effect of altered eating habits and periods during Ramadan fasting on intraocular pressure, tear secretion, corneal and anterior chamber parameters

Evaluating macular and optic nerve changes during Ramadan fasting by optical coherence tomography angiography-a prospective before-and-after study

PURPOSE

During Ramadan, millions of Muslims fast from sunrise to sunset. Fasting influences the hormonal system, sympathetic activity, blood circulation, and metabolic pathways. Because of these changes, we employed optical coherence tomography angiography (OCTA) to investigate the effects of fasting on the macula and optic nerve.

METHODS

In this prospective before-and-after study, both eyes of 45 participants were examined. Vascular characteristics of the macula and optic nerve head were evaluated in the morning and evening, once before Ramadan and once on the 20th day of Ramadan.

RESULTS

Compared to the non-fasting condition, fasting significantly reduced inner parafoveal retinal thickness in both eyes and total foveal retinal thickness in the left eye in the morning and evening. Fasting in the morning also considerably reduced inner foveal retinal thickness in both eyes and total parafoveal retinal thickness in the right eye. Fasting significantly reduced central choroidal flow (1 mm) in both eyes in the evening (all p-values are < 0.05). In the morning, there were significant increases in the foveal avascular zone (FAZ) area (p-value = 0.006) and deep parafoveal vascular density in the left eye (p-value = 0.001).

CONCLUSION

Fasting alters both the macular characteristics and the optic nerve head, as seen in OCTA, although it did not affect participants' vision. However, further research is needed before reaching a broad conclusion.

TFOS Lifestyle: Impact of nutrition on the ocular surface

Nutrients, required by human bodies to perform life-sustaining functions, are obtained from the diet. They are broadly classified into macronutrients (carbohydrates, lipids, and proteins), micronutrients (vitamins and minerals) and water. All nutrients serve as a source of energy, provide structural support to the body and/or regulate the chemical processes of the body. Food and drinks also consist of non-nutrients that may be beneficial (e.g., antioxidants) or harmful (e.g., dyes or preservatives added to processed foods) to the body and the ocular surface. There is also a complex interplay between systemic disorders and an individual's nutritional status. Changes in the gut microbiome may lead to alterations at the ocular surface. Poor nutrition may exacerbate select systemic conditions. Similarly, certain systemic conditions may affect the uptake, processing and distribution of nutrients by the body. These disorders may lead to deficiencies in micro- and macro-nutrients that are important in maintaining ocular surface health. Medications used to treat these conditions may also cause ocular surface changes. The prevalence of nutrition-related chronic diseases is climbing worldwide. This report sought to review the evidence supporting the impact of nutrition on the ocular surface, either directly or as a consequence of the chronic diseases that result. To address a key question, a systematic review investigated the effects of intentional food restriction on ocular surface health; of the 25 included studies, most investigated Ramadan fasting (56%), followed by bariatric surgery (16%), anorexia nervosa (16%), but none were judged to be of high quality, with no randomized-controlled trials.

Perceived changes in the mental well-being among Nigerians due to Ramadan Intermittent Fasting during the COVID-19 pandemic

INTRODUCTION

Muslims fast every year during the month of Ramadan from dawn until dusk. This study examined mental well-being and correlating factors among Nigerian adults who observed Ramadan intermittent fasting (RIF).

METHODS

A validated generalized anxiety disorder-2 and Patient Health Questionnaire-2, the four-item spiritual well-being index, and the Islamic intrinsic religiosity questionnaire were used to collect data about mental well-being (depression, anxiety), spirituality, and intrinsic religiosity through a web-based survey between the May 9, 2021 (27th of Ramadan, 1442) and the June 4, 2021 (29th of Shawwal, 1442). We studied the mental well-being of respondents over a period of 4 weeks before Ramadan (BR) and during the 4 weeks of Ramadan between the April 12, 2021 and the May 12, 2021(DR). Multinomial regression analysis was used to determine the factors associated with depression and anxiety. This research did not receive any grant or funding.

RESULTS

A total of 770 adult Nigerians who observed RIF study were included in this cross-sectional study. When compared to mental well-being BR, observing RIF by Nigerian adult respondents was associated with a significant improvement in their mental well-being. A higher proportion of respondents felt less depressed DR (61.3% vs. 56.5%. < .001). Interest and pleasure in doing things improved DR than BR (p= 0.007) and respondents felt less nervous and anxious (60.7% vs. 57.1%, respectively; p <.001). Mental well-being was independently associated with sociodemographic characteristics, physical activity, and perceived relationships.

CONCLUSIONS

This study found significant improvement in mental well-being DR compared to BR despite the ongoing COVID-19 pandemic. The effect of RIF on mental well-being needs further research with multicentric studies among different sets of ethnic populations.

TFOS lifestyle: Impact of societal challenges on the ocular surface

Societal factors associated with ocular surface diseases were mapped using a framework to characterize the relationship between the individual, their health and environment. The impact of the COVID-19 pandemic and mitigating factors on ocular surface diseases were considered in a systematic review. Age and sex effects were generally well-characterized for inflammatory, infectious, autoimmune and trauma-related conditions. Sex and gender, through biological, socio-economic, and cultural factors impact the prevalence and severity of disease, access to, and use of, care. Genetic factors, race, smoking and co-morbidities are generally well characterized, with interdependencies with geographical, employment and socioeconomic factors. Living and working conditions include employment, education, water and sanitation, poverty and socioeconomic class. Employment type and hobbies are associated with eye trauma and burns. Regional, global socio-economic, cultural and environmental conditions, include remoteness, geography, seasonality, availability of and access to services. Violence associated with war, acid attacks and domestic violence are associated with traumatic injuries. The impacts of conflict, pandemic and climate are exacerbated by decreased food security, access to health services and workers. Digital technology can impact diseases through physical and mental health effects and access to health information and services. The COVID-19 pandemic and related mitigating strategies are mostly associated with an increased risk of developing new or worsening existing ocular surface diseases. Societal factors impact the type and severity of ocular surface diseases, although there is considerable interdependence between factors. The overlay of the digital environment, natural disasters, conflict and the pandemic have modified access to services in some regions.

Intermittent Fasting to the Eye: A New Dimension Involved in Physiological and Pathological Changes

Intermittent fasting (IF) is gaining popularity as a therapeutic dietary strategy that regulates metabolism and can alter the development of metabolic disorders. An increasing amount of research has connected ocular diseases to IF and discovered that it has a direct and indirect effect on the eye’s physiological structure and pathological alterations. This article summarizes the progress of research on IF in regulating the physiological structures of the ocular vasculature, the anterior segment of the eye, the retina, and the choroid. We explored the therapeutic potential of IF for various common ocular diseases. In the future, a comprehensive study into the fundamental processes of IF will provide a direct and rigorous approach to eye disease prevention and therapy.

Effect of fasting on diurnal fluctuation of parafoveal and peripapillary vessel density and related oculodynamic and haemodynamic parameters

PURPOSE

To investigate the effects of Ramadan fasting on diurnal superficial-deep parafoveal vessel density (pfVD) and nerve head (NH)-radial peripapillary capillary (RPC) peripapillary vessel density (ppVD) using optical coherence tomography angiography (OCTA), as well as other related oculodynamic and haemodynamic parameters, and to compare these findings with those in the nonfasting period in healthy individuals.

METHODS

A total of 105 healthy individuals, 42 women and 63 men, were included in this prospective study. OCTA was used to examine the superficial-deep pfVD and NH-RPC ppVD. In the third week of Ramadan, OCTA readings were obtained twice daily at 08:00 and 16:00 hour (h) under fasting conditions and compared with nonfasting values 2 weeks after Ramadan. Both intraocular pressure (IOP) and blood pressure values were assessed accordingly.

RESULTS

The mean age (23-51) of individuals was 34.37 ± 7.04 years. In comparison with the 08:00 -h values, the 16:00 -h IOPs, superficial-deep pfVDs and RPC ppVDs were substantially reduced both during the fasting and nonfasting periods (P = 0.001, P = 0.009, P = 0.006, P = 0.006, P = 0.004, P = 0.004, P = 0.41, P = 0.032 and P = 0.021). No differences were found in the diurnal change of superficial-deep pfVDs, NH-RPC ppVDs, IOPs and mean ocular perfusion pressures (MOPPs) between the fasting and nonfasting periods, whereas the same was not true for mean arterial blood pressures (MABPs) (P = 0.049).

CONCLUSIONS

The parafoveal and peripapillary VDs (except for NHpp-VD) and IOPs were found to have decreased significantly throughout the day both in fasting and nonfasting periods. Our study confirms the diurnal changes in the IOPs, MOPPs, superficial-deep pfVDs and NH-RPC ppVDs under dehydration and normal terms.

Evaluation of the effect of fasting on intraocular pressure, anterior segment parameters and density of crystalline lens and cornea

PURPOSE

To evaluate the effect of fasting on anterior chamber depth, anterior chamber volume and corneal and lens density by Scheimpflug technology and to measure intraocular pressure changes.

METHODS

Totals of 50 healthy fasting individuals in Ramadan (study group) and 50 healthy non-fasting subjects (control group) were included. Central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), corneal density (CD) and lens density (LD) were evaluated with Scheimpflug technology. Intraocular pressure (IOP) was measured with applanation tonometry. Both eyes of each participant were examined and also compared.

RESULTS

Comparison of groups: There was a statistically significant difference between CD, ACD, ACV and IOP (respectively, right/left eye: fasting: CD: 12.81 ± 0.76/12.73 ± 0.73; ACD: 2.92 ± 0.37 mm/2.93 ± 0.37 mm; ACV: 168.3 ± 41.82 mm³/183.34 ± 32.46 mm³; IOP: 13.80 ± 1.22 mmHg/14.88 ± 2.73 mmHg; non-fasting: CD: 13.28 ± 1.01/13.17 ± 0.77; ACD: 3.06 ± 0.31 mm/3.07 ± 0.31 mm; ACV: 167.46 ± 42.92 mm³/180.68 ± 31.45 mm³; IOP: 13.60 ± 1.65 mmHg/14.74 ± 2.93 mmHg) values on the right side (p < 0.01, p = 0.03, p = 0.04, p = 0.01, respectively). Although there was a statistically significant difference between the ACV, CD and IOP values on the left side (p < 0.01, p = 0.03, p = 0.01, respectively), no statistical significance was found for the ACV value on the left side (p = 0.08).

CONCLUSION

The results demonstrated that, while fasting did not lead to any change in LD and CCT, it caused a small decrease in ACD and ACV, and a significant decrease in CD and IOP values. Scheimpflug technology seems to be a valuable tool for the evaluation of anterior segment changes in patients who are fasting.

Effect of Fasting on Contrast Sensitivity in Healthy Males

Purpose

To evaluate the effect of fasting on contrast sensitivity (CS) in healthy male individuals during the month of Ramadan.

Methods

This study included 45 healthy male individuals, aged between 20 and 40 years, working in the same environment. Functional acuity contrast testing (F.A.C.T) was performed using the Optec 6500 vision testing system. Measurements taken during a state of satiety one week before Ramadan were compared with those taken a minimum of 12 hours after the start of fasting in the first and fourth weeks of Ramadan.

Results

Contrast sensitivity (CS) was increased at the spatial frequency of three cycles per degree (cpd) at the end of the first week of Ramadan in comparison to the CS measured before Ramadan (P = 0.03). The mean CS values were increased at the spatial frequencies of 3 and 12 cpd at the end of the last week of Ramadan in comparison to the mean values measured before Ramadan (P = 0.01 for both).

Conclusion

Although we found statistically significant increases in CS at certain frequencies, we can conclude that Ramadan fasting has no negative effects on CS.

Quantitative assessment of the effect of fasting on macular microcirculation: an optical coherence tomography angiography study

Aim

To analyse the effect of fasting on the retinal vascular plexus and choriocapillaris structures in healthy subjects via Optical Coherence Tomography Angiography (OCTA).

Methods

In this prospective study, OCTA scans of 98 eyes in 49 healthy subjects were compared in fasting and non-fasting period. All cases had a full ophthalmological examination, with OCTA parameters measured, including superficial flow area (SCP) (mm2), deep flow area (DCP) (mm2), choriocapillaris flow area (CC) (mm2), superficial and deep vascular density (SVD and DVD, respectively) (%), superficial foveal avascular zone area (FAZs) (mm2), deep foveal avascular zone area (FAZd) (mm2), subfoveal choroidal thickness (SFCT) (µm) and central macular thickness (CMT) (µm).

Results

The mean SCP, DCP and CC flow area values were induced to be significantly lower in a fasting than a non-fasting period (p<0.001, p<0.001, p=0.049, respectively). The mean VD in a fasting period was statistically significantly lower than in a non-fasting period at the SCP level (p=0.009). No statistically significant difference was found between the two periods in respect to DVD, FAZd and CMT (p=0.068, p=0.653 and p=0.531, respectively); however, FAZs were significantly lower in a non-fasting than fasting period (p=0.038). The SFCT was determined to be statistically significant and thicker during a fasting period (p<0.001).

Conclusion

The current study documented several physiological changes in a fasting period, such as changes in SCP, DCP, CC flow, SVD and DVD, via OCTA.

Exogenous influences on intraocular pressure

Intraocular pressure (IOP), the pressure within the eyeball, is a function mainly of the production and elimination of aqueous humour. Balanced IOP helps to maintain the eyeball contour, allowing proper refraction of light in the anterior segment of the eye. Increases in IOP can cause injury to the ocular structure, typically the optic nerve head and retinal ganglion cells. IOP increase, additionally, is a risk factor for glaucoma progression. However, it is not unusual that glaucoma worsens despite well-managed IOP; indeed, glaucoma can develop and progress even within the normal IOP range. IOP measured once during daytime office hours might not provide sufficient information for effective glaucoma management. In fact, IOP is not a fixed value but rather changes over time: it fluctuates with the intrinsic circadian rhythm and can also change in various lifestyle-related situations (eg, with body posture, during exercise, while holding breath and according to dietary habits). It is therefore worth exploring the various factors that can affect IOP and glaucoma risk. In this review, the various exogenous influences on IOP in the literature are investigated.

Investigation of the effects of Islamic fasting on ocular parameters

Purpose

To investigate the effects of religious fasting during the month of Ramadan on intraocular pressure (IOP), refractive error, corneal tomography and biomechanics, ocular biometry, and tear film layer properties.

Methods

This prospective study was carried out one week before and in the last week of Ramadan. Ninety-four eyes of 94 healthy adult volunteers (54 males and 40 females) with a mean ± SD age of 35.12 ± 9.07 were enrolled in this study. Patients with any systemic disorder, ocular disease, or a history of previous surgery were excluded. Corneal tomography and biomechanics, ocular biometry, IOP, refractive error, and tear break up time (TBUT) were evaluated in non-fasting and fasting periods by the Pentacam (Oculus), Corvis ST (Oculus), IOL Master (Carl Zeiss), computerized tonometer (Topcon CT-1/CT-1P), auto kerato-refractometer (Topcon KR-1), and Keratograph 5M (Oculus), respectively.

Results

There was no significant difference in the central corneal thickness (CCT) between the study groups (P = 0.123) using the Pentacam while the Corvis ST showed a significant difference in all participants (P < 0.0001). Moreover, the peak distance (distance of the two surrounding peaks of the cornea at the highest concavity) of male and female participants showed a significant difference between the fasting and non-fasting groups (P = 0.002). The anterior chamber depth (ACD) using the Pentacam decreased in the male group (P = 0.004) in the fasting period. During the fasting period, computerized tonometer showed a decrease in IOP only in males in comparison to the non-fasting group (P = 0.018) while the Corvis ST showed decreased IOP in all participants (P < 0.0001). The steep keratometry (K2) in the corneal posterior surface appeared to be different in males between the study groups (P = 0.034). We were unable to show any significant difference in other ocular parameters between fasting and non-fasting periods.

Conclusion

This study showed that ACD, IOP, CCT, and peak distance were different between fasting and non-fasting groups while no difference was observed in other ocular parameters. Interpretations of these significant differences should be considered in the clinical setting.

The Effects of Ramadan Fasting on Anterior Segment Parameters, Visual Acuity and Intraocular Pressures of the Eye

Objective:

It is aimed to determine whether fasting during Ramadan has any significant effect on anterior chamber parameters, visual acuity and intraocular pressures.

Methods:

31 fasting (Group 1) and 30 non-fasting healthy volunteers (Group 2) were enrolled. All cases underwent an ophthalmological examination and anterior segment parameter evaluation (central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), pupil size) with Pentacam before and after the breaking of the Ramadan fast in Group 1, before and after dinner in Group 2.

Results:

The mean age was 43.35 ± 13.20 in Group 1, 43.17 ± 12.90 in Group 2 (p= 0.955). No significant difference was detected in any of the parameters in both groups.

Conclusion:

There is a need for more detailed and associated studies to understand better about the influence of Ramadan fast on various ocular parameters.

Effect of Fasting on Corneal Biomechanical and Structural Parameters

PURPOSE

To evaluate the effects of hunger and thirst on corneal biomechanical and structural parameters during Ramadan fasting.

MATERIALS AND METHODS

Corneal biomechanical properties and intraocular pressures of 29 eyes of 29 healthy subjects were evaluated by Reichert ocular response analyzer; and structural and anatomical properties of cornea and anterior eye chamber of same eyes were scanned with Oculus Pentacam anterior segment analyzer. Each eye has been evaluated at 8 am and 4 pm both during and 1 month after Ramadan. Changes of subjects' weight were calculated and their relationship with corneal biomechanical and structural parameters was assessed.

RESULTS

Intraday changes in horizontal corneal astigmatism (p = 0.02), anterior chamber volume (p = 0.01), intraocular pressure associated with the Goldmann IOPg (p = 0.02) and corneal resistance factor (CRF) (p = 0.04) were significantly different when measured during the fasting period in Ramadan and 1 month thereafter. Moreover, when we compared 8 am measurements taken during and after Ramadan, we observed significant differences for anterior chamber volume (p = 0.04) and anterior chamber angle values (p = 0.03). Similarly, for 4 pm measurements, there were significant differences for IOPg (p = 0.01) and CRF values (p = 0.00).

CONCLUSIONS

Fasting lasting for more than 12 h during Ramadan creates an important window of opportunity to investigate the response of anterior chamber of eye to hunger and thirst. The current study contributes to the existing literature on the effects of dietary habits and water intake on corneal and anterior chamber properties.

Effects of fasting on intraocular pressure in a black population

Introduction:

There is a dearth of literature available on the effects of fasting on Intraocular pressure (IOP) among all races and worldwide.

Objectives:

To determine the effects of fasting on IOP in a black African population.

Materials and Methods:

A population-based survey utilizing multistage random sampling techniques was carried out among healthy adult Muslims who were examined before and during Ramadan fast in Osogbo, Nigeria. Demographics were obtained, visual acuities, clinical examination of both eyes, and IOPs were done. Weights and waist circumference were measured. Data were analyzed using Statistical Package for Social Sciences ( SPSS) Version 16. Analysis generated frequencies and cross tabulations, whereas statistical significant values were derived using paired sample t-test and P < 0.05.

Results:

A total of 60 subjects with 120 eyes were examined. Mean age was 42.3 years standard deviation (SD) 16.7, and the male to female ratio was 3:2. Majority were professionals (33.3%). Only 18.3% had less than secondary school education. Over 90% had normal vision (6/5-6/18). Before and during fasting, the mean weights were 65.92 kg SD 12.98 and 65.29 kg SD 12.41 with a reduction of 0.63 kg SD 3.82 (P = 0.214, 95% confidence interval (CI): 0.372-1.626); and the mean waist circumference was 87.20 cm SD 12.39 and 81.78 cm SD 11.65 (P = 0.000, 95% CI 4.128-6.720), respectively. Mean IOPs were 15.98 mmHg SD 3.11 and 14.08 mmHg SD 2.71 before and during fasting, respectively (P = 0.000, 95% CI 0.98558-2.82798).

Conclusions:

The study shows that fasting significantly reduced IOP in an ocularly healthy black African population.

Evaluation of forensic deaths during the month of Ramadan in Konya, Turkey, between 2000 and 2009

Ramadan is a holy month for Muslim people and includes long fasting periods. During Ramadan, practicing Muslims not only fast, but they also abstain from any kind of medication, smoking, sexual intercourse, and alcohol from sunrise to sunset. In the 10-year period between 2000 and 2009, it was determined that a total of 4881 death examinations and autopsies were performed at the Konya Branch of the Forensic Medicine Council (Turkey). All of the reports were retrospectively evaluated for demographic features of the cases and the manner of death. In the studied time period, a total of 491 deaths (10.1%) occurred in Ramadan. The manner of death was accident in 369 (75.2%) of the cases in Ramadan, 3107 (70.8%) of the other cases; suicide in 27 (5.5%) of the cases in Ramadan, 367 (8.4%) of the other cases; and homicide in 28 (5.7%) of the cases in Ramadan, 375 (8.5%) of the other cases. There was a significant statistical difference in terms of the manner of death between the deaths in Ramadan and in the remaining part of the year (P < 0.05). Our study suggested that there was an increase in accidental and natural deaths and a decrease in suicide and homicides in Ramadan.

Image-guided evaluation and monitoring of treatment response in patients with dry eye disease

BACKGROUND

Dry eye disease (DED) is one of the most common ocular disorders worldwide. The pathophysiological mechanisms involved in the development of DED are not well-understood, and thus treating DED has been a significant challenge for ophthalmologists. Most of the currently available diagnostic tests demonstrate low correlation to patient symptoms and have low reproducibility.

METHODS

Recently, sophisticated in vivo imaging modalities have become available for patient care, namely, in vivo confocal microscopy (IVCM) and optical coherence tomography (OCT). These emerging modalities are powerful and non-invasive, allowing real-time visualization of cellular and anatomical structures of the cornea and ocular surface. Here we discuss how, by providing both qualitative and quantitative assessment, these techniques can be used to demonstrate early subclinical disease, grade layer-by-layer severity, and allow monitoring of disease severity by cellular alterations. Imaging-guided stratification of patients may also be possible in conjunction with clinical examination methods.

CONCLUSIONS

Visualization of subclinical changes and stratification of patients in vivo allows objective image-guided evaluation of tailored treatment response based on cellular morphological alterations specific to each patient. This image-guided approach to DED may ultimately improve patient outcomes and make it possible to study the efficacy of novel therapies in clinical trials.