Peripapillary retinal nerve fiber layer thickness in patients with iron deficiency anemia

Evaluation of optical coherence tomography parameters before and after parenteral iron treatment of patients with iron deficiency anemia

PURPOSE

The aim of our study is to evaluate the relationship between iron deficiency anemia (IDA), which is a common and often chronic condition in young women, and the optical coherence tomography (OCT) findings, which have become an indispensable part of ophthalmology practice. We aim to identify a new biomarker for anemia evaluation by demonstrating the morphological changes in the eye before and after iron replacement treatment through OCT findings.

METHODS

70 eyes of 35 patients diagnosed with IDA and planned to have parenteral iron replacement were included in the study. Patients were evaluated before treatment and between 4-6 weeks and 12-16 weeks after treatment. During visits, peripapillary and macular choroidal thicknesses and retinal nerve fiber layer (RNFL) thicknesses were evaluated with OCT along with serum hemoglobin(Hb) values.

RESULTS

The mean age of the patients was 36.80 ± 7.25. All 35 patients (100%) were female. The mean baseline Hb values of the patients increased statistically significantly both after 4-6 weeks and after 12-16 weeks (p < 0.05). A statistically significant difference was found between baseline and third visit in OCT findings in subfoveal, temporal, nasal, peripapillary temporal and peripapillary nasal choroidal thicknesses and total, inferior, nasal and temporal RNFL thicknes (p < 0.05). There was no statistically significant difference between the baseline and the third visit in the central macular thickness and superior RNFL thickness.

CONCLUSION

Significant increases in choroidal and RNFL thickness were detected after parenteral iron replacement in patients diagnosed with IDA. Our results demonstrate that the changes induced by IDA on the retina can be reversed with treatment.

Peripapillary nerve fiber layer in patients with iron deficiency anemia: A cross-sectional study in a tertiary eye care center in Central India

AIMS

The aim of this study is to evaluate the effect of iron-deficiency anemia (IDA) on peripapillary retinal nerve fiber layer (RNFL) thickness using spectral-domain optical coherence tomography (SD-OCT).

SETTINGS

The study was conducted at tertiary eye care center in Central India.

DESIGN

This study was a prospective, cross-sectional, case-control, and observational study.

MATERIALS AND METHODS

In the present study, 58 eyes of patients with IDA were compared with 58 eyes of healthy individuals. All individuals underwent a thorough hematological, clinical, and ophthalmic examination, followed by peripapillary RNFL analysis using SD-OCT.

RESULTS

A total of 116 eyes were included in the study. The average RNFL thickness (RNFLT) in the cases was 97.26 ± 5.96, and 102.32 ± 6.26 (P = 0.005) in controls. There was a significant RNFL loss in the temporal (66.76 ± 6.1, P = 0.02), superior (119.66 ± 10.47, P = 0.01), nasal (73.59 ± 9.52, P = 0.003), and inferior (129.05 ± 10.96, P = 0.001) quadrants in the cases and controls. Serum hemoglobin, iron, ferritin, total iron-binding capacity, and transferrin saturation were lower in the cases (P < 0.05). A positive correlation was observed between average RNFLT and hemoglobin (r = 0.321), iron (r = 0.122), ferritin (r = 0.152), and transferrin (r = 0.190) levels.

CONCLUSIONS

In patients with IDA, RNFLT was decreased in all quadrants compared to normal healthy individuals. The inferior and nasal RNFL showed a significant decrease in thickness. The presence of myopia, glaucoma, and diabetic and hypertensive retinopathy can exert an additive effect in the thinning of RNFLs and cause significant visual loss; hence, the correction of anemia is essential. There is a pressing need to raise public and health professional awareness of these problems and their prevention, diagnosis, and management.

Effect of nutritional-deficiency anemia on peripapillary retinal nerve fiber layer: A North Indian study

PURPOSE

The purpose of this study was to evaluate the effect of nutritional-deficiency anemia (NDA) on peripapillary retinal nerve fiber layer thickness (PPRNFLT) using spectral-domain optical coherence tomography and to determine any correlation arising thereof. This was a single-center, cross-sectional, observational study.

MATERIALS AND METHODS

A total 115 eyes of 115 NDA patients (50 of each with iron-deficiency anemia [IDA] and Vitamin B12-deficiency anemia [BDA], and 15 with folic acid-deficiency anemia [FDA]) aged 18-65 years were compared with a total 100 eyes of 50 age- and sex-matched healthy controls. All subjects underwent comprehensive clinical, ophthalmic, and hematological evaluation, followed by PPRNFLT assessment for the mean total, superior, inferior, nasal, and temporal quadrants.

RESULTS

PPRNFLT for the mean total and all four quadrants in IDA patients, for the mean total, inferior, nasal, and temporal quadrants in BDA patients, and for the mean total, inferior, and nasal quadrants, in FDA patients, was significantly lower as compared to the controls (P < 0.05). The mean total PPRNFLT of all NDA patients correlated significantly (P < 0.05) with their relevant hematological parameters with Pearson's coefficient (r) value of 0.613, 0.610, 0.336, 0.295, 0.337, 0.374, and - 0.509, respectively, for serum haemoglobin (Hb), iron, ferritin, mean corpuscular volume (MCV), mean cell hemoglobin, mean corpuscular hemoglobin concentration, and total iron binding capacity in IDA; 0.310, 0.435, and - 0.386, respectively, for serum Hb%, Vitamin B12, and MCV in BDA; and 0.557, 0.358, and - 0.294 for Hb%, folate, and MCV, respectively, in FDA cases. Mean total retinal nerve fiber layer thinning of all NDA patients showed progression with the increasing severity grades of anemia, except in very severe BDA where an inverse relationship was documented.

CONCLUSION

Our study revealed that PPRNFLT is significantly thinner in all NDA patients (total and all four quadrants in IDA; total, inferior, nasal, and temporal in BDA; and total, inferior, and nasal in FDA) correlating well with their relevant hematological parameters. Early detection of this may be crucial in preventing potential blinding sequelae and differentiating glaucomatous and other neuro-ophthalmic disorders.

Restless Legs Syndrome and the Eyes: Spectral-Domain Optic Coherence Tomography Study

BACKGROUND

Restless legs syndrome (RLS) is a movement disorder thought to be caused by impaired dopamine action. This study aimed to evaluate possible changes in ocular biometric and optic coherence tomography (OCT) parameters in RLS patients.

METHODS

This is a prospective, cross-sectional comparative study. Consecutive primary and secondary (with iron-deficiency anemia) RLS patients and age-matched and sex-matched controls were enrolled in the study. All participants underwent comprehensive neurological and ophthalmological examinations. Ocular biometric and OCT parameters, such as choroidal thickness, macular thickness, macular volume, ganglion cell layer thickness, inner nuclear cell layer thickness, and retinal nerve fiber layer thickness, were compared.

RESULTS

Fifty-one RLS patients and 50 healthy controls were included in this study. There was no difference between the groups' refraction status, ocular biometric data (axial length, anterior chamber depth, central corneal thickness), or OCT parameters (choroidal thickness, macular thickness, macular volume, ganglion cell layer thickness, inner nuclear cell layer thickness). Primary and secondary (with only iron-deficiency anemia) RLS patients were compared, and there was no difference in their axial length, anterior chamber depth, central corneal thickness or OCT parameters. No significant relationship was found between disease severity or duration and OCT parameters.

CONCLUSIONS

Disease severity and disease duration do not affect OCT parameters in primary or secondary RLS patients. OCT data do not seem to provide information about the course of this disease.

Deep-Learning-Based Hemoglobin Concentration Prediction and Anemia Screening Using Ultra-Wide Field Fundus Images

Background: Anemia is the most common hematological disorder. The purpose of this study was to establish and validate a deep-learning model to predict Hgb concentrations and screen anemia using ultra-wide-field (UWF) fundus images.

Methods: The study was conducted at Peking Union Medical College Hospital. Optos color images taken between January 2017 and June 2021 were screened for building the dataset. ASModel_UWF using UWF images was developed. Mean absolute error (MAE) and area under the receiver operating characteristics curve (AUC) were used to evaluate its performance. Saliency maps were generated to make the visual explanation of the model.

Results: ASModel_UWF acquired the MAE of the prediction task of 0.83 g/dl (95%CI: 0.81–0.85 g/dl) and the AUC of the screening task of 0.93 (95%CI: 0.92–0.95). Compared with other screening approaches, it achieved the best performance of AUC and sensitivity when the test dataset size was larger than 1000. The model tended to focus on the area around the optic disc, retinal vessels, and some regions located at the peripheral area of the retina, which were undetected by non-UWF imaging.

Conclusion: The deep-learning model ASModel_UWF could both predict Hgb concentration and screen anemia in a non-invasive and accurate way with high efficiency.

Combining Optical Coherence Tomography and Fundus Photography to Improve Glaucoma Screening

We aimed to evaluate the accuracy of glaucoma screening using fundus photography combined with optical coherence tomography and determine the agreement between ophthalmologists and ophthalmology residents. We used a comprehensive ophthalmologic examination dataset obtained from 503 cases (1006 eyes). Of the 1006 eyes, 132 had a confirmed glaucoma diagnosis. Overall, 24 doctors, comprising two groups (ophthalmologists and ophthalmology residents, 12 individuals/group), analyzed the data presented in three screening strategies as follows: (1) fundus photography alone, (2) fundus photography + optical coherence tomography, and (3) fundus photography + optical coherence tomography + comprehensive examination. We investigated the diagnostic accuracy (sensitivity and specificity). The respective sensitivity and specificity values for the diagnostic accuracy obtained by 24 doctors, 12 ophthalmologists, and 12 ophthalmology residents were as follows: (1) fundus photography: sensitivity, 55.4%, 55.4%, and 55.4%; specificity, 91.8%, 94.0%, and 89.6%; (2) fundus photography + OCT: sensitivity, 80.0%, 82.3%, and 77.8%; specificity, 91.7%, 92.9%, and 90.6%; and (3) fundus photography + OCT + comprehensive examination: sensitivity 78.4%, 79.8%, and 77.1%; specificity, 92.7%, 94.0%, and 91.3%. The diagnostic accuracy of glaucoma screening significantly increased with optical coherence tomography. Following its addition, ophthalmologists could more effectively improve the diagnostic accuracy than ophthalmology residents. Screening accuracy is improved when optical coherence tomography is added to fundus photography.

Retinochoroidal vascular plexuses in patients with iron deficiency anaemia

Clinical relevance: Optical coherence tomography angiography (OCT-A) may enable the identification of alteration in the retinochoroidal microvasculature in patients with iron deficiency anaemia.Background: To investigate the presence of macular microvascular alterations in females with IDA by using OCT-A.Methods: This is a cross-sectional comparative study. Forty patients with IDA and 35 age-matched healthy women underwent a complete ophthalmologic examination and OCT-A imaging. Foveal avascular zone parameters and the vessel density in the superficial (SCP) and deep capillary plexus (DCP) were calculated using automated software. All measurements were compared between groups. Correlations between the OCT-A metrics and haematological laboratory parameters were evaluated.Results: Compared to healthy subjects, IDA patients revealed significantly decreased vessel density of the SCP in all parafoveal quadrants (p < 0.05). In contrast, vessel density analysis in DCP has shown no statistically significant difference in all parafoveal quadrants (p > 0.05). Although foveal vessel density in both SCP and DCP were higher in the IDA group, only the foveal vessel density in DCP was significantly higher than controls (p = 0.001). The mean values of the foveal avascular zone area and perimeter and choriocapillaris flow area were significantly lower in the IDA group (p < 0.05). The parafoveal vessel density in SCP, foveal avascular zone area, and choriocapillaris flow area were positively correlated with haematological parameters including haemoglobin, haematocrit, mean corpuscular haemoglobin, and mean corpuscular volume (p < 0.01).Conclusion: Patients with IDA had decreased parafoveal vessel density in the SCP, but not the DCP. Foveal avascular zone metrics and choriocapillaris flow area measurements were significantly lower in IDA.

Retinal Nerve Fibre Layer Thinning in Patients with Thalassaemia, Iron Deficiency Anaemia, and Anaemia of Chronic Diseases

Purpose

Retinal nerve fibre layer (RNFL) is a sensitive structure, which is affected by anaemia due to hypoxia. A timely detection of RNFL thinning may aid preventing devastating complications. Optical coherence tomography (OCT) measures RNFL thinning with accuracy and helps in detecting thinning of the retinal layer in anaemic patients. This study was destined to evaluate thinning of RNFL in anaemic patients and their correlation with the haemoglobin level.

Methods

It was a prospective comparative study. Total of 151 patients were included in this study. Patients with retinal diseases were excluded from this study. After initial evaluation, haematological and ophthalmological parameters were measured. RNFL was measured with OCT and corroborated with the Hb level and analysed accordingly. EPI and SPSS softwares were used for detail analysis and the correlation between RNFL thinning and the Hb level. Initially, each eye was separately assigned a value (0, 1, and 2) (normal, borderline, and abnormal, respectively) as per the severity of thinning, and then, the sum of the scores of both eyes were considered as a separate variable, and a multiple linear regression analysis was performed with the independent variables.

Results

RNFL thinning was found to be significant in each group of patients. There was a strong correlation of RNFL thinning with degree of anaemia.

Conclusions

Thalassaemia, iron deficiency anaemia, and anaemia of chronic diseases are associated with the significant damage to RNFL. Degree of anaemia is the most important parameter for such thinning of the RNFL layer.

Evaluation of radial peripapillary capillary density in patients with newly diagnosed iron deficiency anemia

PURPOSE

To investigate the effects of iron deficiency anemia (IDA) on radial peripapillary capillary vessel density (RPCvd) and retinal nerve fiber layer (RNFL) thickness.

METHODS

Forty patients with IDA, and 46 healthy participants, were enrolled in this study. Optical coherence tomography angiography was used to determine RNFL thickness and RPCvd measurements. In addition, hemoglobin (Hb), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and ferritin laboratory values were evaluated.

RESULTS

Analysis of retinal regions (whole images, peripapillary, superior-hemi, inferior-hemi, inferior-nasal, inferior-temporal, temporal-inferior, temporal-superior, superior-nasal) showed that RPCvd values were significantly lower in patients with IDA compared to the control group values (p < 0.05 for all). However, there were no significant differences in RNFL thickness values between the IDA patient group and the control group (p > 0.05 for all). In addition, there were significant positive correlations between RPCvd values and hematological values for Hb, HCT, MCV, MCH, MCHC, and ferritin.

CONCLUSION

It is important to identify changes in retinal vascularity to prevent possible ocular problems in patients with IDA. Specifically, the significant positive correlations between RPCvd values and hematological values suggest that anemia treatment is important for optic nerve perfusion.

Effects of iron deficiency anemia on peripapillary and macular vessel density determined using optical coherence tomography angiography on children

PURPOSE

To evaluate retinal vascular parameters by optical coherence tomography angiography (OCT-A) in iron deficiency anemia (IDA).

METHODS

Thirty-two patients with IDA (study group) and 30 healthy children (control group) were enrolled in the study. All subjects underwent a complete ocular examination. OCT-A scans were performed in a 6 × 6 mm area centered on the macula. Foveal avascular zone (FAZ), non-flow area (NFA), FAZ perimeter (PERIM), acircularity index (AI) of FAZ, and foveal density (FD) were measured in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). SCP and DCP were also scanned centered on the optic disk. Hemoglobin (Hb), mean corpuscular volume (MCV), serum iron, total iron-binding capacity (TIBC), and ferritin were also studied and compared for both groups.

RESULTS

The mean age was 12.22 ± 4.48 years (ranged 5-18 years) in the study group and 12.37 ± 3.76 years (ranged 6-18 years) in the control group. The mean FAZ value was 0.290 ± 0.09 mm² in the study group and 0.298 ± 0.11 mm² in the control group. The mean NFA value was 0.477 ± 0.10 mm² in the study group and 0.486 ± 0.13 mm² in the control group (p > 0.05). FD and AI were not statistically significant between the study group and control group (p > 0.05). The mean value for SCP was statistically significant between the study group and control group (p < 0.05). The mean value for DCP was not significantly different between the study and control groups (p > 0.05). The mean values for capillary density on optic disk were also statistically significant between the study group and control group (p < 0.05). A negative correlation was found between serum iron, TIBC, and capillary plexus density (p < 0.05). A positive correlation was found between MCV and ferritin values and capillary plexus density (p < 0.05).

CONCLUSION

IDA had significantly lower capillary plexus density. We detected retinal microvascular changes in young IDA patients before significant ocular anomalies, especially ischemic changes, developed.

The relation between dietary intake and glaucoma: a systematic review

PURPOSE

A common question of patients to their physician is what they can do themselves against glaucoma, except taking their daily medication. However, for ophthalmologists, it is often hard to give their patients an advice on their dietary intake. To help ophthalmologists in answering this question, an overview of the current scientific literature on the association of nutrients with glaucoma is presented.

METHODS

A comprehensive systematic review was conducted in which articles published up to September 2017 were identified in PubMed and reference lists. Nutrients were categorized into minerals and trace elements, nutrition with antioxidative properties and omega-fatty acids.

RESULTS

The literature search revealed a total of 407 articles of which a total of 46 met the inclusion criteria. Most of these articles studied the effect of nutrients on open-angle glaucoma. Many trace elements have been investigated in the literature, but the most interesting are selenium and iron (both may increase the risk of glaucoma). Investigated nutrients with antioxidative properties and omega-fatty acids included glutathione, nitric oxide, carotenoids, flavonoids, and omega-3 and omega-6 fatty acids. Of these, glutathione, nitric oxide, and flavonoids had a significant protective effect on glaucoma.

CONCLUSION

Intake of selenium and iron may increase the risk of glaucoma, though, only few studies have been done on this topic. Nitric oxide present in other dark green leafy vegetables seems to have a beneficial effect on glaucoma. However, the evidence for an association of dietary intake with glaucoma is still not strong. More (longitudinal and randomized clinical trials) studies are required to make the presented findings clinically applicable.

Assessing reproducibility and the effects of demographic variables on the normal macular layers using the Spectralis SD-OCT

Purpose

To quantify and view the possible influence of demographic variables on normal macular layers. Additionally, we wanted to assess the reproducibility using the Spectralis SD-OCT.

Methods

A Spectralis SD-OCT machine using a commercially available algorithm was used to scan 242 healthy subjects in an outpatient setting. We examined retinal thicknesses in seven layers: retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL) and retinal pigment epithelium (RPE). Combined retinal thicknesses were expressed as inner retinal layer (IRL), photoreceptor layer (PL) and total retinal thickness (TRT). Measurements were taken from each of the nine sectors defined by the Early Treatment Diabetic Retinopathy Study; the center was the fovea, the inner circle (IC) was 1–3 mm away, and the outer circle (OC) was 3–6 mm away.

Results

The TRT was thickest inferiorly in the IC, and superiorly in the OC. The RNFL (P=0.030), GCL (P=0.006), IPL (P=0.006), IRL (P=0.030), PL (P<0.001) and TRT (P=0.001) were found to be thicker in males. The GCL (r=0.078, P=0.001), IPL (r=0.079, P=0.001), IRL (r=0.072, P=0.002), PL (r=0.076, P=0.001) and TRT (r=0.090, P<0.001) were found to decrease with age. The INL (r=0.060, P=0.010), ONL (r=0.078, P=0.001), and RPE (r=0.066, P=0.004) were inversely related to axial length. Excellent reproducibility was observed in all layers.

Conclusion

Our study shows differences in various retinal layers according to age, gender, and axial length. Additionally, we demonstrate excellent reproducibility of this algorithm using the Spectralis SD-OCT.

Effects of age and gender on macular thickness in healthy subjects using spectral optical coherence tomography/scanning laser ophthalmoscopy

PURPOSE

To examine healthy subjects for normal macular thickness values and determine the effects of gender and age in a Turkish population, using spectral optical coherence tomography/scanning laser ophthalmoscopy (OCT/SLO).

MATERIAL AND METHOD

Six hundred fourteen eyes of 307 subjects with no history of ocular diseases and normal ophthalmic examination were recruited in this cross-sectional, prospective study. The participants were divided into three groups based on age (between 20 and 29 years: group 1, between 30 and 39 years: group 2, between 40 and 49 years: group 3). All subjects were scanned with spectral OCT/SLO, performed by one examiner to acquire the retinal thickness map in the ETDRS grid, and values were recorded for nine sectors, and effects of age and gender were evaluated.

RESULTS

When all the subjects were evaluated, the thicknesses were lower in women than men in all sectors (p < 0.001). When divided in groups based on age, this difference remained only in the outer segments. However, the differences in outer layers, except outer nasal layer, were thicker in women in group 3 when compared to others in group 3. When compared between groups, only central thickness in group 3 was shown to be higher than group 1 (p = 0.06). There was no significant difference of thicknesses in any sector when compared right and left eyes of all subjects.

CONCLUSIONS

The study reports the variation in retinal thickness between age and gender in a relatively large sample of a Turkish population. It is important to consider these effects while interpreting the OCT images to make an appropriate diagnosis in retinal diseases.