Abstract
Data on how retinal structural and vascular parameters jointly influence the diagnostic performance of detection of multiple sclerosis (MS) patients without optic neuritis (MSNON) are ...lacking. To investigate the diagnostic performance of structural and vascular changes to detect MSNON from controls, we performed a cross‐sectional study of 76 eyes from 51 MS participants and 117 eyes from 71 healthy controls. Retinal macular ganglion cell complex (GCC), retinal nerve fiber layer (RNFL) thicknesses, and capillary densities from the superficial (SCP) and deep capillary plexuses (DCP) were obtained from the Cirrus AngioPlex. The best structural parameter for detecting MS was compensated RNFL from the optic nerve head (AUC = 0.85), followed by GCC from the macula (AUC = 0.79), while the best vascular parameter was the SCP (AUC = 0.66). Combining structural and vascular parameters improved the diagnostic performance for MS detection (AUC = 0.90;
p
<0.001). Including both structure and vasculature in the joint model considerably improved the discrimination between MSNON and normal controls compared to each parameter separately (
p
= 0.027). Combining optical coherence tomography (OCT)‐derived structural metrics and vascular measurements from optical coherence tomography angiography (OCTA) improved the detection of MSNON. Further studies may be warranted to evaluate the clinical utility of OCT and OCTA parameters in the prediction of disease progression.
To evaluate machine learning (ML) approaches for structure–function modeling to estimate visual field (VF) loss in glaucoma, models from different ML approaches were trained on optical coherence ...tomography thickness measurements to estimate global VF mean deviation (VF MD) and focal VF loss from 24‐2 standard automated perimetry. The models were compared using mean absolute errors (MAEs). Baseline MAEs were obtained from the VF values and their means. Data of 832 eyes from 569 participants were included, with 537 Asian eyes for training, and 148 Asian and 111 Caucasian eyes set aside as the respective test sets. All ML models performed significantly better than baseline. Gradient‐boosted trees (XGB) achieved the lowest MAE of 3.01 (95% CI: 2.57, 3.48) dB and 3.04 (95% CI: 2.59, 3.99) dB for VF MD estimation in the Asian and Caucasian test sets, although difference between models was not significant. In focal VF estimation, XGB achieved median MAEs of 4.44 IQR 3.45–5.17 dB and 3.87 IQR 3.64–4.22 dB across the 24‐2 VF for the Asian and Caucasian test sets and was comparable to VF estimates from support vector regression (SVR) models. VF estimates from both XGB and SVR were significantly better than the other models. These results show that XGB and SVR could potentially be used for both global and focal structure–function modeling in glaucoma.
Different machine learning models for global and focal visual field estimation were compared using independent internal and external test sets with different demographics. We compared several models and show that those based on gradient‐boosted trees generally performed well in both internal and external sets and thus may be a useful approach for future structure–function studies. We also found that all models had difficulties to varying degrees in more severe visual fields.
The reconstruction of an orbit after complex craniofacial fractures can be extremely demanding. For satisfactory functional and aesthetic results, it is necessary to restore the orbital walls and the ...craniofacial skeleton using various types of materials. The reconstruction materials can be divided into autografts (bone or cartilage tissue) or allografts (metals, ceramics, or plastic materials, and combinations of these materials). Over time, different types of materials have been used, considering characteristics such as their stability, biocompatibility, cost, safety, and intraoperative flexibility. Although the ideal material for orbital reconstruction could not be unanimously identified, much progress has been achieved in recent years. In this article, we summarise the advantages and disadvantages of each category of reconstruction materials. We also provide an update on improvements in material properties through various modern processing techniques. Good results in reconstructive surgery of the orbit require both material and technological innovations.
Ocular adverse effects of anti-cancer chemotherapy Stoicescu, Elena Andreea; Iancu, Raluca Claudia; Popa Cherecheanu, Alina ...
Journal of medicine and life,
06/2023, Letnik:
16, Številka:
6
Journal Article
Odprti dostop
Cancer ranks as the second leading cause of mortality in Europe, following cardiovascular diseases. Every year, 2.6 million people are diagnosed with this disease, and 1.2 million die. It has an ...impact not only on individual health but also on society and the economy. The survival rate has improved with the introduction of new diagnostic methods and anti-cancer chemotherapy. While more aggressive chemotherapeutic regimens and combination therapies have demonstrated efficacy against cancer cells, they also have detrimental effects on normal cells, leading to systemic and ocular adverse reactions associated with cytotoxicity, inflammation, and neurotoxicity. Consequently, we have an increased survival rate, but the appearance of these ocular adverse effects decreases the quality of life. Ocular toxicity induced by chemotherapeutic agents is often underestimated. While prevention may not be possible, proper management by an ophthalmologist, an integral part of the oncology patient's medical team, is crucial. The ophthalmologist should assess the patient before initiating chemotherapeutic treatment and continue monitoring throughout to identify any adverse ocular reactions resulting from the systemic chemotherapy. This article aimed to briefly highlight the adverse reactions occurring at the ocular surface in patients undergoing chemotherapeutic treatment. Fortunately, these ocular side effects are limited only to the period in which the chemotherapeutic treatment is done, with most of them disappearing a few weeks after stopping the treatment.
Purpose
Abnormal autoregulation of optic nerve head blood flow (ONHBF) has been postulated to play an important role in primary open‐angle glaucoma (POAG). We used laser Doppler flowmetry (LDF) to ...estimate quantitatively the ONHBF and compared ONHBF autoregulation between glaucoma patients and healthy controls during isometric exercise.
Methods
Forty patients with POAG and 40 healthy age‐ and sex‐matched subjects underwent three periods of isometric exercise, each consisting of 2 min of handgripping. Optic nerve head blood flow (ONHBF) was measured continuously using LDF. Systemic blood pressure, intraocular pressure and ocular perfusion pressure were assessed in all participants.
Results
Isometric exercise was associated with an increase in ocular perfusion pressure during all handgripping periods in both groups (p < 0.001). However, there was no change in ONHBF in either group. Three of the glaucoma patients and two of the healthy subjects showed a consistent 10% decrease in blood flow during isometric exercise, in spite of an increase in their blood pressure. This difference between groups was not significant (p = 0.61). Four other glaucoma subjects showed a consistent increase in blood flow of more than 10% during isometric exercise, whereas this was not seen in healthy subjects (p = 0.035).
Conclusion
This study suggests that abnormal ONHBF autoregulation is more often seen in patients with POAG than healthy control subjects. The relationship to the glaucoma disease process is currently unknown and requires further investigation.
.
Purpose: The aim of the study was to compare the diameter of the central retinal artery (CRA) between patients with diabetes mellitus and healthy subjects in vivo. CRA diameters were calculated ...from retinal haemodynamic parameters measured with noninvasive measurement techniques.
Methods: Sixteen patients with type 1 diabetes with no or mild diabetic retinopathy and 16 age‐matched healthy controls were included in this study. Total retinal blood flow was assessed by combining bidirectional laser Doppler velocimetry in all veins entering the optic disc with measurements of retinal vessel diameters using a Dynamic Vessel Analyser. Blood flow velocity in the CRA was measured with colour Doppler imaging (CDI). The diameter of the CRA in the optic nerve was then calculated for each subject using the individual ocular haemodynamic data.
Results: Calculated CRA diameters were significantly larger in patients with diabetes (180 ± 13 μm) compared with healthy controls (166 ± 10 μm, p = 0.001). No significant differences were found in retinal blood flow, retinal artery or vein diameters or mean flow velocity of the CRA.
Conclusion: The data of the present study show increased calculated CRA diameter in patients with type 1 diabetes with no or mild retinopathy. Blood flow velocity measurements in retrobulbar vessels using CDI need to be interpreted with caution in terms of retinal blood flow, because no information about vessel diameters is obtained by this technique.
Docetaxel is a very effective chemotherapeutic agent for the treatment of metastatic or locally advanced breast cancer. Epiphora (hyperlacrimation) has been shown to be the most common eye condition ...in patients receiving docetaxel-based chemotherapy. This symptom does not decrease visual acuity, but decreases the quality of life. Daily activities (reading, working on the computer, watching TV, and so on) are affected, with patients complaining about an alteration of daily life with the appearance of this symptom. The mechanism by which epiphora occurs is considered to be the canalicular stenosis, but the trials on the subject failed to reach statistical significance. The objective of this scoping review is to determine whether there is a treatment regimen-dependent relationship between docetaxel administration and the presence of epiphora in women with breast cancer. The inclusion criteria were met by 10 trials, from which one was excluded owing to data selection biases. Accordingly, nine studies were evaluated quantitatively and qualitatively in the present review. We included subjects with docetaxel as single treatment or docetaxel in combination with other chemotherapy compounds. The occurrence of epiphora among subjects treated with docetaxel, regardless of the therapeutic regimen used, was statistically significant (p = 0.005). The proportion of patients with epiphora after weekly administration of docetaxel (54 out of 131 subjects, 41.22%) was different compared with that of those who received docetaxel at three week intervals (112 out of 325 subjects, 34.15%), but the difference between the two was not statistically significant (p = 0.732). The present study demonstrates that epiphora occurs more frequently in patients receiving weekly docetaxel-based chemotherapy than those taking the three-weekly regimen, but the difference is not statistically significant. Ophthalmologic assessment of all patients starting this treatment is recommended. The causal relationship between canalicular stenosis and epiphora is not fully elucidated as long as this ocular symptom occurs in women who do not have stenosis of the lacrimal system. Further well-designed trials are required to bring new insights into the mechanisms of epiphora pathogenesis in subjects treated with docetaxel.
In the retina, blood flow and neural activity are tightly coupled. Stimulation of the retina with flickering light is accompanied by an increase in blood flow. The current study seeks to investigate ...whether an increase in oxygen tension modulates flicker (FL)-induced vasodilatation in the human retina. A total of 52 healthy volunteers were included. Via a breathing mask, 100% oxygen (O2) was administered in one, a mixture of 8% carbon dioxide and 92% oxygen (C/O) in a second cohort. Retinal vessel diameters were measured with a Vessel Analyzer and FL responses were assessed before and during the breathing periods. At baseline, FL stimulation increased retinal vessel diameters by +3.7 ± 2.3% in arteries and by +5.1 ± 3.7% in veins. Breathing of C/O led to a decrease in arterial (−9.0 ±,6.9%) and venous (−11.3 ± 5.9%) vessel calibers. Flicker response was increased to 5.7 ± 2.5% in arteries and to 8.6 ± 4.1% in veins. Breathing of pure O2 induced a vasoconstriction of vessel diameters by −14.0 ± 5.3% in arteries and −18.4 ± 7.0% in veins and increased FL responses in arteries (+6.2 ± 2.8%) and veins (+7.2 ± 3.1%). Systemic hyperoxia increases FL-induced retinal vasodilatation in the retina. The mechanism by which oxygen modulates the hyperemic response to FL stimulation remains to be elucidated.
Purpose: Retinal imaging has attracted much interest as a non‐invasive low‐budget biomarker for neurological diseases such as multiple sclerosis (MS). Optical coherence tomography angiography (OCTA) ...is a functional extension of OCT and allows for the non‐invasive visualization of the retinal and choroidal microvasculature. We investigated retinal microvasculature changes in patients with relapsing–remitting MS (RRMS) without history of optic neuritis (ON) and compared them to a healthy control group.
Methods: The study was performed in a prospective, case–control design, including 58 participants (n = 100 eyes) with RRMS without ON and 78 age‐ and sex‐matched control participants (n = 136 eyes). OCTA images of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) were obtained using a commercial OCTA system (Zeiss Cirrus HD‐5000 Spectral‐Domain OCT with AngioPlex OCTA, Carl Zeiss Meditec, Dublin, CA). Perfusion density (PD) and foveal avascular zone (FAZ) features (area and circularity) in both the SCP and DCP, as well as flow deficit in the CC were used as outcome variables.
Results: MS patients showed significantly increased PD in SCP (p = 0.003) and decreased PD in DCP (p < 0.001) as compared to controls when data were corrected for confounders. A significant difference was also noted when large vessels (LV) in the SCP were removed from the PD calculation (p = 0.004). Deep FAZ was significantly larger (p = 0.005) and less circular (p < 0.001) in the eyes of MS patients compared to healthy controls. Neither LV, PD or FAZ features in the SCP, nor flow deficits in the CC showed any statistically significant differences between the MS patients and the controls (p > 0.186).
Conclusions: Our study shows that MS patients have microvascular changes in the macular parafoveal retina even without ON. They show increased PD in SCP and decreased PD in DCP. To which degree retinal biomarkers in MS are associated with the progression of MS remains to be studied.
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