Impact of adherence to gluten-free diet in paediatric celiac patients on optical coherence tomography findings: Ocular imaging based study

ObjectiveThis study aims to measure choroidal thickness, retinal nerve fiber layer thickness, GCC thickness, and foveal thickness by optical coherence tomography and to investigate whether there is a difference between celiac patients who adhere to the gluten-free diet and who do not.Materials and methodsA total of 68 eyes of 34 pediatric patients diagnosed with celiac disease were included in the study. Celiac patients were divided into two groups those who adhere to the gluten-free diet and those who do not. Fourteen patients who adhere to the gluten-free diet and 20 patients who do not adhere to the gluten-free diet were included in the study. Choroidal thickness, GCC, RNFL, and foveal thickness of all subjects were measured and recorded using an optical coherence tomography device.ResultsThe mean choroidal thickness of the dieting and non-diet groups was 249.05 ± 25.60 and 244.18 ± 33.50 µm, respectively. The mean GCC thickness of the dieting and non-diet groups was 96.56 ± 6.26 and 93.83 ± 5.62 µm, respectively. The mean RNFL thickness of the dieting and non-diet groups was 108.83 ± 9.97 and 103.20 ± 9.74 µm, respectively. The mean foveal thickness of the dieting and non-diet groups was 259.25 ± 33.60 and 261.92 ± 32.94 µm, respectively. There was not a statistically significant difference between the dieting group and the non-diet group in terms of choroidal, GCC, RNFL and foveal thicknesses (p = 0.635, p = 0.207, p = 0.117, p = 0.820, respectively).ConclusionIn conclusion, the present study states that adhering to a gluten-free diet does not make any difference in choroidal, GCC, RNFL, and foveal thicknesses in pediatric celiac patients.     

Evaluation of the choroidal vascular index and choroidal changes in migraine subgroups

PurposeTo investigate binarized choroidal structural parameters, retinal nerve fiber layer (RNFL) thickness, and retina changes duringattack-free periods in patients with migraine using enhanced depth imaging optic coherence tomography (EDI-OCT), and compare patients with migraine with aura and without aura (MwA and MoA, respectively) and aura subgroups (visual aura, non-visual aura), with age and sex-matched healthy subjects.MethodThis observational, prospective study included 102 patients with migraine and 36 healthy controls. Central macular thickness (CMT), retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and choroidal thickness (CT) were measured using a Spectralis OCT device. The choroid vascularity index (CVI) was evaluated using the Image-J software. CVI was calculated as the proportion of the luminal area (LA) to the total choroidal area (TCA). RNFL, CMT, CT, and CVI measurements were compared statistically.ResultsChoroidal thickness at 1500 µm temporal of the fovea was found to be statistically significantly thinner in the MwA and MoA groups compared with the control group (p ≤ 0.01). There was a significant difference in the subfoveal CT values of the MwA and control groups (p < 0.05). The mean RNFL thickness of patients with migraine with visual aura was found to be statistically significantly thinner than in the migraine group with non-visual aura (98.73 ± 8.4 and 109.4 ± 16.8) (p < 0.05). There were no statistically significant differences between the RNFL CMT, GCC, and CVI values in the MwA, MoA, and control groups (p > 0.05).ConclusionWe found that the choroidal thickness was significantly decreased in patients with migraine, especially in the MwA group. In the visual aura subgroup, the mean RNFL thickness was significantly decreased compared with the non-visual aura subgroup.     

Evaluation of the role of spectral-domain optical coherence tomography in the early detection of macular and ganglion cell complex thickness changes in patients with rheumatologic diseases taking hydroxychloroquine

BackgroundThe aim was to investigate the effects of hydroxychloroquine (HCQ) on macular and ganglion cell complex (GCC) thickness measured by spectral-domain optical coherence tomography (SD-OCT).MethodsA total of 145 patients were included in the study. Patients who had taken HCQ for at least 6 months formed group 1 (n:81), while 34 patients with rheumatologic diseases who did not receive HCQ therapy, and 30 healthy subjects formed groups 2 and 3. The patients in group 1 were divided into two subgroups one with more than 60 months of usage (A), and the other with less than 60 months (B). All patients underwent a complete ophthalmologic examination, as well as visual field (VF) testing, and the measurement of macular and GCC thickness with SD-OCT.ResultsThe mean duration of taking HCQ was 100.96±46.97 and 26.50±14.45 months and the total dose was 843.37±489.38 g and 208.63±135.01 g in groups 1A and 1B, respectively. Patients in group 1 had significantly worse VF scores than groups 2 and 3, but no difference was found between groups 1A and 1B. The SD-OCT macular thickness was thinner in the inner and outer nasal quadrants according to the ETDRS 9 sector chart in the patients using hydroxychloroquine, while the GCC in the group 1A patients was thinner in the superior, inferior areas and inferior inner nasal, inferior-superior outer temporal quadrants compared to the other groups (p < 0.05).ConclusionAssessment of regional macular and GCC changes by SD-OCT is a valuable tool for early detection of HCQ maculopathy.     

Choroidal structural alterations and choroidal vascularity index in bipolar disorder patients

PurposeThe aim of this study was to compare bipolar disorder (BD) patients with age- and sex-matched healthy individuals in order to assess the choroidal structural alterations, retinal nerve fiber layer (RNFL) thickness, and retinal changes in BD patients using encanhed depth imaging optic coherence tomography (EDI-OCT).MethodFor this research, 39 eyes of BD patients and 36 eyes of age-matched healthy volunteers were used. Five locations were used to assess the choroidal thickness (CT): subfoveal, 500 µm nasal and 1500 µm nasal to the fovea, 500 µm temporal and 1500 µm temporal to the fovea. Image-J was used to determine the total choroidal area (TCA), luminal area (LA), and choroidal vascularity index (CVI). The Spectralis-OCT device was used to evaluate the central macular thickness (CMT), retinal nerve fiber layer (RNFL), and ganglion cell layer (GCL). The data were statistically compared.ResultsBD patients had significantly decreased subfoveal, nasal, and temporal CTs than controls (for all three, p = 0.0001). The results of CMT and GCL were found to be thinner than controls. (for all p = 0.0001) In comparison to the controls, the mean TCA and LA were decreased in the BD group. (p = 0.0001, p = 0.0001, respectively,). Between the RNFL and CVI values in the BD and control groups, there was no statistically significant difference (p>0.05).ConclusionThe results of this investigation showed that the retina and choroid of patients with BD had considerable anatomical changes.     

Comparison of corneal,endothelial, and anterior segment parameters in eyes with and without pigment dispersion

BackgroundTo evaluate the differences of central corneal thickness (CCT), corneal endothelial cell morphology, and biometric parameters of the anterior chamber and iridocorneal angle in pigment dispersion syndrome (PDS), pigmentary glaucoma (PG), primary open-angle glaucoma (POAG), and healthy group.MethodsTwenty- three eyes in the PDS group, 39 eyes in the PG group, 33 eyes in the POAG group, and 45 eyes in the healthy control group were included in this cross-sectional retrospective study. Corneal endothelial cell density, the coefficient of variation in the cell area, hexagonality, and central corneal thickness (CCT) were obtained by specular microscopy (CEM 530, NIDEK, Japan). Anterior chamber depth (ACD), iridocorneal angle parameters and CCT were measured by anterior segment optical coherence tomography (AS-OCT) (Visante OCT, Carl Zeiss AG, Germany).ResultsThe mean CCT via specular microscopy (SM-CCT) was measured at the thinnest value in the PG group (531.20 ± 34.91 µm) and the thickest in the control group (569.13 ± 37.52 µm). CV value was higher in PG (34.65 ± 6.84) and POAG group (34.27 ± 9.93) and lower in control group (28.82 ± 5.18) (p = 0,005). The mean AS-OCT-CCT was the thinnest in the PG group (513.61 ± 39.94 µm), and the thickest in the control group (547.04 ± 36.72 µm) (p = 0.001). All parameters of the iridocorneal angle were larger in the PDS and PG groups (p < 0.001). In the correlation analysis of the glaucomatous eyes, a negative correlation between the C/D ratio and SM-CCT and AS-OCT-CCT (p = 0.037, p = 0.017, respectively) and a positive correlation between the pRNFL thickness and AS-OCT- CCT (p = 0.002).ConclusionCCT values obtained with both SM and AS-OCT were found to be significantly thinner in PG cases. CV, which is the measure of polymegatism, was found to be significantly higher in PG cases.     

The effect of hyperbaric oxygen therapy on retina,choroidal thickness,and choroidal vascularity index

PurposeTo determine the acute and cumulative effect of hyperbaric oxygen therapy (HBOT) on retina and choroid tissue in healthy eyes.Material and methodsThirty-five subjects who were planned to undergo HBOT for non-ophthalmologic indications comprised the population of this prospective study. Central macular thickness (CMT), retinal nerve fiber layer (RNFL), and choroidal thickness (CT) (3 points: subfoveal area, 500 µm nasal and fovea temporal) were measured using spectral-domain optical coherence tomography (SD-OCT) before HBOT and half an hour after the 1st and 20th sessions of HBOT. The subfoveal choroidal area was segmented using ImageJ software with the binarization technique on enhanced depth imaging (EDI) OCT images. Choroidal area (CA), luminal area (LA), and stromal area (SA) were calculated. Choroidal vascularity index (CVI) was determined as the ratio between LA and CA.ResultsThe right eyes of 35 patients aged between 22 and 59 years were enrolled in the study. The mean CMT values of the patients were 259.36 ± 22.31 µm, 256.94 ± 22.72 µm, and 254.58 ± 23.02 µm before HBOT, after the 1st session, and after the 20th session, respectively. The change in CMT values before and after HBOT was statistically significant (p=0.001). When the patients' RNFL, CT, CA, SA, LA, and CVI changes before and after the HBOT were examined, no statistically significant difference was found (p>0.05).ConclusionsOur study jointly evaluates the effect of HBOT on the vascular and stromal components of the choroid and macula in healthy eyes. Due to its thinning effect on the macula, it can be preferred as an adjunctive and facilitating treatment option in addition to current treatments in patients with macular edema due to retinal vascular disorders.     

Anterior segment parameters on optical coherence tomography in healthy South Asian children

PurposeHigh resolution spectral domain optical coherence tomography (SD-OCT) was used to assess the anterior segment structure parameters in healthy South Asian children.Methods108 eyes of 54 healthy children ≤ 16 years were recruited after a thorough eye exam. The anterior segment analysis was be done by Optopol Revo 80 high resolution SD-OCT. Central corneal thickness (CCT), Angle opening distance (AOD), Anterior chamber (AC) angle, Trabecular iris space area (TISA), Trabecular iris angle (TIA), iris thickness at 2 mm, internal AC diameter and lens vault were evaluated.ResultsMean age was 11.38 years. Mean IOP was 13.63 mmHg, mean axial length, 22.82 mm, mean spherical equivalent, -0.14 D, mean CCT, 532.6 µm and mean CDR was 0.31. The mean internal AC diameter was 11609.15 µm. The nasal and temporal AC angles was 53.54° and 50.37°, respectively [P = .033]. The nasal and temporal AOD500 were 0.9 mm and 0.85 mm, respectively [P = .629]. The nasal and temporal AOD750 were 1.21 mm and 1.06 mm, respectively [P = .583]. The nasal TIA was 41.75°; the temporal TIA; 40.24° [P = .325]. The nasal TISA500 was 0.33 mm²; the temporal TISA500, 0.31 mm² [P = .012]. The nasal TISA750 was 0. 59 mm²; the temporal TISA750, 0.56 mm² [P = .746]. The nasal iris thickness at 2 mm was 483.54 µm; the temporal iris thickness, 505.8 µm [P = .273]. The mean lens vault was -519.58 µm.ConclusionsOur study data depicts the normal anterior segment parameters in healthy Pakistani children.     

Analysis of choroidal vascularity index in multiple sclerosis patients without optic neuritis attack

BackgroundTo evaluate the choroidal structural changes in multiple sclerosis (MS) patients without previous optic neuritis (ON) attacks.MethodsForty eyes of 20 MS patients without a history of ON and 40 eyes of 20 age-matched healthy volunteers were included in this study. The choroidal thickness (CT) was measured at three points; subfoveal, 1500 µm nasal to the fovea, and 1500 µm temporal to the fovea. Choroidal area (CA), luminal area (LA), and choroidal vascularity index (CVI) were calculated using ImageJ.ResultsThe mean subfoveal, nasal and temporal CT were decreased in MS patients compared to controls (for all, p < 0.001). The mean LA was 0.572 ± 0.113 mm² in MS group, and 0.729 ± 0.188 mm² in controls (p = 0.002). The mean CVI was decreased in the MS group (69.38% ± 4.87) in comparison to the controls (73.41% ± 5.18) (p = 0.034).ConclusionThe current study demonstrated significant anatomical alterations of the choroid in the eyes of patients with MS.     

Choroidal structural evaluation in inactive Graves’ ophthalmopathy

PurposeTo investigate the changes in the choroidal structure in patients with inactive Graves Ophthalmopathy (GO).DesignA prospective, masked, observational cross-sectional study.MethodsChanges in choroidal vascularity index (CVI) were studied in the patients with inactive GO using binarization on enhanced depth imaging optical coherence tomography (EDI-OCT) images. Choroidal area, subfoveal choroidal thickness (SFCT), stromal area, luminal area, CVI and retinal nerve fiber layer (RNFL) thickness was used to compare the eyes of sixty-four age-, gender-matched healthy subjects. All measurements were done separately both subfoveal (1500 µm) and total choroidal area (7500 µm). The relation between CVI or SFCT and age, gender, duration of disease, the severity of disease, TRAb (thyrotropin receptor autoantibody), smoking status, and exophthalmometer readings were evaluated.ResultsThere were 56 patients (30 female, 26 male; mean age: 39.5 ± 11.4 years) in the GO group and 64 patients (34 female, 30 male; mean age: 42.2 ± 5.6 years) in the healthy subject group. There was no statistically significant difference between subjects with GO and healthy controls regarding age (p = 0.24) and gender distribution (p = 0.55). Patients with GO had significantly higher intraocular pressure (p = 0.001) and exophthalmometer readings (p = 0.0001) than the healthy controls. The SFCT, CVI₁₅₀₀ and the stromal area1500 was significantly different between the groups (p = 0.009, p = 0.009, p = 0.011, respectively). Multivariate analysis showed that age (-0.871, p = 0.02) was highly correlated with the decreased SFCT, and duration of disease (0.524, p = 0.001) was significantly positively correlated with SFCT. Luminal area1500 (-0.416, p = 0.0001)and stromal area1500 (-0.657, p = 0.0001) were significantly negatively correlated with CVI₁₅₀₀ in the patients with GO.ConclusionAlthough higher CVI₁₅₀₀ was observed in GO patients than in healthy controls, the degree of increase was not the same in the CVI₇₅₀₀. Age and duration of disease significantly affect the SFCT, and luminal area₁₅₀₀ and stromal area₁₅₀₀ significantly affect the CVI₁₅₀₀.     

Choroidal vascularity index in adult patients with familial meditteranean fever

PurposeThis study aimed to evaluate choroidal vascular status by the choroidal vascularity index (CVI) in adult patients with familial Mediterranean fever (FMF) in remission period.Materials-methods86 patients diagnosed with FMF and 54 healthy controls were recruited in this study. Retinal, ganglion cell complex and peripapillary retinal nerve fibre layer thicknesses were obtained using Spectralis domain-optical coherence (SD-OCT) tomography. Choroid images were obtained with the enhanced depth imaging mode of SD-OCT, and binarization was applied to the images using ImageJ software. CVI was described as the proportion of the luminal area to the total choroidal area. Blood-derived inflammation markers were calculated by the complete blood count.ResultsThe subfoveal choroidal thickness and nasal and temporal directions from fovea centralis at 500 μm, 1000 μm and 1500 μm were reduced in patients with FMF in comparison to healthy controls (p<0.001, each comparison). CVI was significantly decreased in patients with FMF compared to controls (62.28±2.2 and 64.79±4.3, p<0.001).ConclusionWe concluded that the choroidal vasculature structure may be affected prior to retinal changes in patients with FMF.     

Retrobulbar ocular blood flow and choroidal vascular changes in patients recovering from COVID-19 infection

BackgroundTo evaluate the effects of COVID-19 infection on the ocular vascular structure including choroidal thickness and retrobulbar blood flow values in comparison with healthy subjects.MethodsNinety eyes of 90 patients were included in this study. Participants were divided into Group 1 (n = 30) with mild COVID-19 infection, Group 2 (n = 31) with moderate disease, and Group 3 with age- and sex-matched healthy subjects (n = 29). Choroidal thickness was measured at the subfoveal area and at 500-µm intervals nasal and temporal to the fovea up to a distance of 1500 µm, using the enhanced depth imaging (EDI) technique of spectral coherence tomography (SD-OCT). The peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI), and pulsatility index (PI) values of the central retinal artery (CRA) and ophthalmic artery (OA) were evaluated with color Doppler ultrasonography (CDU).ResultsThe choroidal thickness was significantly thinner in Group 1 and Group 2 than in Group 3 at all measurement points (p <0.001). This difference was not present between Group 1 and Group 2 who had COVID-19 disease of different severity (p>0.05).Among the retrobulbar blood flow parameters, OA PSV value was significantly lower in Group 1 and Group 2 compared to Group 3 (p = 0.025, p = 0.016, respectively). However, the CRA PSV and EDV and OA EDV values, and the CRA and OA PI and RI values were not statistically different between the groups (p> 0.05).ConclusionCOVID-19 infection may predispose patients to ocular vascular pathologies by affecting both choroidal and retrobulbar blood flow.     

Influence of lithium disilicate pretreatment using photodynamic therapy,non-thermal plasma,and laser treatment on surface roughness and bond strength

AimsTo assess the shear bond strength (SBS) and surface roughness (Ra) of lithium disilicate ceramic (LDC) after using different pretreatment methods i.e., Non-Thermal Plasma (NTP), self-etching ceramic primer (SECP), curcumin photosensitizer (CP), Er and Cr: YSGG lasers (ECL) in comparison to hydrofluoric acid + Silane (HF + S).Materials and methodsA total of fifty LDC discs were prepared. All the discs were arbitrarily divided into five groups based on the surface conditioning used (n = 10). Group 1: PDT+S, group 2: HF+ S, group 3: NTP + S, group 4: SECP, and group 5: ECL+ S. A confocal optical microscope was used to calculate Ra for each sample. A self-adhesive resin cement was applied followed by LED light curing. A universal testing machine was used to assess SBS and a stereomicroscope was used to determine the failure mode. Two-way analysis of variance (ANOVA), and a Tukey post hoc test was used to analyze data (p = 0.05).ResultsThe highest bond integrity of resin luting bonded to conditioned LDS ceramics were presented by group 2 (HF+ S) (21.48±1.39 MPa) and lowest by group 1 (CP+S) (13.01±1.19 MPa) respectively. Intergroup comparison analysis revealed that group 1(13.01±1.19 MPa) and group 3 (14.28±0.62 MPa) displayed comparable outcomes of bond integrity(p>0.05). Similarly, it was observed that group 2 (21.48±1.39 MPa) and group 5 (21.31±1.85 MPa) exhibited comparable values of bond strength(p>0.05). Specimens conditioned with HF+ S showed the highest Ra (1445.86±0.019 µm). However, discs treated with SECP exhibited the lowest Ra (0139.76±0.081 µm).ConclusionEr, Cr: YSGG laser retains the ability to be used as an LDC surface conditioner as an alternative to HF+ S.Both the methods of pretreatment results in high surface roughness of LDC.     

Change in retinal vessel diameter and choroidal thickness in patients with severe COVID-19: Change In Retinal Parameters In Patients With Severe COVID-19

Purpose: To compare the differences in retinal vascular structure and choroidal thickness between the active disease and post-recovery periods in COVID-19 patients and healthy controls.Material and Methods: This prospective, cross-sectional study included 30 eyes from 30 patients with severe COVID-19 and 30 eyes of 30 sex-matched healthy controls. Central macular thickness (CMT), subfoveal choroidal thickness (CT) and retinal vascular changes of patients were measured after positive polymerase chain reaction (PCR) (where the patient had COVID-19-related symptoms) and then three months after two negative PCRs. Laboratory parameters, including C-reactive protein and d-dimer levels, were also recorded.Results: The mean age of the patients was 47.90 ± 9.06 years in patients group, 49.07 ± 8.41 years in control goups (p = 0.467). In terms of choroidal thicknesses subfoveal, nasal and temporal region were significantly higher in the active disease period than control group (p = 0.019, p = 0.036, p = 0.003, respectively). When the after recovery period was compared with the control group in terms of choroidal thickness, although the choroidal thickness was higher in all regions, this difference was not found statistically significant. There was no statistically significant difference in CMT between groups (p = 0.506).The mean venous and arterial wall thicknesses were significantly higher in the active period than after recovery (p = 0.023, p = 0.013, respectively) but there were no differences between after recovery and control groups in the pairwise comparison (p = 0.851, p = 0.715, respectively).Conclusion: In patients with severe COVID-19, there are changes in thickness of the choroid and retinal vessel walls. While vascular wall thickness increases due to inflammation, the absence of lumen changes may be associated with hemodynamic variables.     

Anterior segment parameters after uveitic cataract surgery: A prospective study with 1-year results

PurposeTo determine the changes in anterior segment parameters in uveitic patients undergoing uncomplicated cataract surgery.MethodsThe best corrected visual acuity (BCVA), intraocular pressure (IOP), central corneal thickness (CCT), anterior chamber angle (ACA), anterior chamber depth (ACD), and axial length (AXL) of the 38 eyes of 28 well-controlled uveitic patients who underwent cataract surgery were monitored for 12 months.ResultsMean BCVA improved significantly at the postoperative visits when compared to the baseline (all P<0.001). Mean CCT increased on the first day compared to the preoperative value (627.62±71.16 vs. 572.18±53.52 µm, P=0.015) and then returned to the preoperative value at 3 months (572.27±49.93 µm). ACA showed a significant increase postoperatively in the first month (54.65±5.52 vs. 43.50±9.13°) and then decreased at 3 months (51.85±5.52°), remaining stable afterwards (51.73±6.59° at 12 months). ACD as measured by Sirius topography and IOLMaster 500 was higher at the follow-up times compared to the preoperative value (P<0.001). AXL at 1. month was significantly lower than the preoperative level (23.14±0.74 vs. 23.54±0.68 mm, P=0.003).ConclusionFollowing successful cataract surgery in well-controlled uveitic eyes, the CCT showed a rapid increase on the first day and then decreased to the preoperative level at the third month. ACA increased in the postoperative first month and then decreased, but it was higher than the baseline at all postoperative visits. ACD increased in the postoperative first week.     

Prediction of the response to photodynamic therapy in patients with chronic central serous chorioretinopathy based on optical coherence tomography using deep learning

PurposeTo assess the prediction of the response to photodynamic therapy (PDT) in chronic central serous chorioretinopathy (CSCR) based on spectral-domain optical coherence tomography (SD-OCT) images using deep learning (DL).MethodsRetrospective study including 216 eyes of 175 patients with CSCR and persistent subretinal fluid (SRF) who underwent half-fluence PDT. SD-OCT macular examination was performed before (baseline) and 3 months after treatment. Patients were classified into groups by experts based on the response to PDT: Group 1, complete SRF resorption (n = 100); Group 2, partial SRF resorption (n = 66); and Group 3, absence of any SRF resorption (n = 50). This work proposes different computational approaches: 1st approach compares all groups; 2nd compares groups 1 vs. 2 and 3 together; 3rd compares groups 2 vs. 3.ResultsThe mean age was 55.6 ± 10.9 years and 70.3% were males. In the first approach, the algorithm showed a precision of up to 57% to detect the response to treatment in group 1 based on the initial scan, with a mean average accuracy of 0.529 ± 0.035. In the second model, the mean accuracy was higher (0.670 ± 0.046). In the third approach, the algorithm showed a precision of 0.74 ± 0.12 to detect the response to treatment in group 2 (partial SRF resolution) and 0.69 ± 0.15 in group 3 (absence of SRF resolution).ConclusionDespite the high clinical variability in the response of chronic CSCR to PDT, this DL algorithm offers an objective and promising tool to predict the response to PDT treatment in clinical practice.     

Use of Nd:YVO4 laser,photodynamic therapy,sulfuric acid and sand blasting on improving bond integrity of PEEK to resin cement with adhesive

AimThe present study aimed to inspect and compare several PEEK surface treatments modifications using Photodynamic therapy (PDT), Neodymium-doped yttrium orthovanadate (Nd:YVO₄) laser, Sulphuric acid (H₂SO₄), and sandblasting (SB) when bonded to composite resin via an adhesive systemMaterial and methodsOne hundred disk-shaped PEEK specimens were prepared by CAD-CAM milling and randomly distributed into five groups based on surface treatment methods: group1: Control (no treatment), group 2: PDT, group 3: Nd:YVO₄ laser, group 4: H₂SO₄ and group 5 sandblasting. Later bonding was pursued using resin cement with an adhesive system. Measurements of surface roughness employing a surface profilometer, water contact angle by the static drop method, SBS by universal Testing machine, and failure modes of de-bonded PEEK specimens by Stereomicroscope were attained. Execution of statistical analysis was performed by two-way analysis of variance ANOVA and Tukey's post hoc test (p>0.05). The Shapiro–Wilk normality test and Bartlett's test for homoscedasticity were also performed.ResultsThe highest SBS was exhibited by Nd:YVO₄ laser (16.33 ± 0.71 MPa) and the lowest SBS was observed in the control group (9.4 ± 1.02). However, PEEK specimen luted with resin cement treated with PDT (16.21 ± 0.14 MPa) and H₂SO₄ (15.23 ± 0.63 MPa) displayed a comparable SBS to Nd:YVO₄ laser (p>0.05). The results of Ra exhibited that PEEK material when exposed to Nd:YVO₄ laser (15.252 ± 1.581 μm) unveiled the highest Ra. Nd:YVO₄ laser (131.25 ± 2.9 μm) and PDT (130.24 ± 3.7 μm) showed comparable WCA values (p>0.05).Adhesive failure was dominant.ConclusionPEEK surface treated with photodynamic therapy and Neodymium-doped yttrium orthovanadate laser and bonded to composite resin via an adhesive system significantly improved shear bond strength, surface roughness, and water contact angle.     

Quantitative assessment of optic nerve in patients with Leber’s hereditary optic neuropathy using reduced field-of-view diffusion tensor imaging

PurposeTo quantitatively analyze the optic nerve alterations in chronic Leber’s hereditary optic neuropathy (LHON) using reduced field-of-view diffusion tensor imaging (rFOV-DTI) and evaluate the correlation of diffusion parameters with visual functional and peripapillary retinal nerve fiber layer (RNFL) thickness.MethodsTwenty-five patients (50 affected optic nerves) with chronic LHON and 28 healthy controls (56 normal optic nerves) were enrolled. The rFOV-DTI was performed in the bilateral optic nerves for all the subjects. The fractional anisotropy (FA), mean diffusivity (MD), principal eigenvalue (λ//), and orthogonal eigenvalue (λ⊥) were calculated for quantitative analysis. Visual field (VF) and visual acuity (VA) were measured in all subjects. The peripapillary RNFL thickness was assessed using optical coherence tomography (OCT). The correlation of DTI diffusion parameters with visual function and peripapillary RNFL thickness was evaluated.ResultsCompared with optic nerves in the control group, the mean FA was significant decreased (P < 0.005), and the mean MD, λ//and λ⊥ significant increased (P < 0.005). The average and temporal peripapillary RNFL thickness were significantly thinned in LHON patients. There was a significant correlation between optic nerve FA and VA, mean deviation of visual field (MD_VF) (P < 0.005). Also, optic nerve FA correlated significantly with average RNFL thickness (P < 0.05) but not with MD, λ//and λ⊥ (P > 0.05). However, none of the DTI parameters correlated with age and disease duration (P > 0.05).ConclusionsOur study has demonstrated that rFOV-DTI could provide information of optic nerve damage in chronic LHON, and can serve as technique for detecting and evaluating pathological changes in the optic nerve in LHON.     

Calibrated Bioresorbable Microspheres: A Preliminary Study on the Level of Occlusion and Arterial Distribution in a Rabbit Kidney Model

PurposeTo assess the level of occlusion and arterial distribution of calibrated bioresorbable microspheres (BRMS-I and BRMS-II) compared with tris-acryl gelatin microspheres (TGMS) after renal embolization.Materials and MethodsSix rabbits underwent renal embolization with 100–300 µm BRMS-I and TGMS; three rabbits received partial occlusion (group 1, n = 3), and three rabbits received total occlusion (group 2, n = 3). Four other rabbits received 100–300 µm BRMS-II (with higher cross-linking density than BRMS-I) in the left kidneys reaching total occlusion (group 3, n = 4). Coronal sections of the kidneys were histologically analyzed. Ease of injection, microsphere deformation, vessel sizes, and arterial distribution were assessed.ResultsThe injection of BRMS-I, BRMS-II, and TGMS through microcatheters went smoothly without any clogging. In group 1, BRMS identification was easier than TGMS. In group 2, both BRMS-I and TGMS were observed in all three arterial levels (interlobar, arcuate, and interlobular arteries) without a significant difference (P = .84). BRMS-I were not significantly different from TGMS in the mean diameter of vessels occluded (197 µm ± 23 vs 158 µm ± 21, P = .25) or the microsphere deformation (8.85% ± 0.53% vs 11.80% ± 0.64%, P = .071). In group 3, the arterial distribution of BRMS-II was significantly different from BRMS-I and TGMS (P < .0001).ConclusionsIn occluding arteries, 100–300 µm BRMS-I were not significantly different from 100–300 µm TGMS. Arterial distribution of BRMS can be influenced by their cross-linking density.     

Macular and peripapillary optical coherence tomography angiography metrics in thyroid-associated ophthalmopathy with chorioretinal folds

PurposeTo evaluate macular and radial peripapillary capillary (RPC) microvascular densities and the thickness of the retinal nerve fiber layer (RNFL) in thyroid-associated ophthalmopathy (TAO) with chorioretinal folds (CRFs) and the associations of these characteristics with visual function.MethodA cross-sectional study was performed at the Ophthalmology Department of the Sun Yat-sen Memorial Hospital from March 2018 to August 2021. All patients underwent ocular examination, ophthalmic function tests and optical coherence tomography angiography (OCTA). The microvascular densities in the macula and optic papilla in the TAO with CRFs or without CRFs. Correlation analyses were used to examine the association of microvascular density and visual function.ResultsTen TAO patients with CRFs (CRF group, 20 eyes) and 10 TAO patients without CRFs (NCRF group, 20 eyes) were recruited for the study. Visual function measurements, including best-corrected visual acuity (BCVA), were found to be worse in the CRF group (all p < 0.05). The macular whole-image vessel density in the superficial layer (SLR-mwiVD) was significantly decreased in the CRF group (p < 0.05). The RPC whole-image vessel density (RPC-wiVD) was significantly decreased in the CRF group (p < 0.05), particularly in the temporal subfields. The P100 amplitude of visual evoked potentials (VEPs) was positively associated with SLR-mwiVD and RPC-wiVD. The thickness of RNFL in the CRF group was obviously thicker than that in the NCRF group (p < 0.05).ConclusionsOur study showed decreased microvascular density of the macula and RPC and thicker RNFL in TAO patients with CRFs. CRFs with decreased microvascular density should be regard as an indicator of visually threatening conditions.