Comparison of topographic outcomes between HPMC based and vitamin E TPGS based riboflavin solutions after corneal cross-linking.

PURPOSE: To compare the visual and topographic results between patients who underwent epithelium-off cross-linking using riboflavin solutions compounds hydroxypropyl methylcellulose (HPMC) 1.1% and D-alpha-tocopheryl polyethylene-glycol 1000 succinate (VE-TPGS). METHODS: In this study, 37 eyes treated with HPMC and 29 eyes treated with VE-TPGS were evaluated retrospectively. Spherical equivalent (SE), refractive cylinder, corrected distance visual acuity tests (CDVA), corneal topography indices (flat and steep meridians' keratometry (K1 and K2)), maximum keratometry (K max), central, thinnest, and apical corneal thicknesses, the front and back keratoconus vertex index (KVf, KVb), and the surface asymmetry index of the front and back surface (SIf, SIb), and endothelial cell density were compared at baseline and postoperative follow-up visits (1, 3, 6, and 12months). RESULTS: At the end of the 12th-month, K1, K2, and Kmax were decreased in both groups. In comparison to baseline, there was a decline in the HPMC group in the 3rd- month Kmax change, an increase was observed in the VE-TPGS group. In the 12th-month KVb change, an increase was observed in the HPMC group compared to the baseline, while a decrease was observed in the VE-TPGS group. The other parameters did not show a statistically significant difference between the groups (p > 0.05). CONCLUSION: At the end of 12 months, both riboflavins were effective in stopping the progression of keratoconus and were safe for endothelium. Although both riboflavins provide a decrease in keratometry values, it can be said that VE-TPGS is superior to HPMC in correcting the ectasia on the posterior corneal surface.

Comparison of central corneal thickness measured by ultrasound pachymetry, corneal topography, spectral domain- optical coherence tomography, and non-contact specular microscopy.

BACKGROUND: This study aims to investigate the compatibility of central corneal thickness (CCT) measurements obtained with spectral-domain optical coherence tomography (SD-OCT), Scheimpflug-Placido-based corneal topography (CT), non-contact specular microscopy (NCSM), and ultrasonic pachymetry (UP). These four corneal measurement techniques have not been compared in a single study on these many subjects. METHODS: CCT was measured in 185 eyes of 185 volunteers with each of the four devices by a single observer. CCTs from Optovue® iVue SD-OCT, Sirius corneal topography, NonconRobo NCSM, and Accutom UP devices were recorded. Compatibility between devices was evaluated with intraclass correlation coefficient (ICC) and Bland-Altman plots. Pairwise comparisons were performed using the Bonferroni test. Measurement differences between devices were analyzed with the Pearson correlation coefficient. RESULTS: Of the 185 volunteers, 103 were men, and 82 were women. Their mean age was 48.55 ± 16.6 (18-70) years. Mean CCT values measured by UP, CT, OCT, and NCSM were 546.77 ± 39.2, 535.29 ± 39.2, 526.49 ± 39.05, 505.15 ± 46.1 µm, respectively. Statistically significant differences were found between the mean CCT values obtained from the paired devices (p <0.001). The highest difference between pairs was found between UP and NCSM (43.63 ± 1.8 µm; CI 38.74 to 48.5 µm; p <0.001), while the lowest difference was found between OCT and CT (7.3 ± 1.5 µm; 95%CI 3.1 to 11.6 µm; p <0.001). In pairwise comparisons of four devices, the highest ICC value was between UP and CT (ICC: 0.899, 95%CI 0.759-0.947; p <0.001). CONCLUSION: Despite the high correlation between measurements obtained from different methods, notable differences in CCT values exist, rendering devices non-interchangeable. Therefore, alternative brands of the same device may yield different outcomes.

Retinal microvascular changes in patients with coronary artery disease and apnea.

BACKGROUND: Optical coherence tomography angiography (OCT-A) allowed visualization of capillary level of retina; however, the relationship between coronary vascular status and retinal microvascular changes in patients with apnea is not known well. Our aim was to assess the retinal OCT-A parameters in patients with ischemia and angiographically proven microvascular disease and compare them with obstructive coronary disease in patients with apnea. METHODS: Our observational study included 185 eyes of 185 patients, 123 eyes of patients with apnea (72 eyes from mild OSAS, 51 eyes from moderate to severe OSAS) and 62 eyes from healthy controls. Radial scans of the macula and OCT-A scans of the central macula (superficial (SCP) and deep (DCP) capillary plexuses) were performed on all participants. All participants had documented sleep apnea disorder within 2 years prior to coronary angiography. Patients were grouped by severity of apnea and coronary atherosclerosis (50 % stenosis cut-off value for obstructive coronary artery disease). Patients presented with myocardial ischemia and without coronary artery occlusion (<50 % diameter reduction or FFR > 0.80) constitute the microvascular coronary artery (INOCA) group. RESULTS: Compared to healthy controls, patients with apnea showed deterioration in vascular density in all regions of the retina, regardless of obstructive or microvascular coronary artery disease on the ischemia background. This study has provided important observations of a high prevalence of INOCA in patients with OSAS and the presence of OSAS was a significant independent predictor of functional coronary artery disease. The relative decreases in vascular densities were more pronounced in the DCP layer according to SCP layer of macula. Only FAZ area values were significantly different according to the severity of OSAS (0.27 (0.11-0.62) and 0.23 (0.07-0.50) (p = 0.012)). CONCLUSIONS: In patients with apnea, OCT-A can be used as a noninvasive tool to define coronary artery involvement, with similar retinal microvascular changes both in obstructive and microvascular coronary artery group. In patients with OSAS, we observed a high prevalence of microvascular coronary disease, supporting pathophysiological role of OSAS in ischemia of this group of patients.

Evaluation of Corneal Parameters and Meibomian Gland Alterations After Corneal Cross-Linking in Patients With Progressive Keratoconus.

OBJECTIVES: The aim of the study was to evaluate the changes in corneal parameters and meibomian gland alterations after corneal cross-linking (CXL) for progressive keratoconus. METHODS: Thirty nine eyes of 39 keratoconus patients were treated with CXL. Corneal topography, specular microscopy, the Ocular Surface Disease Index© (OSDI), noninvasive tear break-up time (NITBUT), and meibography indices were evaluated preoperatively and at the first, third, and sixth months after CXL. RESULTS: The flattest keratometry (K1) ( P =0.003), steepest keratometry (K2) ( P <0.001), apex, central, and thinnest corneal thicknesses ( P <0.001) showed significant differences after cross-linking, whereas the changes in the maximum keratometry (Kmax) were not significant ( P =0.140). The endothelial cell density, coefficient of variation, and hexagonality were unchanged. The NITBUT values decreased after cross-linking; however, there was no significant change in OSDI index ( P =0.313), meiboscore ( P =0.392), and meibomian gland loss degrees ( P =0.300). No change was detected in the morphology of the meibomian glands after CXL. CONCLUSION: In eyes with keratoconus, a flattening in keratometry readings and thinning in corneal thickness were observed after CXL. The corneal endothelium is protected by dextran-free riboflavin. Cross-linking procedure causes dry eye by changing the corneal structure without affecting the morphology of the meibomian glands.

Investigation of SARS-CoV-2 in Postmortem Ocular Tissues and Evaluation of Its Effects on Corneal Donation.

PURPOSE: The purpose of this study was to investigate the presence of viruses in postmortem nasopharyngeal swabs and ocular tissues of patients with coronavirus disease 19 (COVID-19) confirmed through an antemortem reverse transcription polymerase chain reaction (RT-PCR) test. METHODS: We recorded demographic data, comorbidities, treatments, and vaccination status of the patients diagnosed with COVID-19 and monitored in the intensive care unit. Nasopharyngeal swab samples were collected from the patients within 2 hours postmortem followed by swabs from both eyes, lower and upper conjunctival sacs, corneal epithelial layer, and samples from anterior chamber fluid. The geneMAP 2019-nCoV severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) detection kit was used to detect the samples showing the presence of SARS-CoV-2. RESULTS: Among the 47 patients (mean age 74 years, range 39-92) included in the study, 29 were men and 18 were women. The nasopharyngeal swab samples of 21 patients were positive for the RT-PCR test for SARS-CoV-2, whereas at least one of the ocular tissue samples in 6 of those patients were positive for the RT-PCR test for SARS-CoV-2. However, all ocular swab samples were tested negative for SARS-CoV-2 in the 26 patients with negative nasopharyngeal swab samples. The mean duration from COVID-19 diagnosis to mortality was 10 days (range 2-27 days) in patients with positive postmortem nasopharyngeal swab samples for SARS-CoV-2, compared with an average of 21 days (1-80 days) in patients who tested negative. This difference was statistically significant (P = 0.01). CONCLUSIONS: Cadavers with negative postmortem nasopharyngeal swab samples for SARS-CoV-2 and those with the time from diagnosis to death of >3 weeks may be considered as candidates for corneal donation.

Evaluation of meibomian gland morphology and anterior segment parameters by Sirius topography systems in polycystic ovary syndrome.

Purpose: To compare findings in specular microscopy, corneal topography, and noncontact meibography in polycystic ovary syndrome (PCOS) patients with healthy controls. Methods: A total of 40 women with PCOS and 32 healthy controls were enrolled in the study. Schirmer's test, Ocular Surface Disease Index (OSDI), noninvasive tear break-up time (NITBUT), the mean keratometry (Km), maximum keratometry (Kmax), central (CCT), thinnest (TCT) and apical (ACT) corneal thicknesses, meibomian gland (MG) loss, meiboscores, morphology of MGs, endothelial cell density (ECD), coefficient of variation (CV), and percentage of hexagonal cells (PHEX) were analyzed. Correlations between anti-Mullerian hormone (AMH) and sex hormones and the findings of PCOS patients were evaluated. Results: Mean OSDI score, intraocular pressure, Km and Kmax values, the mean MG loss of upper and lower eyelids, lower eyelid meiboscore, and degree of morphological abnormalities of MGs were higher in cases with PCOS than healthy controls. There were no significant differences between groups in Schirmer results, first and average NITBUT, mean values of TCT, ACT, CCT, ECD, CV, and PHEX (P > 0.05, for all). There were correlations between plasma AMH level and Kmax, back Km and PHEX, and between estradiol (E2) and PHEX; there were negative correlations between E2 and total MG loss and CV and between total testosterone and ACT. Conclusion: Loss and morphological deterioration of the MGs are observed in PCOS patients, even if the tear parameters are not impaired yet. In eyes with PCOS, keratometry values become steeper in proportion to AMH levels. The PCOS patients should be followed carefully for the development of corneal ectasia.

Evaluation of corneal and lens densitometry in children with familial Mediterranean fever.

BACKGROUND: This study aimed to investigate the presence of subclinical inflammation in the eye by examining corneal and lens changes in children with familial Mediterranean fever (FMF) and provide the regulation for follow-up and treatment protocols according to the presence of signs of inflammation. DESIGN: This is a cross-sectional, case-control study. METHODS: Topographic parameters and corneal and lens densitometry of 48 patients with FMF (10.12 ± 3.84 years [range: 5-19 years]) and 33 healthy volunteers (10.94 ± 3.78 years [range: 5-19 years]; p > 0.05) were evaluated with a Scheimpflug camera. For corneal densitometric measurements, the cornea was divided into four concentric radial zones and anterior, central, and posterior layers according to corneal thickness. The mean densitometry value for the crystalline lens was calculated in three zones around the center of the pupil. RESULTS: Corneal light backscattering in all layers and zones of the cornea were similar between the patient and control groups. Lens densitometry values in the three zones did not differ between the two groups (p > 0.05). Maximum lens densitometry values were found to be significantly higher in the patient group (22.14 vs 19.11; p = 0.011). CONCLUSION: Monitoring the cornea and lens density in patients with FMF using Pentacam may help to show the presence of subclinical inflammation and regulate the follow-up and treatment protocols. Larger sample sizes and prospective design studies are needed to reach more conclusive results.

Nasolacrimal canal morphology with or without idiopathic obstruction in Caucasian adults: a multidetector CT study.

PURPOSE: To compare the morphological features of the bony nasolacrimal canal (NLC) in Caucasian adults with and without primary acquired nasolacrimal duct obstruction (PANDO). METHODS: The study included one eye each from 38 patients with PANDO and 38 age- and gender-matched controls without PANDO, all of whom underwent multidetector computed tomography. In tomographic images, length, and orientation angles of the NLC, transverse canal diameters at the duct entrance and lower end, and minimum (narrowest) transverse and anterior-posterior canal diameters were measured. RESULTS: The two groups were similar for NLC length and angulations. The transverse entrance diameter was significantly narrower in the PANDO group (mean, 4.6 mm vs. 5.1 mm) (p = 0.09). The narrowest site was most frequently in the middle duct or slightly above the middle in both groups (p > 0.05). The minimum canal diameters were significantly smaller in the PANDO group (p = 0.010 and p = 0.003). When gender subgroups were compared, the significant differences continued for the transverse entrance and minimum diameters in females with PANDO (p = 0.006) and for the minimum anterior-posterior diameter in males with PANDO (p = 0.02). CONCLUSION: Narrowness of the upper and/or middle part of the bony nasolacrimal duct may play a role in the development of PANDO in the adult Caucasian population.

The relationship between carotid intima-media thickness and microvascular changes in retinal zones and optic disc in patients with type 1 diabetes mellitus.

PURPOSE: The aim of this study was to detect early retinal vascular changes with optical coherence tomography angiography (OCTA) in type 1 diabetes mellitus (T1DM) patients without diabetic retinopathy and to evaluate the correlation of the results with carotid intima-media thickness (IMT). DESIGN: This is a case-control and cross-sectional study. METHODS: This study included 38 adult patients with T1DM, and 38 age and gender-matched healthy controls. Retinal and optic disc (OD) measurements were taken using OCTA. The carotid artery IMT of each patient was measured using Doppler ultrasonography. Superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density, foveal avascular zone (FAZ), non-flow area (NFA) and foveal density (FD) were analysed in the fovea centred 6 × 6 mm macular area. The superficial capillary plexus and DCP were also scanned centred on the peripapillary region. The correlations between OCTA measurements and carotid IMT, duration of DM and haemoglobin A1c levels in patients with T1DM were evaluated. RESULTS: The mean values for carotid IMT were significantly higher in diabetic patients than in controls (p < 0.001). The mean values for vessel density SCP, DCP and OD were significantly lower in the diabetic group (p < 0.05). There were correlations between the carotid IMT and duration of T1DM and the evaluated parameters of OCTA. CONCLUSION: Microvascular changes in the SCP and DCP in patients with T1DM without DR offer important data. OCTA can be used to detect early microvascular changes in patients with T1DM without DR. In addition, a relationship was found between SCP vascular dropout and carotid IMT.

Evaluation of corneal and lens densitometry with Pentacam HR in children with Nephrotic Syndrome: A controlled, prospective study.

BACKGROUND: This study aimed to compare the corneal and lens densitometry values between children with Nephrotic Syndrome (NS) and healthy individuals. METHODS: This cross-sectional comparative study included 23 patients with NS and 26 healthy controls. Corneal topographic and corneal and lens densitometric values were measured using Pentacam HR. Densitometry measurements in different layers were analyzed and compared between groups. Correlations between steroid cumulative dose, age at diagnosis of the disease, duration of disease, number of relapses, and patients' densitometries values were evaluated. RESULTS: The measurements of the keratometry, horizontal white-to-white, and iridocorneal angle values were significantly different between groups (p < 0.05). The 0-2 mm and 2-6 mm anterior corneal densitometry values were significantly higher in NS patients. (p = 0.009 and p = 0.033, respectively). The lens densitometry values of all zones were higher in the eyes with NS but there was no statistically significant difference from the healthy control eyes (p > 0.05). There was a positive strong correlation between the cumulative steroid dose and the posterior lens zone densitometry, a positive weak correlation between the number of attacks and anterior corneal densitometry, and between disease duration and central corneal densitometry and average lens density. CONCLUSION: In eyes with NS, changes occur in corneal and lens densitometry in correlation with disease duration, number of attacks, and cumulative steroid dose. Significant density changes were detected especially in the anterior cornea and central 0-6 mm area.

Effects of Intravitreal Injection on Ocular Surface and Anterior Segment Parameters.

OBJECTIVES: This study was designed to investigate the long-term effects of intravitreal anti-vascular endothelial growth factor (VEGF) injections on ocular surface and anterior segment parameters. A comparison was performed of the treated eye and the fellow healthy eye. METHODS: The study group included patients who had received at least 3 intravitreal injections of anti-VEGF agents (bevacizumab, ranibizumab, or aflibercept) for retinal vascular disorders. All of the subjects were treated in only 1 eye. A complete ophthalmological examination, including evaluation of tear break-up time (TBUT), the Schirmer 1 test, the Oxford Grading Scale, and the Ocular Surface Disease Index (OSDI) questionnaire, corneal topography, and specular microscopy were performed in both eyes 1 month after the last injection. RESULTS: In this study, 49 eyes of 49 patients who underwent regular intravitreal injection in 1 eye were enrolled. The mean age was 63.85±9.8 years (range: 29-86 years). A mean of 4.06±1.7 (range: 3-11) injections were administered. There was no significant difference in the intraocular pressure, TBUT, Schirmer 1, fluorescein staining, or specular microscopy parameters (p>0.05). The mean non-invasive TBUT first and average values; the central, thinnest, and apex corneal thickness measurements; the anterior chamber depth, irido-corneal angle, corneal volume, and keratometry values were similar in each individual (p>0.05 for all parameters). The mean OSDI score was 27.5±17.6 for the injected eyes and 15.9±12.9 for the non-injected eyes (p<0.0001). CONCLUSION: Intravitreal anti-VEGF injections had no effect on ocular surface, corneal endothe-lium, and anterior segment parameters.

Relationship Between Primary Acquired Nasolacrimal Duct Obstruction, Paranasal Abnormalities and Nasal Septal Deviation.

OBJECTIVES: This study aimed to investigate the relationship between nasal septal deviation and paranasal abnormalities in the etiology of primary acquired nasolacrimal duct obstruction (PANDO). METHODS: A total of 37 (8 men, 29 women) patients (48 eyes with PANDO) between the ages 20 and 77 years (mean age, 52.8 ±â€Š13.1 years) were included in the study. In the axial sections of paranasal sinus computed tomography, the transverse diameters at the most upper part and the most distal part of the nasolacrimal canal were separately measured. In addition, the relationships between PANDO and nasal septal deviation, inferior turbinate hypertrophy, agger nasi cells, paradoxical middle turbinate, concha bullosa, and the angle between the bony inferior turbinate and medial wall of the maxillary sinus were investigated. RESULTS: A statistically significant relationship was found between PANDO and the axial location of septal deviation classification, axial angle of septal deviation classification, paradoxical middle turbinate, angle between the bony inferior turbinate and medial wall of the maxillary sinus and inferior meatus measure. CONCLUSION: The authors concluded that the location and angle of the nasal septal deviation in the axial plane, width of the angle between the bony inferior turbinate and medial wall of the maxillary sinus, inferior meatus measure, and paradoxical middle turbinate may be effective factors in the etiology of PANDO.

Investigating the effects of inferior turbinate outfracture on the lacrimal system by evaluating the results of paranasal sinus computed tomography and nasolacrimal irrigation test.

OBJECTIVES: This study aims to investigate the effects of inferior turbinate outfracture on the nasolacrimal system and tear flow. METHODS: Forty-seven patients (26 males, 21 females) between the ages 18 and 52 years (mean age-29.0 ± 9.6 years) were included in the study. Preoperative nasal examinations and paranasal sinus computed tomography of the patients were carried out; the direction, location, nasal septum deviation classification and inferior turbinate hypertrophy size classification were evaluated. Lacrimal irrigation test was performed preoperatively and 14 days postoperatively. RESULTS: The study included 47 patients who underwent septoplasty and inferior turbinate outfracture. The mean duration of lacrimal irrigation test was 2.9 ± 0.8 s on the right side and 3.0 ± 1.1 s on the left side preoperatively, and 2.1 ± 0.8 s on the right side and 2.2 ± 1.0 s on the left side postoperatively. No significant relationship between direction, location classification, angle nasal septum deviation classification and lacrimal irrigation test duration was found. A significant relationship between size classification of the left inferior turbinate and preoperative lacrimal irrigation test duration was noted (p = 0.030). Moreover, a significant decrease between preoperative and postoperative lacrimal irrigation test duration after inferior turbinate outfracture (p = 0.000) was noted. CONCLUSION: We concluded that outfracture of the inferior turbinate with septoplasty surgery may benefit the regulation of tear flow. In addition, we concluded that lacrimal irrigation test duration may be effective in determining the patients with subclinical nasolacrimal duct partial obstruction due to inferior turbinate pathologies.