Ocular blood flow as it relates to race and disease on glaucoma

Factors Associated With Corneal Hysteresis in an Elderly White Population: The Thessaloniki Eye Study

PRCIS

Corneal hysteresis (CH) was positively associated with female sex and central corneal thickness, and negatively with age and axial length. Diabetes showed no significant association with CH in the adjusted models.

PURPOSE

To provide values of corneal hysteresis (CH) in an elderly, healthy Greek population and to investigate its association with demographic, ocular, and systemic factors.

METHODS

Cross-sectional population-based study. Out of 1092 participants in the incidence cohort of the Thessaloniki Eye Study (TES) who were re-examined between 2013 and 2015, there were 801 eligible subjects in this study according to prespecified criteria. All subjects underwent an interview and a comprehensive clinical examination. Demographic data and medical and ophthalmic, family, and smoking histories were recorded. CH was evaluated with an Ocular Response Analyzer (ORA).

RESULTS

The mean age of study subjects was 79.7±3.9 years and 345 out of 801 participants (43.1%) were female. The mean CH among all subjects was 10.1±1.5 mm Hg. After adjusting for age, sex, central corneal thickness (CCT), axial length (AL), and diabetes, CH was positively associated with female sex (β=0.446; P <0.0001) and CCT (β=0.017; P <0.0001), and negatively associated with age (β=-0.024; P =0.038) and AL (β=-0.181; P <0.0001). There was no association between CH and diabetes (β=0.186; P =0.10). In a supplementary multivariable analysis of a smaller sample size, where we included corneal curvature (CC) as an additional covariate, no association was found between CH and CC (β=-0.235; P =0.26) or age (β=-0.023; P =0.09).

CONCLUSION

This study outlined variations in CH among a Greek population. CH decreased with advancing age while women had greater CH compared with men. In addition, eyes with thinner corneas and longer AL had lower CH values. No significant associations were found between CH and CC or the presence of diabetes.

Artificial intelligence and glaucoma: a lucid and comprehensive review

Glaucoma is a pathologically irreversible eye illness in the realm of ophthalmic diseases. Because it is difficult to detect concealed and non-obvious progressive changes, clinical diagnosis and treatment of glaucoma is extremely challenging. At the same time, screening and monitoring for glaucoma disease progression are crucial. Artificial intelligence technology has advanced rapidly in all fields, particularly medicine, thanks to ongoing in-depth study and algorithm extension. Simultaneously, research and applications of machine learning and deep learning in the field of glaucoma are fast evolving. Artificial intelligence, with its numerous advantages, will raise the accuracy and efficiency of glaucoma screening and diagnosis to new heights, as well as significantly cut the cost of diagnosis and treatment for the majority of patients. This review summarizes the relevant applications of artificial intelligence in the screening and diagnosis of glaucoma, as well as reflects deeply on the limitations and difficulties of the current application of artificial intelligence in the field of glaucoma, and presents promising prospects and expectations for the application of artificial intelligence in other eye diseases such as glaucoma.

Comparing Optical Coherence Tomography Angiography Metrics in Healthy Chinese and Caucasian Adults

BACKGROUND

The goal of the present study was to identify differences in retinal microvasculature between healthy Caucasians and healthy Asians in order to provide a better understanding of the variability between different ethnic groups.

METHODS

In this cross-sectional study, 191 healthy Chinese and Caucasian participants were enrolled. They underwent optical coherence tomography angiography (OCTA) scans with Zeiss Cirrus HD-5000 Spectral-Domain with AngioPlex. Linear regression models were used to investigate the association of OCTA metrics with potential risk factors.

RESULTS

Whereas participants in both groups are comparable in age and sex, Chinese participants had a longer axial length, higher spherical equivalent, higher intraocular pressure (p < 0.001), and a significantly higher perfusion density of large vessels in the superficial capillary plexus (p < 0.001). Regarding the foveolar avascular area (FAZ), Chinese participants had a larger superficial FAZ, a wider superficial FAZ perimeter, and a more circular deep FAZ shape (p < 0.001).

CONCLUSIONS

There are significant differences in the retinal vasculature between Caucasian and Asian eyes as measured using OCTA. This needs to be considered when developing normative databases. Whether such findings relate to inter-racial differences in the incidence of retinal vascular disease remains to be shown.

Ocular blood flow biomarkers may predict long-term glaucoma progression

BACKGROUND/AIM

To examine the relationship between baseline blood flow biomarkers and long-term open-angle glaucoma (OAG) progression.

METHODS

112 patients with early to moderate OAG (mean age 64.9±11.0 years; 68 female) were evaluated at baseline and every 6 months from 2008 to 2013. Biomarkers of retinal capillary blood flow were assessed by Heidelberg retinal flowmetry. Functional disease progression was monitored via Humphrey visual field examinations, defined as two consecutive visits with a mean deviation decrease ≥2 decibels and/or Advanced Glaucoma Intervention Study score increase ≥2 compared with baseline. Structural progression was monitored with optical coherence tomography and Heidelberg retinal tomograph, defined as two consecutive visits with retinal nerve fibre layer thickness decrease ≥8% and/or horizontal or vertical cup/disk ratio increase ≥0.2 compared with baseline. Mixed-model analysis of covariance was used to test for significant change from baseline to 5-year follow-up. Times to functional and structural progression were analysed using Cox proportional hazards models.

RESULTS

Lower HRF retinal capillary blood flow in the superior retina was significantly associated with structural progression (p=0.0009).

CONCLUSION

In our OAG sample, baseline lower retinal capillary perfusion in the superior retina was predictive of structural progression after 5 years.

TRIAL REGISTRATION NUMBER

NCT01145911.

Effect of treatment with carteolol and latanoprost in newly diagnosed primary open-angle glaucoma on peripapillary vessel density

BACKGROUND AND AIM

In a previous follow-up of glaucoma patients taking carteolol or latanoprost, we found a greater progression of visual field changes with the prostaglandin than the betablocker. In the present study we compared the impact of carteolol and latanoprost on peripapillary vessel density in newly diagnosed primary open-angle glaucoma (POAG) patients.

METHODS

The study consisted of two groups of POAG patients. There were 46 patient eyes treated with carteolol (Carteol LP 2%) in the first group and 52 eyes treated with latanoprost (Xalatan 0.005%) in the second. Intraocular pressure (IOP), vessel density (VD) and visual field were assessed in all patients. VD was measured peripapillary by optical coherence tomography angiography (OCTA) with the Avanti RTVue XR in eight segments: Inferior Temporal - IT (1); Temporal Inferior -TI (2); Temporal Superior - TS (3); Superior Temporal - ST (4); Superior Nasal - SN (5); Nasal Superior - NS (6); Nasal Inferior - NI (7) and Inferior Nasal - IN (8). The measurements were compared before and after three months of treatment. The visual field was examined with a fast threshold glaucoma program using a Medmont M 700 instrument from Medmont International Pty Ltd. and only when a diagnosis of POAG was done. The overall defect (OD) was assessed.

RESULTS

Before treatment, there was no difference between groups in either OD or VD. After treatment, there was a decrease in IOP in both groups. In the carteolol-treated group, the mean decrease was 5.8 mmHg and in the latanoprost-treated eyes, the mean decrease was 7 mmHg. The difference was not statistically significant (P=0.133). After treatment with carteolol, there was a statistically significant increase in VD in segments 4, 5 and 6. After latanoprost treatment, VD was statistically significantly improved only in segment 5. A greater increase in VD values was found in eyes treated with carteolol than in eyes treated with latanoprost.

CONCLUSION

Carteolol had a better effect on vessel density than latanoprost.

Axons of retinal ganglion cells on the optic nerve disc following vessel density correction at different IOP values

The present study aimed to determine how the vascular density (VD) in each segment peripapillary influences the retinal nerve fiber layer (RNFL) and to eliminate its contribution to RNFL in pathological intraocular pressure (IOP). In a cohort of 69 subjects (mean age, 45±6 years old) with untreated ocular hypertension (122 eyes in total) enrolled in this study, Ocular Response Analyser IOP was measured during routine outpatient care. Its value was >21 (range, 21-36) mmHg in all eyes. Furthermore, peripapillary VD and RNFL were measured using optical coherence tomography in the following eight segments: Inferior temporal (segment 1); temporal inferior (segment 2); temporal superior (segment 3); superior temporal (segment 4); superior nasal (segment 5); nasal superior (segment 6); nasal inferior (segment 7); and inferior nasal (segment 8). The visual field examination was performed with the fast threshold glaucoma program using the Medmont M 700. The overall defect was evaluated. Person's correlation coefficient was used to assess the correlation between VD and IOP. The largest changes were observed in peripapillary segments 1, 4, 5, 6, 7 and 8. The second part of the work was to eliminate the contribution of VD to RNFL. The partial correlation coefficient r was used to adjust RNFL from VD to assess the dependence between the selected parameters. The largest changes in RNFL were in segments 5 and 8 after they had been 'cleaned' of peripapillary VD. In conclusion, the present study revealed that the largest changes in RNFL after VD adjustment were observed for the incipient hypertensive glaucoma in segments 5 and 8.

Reproducibility of peripapillary, optic nerve head and macular vessel density by OCT-A according to glaucoma severity staging

OBJECTIVE

To assess the reproducibility of peripapillary, optic nerve head (ONH-PP) and macular vessel density (VD) by Spectral Domain optical coherence tomography angiography (SD OCT-A) in glaucoma patients and healthy subjects.

METHODS

Cross-sectional study assessing 63 eyes of 63 subjects, including 33 glaucoma patients and 30 healthy subjects. Glaucoma was classified in mild, moderate, or advanced. Two consecutive scans were acquired by Spectralis Module OCT-A (Heidelberg, Germany), and provided images of the superficial vascular complex (SVC), nerve fiber layer vascular plexus (NFLVP), superficial vascular plexus (SVP); deep vascular complex (DVC), intermediate capillary plexus (ICP) and deep capillary plexus (DCP). VD (%) was calculated by AngioTool. Intraclass correlation coefficients (ICCs) and coefficients of variation (CV) were calculated.

RESULTS

Among ONH-PP VD, better ICC presented advanced (0.83-0.97) and moderate glaucoma (0.86-0.96) compared with mild glaucoma (0.64-0.86). For the macular VD reproducibility, ICC results for superficial retinal layers were better for mild glaucoma (0.94-0.96) followed by moderated (0.88-0.93) and advanced glaucoma (0.85-0.91), and for deeper retinal layers ICC was better for moderate glaucoma (0.96-0.95) followed by advanced (0.80-0.86) and mild glaucoma (0.74-0.91). CVs ranged from 2.2%% to 10.94%. Among healthy subjects, ICCs for the ONH-PP VD measurements (0.91-0.99) and for the macular VD measurements (0.93-0.97) were excellent in all layers, with CVs from 1.65% to 10.33%.

CONCLUSIONS

SD OCT-A used to quantify macular and ONH-PP VD showed excellent and good reproducibility in most layers of the retina, both in healthy subjects and in glaucoma patients regardless of the severity of the disease.

Genetic association between CDKN2B-AS1 polymorphisms and the susceptibility of primary open-angle glaucoma (POAG): a meta-analysis from 21,775 subjects

Background

Primary open-angle glaucoma (POAG) is affected by both genetics and environmental factors. CDKN2B-AS1 polymorphisms have been reported to be involved in the pathogenesis of POAG. However, the results of the genetic associations between the CDKN2B-AS1 polymorphisms and POAG risk were inconclusive.

Aims

This study aimed to evaluate the correlation of CDKN2B-AS1 polymorphisms and POAG susceptibility using a meta-analysis.

Methods

Meta-analysis was performed by searching PubMed, Web of science, the Cochrane database of system reviews, CNKI, and Embase databases. The relationship of CDKN2B-AS1 rs4977756, rs10120688, rs2157719, and rs7049105 polymorphisms and POAG risk was evaluated by the odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Eleven studies with 8290 cases and 13,485 controls were included in the present meta-analysis. The alleles of rs4977756 and rs10120688 significantly increased the risk of POAG (rs4977756: OR = 1.20, 95%CI = 1.03–1.39, p = 0.02; rs10120688: OR = 1.36, 95%CI = 1.29–1.44, p < 0.00001). As for ethnicity, rs4977756 polymorphism significantly increased POAG risk in Caucasians (OR = 1.33, 95%CI = 1.12–1.57, p = 0.0009), but not in Asians. In addition, the rs2157719 allele was significantly associated with POAG risk in Asians (OR = 0.66, 95%CI = 0.55–0.80, p < 0.0001), but not in Caucasians (p > 0.05).

Conclusions

The CDKN2B-AS1 rs4977756 might increase the POAG risk in Caucasian population, and rs2157719 might decrease the POAG risk in Asian population, while rs10120688 might increase the risk of POAG.