Topographic Differences in Superficial Macular Vessel Density in Eyes with Early Primary Open-Angle Glaucoma and Normal Tension Glaucoma.

INTRODUCTION: The aim of the study was to compare macular vascular microcirculation in early primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and normal subjects. METHODS: 99 patients with early glaucoma (99 eyes: 60 POAG and 39 NTG) and 78 normal subjects were included. All subjects underwent optical coherence tomography angiography scan at 6 × 6 mm macular area. Macular vessel density (VD) and perfusion density (PD) and 9 sectors were compared between the controls, POAG, and NTG groups. Linear regression analysis was used to investigate the relationship between VD and other variables including macular PD, signal strength (SS), and mean macular ganglion cell-inner plexiform layer (mGCIPL) thickness. RESULTS: Significant losses in total area of VD and PD were detected in POAG and NTG groups compared to the controls (all p < 0.01). There were no significant differences in all inner sectors of macular VD and PD between POAG and controls (all p > 0.05). Except for outer-nasal sector, all other outer sectors of macular VD and PD were significantly lower in POAG than in the controls (all p < 0.01). The inferior-inner sector and all outer sectors of VD and PD were significantly lower in NTG than in the controls (all p < 0.01). Macular VD was significantly correlated with macular PD (r = 0.99, p < 0.001), SS (r = 0.60, p < 0.001), and mGCIPL thickness (r = 0.51, p < 0.001). CONCLUSIONS: Macular microcirculation declined significantly in early POAG and NTG patients. Macular microcirculation loss in the NTG group was more central and nasal compared with that in the POAG group. A decrease in macular VD was correlated with lower macular PD, lower SS, and thinner mGCIPL thickness.

Five-year incidence of primary glaucoma and related risk factors - The Handan eye study.

PURPOSE: To determine the 5-year incidence of primary glaucoma and its associated risk factors in rural northern China. METHODS: Population-based cohort study. A total of 5184 participants aged 30 years and older, without glaucoma at baseline, were subjected to comprehensive standardized interviews and ophthalmic and systemic examinations at baseline and after a 5-year interval in the Handan Eye Study. Incident glaucoma was diagnosed by a consensus panel of five senior glaucoma specialists. Univariate and multivariable logistic regression analyses were performed to identify the baseline risk factors that could predict the incidence of glaucoma. RESULTS: During the 5-year follow-up, incident primary glaucoma developed in 82 subjects (1.6%; 95% confidence interval [CI], 1.2%-1.9%). The age- and gender-standardized incidence of glaucoma among subjects ≥40 years old was 2.1% (0.4% annually), calculated according to the 2010 Chinese census. A higher age (odds ratio [OR], 1.06; 95% CI, 1.04-1.09; p < 0.001), higher intraocular pressure (IOP) (OR, 1.11; 95% CI, 1.02-1.20; p = 0.017), and vertical cup disc ratio (VCDR) ≥ 0.60 (OR, 5.30; 95% CI, 3.22-8.73; p < 0.001) were found to be associated with an increased risk of incident glaucoma. For each year, older age and each mmHg higher IOP, the risks of primary glaucoma increased by 1.2% and 2.0% per year, respectively. CONCLUSION: We reported the 5-year incidence of primary glaucoma in a rural Chinese population and found that older age, higher IOP, and VCDR ≥ 0.60 at baseline could help in identifying those at highest risk of disease development.

Retinal nerve fiber layer thickness in amblyopia.

Purpose: To report retinal nerve fiber layer thickness (RNFLT) in eyes with amblyopia compared with contralateral healthy eyes. Methods: In this cross-sectional study, we included patients with anisometropic amblyopia, strabismic amblyopia, and mixed amblyopia. All subjects underwent complete ophthalmic examination, including RNFLT measurement with time-domain OCT (Stratus OCT) and scanning laser polarimeter (GDX VCC). A paired "t" test was used to compare average and quadrant-wise RNFL thickness between the amblyopic and contralateral normal eyes. In addition, an analysis of variance test was used to compare various RNFL thickness parameters between the three groups. Results: A total of 33 eyes of 33 subjects with anisometropic amblyopia, 20 eyes of 20 subjects with strabismic amblyopia, and 38 eyes of 38 subjects with mixed amblyopia were included. In the anisometropic amblyopia group, the average RNFLT in the amblyopic eye was 98.2 µm and 99.8 µm in the fellow normal eye (P = 0.5), the total foveal thickness was 152.82 µm (26.78) in the anisometropic eye and 150.42 µm (23.84) in the fellow eye (P = 0.38). The difference between amblyopic and contralateral normal eye for RNFL and macular parameters was statistically insignificant in all three groups. The RNFL thickness in four quadrants was similar in the amblyopic and non-amblyopic eye between all three groups and statistically non-significant. Conclusion: Our study showed that RNFL thickness was similar in amblyopic and non-amblyopic eyes between all three amblyopia groups.

Development of angle closure and associated risk factors: The Handan eye study.

PURPOSE: To investigate the development of angle closure from baseline open angle and associated risk factors in a rural Chinese population through a longitudinal study over a 5-year period. METHODS: Subjects aged ≥30 years and older with bilateral open angles at baseline of the Handan Eye Study who participated in the follow-up and had undergone both baseline and follow-up gonioscopic examinations were included. Subjects with any form of angle closure, glaucoma, incisional ocular surgery or other conditions that could influence the results were excluded. The development of angle closure was defined as the presence of primary angle closure suspect (PACS) or primary angle closure (PAC)/primary angle closure glaucoma (PACG) during the follow-up in normal subjects with baseline bilateral open angles. Logistic regression was performed to identify the baseline risk factors for the development of angle closure. RESULTS: A total of 457 subjects with bilateral open angles at baseline aged 53.0 (45.5, 58.0) years were enrolled. 94.7% of the included cases developed PACS, 5.3% developed PAC and no one developed PACG after 5 years. In logistic regression, significant risk factors for the development of angle closure were shallower central anterior chamber depth (ACD) (p = 0.002) and narrower mean angle width (p < 0.001). CONCLUSIONS: This study reports the development from baseline open angle to angle closure after a 5-year follow-up. We confirm that the mean angle width and central ACD were independent predictive risk factors for the development of any form of angle closure.

Progression rate to primary angle closure following laser peripheral iridotomy in primary angle-closure suspects: a randomised study.

AIM: To report the progression rate (PR) to primary angle closure (PAC) following laser peripheral iridotomy (LPI) in PAC suspects (PACS). METHODS: Prospective, randomized controlled interventional clinical trial conducted at the Handan Eye Hospital, China. Totally 134 bilateral PACS, defined as non-visibility of the posterior trabecular meshwork for ≥180 degrees on gonioscopy were randomly assigned to undergo LPI in one eye. Gonioscopy and Goldmann applanation tonometry were performed prior to, on day 7 and 12mo post LPI. RESULTS: Eighty of 134 patients (59.7%) could be followed up at one year. The mean intraocular pressure (IOP) in treated eyes was 15.9±2.6 mm Hg at baseline, 15.4±3.0 mm Hg on day 7; 16.5±2.9 mm Hg at one month, and 15.5±2.9 mm Hg at 12mo; the IOP in untreated eyes was similar (P=0.834). One or more quadrants of the angle opened in 93.7% of the LPI treated eyes, but 67.0% (53/79) remained closed in two or more quadrants. The PR to PAC in untreated eyes was 3.75% and one developed acute angle-closure glaucoma (AACG); the PR to PAC in treated eyes was 2.5% and none had developed peripheral anterior synechia (PAS) or AACG. CONCLUSION: LPI can open some of the occludable angle in the majority of eyes with PACS, but 67% continue to have non-visibility of the trabecular meshwork for over 180 degrees.

Association of Hypertriglyceridemia and Incident Glaucoma in a Rural Chinese Population: The Handan Eye Study.

Purpose: The purpose of this paper was to investigate the association between baseline metabolic risk factors and incident glaucoma over a 5-year period in rural Chinese adults. Methods: Population-based prospective cohort study. Participants aged 30 years and older without glaucoma at baseline who underwent comprehensive examinations at baseline and after a 5-year interval in the Handan Eye Study were enrolled. Incident glaucoma was defined as people without glaucoma in either eye at baseline that had developed glaucoma in at least one eye in the 5-year follow-up. Five metabolic syndrome components, mean blood pressure, fasting plasma glucose, total cholesterol, triglycerides (TGs), low density lipoprotein cholesterol, high-density lipoprotein cholesterol, and obesity, determined as body mass index ≥30 kg/m2 at baseline were considered as potential metabolic risk factors for incident glaucoma. Univariate and multivariate logistic regression analyses were carried out to determine baseline metabolic risk factors associated with incident glaucoma. Results: A total of 5184 participants were included in our study. During the 5-year follow-up, incident glaucoma developed in 82 subjects. Age (odds ratio [OR] = 1.060, 95% confidence interval [CI] = 1.034, 1.086, P < 0.001) and TGs level (OR = 1.213, 95% CI = 1.030, 1.429, P = 0.021) were independently and positively associated with incident glaucoma. Conclusions: Our study revealed that increased age and high TGs level, one of the baseline metabolic features, were independent risk factors for incident glaucoma. The data implied that the metabolic features be involved in the pathogenesis of glaucoma. Translational Relevance: This study shed the light on that the TGs level was involved in the pathogenesis of glaucoma.

Optic disc morphology in primary open-angle glaucoma versus primary angle-closure glaucoma in South India.

Purpose: The aim of this study was to investigate the optic disc morphology in primary angle-closure glaucoma (PACG) versus primary open-angle glaucoma (POAG) in South Indians. Methods: A total of 60 patients (60 eyes) with PACG and 52 patients (52 eyes) with POAG were included in a cross-sectional observational study. The glaucoma diagnosis was based on a glaucomatous appearance of the optic disc correlating with visual field defects. The glaucoma was graded as early, moderate, or severe, depending upon perimetric loss. All patients underwent an ophthalmic evaluation, including visual field examination and planimetric analysis of 30° stereoscopic color optic disc photographs. Results: The POAG and PACG groups did not differ significantly in a disc or rim area, rim width, and frequencies of disc hemorrhages or rim notches. However, early POAG group (n = 15) had a significantly deeper cup depth (P = 0.01), larger beta zone (P = 0.01), and a higher frequency of localized retinal nerve fiber layer (RNFL) defects (P = 0.02) than early PACG (n = 20). Conclusion: In the early stage of the disease, POAG compared to PACG may be characterized by deeper disc cupping, a larger beta zone of peripapillary atrophy, and a higher frequency of localized RNFL defects. Such differences in early glaucoma may suggest differences in pathophysiology in POAG and PACG.

Progression of Primary Angle Closure Suspect to Primary Angle Closure and Associated Risk Factors: The Handan Eye Study.

Purpose: To investigate the progression of angle closure from primary angle closure suspect (PACS) and associated risk factors over five years in rural Chinese adults. Methods: In this population-based cohort study, subjects aged ≥30 years old with unilateral or bilateral PACS at baseline of the Handan Eye Study who participated in the follow-up and had undergone baseline and follow-up gonioscopic examinations were included. The progression of angle closure was defined as the presence of primary angle closure (PAC)/primary angle-closure glaucoma (PACG) during the follow-up in subjects with PACS at baseline. Ocular data from the right eye were used for cases with bilateral PACS and unilateral PACS in the right eye at baseline. For those with unilateral PACS in the left eye at baseline, ocular data from the left eye were used. Demographic information, ocular conditions, personal history, and systemic comorbidities were compared between the progression and nonprogression groups. Univariate and multivariate logistic regression was performed to identify the baseline risk factors for progression of angle closure. Results: In total, 526 subjects (111 male, 415 female) with baseline PACS were finally enrolled. The overall progression of PACS to angle closure was 32 cases (31 PAC, 1 PACG). Logistic regression analysis identified narrower mean angle width (P < 0.001) to be associated with the progression. Conclusions: We report the progression from baseline PACS to PAC/PACG after five years. And baseline mean angle width was determined to be independent predictive risk factor for the progression of angle closure.

Superficial macular vessel density in eyes with mild, moderate, and severe primary open-angle glaucoma.

PURPOSE: The aim of this study is to report changes in and associations of macular vessel density (VD) and perfusion density (PD) using optical coherence tomography angiography (OCTA) in mild, moderate, and severe open-angle glaucoma. METHODS: One hundred thirty-three patients with open-angle glaucoma (133 eyes: 47 mild, 33 moderate, and 53 severe glaucoma) and 73 normal subjects (right eyes) were included in this cross-sectional study. All subjects underwent Cirrus OCTA measurements. One-way analysis of variance (ANOVA) was used to compare macular VD and PD between the controls and mild, moderate, and severe glaucoma groups. Multiple linear regression was performed with OCTA parameters as the predicted variable and age, gender, spherical equivalent (SE), intraocular pressure (IOP), mean deviation (MD), signal strength (SS), and mean macular ganglion cell-inner plexiform layer (mGCIPL) thickness as the predictor variables. RESULTS: The total area of VD showed significant differences between the controls vs. mild (p < 0.001) and moderate vs. severe glaucoma (p = 0.003); no significant difference was found between mild and moderate glaucoma (p = 1.000). Macular VD was associated with age (ß = -0.02, p = 0.003), MD (ß = 0.04, p = 0.001), SS (ß = 1.43, p < 0.001), and mGCIPL thickness (ß = 0.04, p = 0.002) but not with gender, SE, and IOP (all p > 0.05). CONCLUSIONS: Macular microcirculation declined significantly in mild and severe glaucoma. No significant difference was found between mild and moderate glaucoma. Decrease macular VD was independently associated with age, severe MD, lower SS, and thinner mGCIPL thickness.

Detection of primary angleclosure suspect with different mechanisms of angle closure using multivariate prediction models.

PURPOSE: We had found that a multivariate prediction model used for the detection of primary angle-closure suspects (PACS) by combining multiple static and dynamic anterior segment optical coherence tomography (ASOCT) parameters had an area under the receiver operating characteristic curve (AUC) of 0.844. We undertook this study to evaluate this method in screening of PACS with different dominant mechanisms of angle closure (AC). METHODS: The right eyes of subjects aged ≥40 years who participated in the 5-year follow-up of the Handan Eye Study and had undergone gonioscopy and ASOCT examinations under light and dark conditions were included. All ASOCT images were analysed by the Zhongshan Angle Assessment Program. The dominant AC mechanism in each eye was determined to be pupillary block (PB), plateau iris configuration (PIC) or thick peripheral iris roll (TPIR). Backward logistic regression (LR) was used for inclusion of variables in the prediction models. LR, Naïve Bayes' classification (NBC) and neural network (NN) were evaluated and compared using the AUC. RESULTS: Data from 796 subjects (413 PACS and 383 normal eyes) were analysed. The AUCs of LR, NBC and NN in the PB group were 0.920, 0.918 and 0.917. The AUCs of LR, NBC and NN in the PIC group were 0.715, 0.708 and 0.707. The AUCs of LR, NBC and NN in TPIR group were 0.867, 0.833 and 0.886. CONCLUSIONS: Prediction models showed the best performance for detection of PACS with PB mechanism for AC and have potential for screening of PACS.

Establishment and Comparison of Algorithms for Detection of Primary Angle Closure Suspect Based on Static and Dynamic Anterior Segment Parameters.

Purpose: To establish and evaluate algorithms for detection of primary angle closure suspects (PACS), the risk factor for primary angle closure disease by combining multiple static and dynamic anterior segment optical coherence tomography (ASOCT) parameters. Methods: Observational, cross-sectional study. The right eyes of subjects aged ≥40 years who participated in the 5-year follow-up of the Handan Eye Study, and underwent gonioscopy and ASOCT examinations under light and dark conditions were included. All ASOCT images were analyzed by Zhongshan Angle Assessment Program. Backward logistic regression (BLR) was used for inclusion of variables in the prediction models. BLR, naïve Bayes' classification (NBC), and neural network (NN) were evaluated and compared using the area under the receiver operating characteristic curve (AUC). Results: Data from 744 subjects (405 eyes with PACS and 339 normal eyes) were analyzed. Angle recess area at 750 µm, anterior chamber volume, lens vault in light and iris cross-sectional area change/pupil diameter change were included in the prediction models. The AUCs of BLR, NBC, and NN were 0.827 (95% confidence interval [CI], 0.798-0.856), 0.826 (95% CI, 0.797-0.854), and 0.844 (95% CI, 0.817-0.871), respectively. No significant statistical differences were found between the three algorithms (P = 0.622). Conclusions: The three algorithms did not meet the requirements for population-based screening of PACS. One possible reason could be the different angle closure mechanisms in enrolled eyes. Translational Relevance: This study provides a promise for basis for future research directed toward the development of an image-based, noncontact method to screen for angle closure.

Comparison of Peripapillary Retinal Nerve Fiber Layer Thickness, Functional Subzones, and Macular Ganglion Cell-Inner Plexiform Layer in Differentiating Patients With Mild, Moderate, and Severe Open-angle Glaucoma.

PRéCIS:: Based on 6 functional subzones of peripapillary retinal nerve fiber layer (pRNFL) thickness, the glaucoma detection ability of zone 2 and zone 4 was high and comparable with that of mean pRNFL in glaucoma groups. PURPOSE: To compare diagnostic performance of pRNFL subzones, mean pRNFL thickness, and macular ganglion cell-inner plexiform layer (mGCIPL) in mild, moderate, and severe open-angle glaucoma. MATERIALS AND METHODS: One hundred eighty-one patients with open-angle glaucoma (318 eyes: 122 mild, 60 moderate, and 136 severe glaucoma) and 70 normal subjects underwent spectral-domain optical coherence tomography measurements. FORUM software was used to determine subzone pRNFL thickness mapping the visual field to the optic disc (6 zones). The thickness and area under the receiver operating curve (AUROC) of each parameter were compared between groups. DeLong's method was used to compare AUROCs between mean pRNFL and mGCIPL and each zone of spectral-domain optical coherence tomography parameters. RESULTS: Mean pRNFL thickness (99.81±10.06 µm) and mGCIPL thickness (83.24±5.91 µm) were higher in controls compared with glaucoma (67.42±13.22 and 63.31±10.85 µm; P<0.001). Mean pRNFL had the best diagnostic performance in mild (0.957) and severe (1.000) glaucoma. Of the 6 zonal parameters, zone 2 (associated with the inferior temporal sector) best discriminated glaucomatous changes between controls and mild and moderate (0.941 and 0.988). Zone 4 (associated with the superior temporal sector) best discriminated glaucomatous changes between controls and severe glaucoma (0.998). AUROCs for zone 2 and zone 4 were not significantly different from mean pRNFL and mGCIPL in all glaucoma groups (all P>0.0038). CONCLUSIONS: Mean pRNFL had the best diagnostic performance in mild and severe glaucoma. Glaucoma detection ability of zone 2 and zone 4 was high and comparable with that of mean pRNFL and mGCIPL in all glaucoma groups.

Determinants of maximum cup depth in non-glaucoma and primary open-angle glaucoma subjects: a population-based study.

BACKGROUND/OBJECTIVES: To study the associations of intraocular pressure (IOP) and retinal vessel diameters: central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) with the maximum cup depth (MCD) in subjects with and without POAG. SUBJECTS/METHODS: Eligible subjects from the Handan Eye Study. All participants underwent physical and comprehensive eye examinations. Univariable and multivariable linear regression models assessed the association between MCD and other parameters. RESULTS: Four thousand one hundred and ninety-four eligible nonglaucoma and 40 POAG subjects were analyzed. On univariable analysis, deeper MCD was significantly associated with younger age, male gender, lower systolic blood pressure (BP), higher IOP, higher estimated cerebro-spinal fluid pressure (ECSFP), lower estimated trans-laminal cribrosa pressure difference (ETLCPD), longer axial length, narrower CRAE, narrower CRVE, larger disc area (DA) and a lower prevalence of hypertension and diabetes. On multivariable analysis, significant independent determinants of MCD were larger DA (P < 0.001; beta: 0.042; B: 0.20; 95% CI: 0.19, 0.22), younger age (P < 0.001; beta: -0.09; B: -0.002; 95% CI: -0.003, -0.001), higher IOP (P < 0.01; beta: 0.040; B: 0.003; 95% CI: 0.001, 0.005), and narrower CRAE (P < 0.001; beta: -0.06; B: -0.001; 95% CI: -0.001, -0.0003). On adding ECSFP and ETLCPD to the model, MCD was associated with IOP but not with estimated CSFP and TLCPD. A 1 µm decrease in CRAE or 1 mmHg increase of IOP was associated with a 1 µm increase of MCD (P < 0.001) and 3 µm increase of MCD respectively (P = 0.009). CONCLUSIONS: Narrow CRVE and higher IOP are associated with an increase in MCD.

Noninvasive evaluation of cerebrospinal fluid pressure in ocular hypertension: a preliminary study.

PURPOSE: To compare the orbital cerebral spinal fluid pressure (CSFP) and trans-lamina cribrosa pressure difference (TLCPD) determined noninvasively in ocular hypertensive (OH) subjects and controls. METHODS: Cross-sectional observational study. Magnetic resonance imaging was used to measure orbital subarachnoid space width (OSASW). The CSFP (mm Hg) was estimated from a published formula as 17.54 × MRI derived OSASW at 15 mm behind the globe + 0.47 × body mass index + 0.13 × mean arterial blood pressure -21.52. Estimated TLCPD was calculated as IOP- CSFP. RESULTS: The orbital subarachnoid space width was significantly wider (p = 0.01) in the OH group than in the control group at all three measurement locations. The MRI derived CSFP value in OH (14.9 ± 2.9 mm Hg) was significantly higher than in the normal group (12.0 ± 2.8 mm Hg; p < 0.01). The estimated TLCPD value in OH (9.0 ± 4.2 mm Hg) was significantly higher than in controls (3.6 ± 3.0 mm Hg; p < 0.01). CONCLUSION: The wider OSASW and higher estimated CSFP in OH subjects suggest a higher orbital CSFP. Despite a higher orbital CSFP that could be protective, the higher TLCPD in OH may play a significant role in the risk of developing glaucoma.

Epithelial changes with corneal punctate epitheliopathy in type 2 diabetes mellitus and their correlation with time to healing.

BACKGROUND: To study basal epithelial cell (BEC), sub-basal nerve plexus (SBN) and Langerhans cell (LC) density in patients with type 2 diabetes mellitus (T2DM) with corneal punctate epitheliopathy (CPE) and to assess their association with time to healing of CPE. METHODS: Retrospective study of in vivo confocal microscopy (IVCM) in 160 eyes from 160 patients with T2DM diagnosed with CPE due to a single cause. Key exclusion criteria included multiple-causes for CPE or treatment with autologous serum. A total of 149 eyes from 149 gender- age- and aetiolgy-matched patients with CPE without T2DM comprised the control group. Electronic records were reviewed for demographic features, history of T2DM and aetiology of CPE. Density of BEC, SBN and LC were compared between the two groups. RESULTS: The healing time in days for CPE with different aetiologies in the T2DM and control groups were as follows: dry eye (21.56 ± 2.41; 7.00 ± 2.19; P = 0.001); meibomian gland dysfunction (26.42 ± 6.04; 9.21 ± 2.55; P = 0.001); cataract extraction (38.00 ± 19.62; 25.83 ± 11.49; P = 0.043); drug induced (53.19 ± 18.83; 41.86 ± 23.87; P = 0.018) and exposure (38.25 ± 14.13; 29.00 ± 13.67; P = 0.026). LC density was 38.70 ± 9.65 cells/mm2 in the T2DM group comparedwith 25.53 ± 3.54 cells/mm2 in the controls (P = 0.001). SBN density was 11.76 ± 1.69 mm/mm2 in the T2DM group compared with 20.92 ± 1.43 mm/mm2 in the controls (P = 0.001). BEC density in the T2DM group was 4982 ± 1178 cells/mm2 compared with 5739 ± 394 cells/mm2 in the control group (P = 0.018). Age and duration of T2DM had no relationship with healing time (multiple linear regression, P = 0.618; P = 0.787). The density of LC in the T2DM group showed a negative correlation with SBN density (r = 0.350; R2 = 0.1225; P = 0.034). The density of SBN in the T2DM group showed a positive correlation with BEC density (r = 0.427; R2 = 0.1823; P = 0.008). The density of BEC in the T2DM group showed a negative correlation with healing time (r = 0.931; R2 = 0.8668; P = 0.001). CONCLUSIONS: Utilising IVCM, we have demonstrated increased LC and decreased SBN in patients with T2DM and CPE. Both may be related to lower BEC density and nuclei enhanced reflection. Furthermore, decreased BEC density may lead to delay in cornea epithelium healing in the T2DM group comparedwith controls. An immune-mediated response may play a role in delayed wound closure in patients with T2DM.

Association of intraocular pressure-related factors and retinal vessel diameter with optic disc rim area in subjects with and without primary open angle glaucoma.

IMPORTANCE: The data may support the notion that the intra-ocular pressure (IOP)-related factors and vascular factors were implicated concurrently in glaucomatous optic nerve damage. BACKGROUND: To study the association of intraocular pressure (IOP)-related factors, IOP, trans-lamina cribrosa pressure difference (TLCPD), cerebrospinal fluid pressure (CSFP) and retinal vessel diameters (RVD), central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE) with neuro-retinal rim area (RA). DESIGN: A population-based, cross-sectional study. PARTICIPANTS: A total of 6830 people aged 30 years and over. METHODS: All participants underwent a comprehensive eye examination, fundus photograph-based measurements of RVD and Heidelberg retinal tomogram (HRT) measurement of optic disc. MAIN OUTCOME MEASURES: RA, CRAE, CRVE, IOP, body mass index (BMI), CSFP and TLCPD. RESULTS: Primary open-angle glaucoma (POAG) was diagnosed using two separate methods: 67 from expert consensus, and 125 from the International Society of Geographical and Epidemiologic Ophthalmology (ISGEO) classification. After excluding of those with high myopia or without gradable HRT images, 4194 non-glaucoma and 40 POAG were analysed for determinants of RA. On multivariable analysis determinants of reduced RA were POAG (P < 0.001), higher IOP (P = 0.03), higher refractive error (P < 0.01), longer axial length (P = 0.01), CRVE (P < 0.001), lower BMI (P = 0.015), older age (P < 0.001) smaller disc area (P < 0.001) and higher TLCPD (P = 0.03). When age and/or BMI were omitted from the model, reduced RA was also associated with lower CSFP (P < 0.001). CONCLUSIONS AND RELEVANCE: Reduced RA is associated with narrow CRVE and higher IOP or lower CSFP. The data supports the concurrent role of IOP-related and vascular factors in glaucomatous optic nerve damage.

Age-related changes in and determinants of macular ganglion cell-inner plexiform layer thickness in normal Chinese adults.

IMPORTANCE: Consideration of age-related changes in macular ganglion cell-inner plexiform layer (mGCIPL) thickness are important for glaucoma progression analysis. BACKGROUND: To report age-related changes in and the determinants of high-definition optical coherence tomography (HD-OCT) measurements of mGCIPL thickness. DESIGN: Cross-sectional study. PARTICIPANTS: 326 healthy adults. METHODS: All subjects underwent Cirrus HD-OCT measurements of mGCIPL. One-way analysis of variance (ANOVA) was used to compare mGCIPL thickness between 7 decades based age groups and macular sectors. Multiple regression analysis determined the association between mGCIPL thickness and age, gender, intraocular pressure (IOP), peripapillary retinal nerve fibre layer thickness (pRNFL) and spherical equivalent. MAIN OUTCOME MEASURES: Change in mGCIPL thickness and determinants of thickness. RESULTS: Mean mGCIPL thickness in 295 subjects was 80.80 ± 6.42 µm. Mean mGCIPL decreased by 0.12 µm (95% CI [confidence interval], 0.09-0.16) with every year of age; 1.61 µm (95% CI, 0.08-2.41) per decade. It showed two steep declines with age, first in the fifth and next in the seventh decade with relative stability between them. mGCIPL thickness was associated with pRNFL thickness (ß = 0.30, P < 0.001) and IOP (ß = -0.19, P = 0.03) but not with gender (ß = -1.09, P = 0.116) or spherical equivalent (ß = -0. 24, P = 0.145). CONCLUSIONS AND RELEVANCE: Mean mGCIPL thickness showed a small age-related linear decrease with two steep drops in the fifth and seventh decades. Thinner mGCIPL was independently associated with age, thinner pRNFL and higher IOP. These factors should be considered if using mGCIPL to detect progression of glaucoma and other optic neuropathies characterized by the loss of retinal ganglion cells.

Pupil Size Associated with the Largest Iris Volume in Normal Chinese Eyes.

BACKGROUND: To determine the range of pupil size that has the largest iris volume in normal eyes. METHODS: 31 healthy adult Chinese volunteers underwent swept-source anterior segment OCT examination in both eyes. Pilocarpine 1% was instilled in a randomly selected eye (eye with induced miosis (ME)) of each participant to obtain iris volume (IV) measurements over a range of pupil sizes. OCT was performed prior to and one hour after pilocarpine in both ME and fellow eye (FE). Iris volume (IV), anterior chamber volume (ACV), anterior chamber depth (ACD), and pupil size (PS) were recorded. A scatter plot was used to depict the association between each pupil size and IV. RESULTS: The pupillary sizes for which IV was recorded in ME and FE ranged from 1.161 mm to 6.665 mm. The mean IV increased with miosis in both ME and FE; in 13 eyes, IV decreased with a decrease in pupillary size. PS between 3.812 and 6.665 mm was associated with an increase in IV, while PS between 3.159 and 5.54 mm was associated with a decrease. The relationship between PS and IV was in the shape of a downward parabola and was modeled using a quadratic equation (y = -1.3121x 2 + 8.8429x + 16.423, R 2 = 0.26886). The largest IV occurred at PS between 3 and 4 mm. CONCLUSIONS: The relationship between PS and IV in this study was in the shape of a downward parabola. The largest IV was recorded at a pupillary size between 3 and 4 mm. This trial is registered with ChiCTR-ROC-17013572.