Surgically induced astigmatism following trabeculectomy.

PURPOSE: Surgically induced astigmatism (SIA) has attracted much interest in recent times because changes in corneal astigmatism can lead to decreased uncorrected visual acuity and patient discomfort. This study aimed to evaluate SIA and to identify factors correlated therewith after trabeculectomy. METHODS: We retrospectively reviewed medical charts of patients who were treated with trabeculectomy at 120° meridian (superotemporal area on right eye and superonasal area on left eye) by the same surgeon. Preoperative keratometric data were compared with data collected from 2 months to 12 months postoperatively. SIA was evaluated using Naeser's polar value analysis. RESULTS: Using Naeser's method, ΔKP(120) was calculated as 0.7 ± 0.7 (0.82@104°), which indicates a with-the-rule change. After surgery, the combined mean polar values changed significantly (Hotelling T2 = 22.47; p < 0.001). Multivariate analysis of variance indicated that postoperative intraocular pressure and location of surgery were independent factors that were significantly associated with SIA (p = 0.002 and 0.03, respectively). CONCLUSIONS: Trabeculectomy at the 120° meridian was not astigmatically neutral. In addition, the SIA after trabeculectomy appears to be greater in eyes with low postoperative intraocular pressure and a superonasal surgical wound rather than a superotemporal wound.

The association between socioeconomic status and visual impairments among primary glaucoma: the results from Nationwide Korean National Health Insurance Cohort from 2004 to 2013.

BACKGROUND: Glaucoma is one of the most leading causes of permanent visual impairments in Korea, and social expenses spent for the glaucoma are increasing. This study is to identify association between socioeconomic status and the visual impairments caused by primary glaucoma in Korea. METHODS: This study is based on a cohort study using stratified representative samples in the National Health Insurance claim data from 2002 to 2013 with 1,025,340 representative subjects. Target subjects were patients who are newly diagnosed with primary glaucoma from 2004 to 2013. We conducted a multiple logistic regression analysis depending on the occurrence of visual impairment and its temporal order compared to the glaucoma diagnosis. RESULTS: Among 1728 patients with primary glaucoma, those with low and middle income shows higher odds ratio (OR) of the visual impairments than those with high income group (low income; OR = 3.42, 95% Confidential Interval (CI):2.06-5.66, middle income; OR = 2.13, 95% CI: 1.28-3.55), in case of the occurrence of the visual impairments preceded the diagnosis of glaucoma. CONCLUSIONS: Glaucoma patients without pre-existing glaucoma history before visual impairment have higher association between socioeconomic status and the occurrence of visual impairments by primary glaucoma. Since glaucoma had not been diagnosed and recognized yet, the differences may have been derived from the disparities of the awareness of the glaucoma. These findings call attention to the correlation between socioeconomic factors and the visual impairments by glaucoma, and raise public health needs over the importance of glaucoma awareness and eye screening for glaucoma, especially for low socioeconomic status.

Vascular and metabolic comorbidities in open-angle glaucoma with low- and high-teen intraocular pressure: a cross-sectional study from South Korea.

PURPOSE: To assess the associations between vascular and metabolic comorbidities and the prevalence of open-angle glaucoma (OAG) with low-teen and high-teen intraocular pressure (IOP) in Korea. METHODS: Cross-sectional data from the Korean National Health and Nutrition Examination Survey from 2008 to 2012 were analysed. Participants diagnosed with OAG with normal IOP were further classified into low-teen IOP (IOP ≤ 15 mmHg) and high-teen IOP (15 mmHg < IOP ≤ 21 mmHg) groups. Using multiple logistic regression analyses, the associations between vascular and metabolic comorbidities and the prevalence of glaucoma were investigated for the low- and high-teen IOP groups. RESULTS: The prevalences of hypertension, hyperlipidemia, ischaemic heart disease, stroke and metabolic syndrome were significantly higher among subjects with low-teen OAG compared with normal subjects, while only the prevalences of hypertension and stroke were higher among subjects with high-teen OAG compared with normal subjects. In multivariate logistic regression models adjusted for confounding factors, low-teen OAG was significantly associated with hypertension (OR, 1.68; 95% CI, 1.30-2.18), hyperlipidemia (OR, 1.49; 95% CI, 1.07-2.08), ischaemic heart disease (OR, 1.83; 95% CI, 1.07-3.11), stroke (OR, 1.91; 95% CI, 1.12-3.25) and metabolic syndrome (OR, 1.46; 95% CI, 1.12-1.90). High-teen OAG was only associated with stroke (OR, 2.58; 95% CI, 1.20-5.53). CONCLUSION: Various vascular and metabolic comorbidities were significantly associated with low-teen OAG, but not with high-teen OAG. These data support the hypothesis that vascular factors play a more significant role in the pathogenesis of OAG with low-teen baseline IOP.

Surgical outcomes of lamellar macular holes with and without lamellar hole-associated epiretinal proliferation.

PURPOSE: To report the clinical findings and surgical outcomes of lamellar macular holes (LMHs) with and without lamellar hole-associated epiretinal proliferation (LHEP). METHODS: A retrospective review was performed of 73 eyes of 73 patients who underwent vitrectomy for LMH. Patients were grouped according to the presence of LHEP on preoperative spectral-domain optical coherence tomography (SD-OCT). Postoperative best-corrected visual acuity (BCVA) and OCT features were compared between LMH patients with and without LHEP. RESULTS: Lamellar hole-associated epiretinal proliferation (LHEP) was found in 15 of 73 eyes with LMHs (20.5%). The mean age was 65.0 years. The mean follow-up duration was 21.5 months. Preoperatively, eyes with LHEP were characterized by a greater hole diameter (p = 0.007), thinner fovea (p = 0.002) and greater incidence of outer retinal disruption (p < 0.001). Best-corrected visual acuity (BCVA) significantly improved after surgery in eyes without LHEP (p < 0.001), but showed no change in eyes with LHEP (p = 0.185). Initial BCVA was not different between the two groups; however, final BCVA was better in eyes without LHEP (logarithm of the minimum angle of resolution (logMAR) BCVA, 0.10 ± 0.10 versus 0.33 ± 0.40, p = 0.003). OCT evaluations of postoperative foveal configurations showed no difference between the two groups (p = 0.171). No case developed a full-thickness macular hole after surgery. CONCLUSION: There was no visual benefit after surgery in LMH patients with LHEP. Different surgical indications for LMHs may be warranted based on the presence of LHEP-associated pathology.

Albuminuria Is Associated with Open-Angle Glaucoma in Nondiabetic Korean Subjects: A Cross-Sectional Study.

OBJECTIVE: Systemic vascular dysfunction has been suggested to contribute to glaucomatous damage. Albuminuria is a surrogate marker of endothelial injury, including vessels. However, their relationship is not well understood. This study aimed to investigate the association between albuminuria and the prevalence of open-angle glaucoma (OAG) in nondiabetic subjects. METHODS: We conducted a cross-sectional study of 4186 nondiabetic participants aged 19 years or older from the 2011-2012 Korea National Health and Nutrition Examination Survey. OAG was defined based on the criteria of the International Society for Geographic and Epidemiologic Ophthalmology. Urinary albumin excretion was assessed by the urinary albumin-to-creatinine ratio (UACR). A multivariate logistic regression analysis was performed to evaluate the relationship between albuminuria and OAG. RESULTS: Among the subjects, 124 had OAG. The weighted prevalences of microalbuminuria (UACR of 30-299 mg/g creatinine [Cr]) and macroalbuminuria (UACR ≥ 300 mg/g Cr) were 3.2 ± 0.3% and 0.4 ± 0.1%, respectively. The percentages of OAG increased in accordance with increasing UACR tertiles. Compared with subjects in the lower UACR tertile, those in the upper tertile showed an increased prevalence of OAG (odds ratio, 1.963; 95% confidence interval 1.072-3.595, P = 0.029) after adjusting for demographic factors, laboratory parameters, kidney function, and intraocular pressure. Furthermore, even after excluding 155 subjects with microalbuminuria and 19 subjects with macroalbuminuria, a positive association persisted between the upper UACR tertile (low-grade albuminuria) and an increased prevalence of OAG (odds ratio, 2.170; 95% confidence interval, 1.174-4.010, P = 0.014). CONCLUSION: Albuminuria, even low-grade, was significantly associated with OAG in nondiabetic subjects. This result implies the role of vascular endothelial dysfunction in the pathogenic mechanism of OAG and suggests that careful monitoring of OAG is required in nondiabetic subjects with albuminuria.

Three Toxic Heavy Metals in Open-Angle Glaucoma with Low-Teen and High-Teen Intraocular Pressure: A Cross-Sectional Study from South Korea.

BACKGROUND: To investigate the association between heavy metal levels and open-angle glaucoma (OAG) with low- and high-teen baseline intraocular pressure (IOP) using a population-based study design. METHODS: This cross-sectional study included 5,198 participants older than 19 years of age who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) from 2008 to 2012 and had blood heavy metal levels available. The OAG with normal baseline IOP (IOP ≤ 21 mmHg) subjects were stratified into low-teen OAG (baseline IOP ≤ 15 mmHg) and high-teen OAG (15 mmHg < baseline IOP ≤ 21 mmHg), and the association between blood lead, mercury, and cadmium levels and glaucoma prevalence was assessed for low- and high-teen OAG. RESULTS: The adjusted geometric mean of blood cadmium levels was significantly higher in subjects with low-teen OAG than that of the non-glaucomatous group (P = 0.028), whereas there were no significant differences in blood lead and mercury levels. After adjusting for potential confounders, the low-teen OAG was positively associated with log-transformed blood cadmium levels (OR, 1.41; 95% confidence interval (CI), 1.03-1.93; P = 0.026). For high-teen OAG, log-transformed blood levels of the three heavy metals were not associated with disease prevalence. The association between log-transformed blood cadmium levels and low-teen OAG was significant only in men (OR, 1.65; 95% CI, 1.10-2.48; P = 0.016), and not in women (OR, 1.10; 95% CI, 0.66-1.85; P = 0.709). CONCLUSIONS: The results of this study suggest that cadmium toxicity could play a role in glaucoma pathogenesis, particularly in men and in OAG with low-teen baseline IOP.

Estimated Trans-Lamina Cribrosa Pressure Differences in Low-Teen and High-Teen Intraocular Pressure Normal Tension Glaucoma: The Korean National Health and Nutrition Examination Survey.

BACKGROUND: To investigate the association between estimated trans-lamina cribrosa pressure difference (TLCPD) and prevalence of normal tension glaucoma (NTG) with low-teen and high-teen intraocular pressure (IOP) using a population-based study design. METHODS: A total of 12,743 adults (≥ 40 years of age) who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) from 2009 to 2012 were included. Using a previously developed formula, cerebrospinal fluid pressure (CSFP) in mmHg was estimated as 0.55 × body mass index (kg/m2) + 0.16 × diastolic blood pressure (mmHg)-0.18 × age (years)-1.91. TLCPD was calculated as IOP-CSFP. The NTG subjects were divided into two groups according to IOP level: low-teen NTG (IOP ≤ 15 mmHg) and high-teen NTG (15 mmHg < IOP ≤ 21 mmHg) groups. The association between TLCPD and the prevalence of NTG was assessed in the low- and high-teen IOP groups. RESULTS: In the normal population (n = 12,069), the weighted mean estimated CSFP was 11.69 ± 0.04 mmHg and the weighted mean TLCPD 2.31 ± 0.06 mmHg. Significantly higher TLCPD (p < 0.001; 6.48 ± 0.27 mmHg) was found in the high-teen NTG compared with the normal group. On the other hand, there was no significant difference in TLCPD between normal and low-teen NTG subjects (p = 0.395; 2.31 ± 0.06 vs. 2.11 ± 0.24 mmHg). Multivariate logistic regression analysis revealed that TLCPD was significantly associated with the prevalence of NTG in the high-teen IOP group (p = 0.006; OR: 1.09; 95% CI: 1.02, 1.15), but not the low-teen IOP group (p = 0.636). Instead, the presence of hypertension was significantly associated with the prevalence of NTG in the low-teen IOP group (p < 0.001; OR: 1.65; 95% CI: 1.26, 2.16). CONCLUSIONS: TLCPD was significantly associated with the prevalence of NTG in high-teen IOP subjects, but not low-teen IOP subjects, in whom hypertension may be more closely associated. This study suggests that the underlying mechanisms may differ between low-teen and high-teen NTG patients.

Reproducibility of peripapillary retinal nerve fiber layer thickness measured by spectral domain optical coherence tomography in pseudophakic eyes.

PURPOSE: To assess the reproducibility of circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurement (measurement agreement) and its color-coded classification (classification agreement) by Cirrus spectral domain optical coherence tomography (OCT) in pseudophakic eyes. METHODS: Two-hundred five participants having glaucoma or glaucoma suspected eyes underwent two repeated Cirrus OCT scans to measure cpRNFL thickness (optic disc cube 200 × 200). After classifying participants into three different groups according to their lens status (clear media, cataract, and pseudophakic), values of intra-class coefficient (ICC), coefficient of variance, and test-retest variability were compared between groups for average retinal nerve fiber layer (RNFL) thicknesses and that corresponding to four quadrant maps. Linear weighted kappa coefficients were calculated as indicators of agreement of color code classification in each group. RESULTS: ICC values were all excellent (generally defined as 0.75 to 1.00) for the average and quadrant RNFL thicknesses in all three groups. ICC values of the clear media group tended to be higher than those in the cataract and pseudophakic groups for all quadrants and average thickness. Especially in the superior and nasal quadrants, the ICC value of the cataract group was significantly lower than that of the clear media and pseudophakic groups. For average RNFL thickness, classification agreement (kappa) in three groups did not show a statistically significant difference. For quadrant maps, classification agreement (kappa) in the clear media group was higher than those in the other two groups. CONCLUSIONS: Agreement of cpRNFL measurement and its color code classification between two repeated Cirrus OCT scans in pseudophakic eyes was as good as that in eyes with clear crystalline lens. More studies are required to ascertain the effect of lens status on the reproducibility of Cirrus OCT according to different stages of glaucoma patients.