High Polygenic Risk is Associated with Earlier Initiation and Escalation of Treatment in Early Primary Open Angle Glaucoma

PURPOSE

To assess whether a glaucoma polygenic risk score (PRS) was associated with treatment commencement or escalation in early primary open angle glaucoma.

DESIGN

Prospective longitudinal observational cohort study.

PARTICIPANTS

Participants from the PROGRESSA study (Progression Risk of Glaucoma: RElevant SNPs with Significant Association) were divided into a cohort of glaucoma suspects who were treatment naive at enrolment, and early manifest and suspect glaucoma cases on treatment at enrolment.

METHODS

A per-allele weighted glaucoma PRS was calculated for 1,107 participants. Multivariable mixed effects Cox proportional regression analysis assessed the association between PRS and time to commencement of intraocular pressure (IOP) lowering therapy in 416 glaucoma suspects who were treatment naive at study enrolment. Secondary analysis evaluated the association between PRS and escalation of IOP lowering therapy amongst 691 suspect and early manifest glaucoma cases who were on IOP lowering therapy at enrolment.

MAIN OUTCOME MEASURES

Commencement or escalation of IOP lowering therapy.

RESULTS

A higher glaucoma PRS was associated with a greater risk of commencing IOP-lowering therapy within 5 years (HR: 1.45/Standard Deviation (SD) 95% Confidence Interval (CI) [1.27, 1.62] P<0.001). This finding persisted after adjustment for relevant demographic and clinical parameters (adjusted HR: 1.23/SD 95%CI [1.07, 1.43] P=0.005). Participants in the upper population-based quintile had a 3.3 times greater risk of commencing therapy by 5 years than the lowest quintile (HR: 3.30 95%CI [1.63, 6,70] P<0.001), and a 5.4 greater risk of commencing IOP lowering therapy by 2 years than the lowest quintile (HR: 5.45 95%CI [2.08, 14.25] P<0.001). A higher glaucoma PRS was associated with a greater risk of treatment escalation amongst cases on treatment at enrolment (HR: 1.19/SD 95%CI [1.09, 1.31] P<0.001). In combined analysis of treatment naive suspects and treated cases, participants in the top population-based quintile were at 2.3 times greater risk of requiring initiation or escalation of IOP lowering therapy than the lowest quintile (HR: 2.33 95%CI [1.75, 3.01] P<0.001).

CONCLUSIONS

This study demonstrates novel associations between glaucoma polygenic risk and risk of commencement or escalation of IOP lowering therapy, building upon previous work highlighting the potential clinical utility of genetic risk stratification in glaucoma.

Predictive factors for treatment outcomes with intravitreal anti-vascular endothelial growth factor injections in diabetic macular edema in clinical practice

BACKGROUND

Intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections are the standard of care for diabetic macular edema (DME), a common complication of diabetes. This study aimed to identify factors influencing DME intravitreal anti-VEGF treatment outcomes in real-world practice.

METHODS

This was a multi-center retrospective observational study using medical chart review of participants receiving anti-VEGF injections for DME (N = 248). Demographic and clinical variables were assessed for association with best corrected visual acuity (BCVA) and central macular thickness (CMT) outcomes using regression models.

RESULTS

There was a significant improvement in BCVA (p < 0.001) and CMT (p < 0.001) after 12 months of treatment, although 21% of participants had decreased BCVA, and 41% had a < 10% CMT reduction at 12 months. Higher baseline BCVA (p = 0.022, OR=-0.024, 95% CI=-0.046,-0.004) and longer duration of diabetic retinopathy (p = 0.048, OR=-0.064, 95% CI=-0.129,-0.001) were negative predictors for BCVA response, whereas Aflibercept treatment (p = 0.017, OR = 1.107, 95% CI = 0.220,2.051) compared with other drugs and a positive "early functional response" (p < 0.001, OR=-1.393, 95% CI=-1.946,-0.857) were positive predictors. A higher baseline CMT (p < 0.001, OR = 0.019, 95% CI = 0.012,0.0261) and an "early anatomical response", (p < 0.001, OR=-1.677, 95% CI=-2.456, -0.943) were predictors for greater reduction in CMT. Overall, the variables could predict only 23% of BCVA and 52% of CMT response.

CONCLUSIONS

The study shows a significant proportion of DME patients do not respond to anti-VEGF therapy and identifies several clinical predictors for treatment outcomes.

TRIAL REGISTRATION

The study was approved through the Human Research Ethics Committee, University of Tasmania (approval number H0012902), and the Southern Adelaide Clinical Human Research Ethics Committee (approval number 86 - 067).

Physical Activity Is Associated With Macular Thickness: A Multi-Cohort Observational Study

Purpose

To assess the association between physical activity and spectral-domain optical coherence tomography (SD-OCT)-measured rates of macular thinning in an adult population with primary open-angle glaucoma.

Methods

The correlation between accelerometer-measured physical activity and rates of macular ganglion cell-inner plexiform layer (GCIPL) thinning was measured in 735 eyes from 388 participants of the Progression Risk of Glaucoma: RElevant SNPs with Significant Association (PROGRESSA) study. The association between accelerometer-measured physical activity and cross-sectional SD-OCT macular thickness was then assessed in 8862 eyes from 6152 participants available for analysis in the UK Biobank who had SD-OCT, ophthalmic, comorbidity, and demographic data.

Results

Greater physical activity was associated with slower rates of macular GCIPL thinning in the PROGRESSA study (beta = 0.07 µm/y/SD; 95% confidence interval [CI], 0.03-0.13; P = 0.003) after adjustment for ophthalmic, demographic and systemic predictors of macular thinning. This association persisted in subanalyses of participants characterized as glaucoma suspects (beta = 0.09 µm/y/SD; 95% CI, 0.03-0.15; P = 0.005). Participants in the upper tertile (greater than 10,524 steps/d) exhibited a 0.22-µm/y slower rate of macular GCIPL thinning than participants in the lower tertile (fewer than 6925 steps/d): -0.40 ± 0.46 µm/y versus -0.62 ± 0.55 µm/y (P = 0.003). Both time spent doing moderate/vigorous activity and mean daily active calories were positively correlated with rate of macular GCIPL thinning (moderate/vigorous activity: beta = 0.06 µm/y/SD; 95% CI, 0.01-0.105; P = 0.018; active calories: beta = 0.06 µm/y/SD; 95% CI, 0.006-0.114; P = 0.032). Analysis among 8862 eyes from the UK Biobank revealed a positive association between physical activity and cross-sectional total macular thickness (beta = 0.8 µm/SD; 95% CI, 0.47-1.14; P < 0.001).

Conclusions

These results highlight the potential neuroprotective benefits of exercise on the human retina.

Association Between Body Mass Index and Primary Open Angle Glaucoma in Three Cohorts

PURPOSE

To evaluate the relationship between body mass index (BMI) and glaucoma progression.

DESIGN

Multicohort observational study.

METHODS

This study combined a retrospective longitudinal analysis of suspect and early manifest primary open angle glaucoma cases from the Progression Risk of Glaucoma: RElevant SNPs with Significant Association (PROGRESSA) study with 2 replication cohorts from the UK Biobank and the Canadian Longitudinal Study of Ageing (CLSA). In the PROGRESSA study, multivariate analysis correlated BMI with longitudinal visual field progression in 471 participants. The BMI was then associated with glaucoma diagnosis and cross-sectional vertical cup-disc ratio (VCDR) measurements in the UK Biobank, and finally prospectively associated with longitudinal change in VCDR in the CLSA study.

RESULTS

In the PROGRESSA study, a lower BMI conferred a faster rate of visual field progression (mean duration of monitoring (5.28 ± 1.80 years (10.6 ± 3.59 visits) (β 0.04 dB/year/SD95% CI [0.005, 0.069]; P = .013). In the UK Biobank, a 1 standard deviation lower BMI was associated with a worse cross-sectional VCDR (β -0.048/SD 95% CI [-0.056, 0.96]; P < .001) and a 10% greater likelihood of glaucoma diagnosis, as per specialist grading of retinal fundus imaging (OR 0.90 95% CI [0.84, 0.98]; P = .011). Similarly, a lower BMI was associated with a greater risk of glaucoma diagnosis as per International Classification of Disease data (OR 0.94/SD; 95% CI [0.91, 0.98]; P = .002). Body mass index was also positively correlated with intraocular pressure (β 0.11/SD; 95% CI [0.06, 0.15]; P < .001). Finally, a lower BMI was then associated with greater VCDR change in the CLSA (β -0.007/SD; 95% CI [-0.01, -0.001]; P = .023).

CONCLUSIONS

Body mass index correlated with longitudinal and cross-sectional glaucomatous outcomes. This supports previous work illustrating a correlation between BMI and glaucoma.

Quality of life in children with glaucoma: a qualitative interview study in Australia

OBJECTIVE

Childhood glaucoma is a chronic vision-threatening condition that may significantly impact an individual's psychosocial well-being. There is a paucity of literature investigating the quality of life (QoL) in children with glaucoma. The aim of this study was to investigate and report on the QoL issues encountered by children with glaucoma.

DESIGN

This is a qualitative interview study. Data were collected through semistructured interviews. NVivo V.12 software (QSR International Pty Ltd, Melbourne, Australia) was used to analyse and code data to identify QoL themes. The prominence of QoL themes was determined by the number of children who raised issues connected to the corresponding theme.

SETTING

Interviews were conducted via telephone or videoconferencing between April 2020 and July 2021.

PARTICIPANTS

Eighteen children with glaucoma, aged 8-17 years, who resided in Australia, were recruited from the Australian and New Zealand Registry of Advanced Glaucoma.

RESULTS

Median child age was 12.1 years (IQR: 9.7-14.5 years) and 33% were female. Seven QoL themes were identified: 'coping', 'inconveniences' and 'emotional well-being' were more prominent themes than 'symptoms', 'ocular health concerns', 'social well-being' and 'autonomy'. Adaptive coping strategies included resilience throughout clinical examinations and establishing positive relationships with ophthalmologists. These minimised inconveniences related to clinic waiting times and pupillary dilatation. External to the clinical setting, children often dissociated from their glaucoma but struggled with glare symptoms and feeling misunderstood by fellow peers. Older children aged 13-17 years commonly disengaged from their glaucoma care and expressed an unwillingness to attend ophthalmic appointments. Older children further raised issues with career options, obtaining a driver's licence and family planning under the theme of autonomy.

CONCLUSIONS

The psychosocial impact of childhood glaucoma extends beyond the clinical environment and was minimised using coping strategies. Older children may require additional social and ophthalmic support as they transition into adulthood.

Genetic Risk of Cardiovascular Disease Is Associated with Macular Ganglion Cell-Inner Plexiform Layer Thinning in an Early Glaucoma Cohort

PURPOSE

To evaluate the association between genetic risk for cardiovascular disease and retinal thinning in early glaucoma.

DESIGN

Prospective, observational genetic association study.

PARTICIPANTS

Multicohort study combining a cohort of patients with suspect and early manifest primary open-angle glaucoma (POAG), a cohort of patients with perimetric POAG, and an external normative control cohort.

METHODS

A cardiovascular disease genetic risk score was calculated for 828 participants from the Progression Risk of Glaucoma: Relevant SNPs [single nucleotide polymorphisms] with Significant Association (PROGRESSA) study. Participants were characterized as showing either predominantly macular ganglion cell-inner plexiform layer (GCIPL), predominantly peripapillary retinal nerve fiber layer (pRNFL) or equivalent macular GCIPL and pRNFL spectral-domain OCT thinning. The cardiovascular disease genetic risk scores for these groups were compared to an internal reference group of stable suspected glaucoma and of an external normative population. Replication was undertaken by comparing the phenotypes of participants from the Australia New Zealand Registry of Advanced Glaucoma (ANZRAG) with the normative control group.

MAIN OUTCOME MEASURES

Spectral-domain OCT and Humphrey Visual Field (HVF) change.

RESULTS

After accounting for age, sex, and intraocular pressure (IOP), participants with predominantly macular GCIPL thinning showed a higher cardiovascular disease genetic risk score than reference participants (odds ratio [OR], 1.76/standard deviation [SD]; 95% confidence interval [CI], 1.18-2.62; P = 0.005) and than normative participants (OR, 1.32/SD; 95% CI, 1.12-1.54; P = 0.002). This finding was replicated by comparing ANZRAG participants with predominantly macular GCIPL change with the normative population (OR, 1.39/SD; 95% CI, 1.05-1.83; P = 0.022). Review of HVF data identified that participants with paracentral visual field defects also demonstrated a higher cardiovascular disease genetic risk score than reference participants (OR, 1.85/SD; 95% CI, 1.16-2.97; P = 0.010). Participants with predominantly macular GCIPL thinning exhibited a higher vertical cup-to-disc ratio genetic risk score (OR, 1.48/SD; 95% CI, 1.24-1.76; P < 0.001), but an IOP genetic risk score (OR, 1.12/SD; 95% CI, 0.95-1.33; P = 0.179) comparable with that of the normative population.

CONCLUSIONS

This study highlighted the relationship between cardiovascular disease and retinal thinning in suspect and manifest glaucoma cases.

The effect of insulin on response to intravitreal anti-VEGF injection in diabetic macular edema in type 2 diabetes mellitus

Objectives

To assess whether insulin therapy impacts the effectiveness of anti-vascular endothelial growth factor (anti-VEGF) injection for the treatment of diabetic macular edema (DME) in type 2 diabetes mellitus.

Methods

This was a retrospective multi-center analysis. The best-corrected visual acuity (BCVA) at 12 months, BCVA change, central macular thickness (CMT), CMT change, and cumulative injection number were compared between the insulin and the oral hypoglycemic agent (OHA) groups.

Results

The mean final BCVA and CMT improved in both the insulin (N = 137; p < 0.001; p < 0.001, respectively) and the OHA group (N = 61; p = 0.199; p < 0.001, respectively). The two treatment groups were comparable for final BCVA (p = 0.263), BCVA change (p = 0.184), final CMT (p = 0.741), CMT change (p = 0.458), and the cumulative injections received (p = 0.594). The results were comparable between the two groups when stratified by baseline vision (p > 0.05) and baseline HbA1c (p > 0.05).

Conclusion

Insulin therapy does not alter treatment outcomes for anti-VEGF therapy in DME.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02325-x.

The caregiver experience in childhood glaucoma: An interview study

PURPOSE

To investigate and report on the quality of life (QoL) issues experienced by caregivers of individuals with childhood glaucoma.

DESIGN

Exploratory qualitative study PARTICIPANTS: Thirty-five caregivers of individuals with childhood glaucoma (defined as disease onset <18 years) recruited from the Australian and New Zealand Registry of Advanced Glaucoma.

METHODS

A qualitative research methodology (interpretive phenomenology) was applied. Data were collected through semi-structured in-depth interviews. NVivo-12 software (QSR International Pty Ltd) was used to inductively analyze, code, and organize data into QoL themes.

MAIN OUTCOME MEASURES

Quality of life themes and their sub-themes.

RESULTS

The mean caregiver age was 50.2 ± 13.6 years and 27/35 (77%) were mothers of an individual with childhood glaucoma. A total of six QoL themes were identified. Coping strategies and emotional well-being were the most prominent themes. Caregivers frequently adopted problem-focused adaptive coping strategies including partner and/or peer support and normalization. A caregivers' psychosocial well-being was often impacted by feelings of guilt and regret regarding their child's delayed diagnosis, fear and anxiety related to medical and social support, and loss of control as their child developed medical autonomy. The effect of family planning from the perspective of the caregiver formed a novel QoL theme and was associated with normalization and parental confidence in management of the condition.

CONCLUSION

Childhood glaucoma poses a substantial threat to a caregivers' psychosocial well-being. Strategies which promote normalization, peer support, psychotherapeutic intervention and genetic counseling may be indicated and indeed critical to the caregiver as they adapt to supporting their child with glaucoma.

Quantification of localised vascular wedge-shaped defects in glaucoma

BACKGROUND

Vascular dysfunction plays a considerable role in glaucoma pathogenesis. Previous glaucoma case studies described localised wedge-shaped vascular defects, similar to retinal nerve fibre layer (RNFL) wedge defects. This study investigates the prevalence and quantification of this vessel loss, in relation to primary open angle glaucoma (POAG) parameters.

METHODS

This study included 608 eyes (351 participants): 192 PROGRESSA study participants (342 eyes) with suspect, preperimetric or early manifest POAG, observed for vascular wedge defect presence (cohort one); an additional 114 individuals (cohort two-208 eyes) with POAG at various stages of progression for wedge characterisation; and 38 controls (56 eyes). Vascular wedge defects were observed using optical coherence tomography angiography (OCTA). Wedge parameters and vessel densities were quantified using ImageJ software. RNFL and ganglion cell layer inner plexiform layer (GCLIPL) from OCT scans, and mean deviation (Humphrey visual field 24-2) were also assessed.

RESULTS

Vascular wedge defects were found in 45/342 eyes (13.2%) in cohort one, in 41/208 eyes (19.7%) in cohort two and were not found in controls. Wedge defects were mostly inferotemporal (80%), and present at all disease stages. They were associated with visual field loss in the opposite hemisphere, thinner RNFL (p < 0.001), thinner GCLIPL (p = 0.003), and focal RNFL loss corresponding with the vascular defect region.

CONCLUSION

Vascular wedge defects are present at all POAG stages even before functional change and are strongly concordant with focal RNFL loss. Further research is needed to explore these defects in particular their temporal relationship with clinical measures of POAG.

Cardiovascular Disease Predicts Structural and Functional Progression in Early Glaucoma

PURPOSE

To investigate the association between cardiovascular disease and baseline structural defects and disease progression in glaucoma.

DESIGN

Prospective, longitudinal study of preperimetric and perimetric glaucoma.

PARTICIPANTS

Two thousand six hundred twenty-eight eyes from 1314 participants recruited to the Progression Risk of Glaucoma: Relevant SNPs with Significant Association (PROGRESSA) study were evaluated for baseline and longitudinal structural thinning using spectral-domain OCT and for visual field progression on Humphrey visual field (HVF) assessment.

METHODS

Patients were classified as either predominantly macula ganglion cell-inner plexiform layer (mGCIPL), predominantly peripapillary retinal nerve fiber layer (pRNFL), or both mGCIPL and pRNFL structural change at enrollment, and then evaluated for longitudinal OCT or HVF progression. Cardiovascular disease and medication characteristics of the participants were compared with a reference group of stable patients.

MAIN OUTCOME MEASURES

OCT and HVF baseline status and longitudinal progression.

RESULTS

After accounting for age and cardiovascular characteristics, patients with predominantly mGCIPL thinning at baseline showed a higher prevalence of hypertension (odds ratio [OR], 2.70; 95% confidence interval [CI], 1.66-4.41; P < 0.001), antihypertensive use (OR, 2.03; 95% CI, 1.20-3.46; P = 0.008), and statin use (OR, 1.98; 95% CI, 1.07-3.66; P = 0.029) than reference patients. Patients with predominantly pRNFL thinning exhibited a comparable prevalence of cardiovascular disease or medication with reference patients. Review of longitudinal OCT and HVF data (mean follow-up, 5.34 ± 1.29 years) showed that hypertension was associated with an increased risk of both OCT (OR, 1.79; 95% CI, 1.17-2.75; P = 0.006) and HVF progression (OR, 1.92; 95% CI, 1.18-3.15; P = 0.013). A 1-standard deviation (approximately 21 mmHg) increase in systolic blood pressure at baseline was associated with a greater risk of OCT progression (OR, 1.27; 95% CI, 1.01-1.63; P = 0.041) and HVF progression (OR, 1.32; 95% CI, 1.01-1.73; P = 0.043). The association between systolic blood pressure and structural progression was comparable to that observed between intraocular pressure and structural progression (OR, 1.30; 95% CI, 1.01-1.67; P = 0.039).

CONCLUSIONS

Cardiovascular disease is an important risk factor for glaucoma progression.

Rare, potentially pathogenic variants in 21 keratoconus candidate genes are not enriched in cases in a large Australian cohort of European descent

Many genes have been suggested as candidate genes for keratoconus based on their function, their proximity to associated polymorphisms or due to the identification of putative causative variants within the gene. However, very few of these genes have been assessed for rare variation in keratoconus more broadly. In contrast, VSX1 and SOD1 have been widely assessed, however, the vast majority of studies have been small and the findings conflicting. In a cohort of Australians of European descent, consisting of 385 keratoconus cases and 396 controls, we screened 21 keratoconus candidate genes: BANP, CAST, COL4A3, COL4A4, COL5A1, FOXO1, FNDC3B, HGF, IL1A, IL1B, ILRN, IMMP2L, MPDZ, NFIB, RAB3GAP1, RAD51, RXRA, SLC4A11, SOD1, TF and VSX1. The candidate genes were sequenced in these individuals by either whole exome sequencing or targeted gene sequencing. Variants were filtered to identify rare (minor allele frequency <1%), potentially pathogenic variants. A total of 164 such variants were identified across the two groups with no variants fulfilling these criteria in cases in IL1RN, BANP, IL1B, RAD51 or SOD1. The frequency of variants was compared between cases and controls using chi-square or Fishers' Exact tests for each gene with at least one rare potentially pathogenic variant identified in the case cohort. The number of rare potentially pathogenic variants per gene ranged from three (RXRA) to 102 (MPDZ), however for all genes, there was no difference in the frequency between the cases and controls. We conclude that rare potentially pathogenic variation in the 21 candidate genes assessed do not play a major role in keratoconus susceptibility and pathogenesis.

Analysis combining correlated glaucoma traits identifies five new risk loci for open-angle glaucoma

Open-angle glaucoma (OAG) is a major cause of blindness worldwide. To identify new risk loci for OAG, we performed a genome-wide association study in 3,071 OAG cases and 6,750 unscreened controls, and meta-analysed the results with GWAS data for intraocular pressure (IOP) and optic disc parameters (the overall meta-analysis sample size varying between 32,000 to 48,000 participants), which are glaucoma-related traits. We identified and independently validated four novel genome-wide significant associations within or near MYOF and CYP26A1, LINC02052 and CRYGS, LMX1B, and LMO7 using single variant tests, one additional locus (C9) using gene-based tests, and two genetic pathways - "response to fluid shear stress" and "abnormal retina morphology" - in pathway-based tests. Interestingly, some of the new risk loci contribute to risk of other genetically-correlated eye diseases including myopia and age-related macular degeneration. To our knowledge, this study is the first integrative study to combine genetic data from OAG and its correlated traits to identify new risk variants and genetic pathways, highlighting the future potential of combining genetic data from genetically-correlated eye traits for the purpose of gene discovery and mapping.

Genetic Association at the 9p21 Glaucoma Locus Contributes to Sex Bias in Normal-Tension Glaucoma

PURPOSE

Many genome-wide association studies have identified common single nucleotide polymorphisms (SNPs) at the 9p21 glaucoma locus (CDKN2B/CDKN2B-AS1) to be significantly associated with primary open-angle glaucoma (POAG), with association being stronger in normal tension glaucoma (NTG) and advanced glaucoma. We aimed to determine whether any observed differences in genetic association at the 9p21 locus are influenced by sex.

METHODS

Sex was assessed as a risk factor for POAG for 2241 glaucoma participants from the Australian and New Zealand Registry of Advanced Glaucoma, the Glaucoma Inheritance Study in Tasmania, and the Flinders Medical Centre. A total of 3176 controls were drawn from the Blue Mountains Eye Study and South Australia: 1523 advanced POAG and 718 nonadvanced POAG cases were genotyped along with 3176 controls. We selected 13 SNPs at the 9p21 locus, and association results were subanalyszd by sex for high-tension glaucoma (HTG) and NTG. Odds ratios (ORs) between sexes were compared.

RESULTS

A sex bias was present within advanced NTG cases (57.1% female versus 42.9% male, P = 0.0026). In all POAG cases, the strongest associated SNP at 9p21 was rs1063192 (OR, 1.43; P = 4 × 10-18). This association was stronger in females (OR, 1.5; P = 5 × 10-13) than in males (OR, 1.35; P = 7 × 10-7), with a statistically significant difference in female to male OR comparison (P = 1.0 × 10-2). An NTG to HTG subanalysis yielded statistically significant results only in females (OR, 1.63; P = 1.5 × 10-4) but not in males (OR, 1.15; P = 2.8 × 10-1), with a statistically significant difference in female to male OR comparison (P = 1.4 × 10-4).

CONCLUSIONS

This study demonstrated that female sex is a risk factor for developing advanced NTG. The stronger genetic signals at the 9p21 locus among females may contribute at least in part to the observed sex bias for NTG.

A novel de novo Myocilin variant in a patient with sporadic juvenile open angle glaucoma

Background

Glaucoma is a leading cause of irreversible blindness. Pathogenic variants in the Myocilin gene (MYOC) cause juvenile open angle glaucoma (JOAG) in 8–36 % of cases, and display an autosomal dominant inheritance with high penetrance. Molecular diagnosis is important for early identification as therapies are effective in minimizing vision loss and MYOC variants can be associated to severe glaucoma. MYOC variants are usually inherited, however a fifth of carriers do not report a family history. The occurrence of de novo MYOC variants is currently unknown.

Case presentation

In this study we investigated a 14 year old male Caucasian patient diagnosed with JOAG, and no family history of glaucoma. A novel probably deleterious MYOC:p.(Pro254Leu) variant was identified in the index case. This variant was not present in the parents or the siblings.

Conclusion

This is the second report of a de novo MYOC variant in a sporadic case of JOAG and it is currently unknown if this mechanism occurs more frequently. This finding emphasizes the importance of screening individuals with JOAG for MYOC mutations irrespective of a negative family history.

Occurrence of CYP1B1 Mutations in Juvenile Open-Angle Glaucoma With Advanced Visual Field Loss

IMPORTANCE

Juvenile open-angle glaucoma (JOAG) is a severe neurodegenerative eye disorder in which most of the genetic contribution remains unexplained.

OBJECTIVE

To assess the prevalence of pathogenic CYP1B1 sequence variants in an Australian cohort of patients with JOAG and severe visual field loss.

DESIGN, SETTING, AND PARTICIPANTS

For this cohort study, we recruited 160 patients with JOAG classified as advanced (n = 118) and nonadvanced (n = 42) through the Australian and New Zealand Registry of Advanced Glaucoma from January 1, 2007, through April 1, 2014. Eighty individuals with no evidence of glaucoma served as a control group. We defined JOAG as diagnosis before age 40 years and advanced JOAG as visual field loss in 2 of the 4 central fixation squares on a reliable visual field test result. We performed direct sequencing of the entire coding region of CYP1B1. Data analysis was performed in October 2014.

MAIN OUTCOMES AND MEASURES

Identification and characterization of CYP1B1 sequence variants.

RESULTS

We identified 7 different pathogenic variants among 8 of 118 patients with advanced JOAG (6.8%) but none among the patients with nonadvanced JOAG. Three patients were homozygous or compound heterozygous for CYP1B1 pathogenic variants, which provided a likely basis for their disease. Five patients were heterozygous. The allele frequency among the patients with advanced JOAG (11 in 236 [4.7%]) was higher than among our controls (1 in 160 [0.6%]; P = .02; odds ratio, 7.8 [95% CI, 0.02-1.0]) or among the control population from the Exome Aggregation Consortium database (2946 of 122 960 [2.4%]; P = .02; odds ratio, 2.0 [95% CI, 0.3-0.9]). Individuals with CYP1B1 pathogenic variants, whether heterozygous or homozygous, had worse mean (SD) deviation on visual fields (-24.5 [5.1] [95% CI, -31.8 to -17.2] vs -15.6 [10.0] [95% CI, -17.1 to -13.6] dB; F1,126 = 5.90; P = .02; partial ηp2 = 0.05) and were younger at diagnosis (mean [SD] age, 23.1 [8.4] [95% CI, 17.2-29.1] vs 31.5 [8.0] [95% CI, 30.1-33.0] years; F1,122 = 7.18; P = .008; ηp2 = 0.06) than patients without CYP1B1 pathogenic variants.

CONCLUSIONS AND RELEVANCE

Patients with advanced JOAG based on visual field loss had enrichment of CYP1B1 pathogenic variants and a more severe phenotype compared with unaffected controls and patients with nonadvanced JOAG.

CYP1B1 copy number variation is not a major contributor to primary congenital glaucoma

PURPOSE

To evaluate the prevalence and the diagnostic utility of testing for CYP1B1 copy number variation (CNV) in primary congenital glaucoma (PCG) cases unexplained by CYP1B1 point mutations in The Australian and New Zealand Registry of Advanced Glaucoma.

METHODS

In total, 50 PCG cases either heterozygous for disease-causing variants or with no CYP1B1 sequence variants were included in the study. CYP1B1 CNV was analyzed by Multiplex Ligation-dependent Probe Amplification (MLPA).

RESULTS

No deletions or duplications were found in any of the cases.

CONCLUSION

This is the first study to report on CYP1B1 CNV in PCG cases. Our findings show that this mechanism is not a major contributor to the phenotype and is of limited diagnostic utility.

Copy number variations of TBK1 in Australian patients with primary open-angle glaucoma

PURPOSE

To investigate the presence of TBK1 copy number variations in a large, well-characterized Australian cohort of patients with glaucoma comprising both normal-tension glaucoma and high-tension glaucoma cases.

DESIGN

A retrospective cohort study.

METHODS

DNA samples from patients with normal-tension glaucoma and high-tension glaucoma and unaffected controls were screened for TBK1 copy number variations using real-time quantitative polymerase chain reaction. Samples with additional copies of the TBK1 gene were further tested using custom comparative genomic hybridization arrays.

RESULTS

Four out of 334 normal-tension glaucoma cases (1.2%) were found to carry TBK1 copy number variations using quantitative polymerase chain reaction. One extra dose of the TBK1 gene (duplication) was detected in 3 normal-tension glaucoma patients, while 2 extra doses of the gene (triplication) were detected in a fourth normal-tension glaucoma patient. The results were further confirmed by custom comparative genomic hybridization arrays. Further, the TBK1 copy number variation segregated with normal-tension glaucoma in the family members of the probands, showing an autosomal dominant pattern of inheritance. No TBK1 copy number variations were detected in 1045 Australian patients with high-tension glaucoma or in 254 unaffected controls.

CONCLUSION

We report the presence of TBK1 copy number variations in our Australian normal-tension glaucoma cohort, including the first example of more than 1 extra copy of this gene in glaucoma patients (gene triplication). These results confirm TBK1 to be an important cause of normal-tension glaucoma, but do not suggest common involvement in high-tension glaucoma.

Kayak

The anthropometry and equipment set-up for sprint (31 male; 11 female) and slalom (12 male; 12 female) kayak paddlers who competed at the 2000 Olympic Games in Sydney were measured in the 15 day period before competition. This paper provides normative data for equipment set-up in these sports, as well as information about differences in rigging and paddle dimensions between sprint and slalom kayak paddlers. These differences were consistent for both male and female athletes, with sprint paddlers seated higher and using longer paddles with longer, though narrower, blades (p < 0.0001). Among male sprint paddlers, only minor differences in equipment set-up were found between competitors ranked in the top 10 places compared to the rest of the field. Considering all male paddlers initially, then sprint paddlers alone, significant (p < 0.01) regression equations were developed for the prediction of foot bar distance (r2 = 0.482 and 0.589 respectively) and hand grip distance (r2 = 0.400 and 0.541 respectively). The process of fine tuning equipment set-up often requires hours of practice with subjective feedback from the athlete. The normative data presented in this paper should assist coaches with this process as their athletes evolve toward their individual optimum set-up.

Morphological characteristics of Olympic sprint canoe and kayak paddlers

Canoe and kayak paddlers (n = 50 M & 20 F) who competed in the sprint events at the 2000 Olympic Games in Sydney were measured on a battery of 38 anthropometry dimensions prior to competition. The ensuing analysis aimed to identify common physical characteristics that provide these elite paddlers with a competitive advantage. This study demonstrated that participants in Olympic sprint paddling events can be considered homogeneous in shape and physical size; male and female paddlers have SAMs of 1.1 and 1.0 respectively. Compared to other athlete groups, the variance in stature and body mass of paddlers is generally low. Whilst sprint paddlers are not athletes with extreme proportionality profiles, they do possess unique characteristics not commonly observed in the general population. These include a lean body composition (Phantom z-scores for skinfolds range from -1.5 to -2.5 for most sites) with proportionally large upper body girths (z-scores > +1.0 for arm and chest girths), and narrow hips (for males). The morphology of elite paddlers appears to have altered during the past 25 years toward a more compact, robust physique. This trend is especially noticeable for the female competitors.

Interaction of temperamental resistance to control and restrictive parenting in the development of externalizing behavior

Child temperament and parental control were studied as interacting predictors of behavior outcomes in 2 longitudinal samples. In Sample 1, data were ratings of resistant temperament and observed restrictive control in infancy-toddlerhood and ratings of externalizing behavior at ages 7 to 10 years; in Sample 2, data were retrospective ratings of temperament in infancy-toddlerhood, observed restrictive control at age 5 years, and ratings of externalizing behavior at ages 7 to 11 years. Resistance more strongly related to externalizing in low-restriction groups than in high-restriction groups. This was true in both samples and for both teacher- and mother-rated outcomes. Several Temperament x Environment interaction effects have been reported previously, but this is one of very few replicated effects.