A Polygenic Risk Score Predicts Intraocular Pressure Readings Outside Office Hours and Early Morning Spikes as Measured by Home Tonometry

PURPOSE

Intraocular pressure (IOP) elevations may occur in early morning or outside office hours and can be missed during routine in-clinic IOP measurements. Such fluctuations or peaks likely contribute to glaucoma progression. We sought to investigate the relationship between an IOP polygenic risk score (PRS) and short-term IOP profile.

DESIGN

Cross-sectional study.

PARTICIPANTS

Four hundred seventy-three eyes from 239 participants with suspected or established primary open-angle glaucoma sampled from 4 outpatient clinics in Australia between August 2016 and December 2019.

METHODS

Participants underwent Icare HOME (Icare Oy, Vanda, Finland) tonometer measurements to record IOP 4 times daily for 5 days. Unreliable measurements were excluded. A minimum of 2 days with at least 3 reliable measurements were required. We used a validated IOP PRS derived from 146 IOP-associated variants in a linear regression model adjusted for central corneal thickness and age.

MAIN OUTCOME MEASURES

Highest recorded early morning IOP and mean IOP within and outside office hours. Early morning IOP spikes were defined by a higher early morning IOP than the maximum in-office hours IOP.

RESULTS

Reliable measurements were obtained from 334 eyes of 176 participants (mean age, 64 ± 9 years). Eyes in the highest IOP PRS quintile showed an early morning IOP increase of 4.3 mmHg (95% confidence interval [CI], 1.4-7.3; P = 0.005) and mean increase in IOP outside office hours of 2.7 mmHg (95% CI, 0.61-4.7; P = 0.013) than the lowest quintile, which were significant independently after accounting for a recent in-clinic IOP measured by Goldmann applanation tonometry. Eyes in the highest PRS quintile were 5.4-fold more likely to show early morning IOP spikes than the lowest quintile (odds ratio 95% CI, 1.3-23.6; P = 0.023).

CONCLUSIONS

A validated IOP PRS was associated with higher early morning IOP and mean IOP outside office hours. These findings support a role for genetic risk prediction of susceptibility to elevated IOP that may not be apparent during in-clinic hours, requiring more detailed clinical phenotyping using home tonometry, the results of which may guide additional interventions to improve IOP control.

Low-Grade Versus Medium-Grade Nuclear Sclerotic Cataract Density Produces Identical Surgical and Visual Outcomes: A Prospective Single-Surgeon Study

Purpose To determine whether the incidence of major complications and postoperative corrected distance visual acuity are comparable for surgery on low-grade versus medium-grade nuclear sclerotic cataracts. Design This was a prospective, consecutive, single-surgeon, no-exclusion study of 1025 cataract cases with one-month follow-up. Methods Patients were divided into two cohorts according to the nuclear sclerosis grade at presentation, as classified using the Lens Opacities Classification System (LOCS) III. Cohort A, representing low-grade nuclear sclerotic cataracts (grades 1-2), consisted of 739 eyes, while Cohort B, representing medium-grade nuclear sclerotic cataracts (grades 3-6), consisted of 286 eyes. Results There was no significant difference in major intraoperative or postoperative complications (p>0.999) between Cohorts A and B. The mean logMar preoperative corrected distance visual acuity (CDVA) in Cohort A was 0.245 as compared with 0.346 in Cohort B (p<0.001). There was no significant difference between cohorts for postoperative CDVA at one day (-0.168 versus -0.118; p=0.070), one week (-0.180 versus -0.147; p=0.405), or one month (-0.185 versus -0.161; p=0.569). Conclusions There was no significant difference in the incidence of operative complications or postoperative CDVA between the cohorts. These findings suggest that, in experienced hands, surgery for medium-grade nuclear sclerotic cataracts is equally effective and safe as compared with that for low-grade nuclear sclerotic cataracts.

Curettage for Copious Conjunctival Concretions

Management of multiple exposed eyelid concretions can be performed successfully in an anesthetized eyelid with gentle curettage of the concretions using a small chalazion curette. It has the advantage of managing the patient supine, providing better eyelid stability and visibility, and minimizing risk in the event of patient movement. This curettage technique was used to facilitate the successful resolution of a patient’s ocular surface irritative symptomatology due to multiple exposed concretions.

Corneal Stiffness Parameters Are Predictive of Structural and Functional Progression in Glaucoma Suspect Eyes

PURPOSE

To investigate corneal stiffness parameters (SPs) as predictors of future progression risk in glaucoma suspect eyes.

DESIGN

Prospective, longitudinal study.

PARTICIPANTS

Three hundred seventy-one eyes from 228 primary open-angle glaucoma suspects, based on optic disc appearance, with normal baseline Humphrey Visual Field (HVF; Carl Zeiss Meditec) results.

METHODS

Baseline corneal SPs were measured using Corvis ST (Oculus Optikgeräte GmbH). Participants were followed up every 6 months with clinical examination, HVF testing, and OCT. The baseline SP at first applanation (SP-A1) and highest concavity predicted the prospective outcome measures.

MAIN OUTCOME MEASURES

Structural progression was measured by the OCT rate of thinning of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL). Functional progression was assessed by permutation analysis of pointwise linear regression criteria on HVF testing.

RESULTS

Stiffness parameters correlated positively with central corneal thickness (CCT), which was adjusted for in all analyses. A higher SP-A1, suggestive of a stiffer cornea, was associated with a faster rate of RNFL thinning (P < 0.001), synergistic with thinner CCT (P = 0.004) over a mean follow-up of 4.2 years. Eyes with higher SP-A1 and thinner CCT (thin and stiff corneas) showed accelerated RNFL thinning by 0.72 μm/year relative to eyes with lower SP-A1 and thicker CCT (95% confidence interval [CI], 0.17-1.28; P = 0.011) and were at 2.9-fold higher likelihood of fast RNFL progression of more than 1 μm/year (95% CI, 1.4-6.1; P = 0.006). Consistent results also were observed with GCIPL thinning. Furthermore, a higher SP-A1 was associated with a greater risk of visual field progression (P = 0.002), synergistic with thinner CCT (P = 0.010). Eyes with higher SP-A1 and thinner CCT were at 3.7-fold greater risk of visual field progression relative to eyes with thicker CCT and lower SP-A1 (95% CI, 1.3-10.5; P = 0.014).

CONCLUSIONS

Glaucoma suspect eyes with higher corneal SPs and lower CCT, suggestive of thin and stiff corneas, are at greater risk of progression. Corneal SPs seem to act synergistically with CCT as risk factors for glaucoma progression.

Assessment of Obstructive Sleep Apnoea and Sleeping Laterality by Evaluating Upper Eyelid Distraction: A Prospective, Comparative Polysomnographic Study

Objective Our goal was to evaluate upper eyelid laxity by digital distraction, with the aim to determine sleeping laterality and the likelihood of obstructive sleep apnoea (OSA), and correlate these findings with polysomnography (PSG). Design We conducted a prospective, single-centre multidisciplinary study in a large sleep and respiratory department and an ophthalmology department within a tertiary referral university teaching hospital. Methods Patients with known OSA were evaluated using techniques based on the Lateralising Eyelid Sleep Compression (LESC) study. Upper eyelid laxity was assessed by two masked investigators, and the eyelid side with greater laxity was regarded as indicative of that patient's sleeping laterality: 'investigator-detected sleeping laterality' (ID SL). Each patient was then asked about the laterality of his or her accustomed sleeping position: 'patient-reported sleeping laterality' (PR SL). PSG was conducted according to the standard protocol of the Department of Sleep and Respiratory Medicine (DSRM). 'Polysomnography-detected sleeping laterality' (PSG SL) permitted the extraction of sleep positional data by two masked sleep scientists. Results The reliability of the LESC technique for diagnosing ID SL was demonstrated to be statistically significant (p<0.01). Upper eyelid laxity was significantly greater on the patients' sleeping side (t=6.340, df=45, p<0.01, two-tailed). There was a significant correlation between PR SL and ID SL (r_s =0.33). However, PSG SL did not correlate with sleeping laterality compared with both ID SL and PR SL. Conclusion This study confirms that there is a statistically significant correlation of sleeping laterality with increasing upper eyelid laxity in OSA. Counterintuitively, PSG SL correlated poorly with ID SL and PR SL. This may likely be explained by the technical limitations implicit in current PSG techniques.

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.

Assessment of Saccadic Velocity at the Bedside

Saccades are a key component for the assessment and diagnosis of Neuro-ophthalmological disorders. Traditionally, clinicians have been taught to use large amplitude saccades (LAS) to assess saccadic velocity (SV), when small amplitude saccades (SAS) may be more effective. This study aimed to evaluate the advantages of SAS over LAS by presenting a video to 108 clinicians where both methods were used to assess a patient with a unilateral partial 6th nerve palsy. SAS was the preferred method in identifying the 6th nerve palsy by 43/55 (78.2%) of Neurologists, and 36/53 (67.9%) of Ophthalmologists. These findings indicate that SAS may be a more effective method than LAS for determining SV.

Objective Quantification of Spontaneous Retinal Venous Pulsations Using a Novel Tablet-Based Ophthalmoscope

Purpose

Dynamic assessment of retinal vascular characteristics can aid in identifying glaucoma-specific biomarkers. More specifically, a loss of spontaneous retinal venous pulsations (SVPs) has been reported in glaucoma, but a lack of readily available tools has limited the ability to explore the full potential of SVP analysis in glaucoma assessment. Advancements in smart technology have paved the way for the development of portable, noninvasive, and inexpensive imaging modalities. By combining off-the-shelf optical elements and smart devices, the current study aims to determine whether SVPs can be detected and quantified using a novel tablet-based ophthalmoscope in glaucoma and glaucoma suspects.

Methods

Thirty patients, including 21 with confirmed glaucoma (9 men; average age 75 ± 8 years) and 9 glaucoma suspects (5 men; average age 64 ± 9 years), were studied. All patients had intraocular pressure measurements, Humphrey visual field assessment, optical coherence tomography, and a 10-second videoscopy of the retinal circulation. The retinal vasculature recordings (46° field of view at 30 frames per second) were analyzed to extract SVP amplitudes.

Results

SVPs were detected and quantified in 100% of patients with glaucoma and those with suspected glaucoma using the novel device. The average SVP amplitudes in glaucoma and glaucoma suspects were 42.6% ± 10.7% and 34% ± 6.7%, respectively.

Conclusions

Our results suggest that a novel tablet-based ophthalmoscope can aid in documenting and objectively quantifying SVPs in all patients.

Translational Relevance

Outcomes of this study provide an innovative, portable, noninvasive, and inexpensive solution for objective assessment of SVPs, which may have clinical relevance in glaucoma screening.

An Intraocular Pressure Polygenic Risk Score Stratifies Multiple Primary Open-Angle Glaucoma Parameters Including Treatment Intensity

PURPOSE

To examine the combined effects of common genetic variants associated with intraocular pressure (IOP) on primary open-angle glaucoma (POAG) phenotype using a polygenic risk score (PRS) stratification.

DESIGN

Cross-sectional study.

PARTICIPANTS

For the primary analysis, we examined the glaucoma phenotype of 2154 POAG patients enrolled in the Australian and New Zealand Registry of Advanced Glaucoma, including patients recruited from the United Kingdom. For replication, we examined an independent cohort of 624 early POAG patients.

METHODS

Using IOP genome-wide association study summary statistics, we developed a PRS derived solely from IOP-associated variants and stratified POAG patients into 3 risk tiers. The lowest and highest quintiles of the score were set as the low- and high-risk groups, respectively, and the other quintiles were set as the intermediate risk group.

MAIN OUTCOME MEASURES

Clinical glaucoma phenotype including maximum recorded IOP, age at diagnosis, number of family members affected by glaucoma, cup-to-disc ratio, visual field mean deviation, and treatment intensity.

RESULTS

A dose-response relationship was found between the IOP PRS and the maximum recorded IOP, with the high genetic risk group having a higher maximum IOP by 1.7 mmHg (standard deviation [SD], 0.62 mmHg) than the low genetic risk group (P = 0.006). Compared with the low genetic risk group, the high genetic risk group had a younger age of diagnosis by 3.7 years (SD, 1.0 years; P < 0.001), more family members affected by 0.46 members (SD, 0.11 members; P < 0.001), and higher rates of incisional surgery (odds ratio, 1.5; 95% confidence interval, 1.1-2.0; P = 0.007). No statistically significant difference was found in mean deviation. We further replicated the maximum IOP, number of family members affected by glaucoma, and treatment intensity (number of medications) results in the early POAG cohort (P ≤ 0.01).

CONCLUSIONS

The IOP PRS was correlated positively with maximum IOP, disease severity, need for surgery, and number of affected family members. Genes acting via IOP-mediated pathways, when considered in aggregate, have clinically important and reproducible implications for glaucoma patients and their close family members.

Impact of referral refinement on management of glaucoma suspects in Australia

BACKGROUND

In ageing populations, the prevalence of chronic diseases such as glaucoma is projected to increase, placing additional demands on limited health-care resources. In the UK, the demand for secondary care in hospital eye clinics was inflated by high rates of false positive glaucoma referrals. Collaborative care models incorporating referral refinement, whereby glaucoma suspect referrals are triaged by suitably trained optometrists through further testing, can potentially reduce false positive referrals. This study examined the impact of a referral refinement model on the accuracy of glaucoma referrals in Australia.

METHODS

Optometrist-initiated glaucoma suspect referrals to the Glaucoma Management Clinic (Sydney, Australia) were prospectively recruited. Glaucoma suspect referrals arising from two pathways were eligible for inclusion, either directly from a community optometrist (standard care) or following comprehensive assessment at the Centre for Eye Health (referral refinement). Main outcome measures were the positive predictive value and false positive rate of referrals. The impact of referral letter content on management outcomes was also investigated.

RESULTS

Of 464 referrals received between March 2015 and June 2018, 252 were for treatment of naïve glaucoma suspects and eligible for inclusion. Following ophthalmological assessment, 45.6 per cent (n = 115/252) were prescribed treatment for open angle glaucoma or ocular hypertension. Positive predictive value of community optometry referrals was 33.8 per cent (n = 25/74) and 50.6 per cent (n = 90/178) following referral refinement. The first visit discharge (false positive) rate was 26 per cent (n = 19/74) for community referrals compared to four per cent (n = 8/178) with referral refinement. Positive predictive value increased with the number of abnormal clinical examination findings associated with referral (χ² test, p < 0.0001). The number of abnormal findings reported in referrals was significantly higher with referral refinement compared to without (n = 1.9 versus 1.5, t-test, p < 0.0001).

CONCLUSION

Referral refinement can improve the diagnostic accuracy of optometry-initiated referrals for glaucoma suspects in Australia, thereby decreasing unnecessary referrals to hospital and other secondary clinics.

Clinical Evaluation of Swedish Interactive Thresholding Algorithm-Faster Compared With Swedish Interactive Thresholding Algorithm-Standard in Normal Subjects, Glaucoma Suspects, and Patients With Glaucoma

PURPOSE

To compare the visual fields results obtained using the Swedish interactive thresholding algorithm-Standard (SS) and the Swedish interactive thresholding algorithm-Faster (SFR) in normal subjects, glaucoma suspects, and patients with glaucoma and to quantify potential time-saving benefits of the SFR algorithm.

DESIGN

Prospective, cross-sectional study.

METHODS

One randomly selected eye from 364 patients (77 normal subjects, 178 glaucoma suspects, and 109 patients with glaucoma) seen in a single institution underwent testing using both SS and SFR on the Humphrey Field Analyzer. Cumulative test time using each algorithm was compared after accounting for different rates of test reliability. Pointwise and cluster analysis was performed to determine whether there were systematic differences between algorithms.

RESULTS

Using SFR had a greater rate of unreliable results (29.3%) compared with SS (7.7%, P < .0001). This was mainly because of high false positive rates and seeding point errors. However, modeled test times showed that using SFR could obtain a greater number of reliable results within a shorter period of time. SFR resulted in higher sensitivity values (on average 0.5 dB for patients with glaucoma) that was greater under conditions of field loss (<19 dB). Cluster analysis showed no systematic patterns of sensitivity differences between algorithms.

CONCLUSIONS

After accounting for different rates of test reliability, SFR can result in significant time savings compared with SS. Clinicians should be cognizant of false positive rates and seeding point errors as common sources of error for SFR. Results between algorithms are not directly interchangeable, especially if there is a visual field deficit <19 dB.

Factors Affecting Adherence to Topical Glaucoma Therapy: A Quantitative and Qualitative Pilot Study Analysis in Sydney, Australia

PURPOSE

To assess which factors in the lives and disease of patients with glaucoma affect their adherence to topical glaucoma therapy and the quantitative significance of this effect. To assess qualitatively the most influential barriers to adherence from the perspective of the patient.

DESIGN

Multicenter, prospective, cross-sectional pilot study.

PARTICIPANTS

A total of 145 patients, attending outpatient metropolitan glaucoma clinics in Sydney, Australia, who were prescribed topical glaucoma medications.

METHODS

A structured interview-based questionnaire was conducted with 145 individuals using glaucoma eye drops that had been prescribed at least 2 weeks previously. The questionnaire involved 2 novel questions on adherence, 29 questions on factors identified or postulated in the literature as affecting adherence for quantitative analysis, and 1 open-response question on patient-identified causes of nonadherence for qualitative analysis. This questionnaire represents the broadest coverage of factors hypothesized to affect adherence in a single study in the glaucoma medication adherence literature to date.

MAIN OUTCOME MEASURES

Adherence rate, risk factors for poor adherence, and patient-identified barriers to adherence.

RESULTS

In response to the question "How many days have you missed a drop in the last 2 weeks," 69.7% of patients reported total adherence. Four factors were significantly related to an increased likelihood of reporting having missed drops in the last 2 weeks. These were difficulty applying drops (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.02-5.44; P < 0.05), a past or current diagnosis of depression (OR, 3.61; 95% CI, 1.53-8.52; P < 0.01), patient self-rating of own memory ≤ 7 of 10 (OR, 3.15; 95% CI, 1.36-7.30; P < 0.01), and self-reported motivation score ≤ 6 of 10 (OR, 10.94; 95% CI, 3.00-39.81; P < 0.01). Patient understanding of glaucoma, ethnicity, and socioeconomic status were among the 25 factors found not to have a statistically significant correlation with adherence.

CONCLUSIONS

There is a significant proportion of patients taking their topical glaucoma medications less often than prescribed. Adherence to topical glaucoma therapies is negatively correlated to several factors: difficulty applying drops, a past or current diagnosis of depression, poor self-rating of own memory, and poor self-rating of own motivation. These may prove useful in designing interventions to improve adherence in these patients.

Prevalence and type of artefact with spectral domain optical coherence tomography macular ganglion cell imaging in glaucoma surveillance

Purpose

The ganglion cell analysis (GCA) of the CIRRUS^TM HD-OCT (Carl Zeiss, Meditec; Dublin, CA) provides measurement of the macular ganglion cell-inner plexiform layer (GCIPL) thickness. This study determined the frequency of scan artefacts and errors in GCIPL imaging in individuals undergoing HD-OCT surveillance for glaucoma.

Method

A total of 1439 eyes from 721 subjects enrolled in a prospective study assessing predictors of glaucoma progression underwent macular GCIPL imaging with the CIRRUS HD-OCT at recruitment. The prevalence of acquisition errors, segmentation errors, and co-morbid macular pathology was determined.

Results

A total of 87 (6.0%) of the 1439 scans had either acquisition errors, segmentation artefacts, or other macular pathology. The most common co-morbid macular pathology was epiretinal membrane in 2.2% of eyes.

Conclusion

The macular GCIPL scan was artefact free in 94% of eyes. However, epiretinal membrane and high myopia can cause scan artefact and should be considered when interpreting the results.