Severe myopia as a risk factor for progressive visual field loss in primary open-angle glaucoma

Longitudinal changes in optical coherence tomography angiography characteristics in normal-tension glaucoma with or without high myopia

PURPOSE

To evaluate the structural, microvascular, and functional progression of normal tension glaucoma (NTG) with or without high myopia by examining longitudinal changes in optical coherence tomography angiography (OCTA) and visual field (VF) parameters.

METHODS

We evaluated 61 NTG eyes and classified 25 of the eyes with axial lengths (ALs) of ≥26 mm as highly myopic. We assessed the rate of change in OCTA parameters, namely radial peripapillary capillary (RPC) vessel density (VD), parafovea VD, deep parafovea VD, retinal nerve fibre layer (RNFL) thickness, and ganglion cell complex thickness. We evaluated the correlation of the rate of change in OCTA parameters with VF loss and AL.

RESULTS

Among the 61 NTG eyes, rates of loss of RPC VD, parafovea VD, deep parafovea VD, and RNFL thickness were significantly different from zero despite the nonsignificant rate of change in VF mean deviation (MD). Changes in these OCTA parameters did not differ significantly in highly myopic NTG eyes. The rate of change in VF MD was significantly correlated with the rate of change in parafovea VD in highly myopic and non-highly myopic NTG eyes. In highly myopic NTG eyes, AL was negatively correlated with the rates of loss of RNFL thickness, VF MD, and VF PSD.

CONCLUSION

NTG eyes with a relatively stable VF exhibited loss of VD and RNFL thickness. VF progression in NTG was correlated with decreasing parafovea VD, indicating a structure-function correlation. Greater AL may indicate faster VF loss and RNFL thinning in highly myopic NTG eyes.

Prevalence and Associations of Nonglaucomatous Optic Nerve Atrophy in High Myopia: The Ural Eye and Medical Study

PURPOSE

To assess the prevalence of nonglaucomatous optic nerve atrophy (NGOA) in highly myopic individuals.

DESIGN

Population-based study.

PARTICIPANTS

The Ural Eye and Medical Study included 5899 (80.5%) of 7328 eligible individuals (80.5%).

METHODS

Nonglaucomatous optic nerve atrophy, graded into 5 arbitrary stages, was characterized by decreased visibility of the retinal nerve fiber layer (RNFL) on photographs, neuroretinal rim pallor, abnormally thin retinal arteriole diameter, and abnormally thin peripapillary RNFL as measured by OCT.

MAIN OUTCOME MEASURES

Nonglaucomatous optic nerve atrophy prevalence and degree.

RESULTS

Of 5709 participants (96.9%) with axial length measurements, 130 individuals (2.3%) were highly myopic, of whom 116 individuals (89.2%; age, 57.8 ± 11.1 years; axial length, 27.0 ± 1.2 mm) had available fundus photographs and OCT images and were included into the study. Nonglaucomatous optic nerve atrophy prevalence was 34/116 individuals (29.3%; 95% confidence interval [CI], 21.0-38.0), and mean NGOA degree in eyes with NGOA was 1.7 ± 1.0 arbitrary units. Higher NGOA degree correlated (multivariable analysis; regression coefficient, r2 = 0.59) with longer axial length (β, 0.22; P = 0.007), wider temporal parapapillary γ zone width (β, 0.50; P < 0.001), higher prevalence of diabetes (β, 0.20; P = 0.005), and higher systolic blood pressure (β, 0.15; P = 0.03). Higher NGOA prevalence was associated with longer axial length (odds ratio [OR], 7.45; 95% CI, 2.15-25.7), wider temporal parapapillary γ zone (OR, 6.98; 95% CI, 2.61-18.7), and higher systolic blood pressure (OR, 1.05; 95% CI, 1.01-1.10).

CONCLUSIONS

In this ethnically mixed population from Russia with an age of 40 years or more, high axial myopia showed a relatively high prevalence of NGOA, increasing with longer axial length and wider temporal parapapillary γ zone. For each 1 mm of axial elongation and γ zone widening, the odds for NGOA increased 7.45-fold and 6.98-fold, respectively. The axial elongation-associated and γ zone-related increase in the distance between the retinal ganglion cells and the optic disc may lead to a lengthening and stretching of the retinal ganglion cell axons and may be of importance pathogenetically. In highly myopic eyes, NGOA may be a reason for visual field and central visual acuity loss, unexplainable by myopic macular pathologic features.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Myopia: Histology, clinical features, and potential implications for the etiology of axial elongation

Myopic axial elongation is associated with various non-pathological changes. These include a decrease in photoreceptor cell and retinal pigment epithelium (RPE) cell density and retinal layer thickness, mainly in the retro-equatorial to equatorial regions; choroidal and scleral thinning pronounced at the posterior pole and least marked at the ora serrata; and a shift in Bruch's membrane opening (BMO) occurring in moderately myopic eyes and typically in the temporal/inferior direction. The BMO shift leads to an overhang of Bruch's membrane (BM) into the nasal intrapapillary compartment and BM absence in the temporal region (i.e., parapapillary gamma zone), optic disc ovalization due to shortening of the ophthalmoscopically visible horizontal disc diameter, fovea-optic disc distance elongation, reduction in angle kappa, and straightening/stretching of the papillomacular retinal blood vessels and retinal nerve fibers. Highly myopic eyes additionally show an enlargement of all layers of the optic nerve canal, elongation and thinning of the lamina cribrosa, peripapillary scleral flange (i.e., parapapillary delta zone) and peripapillary choroidal border tissue, and development of circular parapapillary beta, gamma, and delta zone. Pathological features of high myopia include development of macular linear RPE defects (lacquer cracks), which widen to round RPE defects (patchy atrophies) with central BM defects, macular neovascularization, myopic macular retinoschisis, and glaucomatous/glaucoma-like and non-glaucomatous optic neuropathy. BM thickness is unrelated to axial length. Including the change in eye shape from a sphere in emmetropia to a prolate (rotational) ellipsoid in myopia, the features may be explained by a primary BM enlargement in the retro-equatorial/equatorial region leading to axial elongation.

Relationship between Inter-Eye Asymmetries in Corneal Hysteresis and Visual Field Severity in Patients with Primary Open-Angle Glaucoma

This study investigated the influence of asymmetric corneal hysteresis (CH) on asymmetric visual field impairment between right and left eyes in patients with primary open-angle glaucoma (POAG) without a history of intraocular surgery. CH, corneal resistance factor (CRF), and corneal compensated intraocular pressure (IOPcc) were measured using the Ocular Response Analyzer. Differences between the eyes (right eye-left eye: DIF_RL) and CH-based and in target parameters (higher CH eye-lower CH eye: DIF_CH) were calculated in the same patient. In 242 phakic eyes of 121 patients, older age (p < 0.001), lower CH (p = 0.001), and lower CRF (p = 0.007) were significantly associated with worse standard automated perimetry (SAP) 24-2 mean deviation (MD). The DIFs_RL in axial length (p = 0.003), IOPcc (p = 0.028), and CH (p = 0.001) were significantly associated with the DIF_RL in SAP24-2 MD, but not in central corneal thickness (CCT), Goldmann applanation tonometry (GAT) measurement, and CRF. When dividing the patients into two groups based on the median of the CH DIFs_CH (0.46), the DIFs_CH in CRF (p < 0.001), IOPcc (p < 0.001), CCT (p = 0.004), SAP24-2 MD (p < 0.001), and SAP10-2 MD (p = 0.010) were significantly different between the groups. Large inter-eye asymmetry in CH is an important explanatory factor for disease worsening in patients with POAG.

Atropine Ophthalmic Solution to Reduce Myopia Progression in Pediatric Subjects: The Randomized, Double-Blind Multicenter Phase II APPLE Study

PURPOSE

The purpose of this study was to assess the dose-response effects of low-dose atropine on myopia progression and safety in pediatric subjects with mild-to-moderate myopia.

METHODS

This phase II, randomized, double-masked, placebo-controlled study compared the efficacy and safety of atropine 0.0025%, 0.005%, and 0.01% with placebo in 99 children, aged 6-11 years, with mild-to-moderate myopia. Subjects received 1 drop in each eye at bedtime. The primary efficacy endpoint was change in spherical equivalent (SE), while secondary endpoints included changes in axial length (AL) and near logMAR (logarithm of the minimum angle of resolution) visual acuity and adverse effects.

RESULTS

The mean±SD changes in SE from baseline to 12 months in the placebo and atropine 0.0025%, 0.005%, and 0.01% groups were -0.55±0.471, -0.55±0.337, -0.33±0.473, and -0.39±0.519 D, respectively. The least squares mean differences (atropine-placebo) in the atropine 0.0025%, 0.005%, and 0.01% groups were 0.11 D ( P =0.246), 0.23 D ( P =0.009), and 0.25 D ( P =0.006), respectively. Compared with placebo, the mean change in AL was significantly greater for atropine 0.005% (-0.09 mm, P =0.012) and 0.01% (-0.10 mm, P =0.003). There were no significant changes in near visual acuity in any of the treatment groups. The most common ocular adverse events were pruritus and blurred vision, each occurring in 4 (5.5%) atropine-treated children. Changes in mean pupil size and amplitude of accommodation were minimal.

CONCLUSIONS

Atropine doses of 0.005% and 0.01% effectively reduced myopia progression in children but no effect was noted with 0.0025%. All doses of atropine were safe and well tolerated.

Effect of myopia on the progression of normal tension glaucoma

PURPOSE

Identify risk factors of progression in treated normal-tension glaucoma (NTG) in highly myopic and non-highly myopic eyes.

METHODS

This retrospective, observational case series study included 42 highly myopic glaucoma (HMG, <-6D) eyes and 39 non-highly myopic glaucoma (NHG,≧-6D) eyes. Glaucoma progression was determined by serial visual field data. Univariate and multivariate logistic regression method were used to detect associations between potential risk factors and glaucoma progression.

RESULTS

Among 81 eyes from 81 normal-tension glaucoma patients (mean follow-up, 3.10 years), 20 of 42 eye (45.24%) in the HMG and 14 of 39 eyes (35.90%) in the NHG showed progression. The HMG group had larger optic disc tilt ratio (p = 0.007) and thinner inferior macular thickness (P = 0.03) than the NHG group. Changes in the linear regression values for MD for each group were as follows: -0.652 dB/year for the HMG and -0.717 dB/year for the NHG (P = 0.298). Basal pattern standard deviation (PSD) (OR: 1.55, p = 0.016) and post treatment IOP (OR = 1.54, p = 0.043) were risk factors for visual field progression in normal tension glaucoma patients. In subgroup analysis of HMG patients, PSD (OR: 2.77, p = 0.017) was a risk factor for visual field progression.

CONCLUSION

Reduction IOP was postulated to be contributing in the prevention of visual field progression, especially in highly myopic NTG patients with large basal pattern standard deviation.

Progress in clinical characteristics of high myopia with primary open-angle glaucoma

High myopia (HM) is a significant risk factor for the occurrence and progression of primary open-angle glaucoma (POAG). Identification with POAG in the HM population is an emergent challenge. Patients with HM have a significantly higher probability of complicating POAG than those without HM. When HM is associated with POAG, the changes to the fundus caused by both of them are confused with each other, making the diagnosis of early glaucoma difficult. This article reviews available researches on HM with POAG, summarizing the characteristics of the fundus structure such as epidemiology, intraocular pressure, optic disc, ganglion cell layer, retinal nerve fiber layer, vascular density, and visual field.

IMI-Nonpathological Human Ocular Tissue Changes With Axial Myopia

Purpose

To describe nonpathological myopia-related characteristics of the human eye.

Methods

Based on histomorphometric and clinical studies, qualitative and quantitative findings associated with myopic axial elongation are presented.

Results

In axial myopia, the eye changes from a spherical shape to a prolate ellipsoid, photoreceptor, and retinal pigment epithelium cell density and total retinal thickness decrease, most marked in the retroequatorial region, followed by the equator. The choroid and sclera are thin, most markedly at the posterior pole and least markedly at the ora serrata. The sclera undergoes alterations in fibroblast activity, changes in extracellular matrix content, and remodeling. Bruch's membrane (BM) thickness is unrelated to axial length, although the BM volume increases. In moderate myopia, the BM opening shifts, usually toward the fovea, leading to the BM overhanging into the nasal intrapapillary compartment. Subsequently, the BM is absent in the temporal region (such as parapapillary gamma zone), the optic disc takes on a vertically oval shape, the fovea-optic disc distance elongates without macular BM elongation, the angle kappa reduces, and the papillomacular retinal vessels and nerve fibers straighten and stretch. In high myopia, the BM opening and the optic disc enlarge, the lamina cribrosa, the peripapillary scleral flange (such as parapapillary delta zone) and the peripapillary choroidal border tissue lengthen and thin, and a circular gamma and delta zone develop.

Conclusions

A thorough characterization of ocular changes in nonpathological myopia are of importance to better understand the mechanisms of myopic axial elongation, pathological structural changes, and psychophysical sequelae of myopia on visual function.

Effects of Myopia and Glaucoma on the Neural Canal and Lamina Cribrosa Using Optical Coherence Tomography

PRCIS

Glaucoma was associated with axial bowing and rotation of Bruchs membrane opening (BMO) and anterior laminar insertion (ALI), skewed neural canal, and deeper anterior lamina cribrosa surface (ALCS). Longer axial length was associated with wider, longer, and more skewed neural canal and flatter ALCS.

PURPOSE

Investigate the effects of myopia and glaucoma in the prelaminar neural canal and anterior lamina cribrosa using 1060-nm swept-source optical coherence tomography.

PATIENTS

19 control (38 eyes) and 38 glaucomatous subjects (63 eyes).

MATERIALS AND METHODS

Participants were imaged with swept-source optical coherence tomography, and the images were analyzed for the BMO and ALI dimensions, prelaminar neural canal dimensions, and ALCS depth.

RESULTS

Glaucomatous eyes had more bowed and nasally rotated BMO and ALI, more horizontally skewed prelaminar neural canal, and deeper ALCS than the control eyes. Increased axial length was associated with a wider, longer, and more horizontally skewed neural canal and a decrease in the ALCS depth and curvature.

CONCLUSION

Our findings suggest that glaucomatous posterior bowing or cupping of lamina cribrosa can be significantly confounded by the myopic expansion of the neural canal. This may be related to higher glaucoma risk associated with myopia from decreased compliance and increased susceptibility to IOP-related damage of LC being pulled taut.

In vitro and in vivo evaluation of brimonidine loaded silica nanoparticles-laden silicone contact lenses to manage glaucoma

Glaucoma is treated by frequent instillation of 0.2% w/v brimonidine tartrate eye drop solution, which showed poor ocular bioavailability of 1-3%. Medicated contact lenses can be used to improve the ocular drug bioavailability. However, drug loading in the contact lens matrix showed high burst release and changes the optophysical properties of the contact lens material. In this paper, a novel brimonidine loaded silica nanoparticles-laden silicone contact lenses (Bri-Si) were designed to achieve controlled drug delivery without altering the optophysical properties of the contact lens. Silica nanoparticles were prepared by polymerizing octadecyltrimethoxysilane (OTMS) molecules at the oil/water interface of microemulsion. Traditional soaking method (Bri-SM), direct brimonidine-loading method (Bri-DL) and microemulsion-laden contact lens (Bri-ME) were developed for comparison. The Bri-Si lens showed improved swelling, transmittance, oxygen permeability and lysozyme adherence compared to Bri-SM, Bri-DL and Bri-ME lenses. The Bri-DL lens showed high brimonidine leaching during extraction and sterilization steps, with low cumulative drug release. While, Bri-Si lens show controlled brimonidine release for 144 h. In a rabbit tear fluid model, the Bri-Si lens showed high brimonidine concentration for 96 h compared to Bri-ME lens and eye drop therapy. Based on histopathological studies of cornea, the Bri-Si lens was found to be safe for human applications. The data demonstrated the novel application of silica nanoparticles to control brimonidine release from the contact lens without altering the optophysical properties of the contact lens.

Peripapillary Vascular Reactivity in Primary Open-Angle Glaucoma With High Myopia by Using Optical Coherence Tomography Angiography

Purpose

To evaluate peripapillary vascular reactivity in primary open-angle glaucoma (POAG) with and without high myopia (HM) by using optical coherence tomography angiography (OCTA).

Methods

This prospective study enrolled 48 eyes with POAG, including 16 and 32 eyes with and without HM, respectively. The retinal peripapillary vessel density (VD) was repeatedly assessed using OCTA at baseline and after a hyperoxia test (breathing 80% oxygen). The VD changes between different oxygenation conditions were calculated to reflect the vasoreactivity. Linear regression was performed to determine the relationship between myopia and retinal vascular reactivity in patients with POAG. Systemic hemodynamic characteristics were also evaluated under both conditions.

Results

The VD was significantly reduced after hyperoxia in the whole image (baseline and hyperoxia: 41.4 ± 4.5 and 38.8 ± 4.4, respectively, P < 0.001) and in the peripapillary regions (44.3 ± 5.7 and 41.1 ± 5.4, respectively, P < 0.001) in POAG eyes without HM. However, in eyes with HM, the whole-image VD in hyperoxia was not significantly different from the baseline (baseline and hyperoxia: 40.5 ± 6.2 and 40.2 ± 6.2, respectively, P = 0.481). The VD changes in eyes with HM were significantly smaller than those in eyes without HM in both the whole image (0.3 ± 1.8 and 2.6 ± 2.0, respectively, P < 0.001) and peripapillary regions (1.1 ± 2.0 and 3.2 ± 2.3, respectively, P = 0.003). Linear regression results showed a significant correlation between retinal vascular reactivity and spherical equivalent (SE) (β = 0.28, P < 0.001, R² = 0.31) and axial length (AL) (β = −0.72, P < 0.001, R² = 0.33).

Conclusion

Retinal vasoreactivity of peripapillary capillaries in POAG eyes with HM was significantly impaired in comparison with that in POAG eyes without HM. A lower peripapillary vascular response was significantly associated with worse SE and elongated AL.

High myopia as risk factor for the 10-year incidence of open-angle glaucoma in the Beijing Eye Study

PURPOSE

To assess the 10-year incidence of open-angle glaucoma (OAG) and its associations in an adult Chinese population.

METHODS

Longitudinal observational population-based study. Out of 4439 participants aged 40+ years participating in the Beijing Eye Study in 2001, 2695 individuals (60.7%) were re-examined in 2011, while 397 participants had died (8.5%).

RESULTS

Incident OAG was found in 75 participants among 2494 individuals free of glaucoma at baseline. The 10-year OAG incidence (mean: 3.0%; 95% CI 2.5 to 3.5) increased from 1.8% (95% CI 1.3 to 2.4) in individuals aged 40-49 years, to 5.9% (95% CI 3.1 to 9.6) in participants aged 70+ years. OAG incidence was highest in the high myopia group (13.3%±6.3%, OR: 7.3; 95% CI 3.3 to 16.3), followed by the moderately myopic group (8.1%±4.3%, OR: 4.2; 95% CI 2.0 to 8.8) and the low myopic group (6.2%±2.8%, OR: 3.2; 95% CI 1.7 to 5.8), as compared with the emmetropic/hyperopic group (2.1%±0.8%). In multivariable analysis, higher OAG incidence was associated with older age (OR: 1.06; 95% CI 1.03 to 1.09), longer axial length (OR: 1.72; 95% CI 1.45 to 2.05), higher intraocular pressure (IOP) in 2001 (OR: 1.18; 95% CI 1.08 to 1.29), higher vertical cup/disc ratio (VCDR) (OR: 60.8; 95% CI 6.7 to 556) and thinner central corneal thickness (CCT) (OR: 0.98; 95% CI 0.97 to 0.99).

CONCLUSIONS

In a 10-year follow-up, high myopia was a major risk factor for the development of OAG with a 7.3-fold risk increase as compared with emmetropic eyes. Higher age, IOP, VCDR and thinner CCT were additionally related with an increased OAG incidence. The findings may be of importance to clinical protocols and screening strategies.

Association of progressive optic disc tilt with development of retinal nerve fibre layer defect in children with large cup-to-disc ratio

BACKGROUND/AIMS

Whereas myopic optic disc deformation has been posited as a risk factor for glaucomatous damage, longitudinal studies evaluating their association have been sparse. We investigated whether the optic nerve head (ONH)'s morphological alteration during myopia progression play any role in development of retinal nerve fibre layer defect (RNFLD) in children with a large vertical cup-to-disc ratio (vCDR).

METHODS

Sixty-five normotensive eyes of 65 children aged under 8 years with (1) vCDR ≥0.5 but no additional signs of glaucoma and (2) who could be tracked at young adulthood (18-28 years) were included. Children's spherical equivalent (SE), intraocular pressure, vCDR and optic disc tilt ratio were recorded. Rare events logistic regression analysis was employed to identify factors associated with RNFLD-development risk.

RESULTS

The study group's mean age was 5.4±1.3 years, its average vCDR was 0.62±0.07, and the average SE was -0.3±1.4 dioptres ((D), range -3.15 to 2.75D) at the baseline. After an average follow-up of 16.1±3.0 years, the mean vCDR was 0.64±0.09, and the mean SE, -3.2±2.2D (range -7.25 to 0.00 D). Among the 65 eyes, 12 (18.5%) developed RNFLD. A greater SE change (OR=1.737, p=0.016) and a greater increase in tilt ratio (OR=2.364, p=0.002) were both significantly associated with higher RNFLD-development risk.

CONCLUSION

In this cohort of Korean children with large vCDR, progressive optic disc tilt in the course of myopia progression was associated with higher RNFLD-development risk. This finding suggests that morphological alterations in the ONH during axial elongation might represent an underlying susceptibility to glaucomatous damage in large-vCDR children.

The Association between Myopia and Primary Open-Angle Glaucoma: A Systematic Review and Meta-Analysis

BACKGROUND

Previous studies identified myopia as a risk factor for primary open-angle glaucoma (POAG). However, recent studies have shown different results, the definitive relationship between myopia and POAG remains controversial.

OBJECTIVES

To investigate the relationship between myopia and POAG.

METHODS

Published articles were searched from PubMed, Embase, and Scopus databases between 1970 and 2020. A pooled analysis of the ORs was performed using a random-effects model.

RESULTS

Data on the association between myopia and POAG, were obtained from 16 cross sectional studies, and the pooled OR was 2.26 (95% confidence interval [CI], 1.77 - 2.89, P < 0.001) in random effects model (I2 = 86%; P < 0.01). For the relationship of myopia and POAG progression, data from seven longitudinal cohort studies were included and the pooled OR was 0.85 (95% CI, 0.73 - 0.99, P = 0.042) in the random-effects model (I2 = 88%; P < 0.01).

CONCLUSION

Our findings demonstrated that myopia may be a risk factor associated with POAG and a possible protective factor for POAG progression. It may due to myopia with the presence of a lamina cribrosa defect slow down the visual field loss also POAG progression, further research for underlying mechanisms is still needed.

Association of Optic Disc Tilt and Torsion with Open-Angle Glaucoma Progression Risk: Meta-Analysis and Meta-Regression Analysis

PURPOSE

To evaluate the association of optic disc deformation with open-angle glaucoma (OAG) progression risk.

DESIGN

Meta-analysis and meta-regression analysis.

METHODS

Reports on the association of optic disc tilt and/or torsion with OAG progression published to June 2020 were identified in the PubMed, EMBASE, and Cochrane databases. Tilt ratio was measured as the longest-to-shortest diameter ratio of the optic disc. The angle (in degrees) between the vertical meridian and the disc's long axis was defined as the torsional angle. We used random-effects models to combine the pooled effects. Random-effects meta-regression was used to quantify the study characteristics' potential moderating influences. The protocol was registered in the PROSPERO International Database (CRD42020201151).

RESULTS

Eleven longitudinal studies (1100 participants) were included. For 10 of them evaluated for tilt ratio and glaucoma progression, the pooled hazard ratio (HR) was 0.988 (95% confidence interval [CI] 0.921-1.059; I² = 59%) per 0.1-unit increase. In the meta-regression-based subgroup analysis, risk tended to decrease as the patients' mean age increased (P = .08). For 7 of the studies (605 patients) reporting data on torsion and glaucoma progression, the pooled HR was 0.936 (95% CI 0.860-1.018; I² = 32%) per 10-degree increase. The meta-regression analyses showed that the glaucoma progression assessment methods had a modulating influence (P = .01). In studies assessing just functional glaucomatous progression, the pooled HR was 0.890 (95% CI 0.831-0.952; I² = 0%).

CONCLUSION

Evidence for the effects of optic nerve deformation on glaucoma progression is still lacking. Future research using stratified analysis according to age and tailored diagnostic criteria will allow for more rigorous analyses for this topic.

Changes in Intraocular Pressure and Factors that Influence such Changes after FS-LASIK and SMILE

Purpose: We compared the intraocular pressure (IOP) changes and the relationships thereof with corneal biomechanics after small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK).Methods: A total of 234 eyes of 117 patients who underwent FS-LASIK surgery and 244 eyes of 122 patients who underwent SMILE surgery were included in this retrospective study. Data were collected preoperatively, and at 1, 3, and 6 months postoperatively, including IOP measured via non-contract tonometry, central corneal thickness (CCT), and mean keratometry (Km), flat keratometry (Kf), and steep keratometry (Ks) data obtained using a dual Scheimpflug analyzer. Between-group differences were compared. Simple linear regression analysis was used to determine the relationship between changes in the IOP and the various parameters.Results: The IOP changes were 5.41 ± 2.28 mmHg in the FS-LASIK group and 4.77 ± 2.38 mmHg in the SMILE group, thus significantly different (p = 0.004). The IOP did not change significantly from 1 to 6 months after FS-LASIK but increased significantly from 12.07 ± 1.77 mmHg at 3 months postoperatively to 12.77 ± 1.89 mmHg at 6 months postoperatively after SMILE (p = 0.002). All of the preoperative spherical equivalent and IOP, and changes in the Km, Kf, Ks, and CCT, were significantly associated with the IOP changes in both groups. The preoperative IOP evidenced the strongest relationship with the IOP changes in both groups (R2 = 0.414 in the FS-LASIK group, R2 = 0.292 in the SMILE group).Conclusions: The IOP fell significantly after FS-LASIK and SMILE surgery, significantly more so after FS-LASIK than SMILE. The preoperative IOP exhibited the greatest influence on the IOP decreases after both FS-LASIK and SMILE.

The Relationship Between Optic Disc and Retinal Artery Position and Glaucomatous Visual Field Progression

Purpose

To investigate whether retinal structural parameters, including positions of the optic disc and major retinal arteries, affect glaucomatous progression of the visual field (VF).

Methods

In this cohort study, 116 eyes of 73 patients with primary open angle glaucoma (POAG) were included. VFs were measured using the Humphrey Field Analyzer 24-2 program and the VF was divided into seven sectors according to the corresponding optic disc angle. Average total deviation (TD) was calculated in each sector. Positions of major retinal arteries in the superotemporal and inferotemporal areas were decided by identifying the points where the retinal artery intersected the 3.4-mm-diameter circle around the optic disc. The relationship between sectorial TD VF progression rate and eight variables (age, mean and standard deviation of intraocular pressure during the observation period, baseline sectorial TD value, papillomacular bundle tilt angle, and axial length, along with superior/inferior arterial angle) was investigated.

Results

The main outcome measures were the association between retinal structural parameters and glaucomatous progression of VF. The superior retinal artery angular position was positively associated with sectorial TD progression rates in two central sectors in the inferior hemifield, which suggests faster VF progression where superior retinal artery angles are narrow. Papillomacular bundle tilt was not associated with TD progression rate in any sector.

Conclusions

Progression of the inferior VF was associated with the superior retinal artery angular position in this study of POAG.

Longitudinal Changes in Macular Optical Coherence Tomography Angiography Metrics in Primary Open-Angle Glaucoma With High Myopia: A Prospective Study

Purpose

To characterize longitudinal changes in macular microvasculature as quantified from optical coherence tomography angiography (OCTA) metrics in primary open-angle glaucoma (POAG) eyes with and without high myopia.

Methods

In total, 63 and 61 POAG eyes with and without high myopia, respectively, underwent swept-source OCTA imaging in at least four follow-up visits at an ophthalmic center, with a scanning protocol of 3- × 3-mm centered at the fovea. The foveal avascular zone (FAZ) area, FAZ circularity, and vessel density (VD) in both the superficial (SCP) and deep capillary plexuses (DCP) were measured. The rate of change in macular OCTA metrics over time was estimated using linear mixed-effects models in both groups of POAG eyes.

Results

The mean follow-up time and number of visits were 27.72 ± 8.57 months and 8.5 (8 to 13) times, and 30.95 ± 10.19 months and 10 (8‒13) times in POAG eyes with and without high myopia, respectively. VD in the DCP reduced significantly more quickly in POAG eyes with high myopia than in those without high myopia (−5.14%/year vs. −3.71%/year, P = 0.008). Moreover, lower baseline VD in the DCP was significantly associated with faster VD reduction in POAG with high myopia eyes (P < 0.001). Conversely, the VD reduction rate in the SCP, FAZ area, and FAZ circularity in both the SCP and DCP were similar in both groups (all Ps > 0.05).

Conclusions

VD in DCP reduced significantly more quickly in POAG eyes with high myopia over time. Density in the DCP reduced more quickly when baseline VD was low.

Correlation of axial length and peripapillary retinal nerve fiber layer thickness measured by Cirrus HD optical coherence tomography in myopes

Purpose:

To evaluate the RNFL thickness by optical coherence tomography (OCT) and correlate it with the axial length and refractive error in myopes.

Methods:

Patients with myopia −1D to −10D attending ophthalmology OPD at a tertiary hospital from October 2013 to April 2015 for evaluation underwent ophthalmic examination including refraction, axial length, and OCT RNFL thickness measurements. The patients were divided into two groups; group A included patients with AL ≤24 mm and group B AL >24 mm.

Results:

The study included 100 eyes with myopia ranging from −1D to −10D. The mean (±SD) age was 26.87 (±5.93) years with a range of 21–48 years and male: female ratio of 2:3. There was a statistically significant difference in the average peripapillary RNFL thickness between the two axial length groups (P = 0.01); RNFL thickness in group A being 91.40 (±10.17) and group B 86.06 (±10.09); and in the average RNFL thickness between the 3 degrees of myopia groups, with higher myopic group having thinner RNFL (P = 0.001).

Conclusion:

There is a significant decrease in RNFL thickness with an increase in the grade of myopia and axial length. This polar RNFL thinning could be wrongly attributed to glaucomatous change. We recommend careful interpretation of RNFL data in myopes with axial length >24 mm, when applying the current OCT nomograms.

SWATH Based Quantitative Proteomics Reveals Significant Lipid Metabolism in Early Myopic Guinea Pig Retina

Most of the previous myopic animal studies employed a single-candidate approach and lower resolution proteomics approaches that were difficult to detect minor changes, and generated limited systems-wide biological information. Hence, a complete picture of molecular events in the retina involving myopic development is lacking. Here, to investigate comprehensive retinal protein alternations and underlying molecular events in the early myopic stage, we performed a data-independent Sequential Window Acquisition of all Theoretical Mass Spectra (SWATH) based proteomic analysis coupled with different bioinformatics tools in pigmented guinea pigs after 4-day lens-induced myopia (LIM). Myopic eyes compared to untreated contralateral control eyes caused significant changes in refractive error and choroid thickness (p < 0.05, n = 5). Relative elongation of axial length and the vitreous chamber depth were also observed. Using pooled samples from all individuals (n = 10) to build a species-specific retinal ion library for SWATH analysis, 3202 non-redundant proteins (with 24,616 peptides) were identified at 1% global FDR. For quantitative analysis, the 10 individual retinal samples (5 pairs) were analyzed using a high resolution Triple-TOF 6600 mass spectrometry (MS) with technical replicates. In total, 37 up-regulated and 21 down-regulated proteins were found significantly changed after LIM treatment (log2 ratio (T/C) > 0.26 or < -0.26; p ≤ 0.05). Data are accepted via ProteomeXchange with identifier PXD025003. Through Ingenuity Pathways Analysis (IPA), "lipid metabolism" was found as the top function associated with the differentially expressed proteins. Based on the protein abundance and peptide sequences, expression patterns of two regulated proteins (SLC6A6 and PTGES2) identified in this pathway were further successfully validated with high confidence (p < 0.05) using a novel Multiple Reaction Monitoring (MRM) assay on a QTRAP 6500+ MS. In summary, through an integrated discovery and targeted proteomic approach, this study serves as the first report to detect and confirm novel retinal protein changes and significant biological functions in the early LIM mammalian guinea pigs. The study provides new workflow and insights for further research to myopia control.

Longitudinal Evaluation of the Structural and Functional Changes Associated with Glaucoma in Myopia

SIGNIFICANCE

This study ascertains that myopia is a risk factor for glaucoma progression among eyes with primary open angle glaucoma. Myopic eyes with primary open angle glaucoma may benefit from measurement and incorporation of axial length information into clinical decision making.

PURPOSE

The purpose of this study was to estimate the rate of change in retinal nerve fiber layer (RNFL) thickness and the rate of change in visual field of glaucoma patients with and without myopia.

METHODS

We conducted a prospective, observational cohort study where we analyzed 245 eyes of 135 glaucoma patients followed for a mean period of 6.08 years. All the subjects had RNFL imaging and standard automated perimetry performed for both eyes in the same visit every 4 months for at least 60 months.

RESULTS

The rate of change of average RNFL thickness and visual field index (VFI) was -0.29 μm/y (95% confidence interval, -1.80 to +1.23 μm/y) and -0.30%/y (95% confidence interval, -2.24 to +1.64%/y), respectively, after adjusting for age, axial length, IOP, baseline RNFL thickness, signal strength, and correlation between fellow eyes. Axial length, as a continuous variable, was not associated with the rates of change of average RNFL thickness and VFI. However, high myopic eyes with axial lengths of ≥26.0 and ≥26.5 mm had an average rate of change of RNFL thickness of 0.15 and 0.16 μm/y faster than eyes with axial lengths of less than 26 and 26.5 mm, respectively. Similarly, myopic eyes with an axial length of ≥26.5 mm were associated with a 0.21%/y faster rate of VFI reduction.

CONCLUSIONS

Both RNFL and visual field progression rates are faster in myopic glaucomatous eyes with an axial length of ≥26.5 mm than in eyes <26.5 mm. However, the small difference that supports high myopia as a risk factor for progression does not indicate the clinical importance or significance of axial length.

The plasminogen protein is associated with high myopia as revealed by the iTRAQ-based proteomic analysis of the aqueous humor

To explore the pathogenesis of high myopia (HM) using quantitative proteomics. The aqueous humor of patients with simple nuclear cataract and nuclear cataract complicated with HM (hereinafter referred to as "C" and "HM" groups, respectively) were collected. The isobaric tags for relative and absolute quantitation (iTRAQ)-based liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics approach was employed to explore differentially expressed proteins (DEPs). Bioinformatics was used to interpret the proteomic results. Furthermore, the plasminogen (PLG) protein was confirmed by enzyme-linked immunosorbent assay (ELISA) as the candidate biomarker for HM through a receiver operating characteristic curve analysis. The study showed 32 upregulated and 26 downregulated proteins. The gene ontology analysis demonstrated that 58 DEPs corresponded to 325 biological processes, 33 cell components, and 45 molecular functional annotations. The Kyoto Encyclopedia of Genes and Genomes analysis showed that the upregulated DEPs were highly enriched in the coagulation and complement cascades, consistent with the gene set enrichment analysis. Our data suggested that some DEPs might be hallmarks of the development of HM. ELISA confirmed that the PLG expression levels were significantly upregulated in HM. This was a new study investigating alterations in protein levels and affected pathways in HM using iTRAQ-based quantitative proteomics. Our study provided a comprehensive dataset on overall protein changes and shed light on its potential molecular mechanism in human HM.

Longitudinal Macular Ganglion Cell-Inner Plexiform Layer Measurements to Detect Glaucoma Progression in High Myopia

PURPOSE

To investigate whether progressive macular ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) thinning are predictive for detecting visual field (VF) progression in eyes with high myopia.

DESIGN

Cohort study.

METHODS

A total of 104 primary open-angle glaucoma (POAG) eyes with high myopia and 104 age- and VF severity-matched POAG eyes without high myopia (mean follow-up, 5.4 years) were included. High myopia was defined as a spherical equivalent <-6.0 diopters or axial length >26.5 mm. Progressive GCIPL, RNFL, and VF deterioration were determined by Guided Progression Analysis (GPA) in optical coherence tomography and standard automated perimetry. The risk of VF progression was evaluated using Cox proportional hazard models.

RESULTS

Highly myopic eyes with progressive GCIPL thinning had a significantly higher risk of developing VF progression after adjusting for the baseline intraocular pressure (HR 4.00; P = .001) or peak intraocular pressure (HR 3.11; P = .011) in the multivariable Cox proportional hazard model, whereas highly myopic eyes with progressive RNFL thinning were not significantly associated with VF progression. In eyes without high myopia, both progressive GCIPL (HR 4.67 or 3.62; P = .008 or .037, respectively) and RNFL (HR 6.60 or 3.97; P = .001 or .016, respectively) thinning were associated with a significantly higher risk of developing VF progression after adjusting for the baseline or peak intraocular pressure.

CONCLUSIONS

Monitoring macular GCIPL thickness was effective for predicting glaucoma progression regardless of the presence of high myopia.

Effect of internal limiting membrane peeling on visual field sensitivity in eyes with epiretinal membrane accompanied by glaucoma with hemifield defect and myopia

PURPOSE

To investigate the effects of internal limiting membrane (ILM) peeling on visual field sensitivities in eyes with epiretinal membrane (ERM) accompanied by glaucoma with hemifield defect and myopia.

STUDY DESIGN

Retrospective clinical study METHODS: We reviewed clinical records of patients with ERM who underwent vitrectomy and ERM/ILM peeling. We first collected clinical data of eyes with ERM and glaucoma with hemifield defect. We recorded visual field sensitivities at 52 points and analyzed differences between before and after surgery. We then compared the changes in visual field sensitivity between glaucomatous and normal hemifields. Next, we collected ERM eyes without glaucoma and stratified them into two groups based on axial length (threshold = 26.0 mm). In these eyes, we also recorded visual field sensitivities at 52 points and analyzed differences between before and after surgery.

RESULTS

The study included 18 eyes with ERM and glaucoma with hemifield defect (11 men; mean age, 68.3 ± 7.2 years). These eyes showed significant sensitivity reductions at 5/26 points, mainly in the nasal area of the glaucomatous hemifield, whereas only 1/26 points exhibited significant sensitivity reduction in the normal hemifield. In eyes with axial length <26.0 mm and axial length ≥26.0 mm, 29 peripheral and seven superior peripheral points showed significant improvements in visual field sensitivities, respectively.

CONCLUSION

Visual field sensitivity reduction occurred mainly in the nasal region of the glaucomatous hemifield. Differences in axial length alone were not a prominent risk factor for reduced visual field sensitivity after ILM peeling in eyes with ERM.

The occurrence of optic disc haemorrhage in primary open-angle glaucoma eyes with lower normal pressure and its relating factors

PURPOSE

To report the occurrence probability of disc haemorrhage (DH) and risk factors for it in otherwise healthy Japanese normal-tension glaucoma (NTG) patients who had lower normal intraocular pressure (IOP) and were followed without treatment for 5 years.

METHODS

A prospective observational study. Normal-tension glaucoma (NTG) patients with IOP consistently ≤15 mmHg without treatment were enrolled. The presence or absence of DH was checked semi-annually on the fundus photographs by three independent observers, while patients were followed without treatment. Cox proportional hazards model taking inter-eye correlation into consideration was adopted to identify risk factors for DH occurrence. The main outcomes were DH occurrence probability during 5-year period and its risk factors.

RESULTS

One hundred seventeen eyes of 90 patients with mean age of 54.1 years, mean deviation value of -3.6 decibels and mean IOP during follow-up of 12.4 mmHg were included. Disc haemorrhage (DH) was observed at least once in 34 eyes and more than twice in 15 eyes during the follow-up. The DH occurrence probability at 5 years was 31% (95% confidence interval: 21-40%), and lower myopic refraction (HR = 1.18; p = 0.018), higher IOP during follow-up (HR = 1.35; p = 0.047) and presence of DH at baseline (HR = 4.19; p = 0.002) were its risk factors.

CONCLUSION

Disc haemorrhage (DH) occurrence probability of Japanese healthy NTG patients with mean IOP of 12.4 mmHg and no systemic and/or topical treatment was 31% at 5 years. Lower myopic refraction, higher IOP and its existence at baseline were its risk factors.

Risk Factors Associated with Structural Progression in Normal-Tension Glaucoma: Intraocular Pressure, Systemic Blood Pressure, and Myopia

Purpose

To determine risk factors associated with structural progression in medically treated normal-tension glaucoma (NTG).

Methods

This retrospective cohort study included 166 NTG patients (average age, 56.5 years; average mean deviation, −4.2 dB). The structural progression endpoint was determined by optical coherence tomography; significant thickness differences in the peripapillary retinal nerve fiber layer (RNFL) or macular ganglion cell inner plexiform layer (GCIPL) that exceeded baseline test-retest variability were identified with event-based guided-progression analysis. Intraocular pressure and systemic blood pressure (BP) were measured at each visit throughout the follow-up period, and the risk for progression was evaluated with Cox regression. Myopic disc features and antihypertensives were also analyzed. Tree analysis was used to determine the cutoff values and elucidate influential risk factors.

Results

Structural progression, defined as progressive peripapillary RNFL or macular GCIPL thinning, was identified in 62 eyes. Occurrence of disc hemorrhages, presence of diabetes, and lower minimum systolic BP were associated with progression (hazard ratio [HR]: 2.116, P = 0.005; HR: 1.998, P = 0.031; HR: 0.968, P = 0.005; respectively). The cutoff value derived from the tree analysis of minimum systolic BP was 108 mm Hg. The tree analysis revealed systolic and diastolic BP to be the most influential risk factors for progressive peripapillary RFNL thinning and progressive macular GCIPL thinning, respectively.

Conclusions

Low BP measured during follow-up correlated with structural progression in medically treated NTG eyes, indicating that the evaluation of hypotension is required during the management of NTG patients. The tree analysis identified BP target values that may help prevent glaucoma progression.

Optic nerve head anatomy in myopia and glaucoma, including parapapillary zones alpha, beta, gamma and delta: Histology and clinical features

The optic nerve head can morphologically be differentiated into the optic disc with the lamina cribrosa as its basis, and the parapapillary region with zones alpha (irregular pigmentation due to irregularities of the retinal pigment epithelium (RPE) and peripheral location), beta zone (complete RPE loss while Bruch's membrane (BM) is present), gamma zone (absence of BM), and delta zone (elongated and thinned peripapillary scleral flange) within gamma zone and located at the peripapillary ring. Alpha zone is present in almost all eyes. Beta zone is associated with glaucoma and may develop due to a IOP rise-dependent parapapillary up-piling of RPE. Gamma zone may develop due to a shift of the non-enlarged BM opening (BMO) in moderate myopia, while in highly myopic eyes, the BMO enlarges and a circular gamma zone and delta zone develop. The ophthalmoscopic shape and size of the optic disc is markedly influenced by a myopic shift of BMO, usually into the temporal direction, leading to a BM overhanging into the intrapapillary compartment at the nasal disc border, a secondary lack of BM in the temporal parapapillary region (leading to gamma zone in non-highly myopic eyes), and an ocular optic nerve canal running obliquely from centrally posteriorly to nasally anteriorly. In highly myopic eyes (cut-off for high myopia at approximately -8 diopters or an axial length of 26.5 mm), the optic disc area enlarges, the lamina cribrosa thus enlarges in area and decreases in thickness, and the BMO increases, leading to a circular gamma zone and delta zone in highly myopic eyes.

Reliability of Intraocular Pressure Measurement by Goldmann Applanation Tonometry After Refractive Surgery: A Review of Different Correction Formulas

Myopia is one of the main risk factors for the onset of open-angle glaucoma. One of the first steps to assess glaucoma occurrence is the measurement of the intraocular pressure (IOP) by the Goldmann applanation tonometry (GAT). Even if this device is considered to be the gold standard for such measurements, it is affected by several sources of errors. Among these, there are the corneal thickness and curvature, both modified by corneal refractive surgery (CRS), that nowadays has become a very popular method to treat refractive errors. Indeed, CRS, by modifying the corneal shape and structure, causes an underestimation of the IOP measurements. In the literature, several IOP correction formulas to utilize with different devices have been proposed to overcome this problem. This paper aims to review the various correction formulas applied to the GAT in the attempt to improve the reliability of this measurement.

Pre-perimetric Open Angle Glaucoma with Young Age of Onset: Natural Clinical Course and Risk Factors for Progression

PURPOSE

To investigate the natural clinical course of more than 5 years and the risk factors of progression in patients with pre-perimetric open angle glaucoma (OAG) of "young age of onset (under age 40)" without treatment.

DESIGN

Retrospective observational case series.

METHODS

Optic disc photography, red-free retinal nerve fiber layer (RNFL) photography, optical coherence tomography, and visual field (VF) examinations were performed every 6 months. Glaucoma progression was defined as structural or functional deterioration. A linear mixed-effects model was used to estimate the rate of structural and functional changes. Kaplan-Meier survival analysis and log-rank testing were used to compare survival experiences, and Cox proportional hazards modeling was performed to identify risk factors for glaucoma progression.

RESULTS

Of the 98 eyes of 98 patients (mean age, 30.6 years old), glaucoma progression was detected in 42 eyes (42.9%). The rate of average RNFL thickness thinning was -0.46 ± 0.50 μm/y, and the mean deviation (MD) change was -0.03 ± 0.13 dB/y. The glaucoma progression probability at 5 years was 39% by structural criteria and 5% by functional criteria. Older age at diagnosis (P = .004), presence of temporal raphe sign (horizontal straight line on macular ganglion cell-inner plexiform layer thickness map) (P = .011), lamina pore visibility (P = .034), and greater pattern standard deviation (P = .005) were significant factors for glaucoma progression.

CONCLUSIONS

In untreated pre-perimetric OAG patients with a "young age of onset" condition, the estimated MD slope for the disease course of more than 5 years was -0.03 dB/y, and the average RNFL thinning rate was -0.46 μm/y. The predictors for progression were structural parameters of temporal raphe sign, lamina pore visibility, and functional parameter of pattern standard deviation.

Impact of myopia on the association of long-term intraocular pressure fluctuation with the rate of progression in normal-tension glaucoma

BACKGROUND/AIMS

To investigate whether the association of long-term intraocular pressure (IOP) fluctuation with the rate of progression of normal-tension glaucoma (NTG) differs between myopia and non-myopia.

METHODS

The medical records of 65 myopic NTG (axial length (AL) > 24.0 mm) and 64 non-myopic NTG eyes (AL < 24.0 mm), who had been treated with topical medications for more than 5 years, were reviewed. Multiple linear regression models were fitted to analyse the relationships of the slope of mean deviation (MD) or visual field index (VFI) with the clinical factors, including the interactions with myopia.

RESULTS

The average follow-up period was 8.3 years. Twenty-two (22) non-myopic eyes (34.4%) and 27 myopic eyes (41.5%) showed NTG progression (p=0.511). The interaction of myopia with IOP fluctuation was a significant factor regarding both MD and VFI slope (p=0.002, 0.024, respectively); stratified analyses suggested that the risk effect of IOP fluctuation was significant only in myopic NTG in terms of both MD (β= -1.27, p=0.003) and VFI slope (β=-2.32, p=0.011).

CONCLUSION

Long-term IOP fluctuation was significantly related to faster visual field progression in myopic NTG eyes, compared with non-myopic NTG eyes.

Posterior scleral deformation and autonomic dysfunction in normal tension glaucoma

In meta-analyses, it has been reported that myopia is a risk factor for glaucoma and there is increasing evidence that autonomic dysfunction causing vascular dysregulation or perfusion dysfunction is considered an important factor in the progression of glaucoma. There have been experimental studies to find out the association between autonomic nervous system and ocular growth, but no clinical study yet has evaluated the relationship between them. Therefore, we enrolled 208 open angle glaucoma patients and measured heart-rate-variability(HRV). We used the standard deviation value of the qualified normal to normal intervals (SDNN) parameter of HRV, which is considered an autonomic influence index and characterized the total effect of the regulation of autonomic blood circulation. Patients were classified into the two groups according to SDNN: those with low possibility of autonomic dysfunction (LoAD group) and those with high possibility of autonomic dysfunction (HiAD group). We evaluated myopic features employing a 'posterior scleral profile' identified by the disc tilt ratio, disc torsion, fovea-BMO center (FoBMO) angle and peripapapillary area(PPA) to disc ratio. HiAD group showed higher values than LoAD group in posterior scleral deformation profile such like axial length, disc tilt, torsion degree. We suggest the possibility of association between myopic deformation and autonomic dysfunction.

Ganglion Cell Complex Analysis in Glaucoma Patients: What Can It Tell Us?

Glaucoma is a group of optic neuropathies characterized by a progressive degeneration of retina ganglion cells (RGCs) and their axons that precedes functional changes detected on the visual field. The macular ganglion cell complex (GCC), available in commercial Fourier-domain optical coherence tomography, allows the quantification of the innermost retinal layers that are potentially involved in the glaucomatous damage, including the retinal nerve fiber (RNFL), ganglion cell and inner plexiform layers. The average GCC thickness and its related parameters represent a reliable biomarker in detecting preperimetric glaucomatous damage. The most accurate GCC parameters are represented by average and inferior GCC thicknesses, and they can be associated with progressive visual field loss. Although the diagnostic accuracy increases with more severe glaucomatous damage and higher signal strength values, it is not affected by increasing axial length, resulting in a more accurate discrimination of glaucomatous damage in myopic eyes with respect to the traditional RNFL thickness. The analysis of the structure-function relationship revealed a good agreement between the loss in retinal sensitivity and GCC thickness. The use of a 10-2° visual field grid, adjusted for the anatomical RGCs displacement, describes more accurately the relationship between RGCs thickness and visual field sensitivity loss.

Clinical Course and Risk Factors for Visual Field Progression in Normal-Tension Glaucoma With Myopia Without Glaucoma Medications

PURPOSE

To investigate the natural clinical course and the risk factors of visual field (VF) progression in untreated normal-tension glaucoma (NTG) with myopia with a minimum 3-year follow-up.

DESIGN

Retrospective cohort study.

METHODS

Kaplan-Meier survival analysis and log-rank test were used to compare survival experiences between the groups. The hazard ratios (HRs) for the associations between potential risk factors and glaucomatous progression were determined using Cox proportional hazards model.

RESULTS

The average follow-up period for the included 97 patients was 71.1 ± 29.7 months and 32 eyes showed progression during the observation period. In NTG with myopia, Kaplan-Meier survival curve showed progression cases in 10.3% at 36 months and 24.8% at 60 months. When age and disc tilt direction were classified into 2 groups, a higher cumulative probability of progression was observed in those aged ≤50 years than >50 years (P = .001) and in those with disc tilt direction <45 degrees than disc tilt direction ≥45 degrees (P = .002). In Cox proportional hazards model, younger age, presence of disc hemorrhage, and more temporally tilted disc or parapapillary atrophy were associated with progression.

CONCLUSIONS

NTG with myopia seems to have a slow progression rate even without glaucoma medications. Only 10.3% and 24.8% of patients showed VF progression at 3 years and 5 years of follow-up in untreated NTG with myopia. To predict VF progression in untreated NTG with myopia, it seems that age and disc morphology should be considered.

Axial length and its associations in a Russian population: The Ural Eye and Medical Study

Purpose

To assess the normal distribution of axial length and its associations in a population of Russia.

Methods

The population-based Ural Eye and Medical Study included 5,899 (80.5%) individuals out of 7328 eligible individuals aged 40+ years. The participants underwent an ocular and systemic examination. Axial length was measured sonographically (Ultra-compact A/B/P ultrasound system, Quantel Medical, Cournon d'Auvergne, France).

Results

Biometric data were available for 5707 (96.7%) individuals with a mean age of 58.8±10.6 years (range:40–94 years; 25%, 50%, 75% quartile: 51.0, 58.0, 66.0 years, respectively). Mean axial length was 23.30±1.10 mm (range: 19.02–32.87mm; 95% confidence interval (CI): 21.36–25.89; 25%, 50%, 75% quartile: 22.65mm, 23.23mm, 23.88mm, resp.). Prevalences of moderate myopia (axial length:24.5-<26.5mm) and high myopia (axial length >26.5mm) were 555/5707 (8.7%;95%CI:9.0,10.5) and 78/5707 (1.4%;95%CI:1.1,1.7), respectively. Longer axial length (mean:23.30±1.10mm) was associated (correlation coefficient r²:0.70) with older age (P<0.001;standardized regression coefficient beta:0.14), taller body height (P<0.001;beta:0.07), higher level of education (P<0.001;beta:0.04), higher intraocular pressure (P<0.001;beta:0.03), more myopic spherical refractive error (P<0.001;beta:-0.55), lower corneal refractive power (P<0.001;beta:-0.44), deeper anterior chamber depth (P<0.001;beta:0.20), wider anterior chamber angle (P<0.001;beta:0.05), thinner peripapillary retinal nerve fiber layer thickness (P<0.001;beta:-0.04), higher degree of macular fundus tessellation (P<0.001;beta:0.08), lower prevalence of epiretinal membranes (P = 0.01;beta-0.02) and pseudoexfoliation (P = 0.007;beta:-0.02) and higher prevalence of myopic maculopathy (P<0.001;beta:0.08). In that model, prevalence of age-related macular degeneration (any type: P = 0.84; early type: P = 0.46), diabetic retinopathy (P = 0.16), and region of habitation (P = 0.27) were not significantly associated with axial length.

Conclusions

Mean axial length in this typically multi-ethnic Russian study population was comparable with values from populations in Singapore and Beijing. In contrast to previous studies, axial length was not significantly related with the prevalences of age-related macular degeneration and diabetic retinopathy or region of habitation.

Visual Subfield Progression in Glaucoma Subtypes

Purpose

To investigate visual field progression pattern and factors associated with progression in patients with primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), and chronic angle-closure glaucoma (CACG).

Methods

The raw data of the 30-2 Humphrey Field Analyzer from glaucoma patients with definite visual field progression were processed with pointwise linear regression (PLR) analysis. The rate of change of retinal threshold sensitivity in the ten glaucoma hemifield test (GHT) zones, the upper and the lower hemifields, and the whole field was evaluated and was correlated with patients' basic demographic data.

Results

An average follow-up of 6.94 ± 2.69 years that showed the rate of change of visual field threshold sensitivity was correlated with the peak posttreatment intraocular pressure (IOP) and the long-term IOP fluctuations in all GHT zones except in the inferior arcuate area. The baseline IOP, the trough posttreatment IOP, the refractive status, and the CCT were not correlated with VF progression.

Conclusion

The rate of visual field progression was correlated with the peak posttreatment IOP and the long-term IOP fluctuation but with subfield differences.

Three-Dimensional Evaluation of Posterior Pole and Optic Nerve Head in Myopes with Glaucoma

The degree of myopia is represented by a global index, such as refractive error or axial length. However, the progression of myopia mainly develops in the posterior eyeball. Therefore, it is reasonable to assume that the evaluation of myopia should be confined to the posterior segment, where most of the growth and lengthening occurs. Swept source optical coherence tomography software can reconstruct the scans to the coronal view of the posterior pole, which provides additional anterior-posterior depth (z axis in the Cartesian coordinates) that is not provided with the common fundus photograph. We deduced that the parameter of deepest point of the eyeball (DPE) as a surrogate for posterior pole configuration. Between myopes with and without normal tension glaucoma (NTG) with similar axial length, myopes with NTG had deeper and more distant location of the DPE from the optic disc. The difference of the DPE position between the myopes with and without NTG may have implications for the larger optic disc tilt and torsion characteristic of myopes with NTG. Furthermore, these data suggest that myopes with NTG go through excessive posterior scleral remodeling, which may result in vulnerable optic nerve head.

Goldmann V Standard Automated Perimetry Underestimates Central Visual Sensitivity in Glaucomatous Eyes with Increased Axial Length

PURPOSE

To investigate the effect of axial length (AL) on the structure-function relationship between retinal nerve fiber layer (RNFL) thickness measurements and visual field (VF) sensitivity measured with Goldmann III and V.

METHOD

There were 85 eyes of 85 patients with primary open angle glaucoma included in the current study. Optical coherence tomography and VF (Humphrey Field Analyzer 24-2 or 30-2) measurements with Goldmann III and V targets were carried out in all patients. The optic disc and the VF were divided into six clusters and the relationship between circumpapillary RNFL (cpRNFL) thickness and VF sensitivity (with Goldmann III or V), age, and AL were investigated in each cluster.

RESULT

Visual sensitivity with Goldmann III (19.3 ± 11.7 dB, mean ± standard deviation) was significantly lower than that with Goldmann V (24.6 ± 11.0 dB, P < 0.001, linear mixed model). Visual sensitivities with both Goldmann III and V were significantly correlated with cpRNFL thickness in all clusters. Visual sensitivity decreased with increasing AL in the nasal retinal area for both targets, however, this phenomenon was only observed with the Goldmann V target in the temporal area.

CONCLUSION

Visual sensitivity measured with the size V target decreases with increasing AL in the temporal area, which corresponds to the papillomacular bundle. In the nasal retinal area, visual sensitivity decreases with the increase of AL for both Goldmann III and Goldmann V.

TRANSLATIONAL RELEVANCE

Careful consideration is needed when measuring visual sensitivity using Goldmann V target in glaucomatous eyes with increased AL.

Intereye comparison of ocular factors in normal tension glaucoma with asymmetric visual field loss in Korean population

PURPOSE

To identify ocular parameters corresponding to asymmetric visual field (VF) loss in normal tension glaucoma (NTG) through intereye comparisons.

PATIENTS AND METHODS

Medical records of NTG patients with asymmetric and symmetric VF losses were retrospectively reviewed. The criterion for asymmetry in VF was 6 dB difference of mean deviation. Refractive error, intraocular pressure (IOP), central corneal thickness, ovality index, and peripapillary atrophy (PPA)/disc area ratio were obtained from each patient. Intereye comparison was performed for asymmetric group, symmetric group, and myopic and nonmyopic asymmetric subgroups.

RESULTS

We included 155 patients; 110 patients in asymmetric group and 45 patients in symmetric group. In intereye comparison for total asymmetric group, refractive error (P = 0.006), initial IOP (P = 0.001), ovality index (P = 0.008), and PPA (P < 0.001) were significantly asymmetric. For myopic subgroup, refractive error (P = 0.004), ovality index (P = 0.001), and PPA (P = 0.003) were significant factors. For nonmyopic subgroup, initial IOP (P = 0.003) and PPA (P = 0.007) were significant factors. Symmetric group showed no significant difference between the eyes. Multivariate analysis demonstrated that refractive error (P = 0.002) and PPA (P = 0.028) were significant factors in myopic subgroup, and initial IOP (P = 0.022) and PPA (P = 0.002) were significant factors in nonmyopic subgroup.

CONCLUSIONS

In this intereye comparison, the more myopic eye in myopic NTG patient, and the more pressured eye in nonmyopic NTG patient demonstrated more severe VF loss. Myopic and nonmyopic patients may follow different pathophysiologic processes. Discriminative attentions should be paid to NTG patients by subtypes.

[Secondary diseases in high myopia]

BACKGROUND

Eyes with high myopia (axial length ≥ 26.5 mm) do not just have a different size. Due to morphological and structural changes there is a considerably increased risk for many different secondary diseases.

OBJECTIVE

Determination of the incidence and mortality in high myopia, discussion of effects and clinical signs, presentation of treatment recommendations and counselling.

MATERIAL AND METHODS

A systematic search of the literature was carried out and a discussion on basic principles and epidemiological investigations is presented.

RESULTS

Findings due to high myopia are not in a closed state but undergo continuous changes. Choroidal neovascularization (adjusted prevalence 2.5-5%), staphyloma, foveoschisis and peripheral retinal degeneration are examples of problems contributing to the increased rate of visual impairment and blindness related to myopia. High myopia is associated with a clearly increased risk of retinal detachment after lens surgery (hazard ratio 6.1) and particularly more frequently in younger people. The associated primary open-angle glaucoma (odds ratio 2.46) is often recognized too late due to relatively low values of intraocular pressure.

CONCLUSION

Understanding of atrophic areas and staphyloma has benefited from recent advances in imaging (e.g. magnetic resonance imaging, optical coherence tomography and wide-field imaging) that complement and explain histological findings. Knowledge of the associated risk profile is of major clinical relevance.

Glaucoma in high myopia and parapapillary delta zone

Purpose

To examine the prevalence of glaucomatous optic neuropathy (GON) in a medium myopic to highly myopic group of patients and its association with parapapillary gamma zone and parapapillary delta zone.

Methods

The retrospective observational hospital-based study included patients who had attended the Tokyo High Myopia Clinics within January 2012 and December 2012 and for whom fundus photographs were available. GON was defined based on the appearance of the optic nerve head on the fundus photographs.

Results

The study included 519 eyes (262 individuals) with a mean age of 62.0±14.3 years (range:13–89 years) and mean axial length of 29.5±2.2 mm (range:23.2–35.3mm). GON was present in 141 (27.2%; 95% confidence intervals (CI): 23.3, 31.0%) eyes. Prevalence of GON increased from 12.2% (1.7, 22.7) in eyes with an axial length of <26.5mm to 28.5% (24.4, 32.5) in eyes with an axial length of ≥26.5mm, to 32.6% (27.9, 37.2) in eyes with an axial length of ≥28mm, to 36.0% (30.5, 41.4) in eyes with an axial length of ≥29mm, and GON prevalence increased to 42.1% (35.5, 48.8) in eyes with an axial length of ≥30mm. In multivariate analysis, higher GON prevalence was associated (Nagelkerke r²: 0.28) with larger parapapillary delta zone diameter (P<0.001; odds ratio (OR):1.86;95%CI:1.33,2.61), longer axial length (P<0.001;OR:1.45;95%CI:1.26,1.67) and older age (P = 0.01;OR:1.03;95%CI:1.01,1.05). If parapapillary delta zone width was replaced by the vertical disc diameter, higher GON prevalence was associated (r²:0.24) with larger vertical optic disc diameter (P = 0.04;OR:1.70;95%CI:1.03,2.81), after adjusting for longer axial length (P<0.001;OR:1.44;95%CI:1.26,1.64) and older age (P<0.001;OR:1.04;95%CI:1.02,1.06).

Conclusions

Axial elongation associated increase in GON prevalence (mean: 28.1% in a medium to highly myopic study population) was associated with parapapillary delta zone as surrogate for an elongated peripapillary scleral flange and with larger optic disc size.

Association of Myopic Deformation of Optic Disc with Visual Field Progression in Paired Eyes with Open-Angle Glaucoma

Purpose

The influence of myopia on glaucoma progression remains unknown, possibly because of the multifactorial nature of glaucoma and difficulty in assessing a solo contribution of myopia. The purpose of this study is to investigate the association of myopia with visual field (VF) progression in glaucoma using a paired-eye design to minimize the influence of confounding systemic factors that are diverse among individuals.

Methods

This retrospective study evaluated 144 eyes of 72 subjects with open-angle glaucoma, with similar intra-ocular pressure between paired eyes, spherical equivalent (SE) ≤ -2 diopter (D), and axial length ≥ 24 mm. Paired eyes with faster and slower VF progression were grouped separately, according to the global VF progression rate assessed by automated pointwise linear regression analysis. The SE, axial length, tilt ratio and torsion angle of optic discs, Bruch’s membrane (BM) opening area, and gamma zone parapapillary atrophy (PPA) width were compared between the two groups. Factors associated with faster VF progression were determined by logistic regression analysis.

Results

The mean follow-up duration was 8.9 ± 4.4 years. The mean value of SE and axial length were -6.31 ± 1.88 D and 26.05 ± 1.12 mm, respectively. The mean global visual field progression rate was -0.32 ± 0.38 dB/y. Tilt ratio, BM opening area, and gamma zone PPA width were significantly greater in the eyes with faster VF progression than those with slower progression. In multivariate analysis, these factors were significantly associated with faster VF progression (all P < 0.05), while SE and axial length were not associated with it.

Conclusion

In myopic glaucoma subjects, tilt of the optic disc and temporal shifting and enlargement of the BM opening were associated with faster rate of VF progression between paired eyes. This suggests that myopia influences VF progression in glaucomatous eyes via optic disc deformations rather than via refractive error itself.

Visual Field Progression Pattern Associated With Optic Disc Tilt Morphology in Myopic Open-Angle Glaucoma

PURPOSE

To understand the long-term characteristics of visual field (VF) progression in myopic open-angle glaucoma (OAG) according to the morphology of optic disc tilt.

DESIGN

Retrospective, comparative, longitudinal cohort study.

METHODS

Myopic OAG eyes were divided into temporally tilted disc and inferiorly tilted disc groups according to optic disc torsional degrees. Kaplan-Meier survival analysis was used to compare the survival rates between nonmyopic OAG, myopic OAG with temporally tilted disc, and myopic OAG with inferiorly tilted disc. The hazard ratio (HRs) for the associations between risk factors and progression were analyzed using Cox proportional hazards modeling. In the inferiorly tilted disc group, subgroups were classified into progression, stationary, and progression-to-stationary groups, and the clinical characteristics of VF progression were compared among the subgroups.

RESULTS

A total of 82 eyes in 82 nonmyopic OAG patients and 150 eyes in 150 myopic OAG patients were included. Myopic OAG with inferiorly tilted disc showed significantly more baseline and final 1-hemifield-involvement cases compared with myopic OAG with temporally tilted disc (P < .001, P < .001, respectively). The cumulative probability of progression was shown to be faster for myopic OAG with inferiorly tilted disc compared with temporally tilted disc and nonmyopic OAG (P = .002, P = .038, respectively). A larger number of medications (HR = 1.339; P = .004), earlier-stage VF defect (HR = 1.217; P < .001), and inferiorly tilted disc (HR = 2.378; P < .001) were predictive of progression. In the analysis of myopic OAG with inferiorly tilted disc, the progression group had younger age and earlier-stage VF defect at baseline compared with the stationary group (P = .01, P < .001, respectively).

CONCLUSIONS

It is likely that VF progression in myopic OAG is associated with the morphology of the optic disc tilt. Especially in OAG with inferiorly tilted disc, VF is likely not to progress after terminating VF progression at the region associated with optic disc tilt.

Relationship between visual field progression and baseline refraction in primary open-angle glaucoma

PURPOSE

To analyze the relationship between visual field (VF) progression and baseline refraction in Japanese patients with primary open-angle glaucoma (POAG) including normal-tension glaucoma.

PATIENTS AND METHODS

In this retrospective study, the subjects were patients with POAG who had undergone VF tests at least ten times with a Humphrey Field Analyzer (Swedish interactive thresholding algorithm standard, Central 30-2 program). VF progression was defined as a significantly negative value of mean deviation (MD) slope at the final VF test. Multivariate logistic regression models were applied to detect an association between MD slope deterioration and baseline refraction.

RESULTS

A total of 156 eyes of 156 patients were included in this analysis. Significant deterioration of MD slope was observed in 70 eyes of 70 patients (44.9%), whereas no significant deterioration was evident in 86 eyes of 86 patients (55.1%). The eyes with VF progression had significantly higher baseline refraction compared to those without apparent VF progression (-1.9±3.8 diopter [D] vs -3.5±3.4 D, P=0.0048) (mean ± standard deviation). When subject eyes were classified into four groups by the level of baseline refraction applying spherical equivalent (SE): no myopia (SE > -1D), mild myopia (-1D ≥ SE > -3D), moderate myopia (-3D ≥ SE > -6D), and severe myopia (-6D ≥ SE), the Cochran-Armitage trend analysis showed a decreasing trend in the proportion of MD slope deterioration with increasing severity of myopia (P=0.0002). The multivariate analysis revealed that baseline refraction (P=0.0108, odds ratio [OR]: 1.13, 95% confidence interval [CI]: 1.03-1.25) and intraocular pressure reduction rate (P=0.0150, OR: 0.97, 95% CI: 0.94-0.99) had a significant association with MD slope deterioration.

CONCLUSION

In the current analysis of Japanese patients with POAG, baseline refraction was a factor significantly associated with MD slope deterioration as well as intraocular pressure reduction rate. When baseline refraction was classified into four groups, MD slope in myopia groups was less deteriorated as compared to those in the emmetropic/hyperopic group.

Factors Associated with Loss of Visual Function in Medically Treated Advanced Normal Tension Glaucoma

PURPOSE

To investigate the risk factors associated with a progressive loss of visual function (LV) in medically treated advanced normal tension glaucoma (NTG).

METHODS

In this retrospective observational study, a total of 87 eyes of the 87 NTG patients with a baseline visual field (VF) mean deviation (MD) of worse than -10 decibel (dB) (average follow-up period: 5.3 years) were included. All the participants were categorized into two groups according to the baseline VF MD [group 1 (≥-16 dB) and group 2 (<-16 dB), respectively]. The participants were also divided into older (≥64 years) and younger (<64 years) groups according to the median split of baseline age. Hazard ratios (HRs) for the association between potential risk factors and LV were obtained using the Cox proportional hazards models.

RESULTS

Fifty-one eyes were classified as group 1 (VF MD; -13.5 ± 1.8 dB), and 36 eyes as group 2 (-21.0 ± 4.1 dB). LV occurred in 33 eyes (64.7%) in group 1 and in 29 eyes (80.6%) in group 2 during the follow-up period. In total participants, younger age (HR; 0.971, p = 0.008) and lower initial best-corrected visual acuity (BCVA) (HR; 18.4, p = 0.007) were found to be significant risk factors for LV. In group 1, younger age and lower baseline BCVA were associated with LV; whereas, no significant risk factor was found in group 2. In the younger group, myopia and disc hemorrhage were found to be the risk factors.

CONCLUSION

The risk factors associated with progressive LV differed according to the baseline VF stages or the age among advanced medically treated NTG patients.