Ocular hypertension: an approach to assessment and management

Reduction-responsive polymeric micelles for trans-corneal targeted delivery of microRNA-21-5p and glaucoma-specific gene therapy

The therapeutic value of microRNA (miRNA) for the treatment of glaucoma has become a focus of attention. However, naked miRNA cannot cross the corneal barrier and reach the target tissue by itself. Thus, the precise transport of miRNA to the target sites is key to the success of gene therapy. Herein, we selected a miRNA, namely miR-21-5p, based on its unique intraocular pressure (IOP) mechano-sensing property. Moreover, a biocompatible polymeric poly(L-lysine) (PLL) micelle conjugated with collagenase and ABCA1 antibody was judiciously constructed to achieve the trans-corneal and target delivery of miR-21-5p to the trabecular meshwork (TM) and Schlemm's canal (SC) tissues inside the eye. The topically administrated PLL micelles as an eye drop successfully crossed the cornea with the help of collagenase and then preferentially accumulated in the target TM/SC tissues under the guidance of the ABCA1 antibody. When endocytosed by TM/SC cells, the PLL micelles could be decomposed in the reductive lysosomal environment to release miR-21-5p for successfully lowering the IOP by activating the miR-21-5p/eNOS/MMP9 signaling axis, which will open new prospects for glaucoma-specific gene therapy.

Sigma-1 receptor agonist, (+)-pentazocine, is neuroprotective in a Brown Norway rat microbead model of glaucoma

PURPOSE

Glaucoma is a worldwide leading cause of irreversible blindness. Standard treatments lower intraocular pressure (IOP). Novel treatments to prevent optic nerve (ON) degeneration are needed. Here, we investigate the hypothesis that sigma-1 receptor (S1R) agonist (+)-pentazocine (PTZ) is neuroprotective in a Brown Norway (BN) rat, microbead model of glaucoma.

METHODS

BN rats (9-11 weeks, male and female) were treated by intraperitoneal injection, 3 times per week with (+)-PTZ (2 mg/kg) or vehicle (VEH) alone. Treatment started 1 week prior to intraocular injection of polystyrene microbeads to elevate IOP. IOP was measured 2-3 times per week. Five weeks post microbead injection, rats were euthanized. ONs were removed, then fixed and processed for 63x oil, light microscope imaging of toluidine blue stained ON cross sections. To facilitate comparison of ON morphology from VEH and (+)-PTZ treated rats with similar ocular hypertensive insults, rats were assigned to low (IOP ≤15.8 mmHg), moderate (15.8 < IOP <28.0 mmHg), and high (IOP ≥28.0 mmHg) groups based on average IOP in the microbead injected eye. Axon numbers, axon density, axonal and glial areas, axon loss, and axon size distributions of naïve, bead, and contralateral ONs were assessed using QuPath program for automated image analysis.

RESULTS

(+)-PTZ treatment of BN rats protected ONs from damage caused by moderate IOP elevation. Treatment with (+)-PTZ significantly reduced axon loss and glial areas, and increased axon density and axonal areas compared to ONs from VEH treated rats with moderate IOP. (+)-PTZ-mediated neuroprotection was independent of IOP lowering effects. At average IOP ≥28.0 mmHg, (+)-PTZ treatment did not provide measurable neuroprotection. ONs from contralateral eyes exhibited subtle, complex changes in response to conditions in the bead eyes.

CONCLUSIONS

S1R agonist (+)-PTZ shows promise as a neuroprotective treatment for glaucoma. Future studies to understand the complex molecular mechanisms by which (+)-PTZ provides this neuroprotection are needed.

Increased Risk of Ocular Hypertension in Patients With Cushing's Disease

PRCIS

An increased risk of ocular hypertension was seen in Cushing's disease.

INTRODUCTION

Systemic steroid use is a significant risk factor for increased intraocular pressure (IOP). The incidence of ocular hypertension may rise to 30%-40% of the general population due to topical or systemic glucocorticoid usage. However, the incidence of ocular hypertension in endogenous hypercortisolemia, as well as the ophthalmological outcomes after endocrine remission due to surgical resection, remain unknown.

MATERIALS AND METHODS

The IOP, visual field, and peripapillary retinal nerve fiber layer thickness were documented in all patients with Cushing's disease (CD) admitted to a tertiary pituitary center for surgery from January to July 2019. Patients with acromegaly and patients with nonfunctioning pituitary adenoma (NFPA) during the same study period served as controls. We calculated the odds ratio (OR), identified the risk factors of developing ocular hypertension, and presented postoperative trends of the IOP.

RESULTS

A total of 52 patients (38.4±12.4 y old) with CD were included. The IOP was higher in patients with CD (left 19.4±5.4 mm Hg and right 20.0±7.1 mm Hg) than in patients with acromegaly (left 17.5±2.3 mm Hg and right 18.6±7.0 mm Hg, P =0.033) and patients with NFPA (left 17.8±2.6 mm Hg and right 17.4±2.4 mm Hg, P =0.005). A total of 21 eyes (20.2%) in patients with CD were diagnosed with ocular hypertension compared with 4 eyes (4.7%) in the acromegaly group and 4 eyes (4.5%) in the NFPA group. The OR of developing ocular hypertension in patients with CD was 5.1 [95% confidence interval (CI), 1.3-25.1, P =0.029] and 6.6 (95% CI, 1.8-30.3, P =0.007) when compared with the 2 control groups. Among patients with CD, those with a higher urine-free cortisol were more likely to develop ocular hypertension (OR=19.4, 95% CI, 1.7-72.6). The IOP decreased at 1 month after surgery in patients with CD, and the change was sustained for 3 months after surgery.

CONCLUSIONS

An increased risk of ocular hypertension was seen in CD and suggests that endogenous hypercortisolemia should be considered as part of the glaucoma assessment. This result warrants the discretion of both ophthalmologists and neuroendocrinologists.

Micropulse laser trabeculoplasty on Chinese patients with glaucoma or ocular hypertension: average 35 months follow-up results

Background

Glaucoma is a group of eye diseases that can damage the optic nerve and cause vision loss. A novel technology micropulse laser trabeculoplasty (MLT) can use duty-circle subvisible laser pulses to treat glaucoma. The aim of this study is to evaluate the efficacy of 360° MLT to alleviate intraocular pressure (IOP) in patients with glaucoma.

Methods

This was a single-center prospective study on patients treated with 360° MLT using a Diode True-Yellow 577-nm Laser with MicroPulse technology. All the patients were recruited from the Department of Ophthalmology. Follow-up visits were carried out at 1 day, 1 week, 1 month, 3 months, 6 months, 18 months, and 36 months after the procedure. Best-corrected visual acuity (BCVA), Intraocular pressure (IOP), and vertical cup-to-disc ratio (C/D ratio) were measured during the follow-up. Repeated-measures analysis of variance (ANOVA) and Kaplan–Meier analysis were performed to evaluate the outcomes.

Results

A total of 39 eyes from 25 patients were included in this study (10 men/15 women). The average age of patients was 41.47 ± 14.39 years old, and the baseline IOP was 21.13 ± 7.75 mmHg. MLT significantly reduced the IOP at 1 day (range 15.61–19.01, P = 0.0218), 3 months (range 16.47–19.22, P = 0.0390), and 6 months (range 15.38–18.56, P = 0.0332) compared with the baseline. However, by the end of the study, only 21.88% of patients demonstrated a ≥ 20% IOP reduction, while seven eyes needed further laser or surgical treatment. The IOP of glaucoma patients was significantly lower than the ocular hypertension patients at 1 month (P = 0.0124), 3 months (P = 0.0004), 18 months (P = 0.0061) and 36 months (P = 0.0119).

Conclusions

Micropulse laser trabeculoplasty reduce IOP in patients with glaucoma or ocular hypertension for a short period, but its lowering efficiency is limited up to 6 months of the follow-up period.

Detection of Intraocular Hypertension during Opportunity Screening (Check-Up Medical Inspections)

The aim of the study is the early detection of OHT (Ocular hypertension) in patients, in the activity of secondary prophylaxis (opportunity screening-medical check-up), to prevent blindness caused by POAG (Primary Open Angle Glaucoma). In Romania, medical examination of personnel with responsibilities in Transport Safety (TS) is legally regulated, being mandatory as a result of the internal transposition of European legislation in the field. The addressability of the patients for examination was determined by personal choice, depending on the accessibility of the medical service on the profile market (availability and price). The design of the study is epidemiological, observational, descriptive and retrospective. The standardized medical protocol included: personal medical history (anamnesis), physical ophthalmological examination, Intraocular pressure (IOP) measurement and Visual Field (VF) performance, with Automated Perimeter “Optopol PTS 910” through “Fast Threshold” strategy. The specialized medical research was completed with a dichotomous questionnaire entitled “Symptom Inventory”, made according to the recommendations of patients resulting from “Focus group” research. The study was carried out within the “Check-up” type medical controls upon request, only for personnel with positions in Transport Safety (TS), during January−December 2021 at S.C. ARTIMED S.R.L. Oradea, Bihor County. Health analysis was performed for 820 people, of whom 71 people (8.65%) tested positive for IOP > 21 mmHg, (suspected OHT) compared to 749 (91.35%) with normal values (Normal intraocular pressure-NIOP); the two lots being statistically significantly different (x2 = 560.590, df = 1, p = 0.000). The study involved 754 men (92.0%) and 66 women (8.0%), the sex ratio is 11.42 (Exp (B) = 0.782, Sig = 0.558, 95% CI = 0.343−1783; sex is not a significant predictor at the 5% level). The prevalence of OHT was 8.66% for the whole group, 8.48% for men and 10.60% for women. In the screening action for the whole group of patients the following was determined: IOP reference = 20.85 mmHg, Sensitivity (Se) = 91.5% and 1-Specificity (Sp) = 0.073, (Sp = 92.7%). The predictive value of the screening test was: Positive Predictive Value (PPV) = 90.1% and Negative Predictive Value (NPV) = 91.7%; Area under the ROC Curve (Receiver Operating Characteristic) = 0.986, Sig. = 0.000, CI95% = 0.979−0.993. A binary logistical model of a questionnaire was developed to determine the screening parameters which significantly predicted OHT: IOP (OR = 4.154, 95% CI: 3.155−5.469), Age < 40 years (OR = 0.408, 95% CI: 0.239−0.698) and Pattern Defect (PD) (OR = 1.475% CI: 1.130−1.925). The results of this study assess health status through regular medical examinations, and highlight their importance and usefulness in secondary prevention activity. The particularity of this “check-up” type for personnel with attributions in transport safety is based on two essential aspects: the legal obligation to perform it and the fact it is financed by the beneficiary (the employer). In patients suspected of OHT after antiglaucoma treatment, IOP statistically significantly decreased.

Structure-function models for estimating retinal ganglion cell count using steady-state pattern electroretinography and optical coherence tomography in glaucoma suspects and preperimetric glaucoma: an electrophysiological pilot study

PURPOSE

To derive and validate structure-function models for estimating retinal ganglion cell (RGC) count using optical coherence tomography (OCT) and steady-state pattern electroretinography (ssPERG) parameters in glaucoma suspects (GS) and preperimetric glaucoma (PPG).

METHODS

In this prospective cross-sectional study, 25 subjects (50 eyes) were recruited at the Manhattan Eye, Ear, and Throat Hospital. Subjects underwent comprehensive eye examinations, OCT, standard automated perimetry (SAP), and ssPERG testing. Eyes were divided into three groups based on the Global Glaucoma Staging System: healthy (N = 30), GS (N = 10), and PPG (N = 10) eyes. The combined structure-function index (CSFI), which estimates retinal ganglion cell count (eRGC_CSFI) from SAP and OCT parameters, was calculated in each study subject. Two prediction formulas were derived using a generalized linear mixed model (GLMM) to predict eRGC_CSFI from ssPERG parameters, age, and average retinal nerve fiber layer thickness (ARNFLT) in 30 eyes selected at random (training group). GLMM predicted values were cross-validated with the remaining 20 eyes (validation group).

RESULTS

The ARNFLT, ssPERG parameters magnitude (Mag) and magnitudeD (MagD), and eRGC_CSFI were significantly different among study groups (ANOVA p ≤ 0.001). Pearson correlations demonstrated significant associations among ARNFLT, ssPERG parameters, and eRGC_CSFI (r² ≥ 0.31, p < 0.001). Two GLMMs predicted eRGC_CSFI from Mag (eRGC_Mag) and MagD (eRGC_MagD), respectively, with significant equations (F(3,18), F(3,19) ≥  58.37, R² = 0.90, p < 0.001). eRGC_Mag and eRGC_MagD in the validation group (R² = 0.89) correlated with eRGC_CSFI similarly to the training group. Multivariate pairwise comparisons revealed that eRGC_Mag and eRGC_MagD distinguished between healthy, GS, and PPG eyes (p ≤ 0.035), whereas independent Mag, MagD, and ARNFLT measures did not distinguish between GS and PPG eyes.

CONCLUSION

This pilot study offers the first combined structure-function models for estimating RGC count using ssPERG parameters. RGC counts estimated with these models were generalizable, strongly associated with CSFI estimates, and performed better than individual ssPERG and OCT measures in distinguishing healthy, GS, and PPG eyes.

Correlation Between Central Corneal Thickness and Radial Peripapillary Capillary Density, in Patients With Ocular Hypertension

Purpose To investigate any possible relationship between the central corneal thickness and the radial peripapillary capillary density detected by optical coherence tomography (OCT) angiography in eyes with ocular hypertension. Materials and methods In this observational study, 135 eyes were examined. OCT angiography of the optic disc (4.5 mm) and ultrasound corneal pachymetry were performed in all cases. Age, medical treatment for ocular hypertension, sex, and retinal nerve fiber layer thickness were evaluated. The main indices of blood flow were also examined. Spearman correlation coefficients were used to explore the association between two continuous variables. Results A directly proportional significance regarding the correlation between central corneal thickness and radial peripapillary network was indicated in eyes with ocular hypertension (p = .036). Conclusions Central corneal thickness and radial peripapillary capillary density constitute two essential screening parameters for patients with ocular hypertension.

Management of the open angle glaucoma in patients with central/hemicentral retinal vein occlusions

AIM

To prospectively assess the cumulative prevalence and management of open angle glaucoma (OAG), including primary open angle glaucoma (POAG) with high and normal-pressure, as well as pseudoexfoliative glaucoma (PEXG), in patients with central/hemicentral retinal vein occlusions (RVOs) over a 3-year follow-up period.

METHODS

The study encompassed 57 patients with unilateral acute central/hemicentral RVOs. A complete ophthalmic examination of both eyes was undertaken for all patients. Patients with OAGs associated with central/hemicentral RVOs were treated with the current ocular hypotensive medications used worldwide and/or surgery and aimed to reduce the intraocular pressure (IOP) by 30% from baseline values for the 3 OAG forms existing in our series. The cumulative prevalence of OAG and the efficacy of treatment were evaluated.

RESULTS

OAG was observed in 3 clinical forms, namely, POAG with increased IOP in 4 patients, POAG with normal IOP in 3 patients, and PEXG in 3 patients. The cumulative prevalence of OAG was 19.6% (95%CI: 8.7-30.5). Using available ocular hypotensive medications (8 patients) and trabeculectomy (2 patients), the IOP decreased significantly from 24.3±4.36 mm Hg to 16.55±2.85 mm Hg, a reduction of 31.89% compared with baseline values. Glaucoma progression was not detected in any of the cases.

CONCLUSION

The high value of the cumulative prevalence of OAG is a risk factor for the development of venous occlusion. The treatment of glaucoma prevented its progression over a follow-up period of 3y.

Analysis of choroidal thickness in ocular hypertensive patients using enhanced depth imaging optical coherence tomography

This study aimed to compare choroidal thickness between subjects with ocular hypertension (OHT) and normal individuals and explore factors affecting choroidal thickness. This study included 60 untreated newly diagnosed OHT eyes and 60 normal eyes. Choroidal thickness obtained from Cirrus HD-OCT was measured at different locations in the macular and peripapillary regions and compared between the two groups before and after adjusting for potential confounding variables. Regression analysis was performed to figure out factors influencing choroidal thickness. The macular choroidal thickness did not vary significantly between OHT patients and normal controls regardless of locations (all P > 0.05). The average peripapillary choroidal thickness was 167 ± 53 μm in OHT eyes and 185 ± 63 μm in the normal eyes; no significant differences were identified (P = 0.107). Only one of the locations in the temporal area in the OHT group demonstrated significantly thinner peripapillary choroidal thickness as compared to the normal group (P = 0.033). Age was the only significant factor affecting choroidal thickness on multivariate analysis regardless of locations (all P < 0.001). Choroidal thickness of the macular and peripapillary regions in OHT patients is not decreased significantly except one location in the temporal area of the optic disc when comparing with the normal subjects. Anatomic peripapillary choroidal thickness measurements with SD-OCT might be one more tool to track changes in OHT patients.

Automated Retinal Layer Segmentation Using Spectral Domain Optical Coherence Tomography: Evaluation of Inter-Session Repeatability and Agreement between Devices

Retinal and intra-retinal layer thicknesses are routinely generated from optical coherence tomography (OCT) images, but on-board software capabilities and image scaling assumptions are not consistent across devices. This study evaluates the device-independent Iowa Reference Algorithms (Iowa Institute for Biomedical Imaging) for automated intra-retinal layer segmentation and image scaling for three OCT systems. Healthy participants (n = 25) underwent macular volume scans using a Cirrus HD-OCT (Zeiss), 3D-OCT 1000 (Topcon), and a non-commercial long-wavelength (1040nm) OCT on two occasions. Mean thickness of 10 intra-retinal layers was measured in three ETDRS subfields (fovea, inner ring and outer ring) using the Iowa Reference Algorithms. Where available, total retinal thicknesses were measured using on-board software. Measured axial eye length (AEL)-dependent scaling was used throughout, with a comparison made to the system-specific fixed-AEL scaling. Inter-session repeatability and agreement between OCT systems and segmentation methods was assessed. Inter-session coefficient of repeatability (CoR) for the foveal subfield total retinal thickness was 3.43μm, 4.76μm, and 5.98μm for the Zeiss, Topcon, and long-wavelength images respectively. For the commercial software, CoR was 4.63μm (Zeiss) and 7.63μm (Topcon). The Iowa Reference Algorithms demonstrated higher repeatability than the on-board software and, in addition, reliably segmented all 10 intra-retinal layers. With fixed-AEL scaling, the algorithm produced significantly different thickness values for the three OCT devices (P<0.05), with these discrepancies generally characterized by an overall offset (bias) and correlations with axial eye length for the foveal subfield and outer ring (P<0.05). This correlation was reduced to an insignificant level in all cases when AEL-dependent scaling was used. Overall, the Iowa Reference Algorithms are viable for clinical and research use in healthy eyes imaged with these devices, however ocular biometry is required for accurate quantification of OCT images.

Optical Quality and Related Factors in Ocular Hypertension: Preliminary Study

Background. To evaluate the optical quality and related factors in patients with ocular hypertension (OHT). Methods. This was a prospective case-control study. A total of 12 eyes with OHT and 20 control eyes underwent testing with Optical Quality Analysis System II (OQAS II) to evaluate the modulation transfer function cut off frequency (MTF cutoff), the Strehl 2D ratio (SR), objective scatter index (OSI), tear-film mean OSI (TFOSI), and the OQAS values (OV100%,OV20%, and OV9%). Results. The optical quality of patients with OHT declined, with lower MTF cutoff (OHT 36.86 ± 7.11 cpd , controls 48.50 ± 4.04 cpd, t = −4.60, P < 0.05), lower SR (OHT 0.22 ± 0.04, controls 0.27 ± 0.05, t = −2.72, P < 0.05), lower OV100% (OHT 1.26 ± 0.25, controls 1.61 ± 0.14, t = −4.03, P < 0.05), lower OV20% (OHT 1.27 ± 0.27, controls 1.72 ± 0.20, t = −4.00, P < 0.05), and lower OV9% (OHT 1.30 ± 0.25, controls 1.69 ± 0.32, t = −2.28, P < 0.05). There were not any statistically significant differences in OSI and TFOSI. The MTF cutoff in patients with OHT was correlated significantly with age (r = −0.59, P < 0.05). Conclusions. Optical quality of patients with OHT is reduced, with lower MTF cutoff, SR, OV100%, OV20%, and OV9%. MTF cutoff is negatively related to age.

Glaucoma Suspect: Diagnosis and Management

Glaucoma suspect is a diagnosis reserved for individuals who do not definitively have glaucoma at the present time but have characteristics suggesting that they are at high risk of developing the disease in the future based on a variety of factors. This review provides a practical approach to individuals classified as glaucoma suspects caused by one or more of the following risk factors or indicators of disease: ocular hypertension, optic nerve features suggestive of glaucoma, visual field abnormalities, and other characteristics placing them at greater risk than the average population. In addition to diagnostic considerations, this overview provides information on therapeutic approaches to the glaucoma suspect.