Unilateral Primary Open-angle Glaucoma Research Articles

Macular and Peripapillary Vascular Densities in Non-Glaucomatous Eyes of Patients with Unilateral Glaucoma.

Our purpose was to investigate vascular alterations in the non-glaucomatous eyes of patients with unilateral primary open angle glaucoma using optical coherence tomography angiography and to evaluate the role of vascular damage in glaucoma pathogenesis. This cross-sectional study included 60 eyes of 30 patients with unilateral glaucoma (63.4±8.8 years) and 30 eyes of 30 healthy subjects (65.6±9.1 years). Three groups were formed: group A, affected eyes of unilateral glaucoma patients; Group B, non-glaucomatous eyes of unilateral glaucoma patients; and group C, healthy controls. When group A was compared with groups B and C, significant differences were detected in rim area, cup volume, mean cup/disc ratio, and retinal nerve fiber layer thickness parameters (p<0.001 for all). No significant difference was detected between groups B and C (p>0.05 for all). In peripapillary and macular vessel density (VD) comparisons, all parameters except intradisc VD were found to be lower in group A (p<0.0167 for all). No statistically significant difference was detected between groups B and C (p>0.05 for all). The VD values in eyes with glaucoma were found to be lower than in the other two groups. However, no difference was observed between the non-glaucomatous eyes of glaucoma patients and those of healthy individuals. Thus, the results did not support our hypothesis that VD alterations would be observed in the fellow eyes of patients with unilateral glaucoma if the vascular pathway were responsible in the pathogenesis of glaucoma.

The choroidal microvasculature of the parapapillary area as a biomarker of glaucoma development in the fellow eye of patients with unilateral glaucoma.

To investigate the factors associated with the development of glaucoma in the healthy eyes of unilateral glaucoma patients. This was a retrospective observational case series study. All participants had unilateral primary open-angle glaucoma at the initial visit and were divided into two groups: one in which the fellow eyes developed glaucoma during the follow-up period and one in which the fellow eyes remained healthy. A complete ophthalmic examination, including best-corrected visual acuity testing, slit-lamp examination, intraocular pressure measurement, retinal nerve fiber layer and optic disk photographs, a 30-2 visual field test, and optical coherence tomography with angiography, was performed over a follow-up period of at least 3years. A total of fifty-six patients were enrolled, and over the course of the study period, 11 patients developed glaucoma in the fellow eyes, while the fellow eyes of 45 patients remained healthy. At the baseline, the glaucomatous eye had a larger area of beta parapapillary atrophy, lower parapapillary choroidal vascular density (pCVD) within the area, and a lower prevalence of microvascular dropout than normal fellow eyes (P < 0.001, 0.013, 0.001, respectively). In the multivariate analysis, a reduced pCVD in the gamma parapapillary atrophy (γPPA) region was significantly associated with the development of glaucoma in normal eyes (odds ratio, 0.566; 95% CI, 0.342, 0.935; P = 0.026). The pCVD within the γPPA region at baseline is the risk factor for the development of glaucoma in the normal fellow eye of patients with unilateral glaucoma.

Sub-foveal choroidal thickness in both eyes of patients with unilateral primary open-angle glaucoma and related influencing factors

Objective: To investigate and compare the sub-foveal choroidal thickness (SFCT) in both eyes of patients with unilateral primary open-angle glaucoma (POAG) and healthy controls. Methods: Cross-sectional study. Patients with unilateral POAG and healthy controls were recruited from September 2018 to September 2019 in the Beijing Tongren Hospital. All subjects underwent enhanced depth imaging optical coherence tomography. The SFCT was measured at the fovea, and at 500 μm, 1 000 μm and 2 000 μm nasal and temporal to the fovea. Paired t test was conducted to compare the choroidal thickness between affected POAG eyes and unaffected fellow eyes. Analysis of covariance was conducted to compare the choroidal thicknesses between POAG eyes and controls. Multiple regression analysis determined the association between choroidal thickness and age, gender, spherical equivalent and mean deviation. Results: Seventy-five patients with unilateral POAG (mean age, 46 years; 48 males, 27 females) and 61 healthy controls (mean age, 44 years; 34 males, 27 females) were included in this study. The SFCT of POAG eyes was (244.41±83.18) μm, which was not significantly different from their unaffected fellow eyes [(254.28±88.92) μm, P>0.05] and controls (right eyes) [(272.98±55.87) μm, P>0.05]. Choroidal thickness at 2 000 μm nasal to the fovea was significantly decreased in the glaucomatous eyes compared with the unaffected fellow eyes [(167.84±70.44) vs. (188.84±89.06) μm, t=-3.55; P<0.01]. There were no significant differences among the glaucomatous eyes, unaffected fellow eyes and healthy controls in choroidal thickness at 500 μm and 1 000 μm nasal and temporal to the fovea, as well as at 2 000 μm temporal to the fovea (all P>0.05). The SFCT of POAG eyes was associated with mean deviation (β=14.66, P<0.05) and spherical equivalent (β=14.95, P<0.01) but not with age and gender (both P>0.05). Conclusions: The SFCT of affected eyes in patients with unilateral POAG has no significant difference from unaffected fellow eyes and healthy controls. However, the choroidal thickness at 2 000 μm nasal to the fovea is thinner in the POAG eyes as compared with the fellow eyes. A thinner SFCT is correlated with the loss of visual field and a higher spherical equivalent in myopia. This may suggest a contributing role of the perfusion of the choroid in the pathogenesis of glaucoma. (Chin J Ophthalmol, 2021, 57: 194-200).

Investigating the effects of glaucomatous damage on the multifocal visual evoked potential parameters.

To investigate the effects of glaucomatous damage on the mfVEP parameters of patients suffering from primary open-angle glaucoma (POAG). Fifteen healthy subjects and 15 patients with unilateral POAG participated in this study. In addition, routine ophthalmological examinations including visual acuity, anterior segment examination, posterior segment examination, intraocular pressure, mfVEP with electrophysiological system, RETI-port/Scan 21, and visual field test with automated Humphrey ZEISS HFA II 750i Perimeter were also performed. The results show that there was a strong correlation between the ∆MDs and the number of abnormal points with the ∆amplitudes more than 256nV, in patients (n = 15, r = 0.802, p < 0.05), but no correlations were found between the mean sensitivity differences (ΔPSDs) and mfVEP parameters. Comparing the monocular mfVEP responses from both eyes is an appropriate method to detect unilateral damage. Achievement of more development and making the mfVEP test more functional can be a solution for early diagnosis in most of the eye diseases.

Investigating the effects of glaucomatous (POAG) damage on the mVEP parameters

Introduction: Glaucoma is considered as a major cause of irreversible vision loss, worldwide. Glaucoma includes a diverse ophthalmopathies characterized by attenuating the neural and connective tissue segments and eventually progression of specific patterns of visual dysfunction. Currently, perimetry is known as the most accurate diagnostic method in glaucoma and its follow up. For all patients with visual field defects, automated perimeters, such as the Humphrey Field Analyzer (HFA), enable rapid screening. This technique suffers from some disadvantages. Electrodiagnosis could be considered as an optional method in ophthalmology. Two important aspects of this method are its functionality and objectivity. The main purpose of this study is to investigate the effects of glaucomatous damage on the mfVEP parameters of patients suffering from primary open angle glaucoma (POAG). Materials and Methods: The study was conducted at the ophthalmology clinic of Imam Khomeini hospital of Ahvaz. 15 healthy subjects and 15 patients with POAG. In addition to routine ophthalmological examinations including visual acuity, anterior segment examination, posterior segment examination, intra-ocular pressure, mfVEP with electrophysiological system, Reti Port/Scan 21 and visual field test with automated Humphrey ZEISS HFA II 750i Perimeter were also performed. All patients were categorized as unilateral POAG. The MD and PSD in more involved eyes in POAG patients were -6.72 (SD= ± -5.61) and 5.6 (SD= ± 4.95), respectively. To obtain an mfVEP, the low- and high- frequency cut off of recording was amplified at 1 and 100 Hz. The sample rate was set at about 1020 times per second. Results: In this study, visual field assessing using mfVEP was applied to diagnose glaucomatous damage and also to determine the correlation of the ΔmfVEP parameters with the Δglobal indices (MD and PSD) between the two eyes of each patient by three following approaches. In the first and the second methods, intersubject and intrasubject comparisions between Δglobal indices of the HFA in the interpolated visual fields and ΔmfVEP parameters were done and no correlations were found. In the third method, the correlation between the number of points in each sector of mfVEP with the Δamplitude and the Δlatency in each patient (> mean ± 2SD) was determined. Moreover, the correlation of those points with the Δglobal indices of patients was clarified. there was a strong correlation between the ∆MDs and the number of abnormal points with the ∆amplitudes more than 256 nV, in POAG subjects (n = 15, r = 0.802, p <0.05). Conclusion: Comparing the monocular mfVEP responses from both eyes is an appropriate method to detect unilateral damage. Achievement of more development and making the mfVEP test more functional, can be a solution for early diagnosis in most of the eye diseases.

Concordance of 24-h intraocular pressure curve in patients with untreated unilateral primary open-angle glaucoma.

The present study aimed to assess the concordance of 24-h intraocular pressure (IOP) curves between glaucomatous and contralateral eyes for patients with untreated unilateral primary open-angle glaucoma (POAG). A total of 32 patients with unilateral POAG and 32 age-matched normal subjects were enrolled. The IOP measurements were performed every 2 h over a 24-h period. The concordance of the 24-h IOP curves was assessed via the correlation coefficient (r), intraclass correlation coefficient (ICC) and repeated-measures analysis of variance (ANOVA). No significant difference was identified between all IOPs, as well as the mean, peak and trough IOP or IOP fluctuations of the paired eyes in the two groups. The strength of association of all IOPs was moderate in the glaucoma group (r, 0.752-0.867) and the normal controls (r, 0.625-0.873). IOP readings at each time-point indicated a high agreement in the glaucoma group (ICC, 0.857-0.929) and the normal controls (ICC, 0.768-0.932). Repeated-measures ANOVA indicated that the 24-h IOP curves of the paired eyes had parallel profiles in the two study groups (P=0.837 and P=0.897, respectively). The glaucoma patients had significantly higher proportions of all IOPs displaying absolute differences of ≥2 and ≥3 mmHg (46.09 vs. 35.68%, P<0.001; 29.69 vs. 12.50%, P<0.001, respectively). In conclusion, the 24-h IOP curves of the paired eyes had parallel profiles in unilateral glaucoma patients and normal subjects. However, unilateral glaucoma patients had a significantly larger proportion of IOP differences of ≥2 and ≥3 mmHg.

Spontaneous Retinal Venous Pulsation in Unilateral Primary Open-angle Glaucoma With Low Intraocular Pressure.

The aim of this study was to investigate the presence of spontaneous retinal venous pulsation (SVP) in patients with unilateral primary open-angle glaucoma (POAG) and low intraocular pressure (IOP). The SVP of 93 POAG patients with unilateral glaucoma and untreated IOP of ≤21 mm Hg was assessed using the movie tool of a confocal scanning laser ophthalmoscope (Spectralis HRA; Heidelberg Engineering). The frequency of SVP was compared between the glaucomatous and fellow eyes. Intereye differences in the frequency of SVP were assessed using McNemar test. A linear mixed-effect model was used to determine the factors associated with glaucomatous eyes, taking into account clustering of eyes within subjects. Forty-five patients had SVP in both eyes and 15 had SVP in neither eye. Of the remaining 33 patients who showed SVP only in 1 eye, 31 had SVP only in the fellow eye, and 2 had SVP only in the glaucomatous eye. The SVP was significantly less prevalent in glaucomatous eyes (50.5%) than in fellow control eyes (81.7%) (P<0.001). In the linear mixed-effect model, the presence of SVP (P<0.001) and higher untreated IOP (P=0.001) were the significant predictors for glaucoma. SVP was less frequently found in glaucomatous eyes than healthy fellow eyes in unilateral POAG patients with low IOP.

Segmental Analysis of Macular Layers in Patients With Unilateral Primary Open-Angle Glaucoma.

To measure the thicknesses of the inner layers of the macula in both eyes of patients with unilateral primary open-angle glaucoma (POAG) and compare them with normal control eyes. This prospective, cross-sectional pilot study enrolled patients with unilateral POAG, who had visual field defect in only 1 eye, and controls with a normal eye examination. Horizontal and vertical B-scan images centered on the fovea were obtained using spectral domain optical coherence. Semiautomatic delineation and segmentation of the inner layers of the retina were performed to evaluate macular retinal nerve fiber layer (mRNFL), ganglion cell complex (GCC) and ganglion cell-inner plexiform layer (GC-IPL) thicknesses. Mean, superior, inferior, nasal, and temporal inner macular layer thicknesses were compared between affected eyes, fellow eyes without visual field defect, and control eyes. Nineteen patients with unilateral POAG and 14 normal control eyes were enrolled. In the affected POAG eyes, thinning of the mRNFL, GCC, and GC-IPL layers on horizontal and vertical scans were significant when compared with controls (P<0.05), particularly on vertical scans (P<0.001). The mean regional macular GCC and GC-IPL were most severely thinned in the inferior and temporal perifoveal regions. The unaffected eye of patients with unilateral POAG showed significant thinning of the mRNFL only in the vertical scan when compared with normal controls (P<0.05). Spectral domain optical coherence tomography detected significant thinning of the mRNFL, GCC, and GC-IPL in the affected eyes of patients with unilateral POAG. Fellow eyes showed early structural changes only in the vertical mRNFL scans when compared with normal controls.

Functional effects of unilateral open-angle glaucoma on the primary and extrastriate visual cortex.

The purpose of this study was to use functional magnetic resonance imaging (fMRI) to investigate the response of the visual cortex to unilateral primary open-angle glaucoma (POAG). Specifically, we assessed whether regions of V1 and V2 with lost input from the glaucomatous eye had a greater response to input from the nonaffected fellow eye. Nine participants with unilateral POAG causing paracentral visual field defects and four controls participated in the study. We found no evidence for an increased response to the fellow eye in glaucoma-affected regions of the visual cortex; however, in agreement with previous studies, there was a pronounced, retinotopically localized reduction of activation in both the primary (V1) and extrastriate visual cortex (V2), when participants viewed through their glaucomatous eye. Our results suggest a remarkable level of stability within the adult primary and extrastriate visual cortex in response to unilateral neurodegeneration of the optic nerve.

Comparison of trabeculectomy with Ex-PRESS shunt implantation in primary-open-angle-glaucoma patients: A retrospective study

PurposeTo investigate the efficacy of intraocular pressure (IOP) control and medication use over time after trabeculectomy (TRBC) and Ex-PRESS shunt implantation in primary-open-angle-glaucoma (POAG) patients. DesignRetrospective case series. Patients and methodsA total of 33 unilateral POAG patients were enrolled, and 17 patients received traditional TRBC and 16 patients received Ex-PRESS device implantation. Data on IOP, reduction of antiglaucoma medication, and major complications were collected and analyzed after 12 months of follow up. ResultsAfter 12 months of follow up, both groups showed good IOP control. The mean preoperative IOP decreased from 38.5 (±6.9) to 18.2 (±11) mmHg after TRBC, and from 38.5 (±9.1) to 19.53 (±12.36) mmHg after Ex-PRESS implantation (both p < 0.05). The mean number of antiglaucoma medications prescribed at the last follow up decreased from 3.2 (±0.5) preoperatively to 1.2 (±1.4) after TRBC versus 3.3 (±0.7) preoperatively to 1 (±0.9) after Ex-PRESS implantation (both p < 0.05). Complete success rate (defined as no medication after surgery with IOP >5 and <18 mmHg) and qualified success rate (defined as with or without medication after surgery with IOP >5 and <18 mmHg) were similar (47% vs. 43% and 76.47% vs. 75%) between the two groups without statistical difference (p > 0.05). However, postoperative hypotony rate was more frequent after Ex-PRESS (37.5%) than after TRBC (17.64%). DiscussionTRBC and Ex-PRESS implantation provided similar IOP control and reduction of postoperative medication with low incidence of postoperative complications at intermediate-term follow up. However, the Ex-PRESS implantation device may last longer but with extra costs. It is up to the surgeon to decide which procedure to use according to the patient's situation and economic circumstances.

Corneal biomechanics measured with the ocular response analyser in patients with unilateral open-angle glaucoma

To evaluate the relationship between biomechanical properties of the cornea and intraocular pressure (IOP) and the role of biomechanical properties in eyes of patients with unilateral primary open-angle glaucoma (POAG). The biomechanical properties of corneal hysteresis (CH) and the corneal resistance factor (CRF) were measured with the ocular response analyser (ORA). In an experimental setting, three human donor eyes with Schiotz-tonometry-controlled IOP were investigated. In addition, a series of patients with unilateral POAG were evaluated. Main outcome measures were CH, CRF, corneal-compensated IOP (IOPcc), standard automated perimetry parameters mean defect (MD) and pattern standard deviation, central corneal thickness, Goldmann applanation tonometry (GAT), and cup-to-disc ratio. A highly significant linear correlation between CH and the corneal-compensated IOP (IOPcc, r = -0.926; p < 0.001) was found. The correlation between IOP(CC) and CRF was not significant (r = 0.335; p = 0.08). In total, 36 eyes of 18 patients with unilateral POAG were examined. Regarding uncorrected CH (mean 7.73 ± 1.46 mmHg glaucomatous eye and 9.28 ± 1.42 mmHg fellow eye), there was a highly significant difference between both eyes. This difference disappears, when CH was corrected for IOP (9.44 ± 3.78 mmHg and 9.97 ± 3.22 mmHg, respectively). Corneal hysteresis but not corneal resistance factor is dependent on IOP. In patients with unilateral POAG, IOP is higher in the affected eye. When CH is corrected for IOP, corneal biomechanical properties do not differ in both eyes of patients with unilateral POAG.

Deepening of eyelid superior sulcus during topical travoprost treatment

Topical travoprost, a prostaglandin F(2alpha) (PGF(2alpha)) analog, has several well-known side effects, including a darkening of the eyelid and eyelash hypertrichosis, but there are no reports of a deepening of the eyelid superior sulcus associated with its use. We examined one patient with unilateral normal-tension glaucoma and another with unilateral primary open-angle glaucoma, both of whom were treated with travoprost monotherapy unilaterally for 2 years. Both patients gradually developed a deepening of the eyelid superior sulcus with hyperpigmentation in the eyelid skin of the treated eye. The disparity between the treated eye and the fellow eye was quite visible. However, the disparity returned to normal after discontinuation of travoprost for 15 months. A deepening of the eyelid superior sulcus is more significant in Asians, who seldom have an eyelid crease or deep sulcus. One proposed mechanism is a mechanical insult to the eyelid causing levator dehiscence. A second possible mechanism is fatty degeneration and reduced collagen fibers in the levator complex caused by the PGF(2alpha) analog. However, the exact mechanism remains to be determined. A deepening of the eyelid superior sulcus should be considered a possible complication of topical travoprost that can be reversed by discontinuation of the medication.