Structural Reversal of Disc Cupping After Trabeculectomy Alters Bruch Membrane Opening-Based Parameters to Assess Neuroretinal Rim

Hemodialysis-induced positional changes in lamina cribrosa

This study is aimed to investigate the effect of hemodialysis (HD) on the lamina cribrosa (LC) of the optic nerve head (ONH) using swept-source optical coherence tomography (SS-OCT) and other ophthalmological parameters in patients with end-stage kidney disease (ESKD). This prospective observational study included 29 patients who underwent HD for ESKD. ONH parameters including neural canal diameter (NCD), peripapillary vertical height (PVH), and anterior LC depth (LCD), were assessed using SS-OCT. Changes in the ONH parameters before and after HD were statistically analysed. Correlations between changes in the LCD and other ocular and systemic measurements were identified using Pearson's correlation analyses. The mean anterior LCD significantly decreased from 441.6 ± 139.8 μm before HD to 413.5 ± 141.7 μm after HD (P = 0.001). Mean NCD and PVH did not show significant changes after HD (P = 0.841 and P = 0.574, respectively). A significant correlation was found between changes in the anterior LCD and the mean ocular perfusion pressure (r = 0.397, P = 0.036). We observed a significant decrease in anterior LCD after HD. Our study suggests that HD can influence the ONH, especially in the LC.

Susceptibility of optic nerve head in children with posture-related elevation of intraocular pressure

BACKGROUND/AIMS

This work aimed to investigate changes in optic nerve head (ONH) morphometry based on Bruch membrane opening in children with extensive nocturnal intraocular pressure (IOP) elevations.

METHODS

The course of Bruch membrane opening-based optic nerve head (ONH) morphometry was analysed in thirty-two patients younger than 18 years with evaluable SD-OCT examinations of the ONH and nocturnal posture-dependent IOP elevation above 25 mmHg. Longitudinal changes in neuroretinal rim tissue, as measured by Bruch Membrane opening minimum rim width (BMO-MRW) and peripapillary retinal nerve fiber layer (RNFL) thickness, were assessed.

RESULTS

One year after the 24 h IOP measurement, global BMO-MRW (- 1.61 ± 16.8 µm, n.s.; p = 0.611) and RNFL (+ 0.64 ± 3.17 µm; n.s.; p = 0.292) measurements were not significantly different from the baseline. No significant BMO-MRW reduction (- 3.91 ± 24.3 µm; n.s. p = 0.458) or deviation in RNFL thickness (+ 1.10 ± 3.52 µm) was observed at the four-year follow-up. Absolute IOP values measured in the supine position did not correlate with changes in global BMO-MRW or RNFL thickness.

CONCLUSION

Posture-dependent IOP elevations do not seem to influence retinal nerve fibre layer thickness or Bruch membrane opening-based morphometric data in childhood.

A comparative study of cystoid macula edema following glaucoma drainage device surgery versus trabeculectomy

PURPOSE

To assess and compare the risk for development of cystoid macula edema (CME) after glaucoma drainage device (GDD) implantation versus conventional trabeculectomy with mitomycin (trab) for glaucoma.

METHODS

Retrospective review of consecutive patients receiving trab or GDD implantation between 2016 and 2018. Inclusion criteria were availability of pre- and postoperative spectral domain optical coherence tomography (SD-OCT) of the macula. SD-OCT images were evaluated for presence of CME qualitatively, central subfield thickness (CST) and macular volume (MV).

RESULTS

73 eyes could be included, 42 received trab and 31 GDD surgery. Eyes receiving trab on average had 0.8 ± 0.8 previous intraocular operations, while eyes with GDD implantation had 3.1 ± 1.9 (p < 0.001). Occurrence of postoperative CME was significantly more frequent after GDD implantation (6 out of 31 (19.4%)) than after trab (2 out of 42 eyes = 4.8%), (p = 0.049). Mean preoperative CST as well as MV was comparable in both groups (CST before trab: 282.7 ± 23.0 µm, CST before GDD 284.2 ± 27.3 µm, p = 0.287; MV before trab: 7.8 ± 1.1 mm3, MV before GDD: 8.0 ± 0.8mm3, p = 0.305). Mean postoperative CST and MV were significantly higher after GDD (CST 338.5 ± 129.3 µm, MV 8.8 ± 2.6 mm3) than after trabeculectomy (CST 290.6 ± 60.2 µm, p = 0.038; MV 7.8 ± 1.2mm3, p = 0.039).

CONCLUSIONS

In real-life conditions, GDD surgery seems to be associated with a higher risk to develop CME when compared to conventional trabeculectomy. This information may be helpful for glaucoma surgeons to advise the patients on postoperative risks of surgery.

Longitudinal Rates of Change in Structural Parameters of Optical Coherence Tomography in Primary Angle Closure Glaucoma following Laser Iridotomy along with Peripheral Iridoplasty

Background

This study aimed to investigate longitudinal rates of change (LRCs) of structural parameters from optical coherence tomography (OCT) in patients with primary angle closure glaucoma (PACG) after laser iridotomy (LI) along with laser peripheral iridoplasty (PI).

Methods

Among 146 patients diagnosed with PACG, thirty-two subjects (32 eyes) who underwent LI plus PI and accomplished more than five times of reliable OCT tests were included in the current retrospective study. Retinal nerve fiber layer (RNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW) were measured by spectral-domain OCT with three month interval. LRCs of global and six Garway-Heath sectors were investigated using the linear mixed-effects model which adjusted BMO area, sex, and age. Imaging of dual Scheimpflug analyzer was performed before and at 1 week after LI with PI and yearly thereafter.

Results

The mean follow-up period was 32.28 ± 13.34 months with a mean number of 10.18 ± 3.33 OCT images. Baseline characteristics are as follows: age, 63 ± 7.9 years; female, 62.5%; intraocular pressure(IOP), 15.48 ± 4.79 mmHg; anterior chamber depth, 2.09 ± 0.18 mm; and mean deviation, -7.97 ± 8.48 dB. Global LRC of BMO-MRW was 0.86 ± 1.34 μm/yr and RNFL was -0.64 ± 0.22 μm/yr. IOP decreased significantly to 13.06 ± 2.21 mmHg (p=0.001) while anterior chamber volume (p=0.011) and mean anterior chamber angle (p=0.022) increased significantly after LI along with PI compared to the baseline at the final visit.

Conclusions

LRC of a new parameter, BMO-MRW, and LRC of RNFL were relatively low in patients with PACG, following LI along with PI. After widening of the anterior chamber angle and decrease of IOP due to LI plus PI, PACG might show stable structural prognosis assessed by OCT.

Changes of Optical Coherence Tomography Parameters after Cataract Surgery in Primary Open-Angle Glaucoma Eyes

PURPOSE

To investigate the impact of uncomplicated cataract surgery on the measurement of Bruch's membrane opening-minimum rim width (BMO-MRW) and retinal nerve fiber layer thickness (RNFLT) using spectral domain optical coherence tomography (SD-OCT) in primary open-angle glaucoma (POAG) patients.

METHODS

This retrospective study included 63 eyes of 63 patients, including 32 POAG eyes and 31 normal eyes who underwent uneventful cataract surgery and follow-up for at least 6 months. Using SD-OCT, BMO-MRW and RNFLT were measured preoperatively and postoperatively at 6 months. Paired t-test was used to compare intraocular pressure (IOP), BMO-MRW, RNFLT, and image quality before and after surgery. These parameters and their changes were compared between POAG and normal groups. Univariate and multivariate linear regression analyses were performed to determine the factors associated with the postoperative change (Δ) in RNFLT and BMO-MRW.

RESULTS

BMO-MRW and RNFLT were significantly increased and IOP was decreased after phacoemulsification in both groups (p < 0.001, respectively). The ΔRNFLT was significantly greater in POAG eyes compared with the normal eyes (p < 0.001). The ΔRNFLT was associated with the postoperative IOP reduction and glaucoma diagnosis (p < 0.001 and p = 0.001, respectively). In the normal group, only the ΔIOP had a significant influence on the ΔRNFLT (p = 0.003), but in the POAG group, not only the ΔIOP (p = 0.044) but also preoperative visual field mean deviation (p = 0.029) showed a significant influence. The ΔBMO-MRW showed no difference between POAG and normal eyes.

CONCLUSIONS

The postoperative increase of RNFLT was significantly greater in the POAG group, and the postoperative increase of RNFLT was associated with the preoperative visual field mean deviation and ΔIOP in POAG eyes and with the ΔIOP in normal eyes. Our results imply that RNFLT is more affected than BMO-MRW in POAG eyes compared to normal eyes by cataract surgery.

Two Year Functional and Structural Changes-A Comparison between Trabeculectomy and XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography

The aim of this study was to analyze retinal nerve fiber layer (RNFL) thickness after trabeculectomy (TE) versus XEN microstent implantation (XEN) in primary open-angle glaucoma (POAG) cases naïve to prior incisional glaucoma surgery. We examined 119 consecutive glaucoma patients retrospectively, who received a TE or XEN for medically uncontrolled POAG. Intraocular pressure (IOP), amount of IOP-lowering medication, mean deviation of standard automated perimetry and peripapillary RNFL thickness were evaluated during the first 24 months after surgery. Fifty eyes were treated with TE and 69 eyes with XEN. Mean IOP decreased from 25.1 ± 0.8 to 13.3 ± 0.6 mm Hg (p < 0.01) and mean number of IOP-lowering eye drops from 3.2 ± 0.2 to 0.4 ± 0.1 (p < 0.01) 24 months after TE. In 69 eyes undergoing XEN, mean IOP dropped from 24.8 ± 0.6 to 15.0 ± 0.4 mm Hg (p < 0.01) and medication from 3.0 ± 0.1 to 0.6 ± 0.1 (p < 0.01) during the 24 months follow-up. Mean deviation of standard automated perimetry remained stable in TE (8.5 ± 0.7 to 8.1 ± 0.8 dB; p = 0.54) and XEN group (11,0 ± 0.5 to 11.5 ± 0.5 dB; p = 0.12) after 24 months, while mean RNFL thickness further deteriorated in the TE (−2.28 ± 0.65 µm/year) and XEN (−0.68 ± 0.34 µm/year) group. Postoperative RNFL loss develops after TE and XEN despite effective and significant lowering of IOP and amount of IOP-lowering medication. RNFL loss was more pronounced in the first year after glaucoma surgery.

Comparison of lamina cribrosa depth shallowing after trabeculectomy between primary open-angle glaucoma and exfoliation glaucoma

The lamina cribrosa (LC) becomes shallower as intraocular pressure (IOP) decreases after trabeculectomy. The LC in eyes with exfoliation syndrome has distinctive properties in the connective tissue and extracellular matrix, but how these affect the changes in LC depth in response to IOP reduction after trabeculectomy is unknown. We analyzed pre- and postoperative spectral-domain optical coherence tomography of exfoliation glaucoma (XFG) and primary open-angle glaucoma (POAG) patients who underwent trabeculectomy and investigated whether LC depth differed between XFG and POAG eyes after trabeculectomy. In total, 30 XFG eyes and 30 visual field mean deviation-matched POAG eyes were included. LC depth was determined at an average of 3.9 months after trabeculectomy. Postoperatively, the LC depth became shallower and the BMO-MRW became thicker in both XFG and POAG eyes. XFG eyes showed lesser amount of LC depth shallowing than POAG eyes. Greater preoperative LC depth, lower postoperative IOP, and absence of XFG were all associated with a greater degree of postoperative LC depth shallowing. These findings suggest that the LC of XFG eyes may inherently possess the distinctive properties of the connective tissue and extracellular matrix contained within it, which could affect the LC response to the reduction in IOP after trabeculectomy.

The Effectiveness of Laser Peripheral Iridotomy in Adolescent Eyes with Ocular Hypertension and Concave Configuration of the Peripheral Iris

Purpose

To evaluate the efficacy of laser peripheral iridotomy (LPI) in preventing deterioration in eyes with ocular hypertension (OHT) and concave configuration of the iris.

Materials and Methods

This was a retrospective study, which was carried out within a period of 3–5 years. Twenty-four patients with OHT and concave irises were treated with LPI and followed up periodically. IOP, central corneal thickness (CCT), anterior chamber depth (ACD), scleral spur angle (SSA), global neuroretinal rim (NRR) thickness, and global retinal nerve fiber layer (RNFL) were examined before and after LPI.

Results

The average age of the 24 patients was 14.21 ± 1.41 (13–17.5) years on admission. The initial IOP of the 48 eyes was 23.21 ± 1.56 mmHg in RE and 22.96 ± 2.1 mmHg in LE before LPI. All 48 eyes had concave irises in both eyes. All eyes treated with LPI have shown iris flattening, which has persisted during follow-up (mean 1.54 ± 0.9 years). At the last follow-up visit, the average IOP was 17.58 ± 2.63 (14–21) mmHg in RE and 17.58 ± 2.86 (14–21) mmHg in LE, which was statistically lower than that of the baseline (p < 0.001). There were significant changes in SSA in both eyes and global RNFL in RE after LPI.

Conclusions

In the current study, LPI resulted in an IOP-lowering effect and iris flattening in adolescent eyes with a concave configuration of the peripheral iris.

Short-term changes in Bruch's membrane opening-based morphometrics during the first week after trabeculectomy

PURPOSE

To evaluate the dynamics of Bruch's membrane opening-based morphometrics of the optic nerve head (ONH) using spectral-domain optical coherence tomography (SD-OCT) during the first week after glaucoma surgery by trabeculectomy with mitomycin C.

METHODS

Prospective, longitudinal analysis of 25 eyes of 25 patients treated by trabeculectomy. Twenty-four eyes had evaluable postoperative SD-OCT examinations. Bruch's membrane opening minimum rim width (BMO-MRW) and peripapillary retinal nerve fiber layer (RNFL) thickness were analyzed at baseline before surgery, 1 day, 2 to 3 days, and 1 week after surgery. Changes compared to baseline were correlated to intraocular pressure (IOP).

RESULTS

One day after surgery, the mean BMO-MRW changed by + 26.17 µm, p = 0.001 (mean IOP reduction by 17.01 mmHg). This increase persisted on day 2-3 with a mean increase of BMO-MRW of + 25.33 µm, p = 0.001 (mean IOP reduction by 20.46 mmHg) and by week 1 with a mean BMO-MRW increase of + 33.17 µm, p < 0.001 (mean IOP reduction by 22.55 mmHg). The increase in BMO-MRW correlated significantly with the reduction of IOP on day 1 (Spearman's rho ρ = 0.656, p = 0.003) and d2-3 (Spearman's rho ρ = 0.479, p = 0.038). There was no statistically significant correlation found between the IOP and the increase in BMO-MRW in week 1. RNFL thickness showed no significant changes at day 1 as well as days 2-3 (p ≥ 0.078, respectively). It showed a small but significant increase in week 1 by 3.94 µm, p = 0.015.

CONCLUSIONS

Structural reversal of disc cupping in BMO-MRW occurs as early as 1 day after trabeculectomy and correlates to the extent of the IOP reduction. During the whole first week after surgery, a strong increase in BMO-MRW can be noted. The changes in BMO-based parameters need to be considered when evaluating patients' longitudinal follow-up.

Change of Retinal Vessel Density After Lowering Intraocular Pressure in Ocular Hypertension

Purpose: To investigate the relationship between retinal microvasculature changes and intraocular pressure (IOP) for ocular hypertension (OHT) patients and further assess the factors associated with retinal microcirculation changes.

Methods: This was a single-center prospective study designed for OHT patients, which consisted of two visits. After collecting baseline data of those who met the eligibility criteria, these patients were treated with latanoprost 0.005% ophthalmic solution for 4 weeks. Peripapillary vessel density (VD) of radial peripapillary capillaries (RPC) layer, macular VD in both superficial and deep layers, and foveal avascular zone (FAZ) area were measured by optical coherence tomography angiography (OCTA) before and after the treatment. We compared the changes in IOP and VD among the two visits by paired-sample t-test. Bonferroni correction was applied. Factors associated with VD changes were analyzed by linear regression analysis.

Results: Thirty-four eyes of thirty-four patients were included. The mean IOP decreased by 6.5 ± 2.2 mmHg (p < 0.001). The peripapillary RPC VD increased significantly from 51.8 ± 2.5 to 53.0 ± 3.1% (Adjusted-p = 0.012). We found no significant difference in detailed sectors of the peripapillary region after correction. In the macular area, both the superficial and deep layers in foveal (superficial: 0.2 ± 1.9%, p = 0.523; deep: 0.0 ± 2.3%, p = 0.969) and parafoveal (superficial: 0.3 ± 3.0%, p = 0.565; deep: 0.5 ± 3.1%, p = 0.423) VD remained unchanged. The decrease of the mean FAZ area was insignificant (p = 0.295). The percentage of IOP reduction (β = 0.330, p = 0.031) and the baseline RNFL thickness (β = 0.450, p = 0.004) significantly correlated with the percentage of peripapillary RPC VD improvement in the multivariate linear regression analysis.

Conclusion: The peripapillary VD in OHT patients increased after the reduction of IOP. The mild change of IOP did not alter the microcirculation in the macula. In addition, the percentage of IOP change and the baseline RNFL thickness were independent factors for the peripapillary RPC VD improvement.

A Decrease in Bruch's Membrane Opening-Minimum Rim Area Precedes Decreased Retinal Nerve Fiber Layer Thickness and Visual Field Loss in Glaucoma

PRCIS

A decrease in Bruch's membrane opening-minimum rim area, which represents the optic nerve head (ONH), preceded a decrease in the peripapillary retinal nerve fiber layer thickness (RNFLT) and the visual field index (VFI).

PURPOSE

This study aimed to investigate the relative comparison between a decrease in BMO-MRA, the peripapillary RNFLT, and the VFI, according to the severity of glaucoma.

MATERIALS AND METHODS

This retrospective cross-sectional study included 121 eyes (73 with open-angle glaucoma and 48 normal eyes). The ONH and retinal nerve fiber layer were analyzed using spectral domain optical coherence tomography, and VFI was obtained using the Humphrey Field Analyzer. The tipping points of RNFLT for VFI and BMO-MRA were estimated using broken-stick regression models. Polynomial regression analysis was performed, and the changes in the 3 parameters were expressed as a graph.

RESULTS

The tipping point of the RNFLT for the VFI was 88.62 μm [95% confidence interval (CI): 79.59-97.65; P=0.001]. The tipping point of the RNFLT for BMO-MRA was 60.00 μm (95% CI: 48.28-71.72; P=0.220). Above the tipping point, BMO-MRA decreased with a decrease in the RNFLT (slope=0.0135; 95% CI: 0.0115-0.0155; P<0.001); below the tipping point, BMO-MRA did not decrease significantly (slope=0.0002; 95% CI: -0.0177 to 0.0181; P=0.983). Polynomial regression analysis showed that with the progression of glaucoma, BMO-MRA decreased more rapidly, and this preceded a decrease in the RNFLT followed by a decrease in the VFI.

CONCLUSION

The ONH parameter, BMO-MRA, showed a faster decrease than RNFLT and VFI in early glaucoma. BMO-MRA may help detect early glaucomatous damage and its progression.

Factors Associated with Increased Neuroretinal Rim Thickness Measured Based on Bruch's Membrane Opening-Minimum Rim Width after Trabeculectomy

Purpose: To investigate the factors associated with an increase in the neuroretinal rim (NRR) thickness measured based on Bruch’s membrane opening-minimum rim width (BMO-MRW) after trabeculectomy in patients with primary open-angle glaucoma (POAG). Methods: We analyzed the BMO-MRW using spectral-domain optical coherence tomography (SD-OCT) of patients with POAG who underwent a trabeculectomy for uncontrolled intraocular pressure (IOP) despite maximal IOP reduction treatment. The BMO-MRW was measured before and after trabeculectomy in patients with POAG. Demographic and systemic factors, ocular factors, pre- and post-operative IOP, and visual field parameters were collected, together with SD-OCT measurements. A regression analysis was performed to investigate the factors that affected the change in the BMO-MRW after the trabeculectomy. Results: Forty-four eyes of 44 patients were included in the analysis. The IOP significantly decreased from a preoperative 27.0 mmHg to a postoperative 10.5 mmHg. The mean interval between the trabeculectomy and the date of post-operative SD-OCT measurement was 3.3 months. The global and sectoral BMO-MRW significantly increased after trabeculectomy, whereas the peripapillary retinal nerve fiber layer thickness did not show a difference between before and after the trabeculectomy. Younger age and a greater reduction in the IOP after the trabeculectomy were significantly associated with the increase in the BMO-MRW after trabeculectomy. Conclusions: The NRR thickness measured based on the BMO-MRW increased with decreasing IOP after trabeculectomy, and the increase in the BMO-MRW was associated with the young age of the patients and greater reduction in the IOP after trabeculectomy. Biomechanically, these suggest that the NRR comprises cells and substances that sensitively respond to changes in the IOP and age.

Structural Changes in the Optic Disc and Macula Detected by Swept-Source Optical Coherence Tomography After Surgical Intraocular Pressure Reduction in Patients with Open-Angle Glaucoma

Purpose

To evaluate the magnitude of change in optic disc, peripapillary retinal nerve fiber layer (RNFL) and macular parameters measured by swept-source optical coherence tomography (SS-OCT) in glaucomatous eyes after filtration surgery, and to determine any possible relationship between these measurements and baseline factors.

Patients and Methods

This multicenter, prospective, consecutive observational study included patients with open-angle glaucoma who required glaucoma filtering surgery (surgical group, 29 eyes) and those with stable disease (control group, 25 eyes). Patients from the surgical group underwent measurement of optic disc, peripapillary retinal nerve fiber layer (RNFL) and macular parameters before and after surgery.

Results

In the surgical group, there was a significant increase in rim area and a significant decrease in the linear cup/disc ratio, vertical cup/disc ratio and cup volume 1 and 2 months postoperatively (p< 0.05). No significant change in the mean RNFL thickness and also sectorial measurements were observed from baseline to 1 and 2 months after surgery (p>0.05). Furthermore, significant increases in macular parameters were observed until 2 months after surgery (p<0.05). No significant changes were observed for all SS-OCT measurements in the control group. There was a significant correlation between the magnitude of the structural measurements change and the IOP reduction for two topographic parameters (rim area and linear cup-disc ratio) and macular average thickness 1 month and 2 months postoperatively.

Conclusion

In open-angle glaucoma patients submitted to surgical IOP reductions, improvements in topographic and macular OCT parameters measured by SS-OCT were observed for at least 2 months.

Changes of Neuroretinal Rim and Retinal Nerve Fiber Layer Thickness Assessed by Optical Coherence Tomography After Filtration Surgery in Glaucomatous Eyes

Purpose

Lowering the intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG) with filtration surgery can induce morphological changes to the bulbus and structures of the retina. In this study, we have evaluated changes of Bruch's membrane-based parameters and retinal nerve fiber layer (RNFL) derived by spectral-domain optical coherence tomography (SD-OCT) in eyes that have undergone glaucoma filtration surgery.

Patients and Methods

SD-OCT imaging of the optic nerve head (ONH) and of the RNFL was performed in 54 eyes of 54 patients with medically uncontrolled POAG before and after IOP-lowering surgery (trabeculectomy or deep sclerectomy). The ONH parameter minimum rim width (MRW) and the size of the Bruch's membrane opening (BMO-Area) were derived from 24 radial B-scans centered on the ONH.

Results

The average preoperative IOP was 23.1 ± 7.5 mmHg. One month postoperatively, the average IOP decreased to 12.1 ± 4.6 mmHg (p < 0.01), which caused a significant increase in the thickness of neuroretinal rim. There was no significant change in the automatically detected BMO-Area (p = 0.32). The pressure-related increase in MRW correlated well with the postoperative IOP and cup-to-disc ratio (CDR). In regression analysis, the alteration in thickness of the neuroretinal rim could be well predicted in a model including CDR, change of IOP and mean deviation (MD) (R² = 0.414, p < 0.001). RNFL showed a significant increase as well.

Conclusion

IOP-lowering surgery in patients with medically uncontrolled POAG causes an increased thickness of the SD-OCT derived ONH parameters. The changes of the RNFL after surgery showed no significant correlations with IOP changes. In contrast to this, highly significant correlations of MRW values with the IOP could be observed. The BMO-Area remained completely stable A preferred use of RNFL for follow-up should be discussed.

Effect of Hemodialysis on Peripapillary Choroidal Thickness Measured by Swept-Source Optical Coherence Tomography

PURPOSE

The aim was to investigate the effects of hemodialysis (HD) on peripapillary choroidal thickness (PCT) by swept-source optical coherence tomography and on other ophthalmologic parameters in patients with end-stage kidney disease.

MATERIALS AND METHODS

This was a prospective observational study. The authors evaluated 29 patients who underwent HD for end-stage kidney disease. Detailed ophthalmologic examinations and swept-source optical coherence tomography were performed immediately before and after HD. PCT was measured using the modification tool in the built-in OCT image viewer program. Changes in PCT before and after HD were statistically analyzed.

RESULTS

The average PCT significantly decreased from 127.3±49.2 μm before HD to 117.1±50.9 μm after HD (P<0.001). A significant correlation was found between changes in PCT and macular choroidal thickness (ρ=0.547, P=0.002). Changes in mean ocular perfusion pressure did not significantly correlate with changes in PCT (ρ=-0.049, P=0.803).

CONCLUSIONS

PCT significantly decreased after HD. HD could influence the optic nerve head and its surrounding structures.

Long-term effects of trabeculectomy in primary open-angle glaucoma on segmented macular ganglion cell complex alterations

PURPOSE

The aim of this study is to compare, using optical coherence tomography (OCT), the changes in the thickness of the macular nerve fiber layer (mNFL), macular ganglion cell layer (mGCL), macular inner plexiform layer (mIPL) and peripapillary global retinal nerve fiber layer (gRNFL) (in a span of 3 years) in surgically treated eyes with primary open-angle glaucoma (POAG).

METHODS

The medical records of 32 consecutive POAG patients who underwent trabeculectomy with mitomycin-C, between January 2013 and December 2014, were retrospectively reviewed. Pre- and postoperative measurements of IOP and OCT were analyzed 1, 2 and 3 years after the operation.

RESULTS

Among all patients, no significant changes in the thickness of the mNFL, mGCL or mIPL were found, with a significant reduction observed only in the IOP values and peripapillary gRNFL thickness during the 3-year postoperative period. In a subgroup analysis based on the preoperative peak IOPs (median value:41 mmHg), the thickness of the mNFL, mGCL and mIPL in the 3-year postoperative period increased significantly in the lower preoperative peak IOP group (IOP < 41 mmHg), whereas the macular OCT parameters in the 3-year postoperative period decreased in the higher preoperative peak IOP group.

CONCLUSIONS

Eyes exhibiting lesser preoperative peak IOP demonstrated greater preservation of the layer-by-layer segmented macular ganglion cell complex thickness as compared to eyes exhibiting greater preoperative peak IOP; also when the IOPs determined for the two groups in the period of follow-up were quite comparable.

Long-Term Follow-Up After Successful Trabeculectomy: A Case Report of Reversal of Cupping and Recovery of Visual Field Progression

Glaucoma is one of the leading causes of blindness worldwide, and reduction of intraocular pressure (IOP) is the only available evidence-based treatment that reduces visual field deterioration in glaucoma. We present a representative case of structural recovery and recovery of visual field progression after successful trabeculectomy (TLE) with long-term follow-up. A 35-year-old woman with glaucoma visited our hospital in 2008. The IOP in her right eye was 11 mmHg at the first visit, and subsequently increased to values in the high teens to 20 mmHg despite treatment with anti-glaucoma eye drops. During this period, the progression of this eye's visual field deterioration was fast (mean deviation [MD] slope = -0.63 dB/year) and the optic disc cupping was advanced. In the seven-year period after successful TLE in 2014, the IOP declined to between 8 and 12 mmHg without any anti-glaucoma medication. During the first two years after TLE, the MD values were poorer than those before TLE. However, by 2020, MD values improved gradually to a state better than that before the surgery (MD slope during this period was +0.75 dB/year). The appearance of the optic disc was monitored using fundus photography, which showed optic disc morphological changes during topical glaucoma medication before and after TLE. In particular, a remarkable reversal of optic disc cupping enlargement started at two weeks after TLE, and the optic disc shape in 2021 was similar to that in 2008. Minimally invasive glaucoma surgeries are often preferred; however, our findings suggest that successful TLE followed by long-term rigorous IOP control can result in structural recoveries. Additionally, despite the deterioration in visual field in the early years after TLE, in the long term, it may settle down to the same level before the surgery with recovery of visual field progression, which may be a part of functional recovery.

Effect of intraocular pressure lowering on the capillary density of optic nerve head and retinal nerve fiber layer in patients with glaucoma

Purpose:

To evaluate the effect of IOP lowering on the capillary density of optic nerve head and retinal nerve fiber layer in patients with primary open angle glaucoma.

Methods:

Twenty eyes of 14 glaucomatous patients and 15 eyes of nine normal patients were enrolled. The most appropriate hypotonic treatment was applied to every patient. A HD Angio Disc 4.5 scan (Avanti-AngioVue) was performed at baseline and after a month in the glaucomatous eyes. The following parameters were analyzed: Radial Papillary Capillaries (RPC) density, inside disc, peripapillary, superior-hemi, inferior-hemi, quadrants, and peripapillary, hemi-superior, hemi-inferior, and quadrants RNFL thickness. Optic nerve head analysis was also evaluated. In addition, the RPC density and the RNFL were assessed in the eight sectors provided by the software.

Results:

The RPC density did not significantly change after IOP reduction ( p > 0.05). The inferior-temporal ( p = 0.005) and inferior-nasal sectors ( p < 0.001) showed a greater capillary density than the respective superior sectors in healthy eyes. In contrast in the glaucomatous eyes, the superior-nasal exhibited greater capillary density with respect to the inferior-nasal sectors. The aggregate RPC density of the inferior sectors was greater than the superior ones in the control group ( p < 0.001). An improvement of the average disc area ( p = 0.01) and the average cup volume ( p = 0.059) were also observed along with increased RNFL thickness at different locations (all, p < 0.05) after IOP lowering therapy was initiated.

Conclusion:

The glaucomatous eyes presented rarefaction of the radial papillary capillaries density in the inferior sectors, but no significant changes in the density after IOP-lowering medications.

Temporary Filtering Bleb Failure Induced by Anterior Chamber Sulfur Hexafluoride Gas: A Complication after Descemet Membrane Endothelial Keratoplasty

Herein, we report two clinical cases with acute temporary filtering bleb obstruction by gas tamponade after Descemet membrane endothelial keratoplasty (DMEK) surgery and postoperative intraocular pressure (IOP) peaks. Both patients underwent uncomplicated DMEK surgery with 20% sulfur hexafluoride (SF₆) anterior chamber tamponade and had previous trabeculectomy for glaucoma. Prior to surgery, both patients showed patent bleb function with low to normal IOP without antiglaucomatous medication. After uneventful DMEK surgery, both patients showed postoperative IOP peaks of up to 50 mm Hg despite patent inferior iridotomy and no sign of a pupillary block. In both cases, SF₆ gas bubbles could be visualized obstructing the bleb. Both patients were treated with IOP-lowering agents topically as well as systemically. In addition, anterior chamber paracenteses were performed to reduce the SF₆ volume within the anterior chamber. Under this treatment, IOP normalized within the first 18 h after surgery. We hypothesize that the SF₆ gas tamponade from the anterior chamber migrates into the ostium and below the bleb, leading to an acute temporary insufficiency of bleb function and to a consecutive IOP peak after surgery. In contrast to a pupillary block, this mechanism cannot be antagonized by preoperative iridotomy and needs to be taken into account for every glaucoma patient with functional bleb undergoing DMEK surgery.

Dynamics of structural reversal in Bruch's membrane opening-based morphometrics after glaucoma drainage device surgery

PURPOSE

Structural reversal of disc cupping is a known phenomenon after trabeculectomy. The aim of this retrospective, longitudinal, cross-sectional analysis was to evaluate the postoperative dynamics of Bruch's membrane opening-based morphometrics of the optic nerve head following glaucoma drainage device surgery.

METHODS

Forty-three eyes, treated by glaucoma drainage device surgery, were included in the study. Individual changes in the spectral domain optic coherence tomography (SD-OCT) parameters Bruch's membrane opening minimum rim width (BMO-MRW), Bruch's membrane opening minimum rim area (BMO-MRA) and peripapillary retinal nerve fiber layer (RNFL) thickness as well as mean defect in 30-2 perimetry were analyzed. Changes were correlated to postoperative intraocular pressure levels over time. Available follow-up visits were aggregated and grouped into a short-term follow-up (20 to 180 days after surgery), a midterm follow-up (181 to 360 days after surgery) and a long-term follow-up (more than 360 days after surgery).

RESULTS

In short-term follow-up, BMO-MRW and BMO-MRA increased significantly (p <= 0.034). This increase correlated negatively with the intraocular pressure at the time of the follow-up (Pearson's rho = - 0.49; p = 0.039). From 6 months after surgery on, there was no statistically significant change in BMO-MRW and BMO-MRA (p >= 0.207). RNFL thickness and mean defect of 30-2 perimetry showed no significant changes after GDD implantation (p >= 0.189).

CONCLUSIONS

Lowering of intraocular pressure by glaucoma drainage device surgery leads to an increase of Bruch's membrane opening based parameters in the first 6 months after surgery. These changes have to be taken into account when evaluating patients' longitudinal follow-up after glaucoma drainage device implantation.

A neuroglia-based interpretation of glaucomatous neuroretinal rim thinning in the optic nerve head

Neuroretinal rim thinning (NRR) is a characteristic glaucomatous optic disc change. However, the precise mechanism of the rim thinning has not been completely elucidated. This review focuses on the structural role of the glioarchitecture in the formation of the glaucomatous NRR thinning. The NRR is a glia-framed structure, with honeycomb geometry and mechanically reinforced astrocyte processes along the transverse plane. When neural damage selectively involves the neuron and spares the glia, the gross structure of the tissue is preserved. The disorganization and loss of the glioarchitecture are the two hallmarks of optic nerve head (ONH) remodeling in glaucoma that leads to the thinning of NRR tissue upon axonal loss. This is in contrast to most non-glaucomatous optic neuropathies with optic disc pallor where hypertrophy of the glioarchitecture is associated with the seemingly absent optic disc cupping. Arteritic anterior ischemic optic neuropathy is an exception where pan-necrosis of ONH tissue leads to NRR thinning. Milder ischemia indicates selective neuronal loss that spares glia in non-arteritic anterior ischemic optic neuropathy. The biological reason is the heterogeneous glial response determined by the site, type, and severity of the injury. The neuroglial interpretation explains how the cellular changes underlie the clinical findings. Updated understandings on glial responses illustrate the mechanical, microenvironmental, and microglial modulation of activated astrocytes in glaucoma. Findings relevant to the possible mechanism of the astrocyte death in advanced glaucoma are also emerging. Ultimately, a better understanding of glaucomatous glial response may lead to glia-targeting neuroprotection in the future.

Effect of Trabeculectomy on OCT Measurements of the Optic Nerve Head Neuroretinal Rim Tissue

Purpose

Ophthalmologists commonly perform glaucoma surgery to treat progressive glaucoma. Few studies have examined the stability of OCT neuroretinal rim parameters after glaucoma surgery for ongoing detection of glaucoma progression.

Design

Longitudinal cohort study.

Participants

20 eyes (16 subjects) with primary open angle glaucoma who had undergone a trabeculectomy.

Methods

We calculated the change in OCT parameters (minimum rim area (MRA), minimum rim width (MRW), Bruch's membrane opening (BMO) area, mean cup depth (MCD), anterior lamina cribrosa surface depth (ALCSD), prelaminar tissue thickness (PLTT), retinal nerve fiber layer thickness (RFNLT) during an interval from the visit before the surgery to the visit after the surgery, a span of approximately 6-months. We also calculated changes in the same eyes over two separate 6-month intervals that did not contain trabeculectomy to serve as control. We compared these intervals using a generalized linear model (with compound symmetry correlation structure), accounting for the correlation between time intervals for the same eye.

Main outcomes measures

MRW, MRA, angle above the reference plane for MRW and MRA, BMO area, MCD, mean ALCSD, PLTT, RNFLT and visual field parameters (mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI)).

Results

The intervals containing trabeculectomy showed a significant decrease in intraocular pressure (-9.2 mmHg, p<.001) when compared to control intervals. Likewise, the following neuroretinal rim parameters showed significant changes with trabeculectomy: increased MRW (+6.04μm, p=.001), increased MRA (+0.014mm², p=.024), increased angle above reference plane of MRW (+2.64°, p<.001), decreased MCD (-11.6μm, p=.007), and decreased mean ALCSD (-18.91μm, p=.006). This is consistent with an increase in rim tissue thickness and a more anterior position of the ILM and ALCS relative to the BMO plane. Conversely, RNFLT change was not significantly different between trabeculectomy and control intervals (p=.37).

Conclusion

Trabeculectomy resulted in anatomical changes to the ONH rim associated with reduced glaucomatous cupping. The RNFL thickness may be a more stable measure of disease progression that clinicians can use to monitor across time intervals containing glaucoma surgery.