DOUBLE-ARC SLOW-COAGULATION TRANSSCLERAL CYCLOPHOTOCOAGULATION LASER PROTOCOL: ONE-YEAR EFFECTIVENESS AND SAFETY OUTCOMES.

PURPOSE: To report the short-term efficacy and safety results of a new continuous laser protocol, double-arc slow-coagulation transscleral cyclophotocoagulation (DA-TSCPC). DESIGN: Multicenter retrospective study. PARTICIPANTS: Refractory glaucoma patients that had undergone DA-TSCPC between April 2019 and July 2022, with at least 12 months of postoperative follow-up, were consecutively enrolled. METHODS: The technique was standardized (energy: 1400mW; duration: 4s; 28 applications). The applications were divided into 2 rows (upper and lower arcs). For each arc, 7 spots were applied over the ciliary body shadow and 7 spots 1.5mm behind, sparing the 3 and 9 o'clock meridians. MAIN OUTCOME MEASURES: Success was defined as postoperative intraocular pressure (IOP) between 6 and 18 mmHg, and an IOP reduction of 30% (without oral acetazolamide). For eyes with no light perception (NLP), in which treatment goal was pain relief, success was defined as a 30% IOP reduction and no pain (without oral acetazolamide). Patients were divided according to visual acuity: ≥20/400 (group 1) and <20/400 (group 2). RESULTS: Ninety eyes of 90 patients (mean age: 61±15 years) were included. Glaucoma diagnosis frequency was: neovascular glaucoma (38%), open-angle glaucoma (28%), silicone oil secondary glaucoma (17%) and others (18%). Overall, the mean IOP was significantly reduced from 35±12 to 22±14 mmHg (p<0.01) at the last follow-up visit. The number of hypotensive eye drops (2.6±1 to 2.3±1; p=0.02) and the use of oral acetazolamide (61% to 11%; p<0.01) were also reduced. Kaplan-Meier survival analysis revealed a global success rate of 65.6% after 12 months. A higher success rate was found for group 1 (78.6%) compared to group 2 (59.6%; p=0.047; logrank test). The main complications observed were corneal ulcer (4.4%), macular edema (1.1%) and hyphema (1.1%). Among the 26 eyes with NLP, 65% achieved success criteria at 12 months and 2 (7.7%) developed phthisis. CONCLUSION: Based on these initial retrospective data, the DA-TSCPC protocol seems to be an alternative for refractory glaucoma management, presenting significant IOP reduction and a good safety profile after one year. Better outcomes were observed in eyes with less severe functional damage.

Vascular parameters and endothelin-1 measurements in glaucoma patients with low- and high-tension optic disc hemorrhages.

This prospective study aimed to compare vascular parameters (endothelin-1 [ET-1] blood levels, laser Doppler imaging [LDI] of distal phalanxes, and nailfold capillaroscopy) between open-angle glaucoma patients with low- and high-tension optic disc hemorrhages (LTDH and HTDH, respectively). The 33 enrolled patients (mean age, 62.3 ± 13 years) were classified as LTDH or HTDH if they presented at the time of DH detection an intraocular pressure (IOP) < 16 mmHg or ≥ 16 mmHg, respectively. Demographic and ophthalmological data, ET-1 concentrations, LDI (before and 1, 10, and 20 min after cold stimulation), and nailfold capillaroscopy findings were evaluated. The ET-1 blood level was 65% higher in the LTDH (2.27 ± 1.46 pg/ml) than in the HTDH (1.37 ± 0.57 pg/ml; p = 0.03) group. Moreover, there was a statistically significant negative correlation between ET-1 blood concentration and IOP at the time of DH detection (r = -0.45, p = 0.02). Blood flow measurements 10 and 20 min after cold stimulation were lower in the LTDH group than in the HTDH group (p < 0.01). Patients developing DH with lower IOPs have higher ET-1 blood levels and more peripheral vascular dysfunction as estimated by LDI than those with higher IOPs. These findings suggest that distinct underlying mechanisms may be involved in patients developing DH within different IOP ranges.

Peripheral Microvascular Abnormalities Associated with Open-Angle Glaucoma.

PURPOSE: To investigate peripheral microvascular abnormalities associated with patients with open-angle glaucoma (OAG). DESIGN: This was a cross-sectional study. PARTICIPANTS: Patients with OAG and controls. METHODS: All subjects underwent detailed ophthalmic evaluation, including Humphrey visual field (HVF) tests and swept source OCT. To evaluate peripheral microvascular abnormalities, nailfold capillaroscopy (NFC) and laser Doppler imaging (LDI) were performed. The presence of microhemorrhages, tortuous capillaries, dilated capillaries, avascular areas, and the capillary density, among other characteristics, were recorded using NFC; fingertip blood flow (FBF) was measured using LDI at different time points, before and 1, 10, and 20 minutes after exposure to a cold stimulus. In addition, venous blood samples were collected to measure serum endothelin-1 (ET-1) concentrations as well as serum autoantibodies. MAIN OUTCOME MEASURES: Presence of microhemorrhages, tortuous capillaries, and dilated capillaries; FBF; ET-1; and autoantibodies. RESULTS: Sixty-eight subjects (43 patients with OAG and 25 controls) were enrolled in the study. Microhemorrhages were found in the nail bed of 65.1% of the patients with OAG compared with 25.0% of the controls (P = 0.003). There was a significant difference in the mean FBF at the baseline in patients with OAG versus controls (293.6 ± 100.2 vs 388.8 ± 52.0 perfusion units, respectively, P < 0.001), together with a significant decrease in the mean FBF 10 and 20 minutes after cold stimulus in patients with OAG in comparison to controls (P < 0.001 for all comparisons). There was a positive correlation between mean baseline FBF and HVF mean deviation (r = 0.27, P = 0.03) and between mean baseline FBF and average retinal nerve fiber layer thickness (r = 0.44, P = 0.001). Neither the analysis of ET-1 concentrations (P= 0.71) nor the autoantibodies measurements (P > 0.05, for all) showed any difference between the 2 groups. CONCLUSIONS: Significant peripheral microvascular abnormalities were found in patients with OAG compared to controls, suggesting that microvascular changes might play a role in the pathogenesis of the disease. In addition, part of these peripheral microvascular abnormalities seems to be correlated with both functional and structural glaucomatous damage. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Clinical Profiles of Glaucomatous Patients With High-tension and Low-tension Optic Disc Hemorrhages: A Comparative Study.

PRCIS: Patients with low-tension optic disc hemorrhages (DHs) are more frequently women, have a diagnosis of normal-tension glaucoma (NTG) diagnosis and greater visual field (VF) loss. Symptoms of vascular dysregulation and Asian race also seem to be more prevalent in this clinical subtype. PURPOSE: Optic DH is an important glaucoma risk factor, and occurs in a wide intraocular pressure (IOP) range. We sought to characterize distinct clinical subtypes of patients with high-tension disc hemorrhage (HTDH) and low-tension disc hemorrhage (LTDH). PATIENTS AND METHODS: In this cross-sectional study, treated glaucomatous patients with DHs from 2 glaucoma services were consecutively enrolled. Disc photographs were evaluated for the presence of DH by 2 glaucoma specialists. After inclusion, patients were classified on HTDH (IOP≥16 mm Hg) and LTDH (IOP<16 mm Hg; median split). Clinical and ocular data from the time of DH detection were compared between groups. RESULTS: One hundred thirty-three DH patients were included (LTDH=66 eyes; HTDH=67 eyes). Patients with LTDH were more often women than those with HTDH (77% vs. 42%; P=0.030). There was also a trend for a higher prevalence of Asian descendants (24% vs. 9%; P=0.058) and symptoms suggestive of vascular dysregulation (34% vs. 14%; P=0.057) in LTDH patients. Eyes with LTDH also had worse VF mean deviation index (P=0.037), higher prevalence of NTG diagnosis (46% vs. 17%; P<0.001), and tended to have thinner central corneas (P=0.066). CONCLUSIONS: Patients developing DHs with treated IOPs in the low teens seem to more frequently fit in a profile represented by women, NTG diagnosis and greater VF loss. The presence of symptoms suggestive of vascular dysregulation and race also seem to differ between these 2 clinical subtypes. A closer optic disc surveillance is recommended for patients with the LTDH subtype, as they may develop DHs despite seemingly well-controlled IOP.

Structural abnormalities associated with glaucoma using swept-source optical coherence tomography in patients with systemic sclerosis.

PURPOSE: Vasospasm represents an early event in systemic sclerosis (SSc). Ocular vasospasm may induce optic nerve head (ONH) damage and has been involved in the pathogenesis of glaucoma, especially normal-tension glaucoma (NTG). We aimed to investigate the presence of structural abnormalities associated with NTG using swept-source optical coherence tomography (SS-OCT) and to correlate the OCT parameters with clinical, capillaroscopy and digital blood flow measures in patients with SSc. METHODS: In this cross-sectional study, 40 patients with SSc and 23 age-matched controls were included. The following parameters were measured using SS-OCT: mean and sectoral retinal nerve fibre layer (RNFL) thickness, macular ganglion cell layer complex (GCC) thickness and ONH morphology. Nailfold capillaroscopy (NFC) and digital blood flow measurements using laser Doppler imaging (LDI) were performed in all subjects. RESULTS: Patients with SSc showed a thinner temporal RNFL than the controls (69.23 ± 11.74 versus 83.35 ± 20.19 µm, p = 0.001). The other parameters were similar between the two groups. In SSc patients, there was an inverse correlation between the disease duration and the average, superior and inferior RNFL thickness and the GCC thickness and between Raynaud's phenomenon duration and the average RNFL and GCC thickness (p < 0.05). NFC and LDI measurements did not show correlations with OCT parameters. CONCLUSION: A thinner temporal RNFL and the correlation between Raynaud's phenomenon and disease duration and structural abnormalities on OCT suggest the presence of early ganglion cell damage in patients with SSc. Although mild, these findings indicate the need to monitor ocular abnormalities in SSc.

Enriched environment contributes to recovery of visual acuity and increases perineuronal nets in monocular-deprived animals

The aim of the present study was to analyze the influence of enriched environment on the distribution of perineuronal nets (PNNs) using a stereogically based unbiased protocol and visual acuity in adult Swiss albino mice that underwent monocular deprivation during the critical period of postnatal development. Eight female Swiss albino mice were monocular deprived on postnatal day 10 and divided into two groups at weaning: standard environment (SE group, n = 4) and enriched environment (EE group, n = 4). After 3 months, all of the mice were subjected to grating visual acuity tests, sacrificed, and perfused with aldehyde fixative. The brains were removed and cut at 70 µm thickness in a vibratome and processed for lectin histochemical staining with Wisteria floribunda agglutinin (WFA). Architectonic limits of area 17 were conspicuously defined by WFA histochemical staining, and the optical fractionator stereological method was applied to estimate the total number of PNNs in the supragranular, granular, and infragranular layers. All groups were compared using Student's t-test at a 95 percent confidence level. Comparative analysis of the average PNN estimations revealed that the EE group had higher PNNs in the supragranular layer (2726.33 ± 405.416, mean ± standard deviation) compared with the SE group (1543.535 ± 260.686; Student's t-test, p = .0495). No differences were found in the other layers. Visual acuity was significantly lower in the SE group (0.55 cycles/degree) than in the EE group (1.06 cycles/degree). Our results suggest that the integrity of the specialized extracellular matrix PNNs of the supragranular layer may be essential for normal visual acuity development.(AU)

Enriched environment contributes to recovery of visual acuity and increases perineuronal nets in monocular-deprived animals

The aim of the present study was to analyze the influence of enriched environment on the distribution of perineuronal nets (PNNs) using a stereogically based unbiased protocol and visual acuity in adult Swiss albino mice that underwent monocular deprivation during the critical period of postnatal development. Eight female Swiss albino mice were monocular deprived on postnatal day 10 and divided into two groups at weaning: standard environment (SE group, n = 4) and enriched environment (EE group, n = 4). After 3 months, all of the mice were subjected to grating visual acuity tests, sacrificed, and perfused with aldehyde fixative. The brains were removed and cut at 70 µm thickness in a vibratome and processed for lectin histochemical staining with Wisteria floribunda agglutinin (WFA). Architectonic limits of area 17 were conspicuously defined by WFA histochemical staining, and the optical fractionator stereological method was applied to estimate the total number of PNNs in the supragranular, granular, and infragranular layers. All groups were compared using Student's t-test at a 95 percent confidence level. Comparative analysis of the average PNN estimations revealed that the EE group had higher PNNs in the supragranular layer (2726.33 ± 405.416, mean ± standard deviation) compared with the SE group (1543.535 ± 260.686; Student's t-test, p = .0495). No differences were found in the other layers. Visual acuity was significantly lower in the SE group (0.55 cycles/degree) than in the EE group (1.06 cycles/degree). Our results suggest that the integrity of the specialized extracellular matrix PNNs of the supragranular layer may be essential for normal visual acuity development.

Human intraocular filariasis caused by Dirofilaria sp. nematode, Brazil.

A case of human intraocular dirofilariasis is reported from northern Brazil. The nematode was morphologically and phylogenetically related to Dirofilaria immitis but distinct from reference sequences, including those of D. immitis infesting dogs in the same area. A zoonotic Dirofilaria species infesting wild mammals in Brazil and its implications are discussed.