Background/Aims Determine the efficacy of stand-alone implantation of the ab externo SIBS or poly(styrene-block-isobutylene-block-styrene) microshunt with mitomycin C in glaucomatous eyes, refractory to previous subconjunctival filtering surgery, over 1 year of follow-up. Methods Consecutive retrospective cohort of patients with intraocular pressure (IOP) above target and previous subconjunctival filtering surgery, who received the microshunt between July 2015 and April 2019. Primary outcome was a complete success, with failure defined as IOP 17 mm Hg or <20% reduction in IOP without medications. Secondary outcomes included thresholds of 6 to 14 mm Hg and 6 to 21 mm Hg for both complete (no medications) and qualified (with medications) success as well as qualified success for thresholds of 6 to 17 mm Hg. Risk factors for failure, IOP, medications and complications were also assessed. Results 85 eyes of 79 patients with a preoperative median IOP of 22.0 mm Hg (IQR 18.0–29.0) on four (IQR 3–4) medications were included. Postoperative median IOP was 13.0 mm Hg (IQR 10.0–17.0) on zero (IQR 0–2) medication at 1 year. 61.0% achieved complete success and 79.7% achieved qualified success. Mild-to-moderate disease was associated with failure (adjusted HR 2.37; 95% CI 1.23 to 4.59). Needling was performed in 11.8%, and 8.2% underwent anterior chamber reformation. Complications were transient, consisting of hyphaema, choroidal detachment and hypotony maculopathy, with 7.1% of patients undergoing reoperation. Conclusions In a group of high-risk eyes that had already failed at least one subconjunctival filtering surgery, the SIBS microshunt demonstrates reasonable surgical success over 1-year follow-up, with relatively few complications.

With the advent of microinvasive glaucoma surgery (MIGS), the spectrum of modalities available to manage patients with this chronic and heterogeneous condition has broadened. Despite its novelty however, there has been a rapid evolution in the development of a multitude of devices, each targeting a structure along the aqueous drainage pathway. A growing body of evidence has demonstrated IOP and medication burden reduction, and a more favorable safety profile with MIGS procedures in contrast to traditional incisional surgeries. Among the array of MIGS, the Hydrus® Microstent (Ivantis, Inc., Irvine, CA) is a recent FDA approved device, designed to bypass the trabecular meshwork and provide a scaffold for Schlemm’s canal. The objective of this article is to review the Hydrus from conception to clinical use, and present data on its efficacy and safety to date. The available literature has shown promise, however inherent to all novel devices, only long-term monitoring will ensure sustained IOP control and an acceptable safety profile. Surgical advancements in glaucoma have revolutionized the field, and continued research and development will establish these approaches in clinical treatment algorithms.

Background To assess the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in uveitic glaucoma (UG). Methods A retrospective interventional case series in which 33 eyes of 32 patients with UG underwent GATT with or without concomitant cataract extraction and intraocular lens implantation (CE/IOL) at three Canadian treatment centres from October 2015 to 2020. The main outcome measure was surgical success defined as an intraocular pressure (IOP) ≤18 mm Hg and at least one of the following: IOP within one mm Hg of baseline on fewer glaucoma medications as compared with baseline or a 30% IOP reduction from baseline on the same or fewer medications. Secondary outcome measures were IOP, medication usage and surgical complications. Results Mean patient age (mean±SD) was 49±16 years (range: 18–79) and 44% were female. GATT was performed as a standalone procedure in 52% of cases and the remainder were combined with CE/IOL. Surgical success was achieved in 71.8% (SE: 8.7%) of cases. Mean preoperative IOP (±SD) was 31.4±10.8 mm Hg on a median of 4 medications. 59% of patients were on oral carbonic anhydrase inhibitors (CAIs) prior to surgery. After 1 year, average IOP was 13.8 mm Hg on a median 1 medication, with 6% of patients being on oral CAIs. No sight threatening complications occurred during surgery or follow-up. Conclusion GATT is an effective surgical strategy in the management of UG. This microinvasive conjunctival-sparing procedure should be considered early in these patients.

The purpose of this study was to examine changes in fixation stability over time during binocular and monocular viewing in patients with age-related macular degeneration (AMD). Seventeen patients with AMD and 17 controls were enrolled. Using an EyeLink eyetracker (SR Research Ltd., Mississauga, Ontario, Canada), fixation stability was recorded binocularly and monocularly with each eye for a duration of 15 s while the fellow eye was covered. Fixation stability was analyzed over 3 s intervals for each condition using a 68% bivariate contour ellipse area. Fixation stability did not change with time during binocular viewing for both groups, both monocular conditions for the control group, and monocular viewing with the better eye for the AMD group. However, during monocular viewing with the worse eye, the test of within-subject contrasts showed linear improvement in fixation stability with time (p = 0.016). In conclusion, in patients with AMD, monocular fixational control with the worse eye is poor, but improves with time.

To characterize proliferative vitreoretinopathy(PVR) with swept-source optical coherence tomography(SS-OCT) in rhegmatogenous retinal detachment(RRD). Prospective cross-sectional cohort study. Consecutive primary RRDs presenting to St. Michael's Hospital from 2021 to 2023. Ultra-widefield(UWF) fundus imaging was staged per the Retina Society 1991 PVR Classification and correlated with retinal microstructural changes assessed with SS-OCT. SS-OCT findings in PVR. 100 patients were included. Patients with no signs of PVR or PVR A (49/100) were more likely to have a preserved bacillary layer on SS-OCT with low-amplitude outer retinal corrugations(ORCs) compared to the PVR B/C group. PVR B(retinal wrinkling/vessel tortuosity) was present in 24%(24/100) of cases, all of which had high-amplitude ORCs. PVR C (27/100) was clinically divided into patients with subretinal membranes(SR) [63%(17/27)] and patients with fixed retinal folds(IR)[37%(10/27)]. The SR subtype was associated with shallow, slowly progressive detachments. On SS-OCT, they had a thick hyperreflective membrane emanating from the retinal pigment epithelium and extending along the outer retinal surface, causing tractional folds of the outer retina in 47%(8/17) of cases and tractional bacillary layer detachment in 12%(2/17) of cases. Outer retinal thinning/atrophy was commonly observed in the SR subtype. Patients with the IR subtype had bullous detachments on fundus examination and extensive intra-retinal changes on SS-OCT. These had a thickened bacillary layer with high-amplitude ORCs with photoreceptor-photoceptor apposition within or between individual corrugations(fused ORCs). Significant pre-retinal membranes with loss of differentiation of the inner and outer retinal lamellae and distortion of underlying ORCs were observed. Our study demonstrates imaging evidence of varying PVR morphology. The IR subtype occurs in bullous detachments with intrinsic retinal changes that span from fused and distorted corrugations to retinal thickening, pre-retinal membranes and loss of differentiation of retinal lamella. The SR subtype occurs in shallow, slowly progressive detachments, where the proliferation is associated with membranes emanating from the RPE, outer retinal thinning/atrophy and tractional outer retinal folds. We present a novel OCT classification of primary PVR, which varies based on RRD morphology. Pathological intraretinal apposition in ORCs may contribute to glial proliferation and subsequent intra-retinal and pre-retinal changes.

Background/Aims: Determine the association between physician-deemed and patient-reported appropriateness and prioritization for cataract surgery. Methods: Prospective cohort study of 471 patients of 7 ophthalmologists referred for cataract surgery. Ophthalmologists rated patients for cataract surgery appropriateness and prioritization using a visual analogue scale of 0–10 preoperatively. All patients completed the eCAPS Quality of Life (QoL), while 313 completed the Catquest-9SF and EQ-5D questionnaires. Regression analyses were applied to determine demographic, clinical and patient-reported outcome measures (PROMs) associated with appropriateness and prioritization. Results: Two clinical factors (study eye and fellow eye best-corrected visual acuity (BCVA)), 2 eCAPS (night driving difficulty, ability to take care of local errands), and 2 Catquest-9SF PROMs (recognizing faces, seeing to walk on uneven ground) were associated with appropriateness. In multivariable regression, the rating physician, 2 clinical criteria (study eye BCVA, anticipated postoperative BCVA) and 1 eCAPS QoL (night driving difficulty) were associated with appropriateness. Prioritization was associated with low income, 8 clinical criteria, 9 eCAPS, 5 Catquest-9SF, and 1 EQ-5D PROMs. In multivariable regression, 1 clinical criterion (study eye BCVA), 2 eCAPS QoL (night driving difficulty, ability to take care of local errands), and 2 Catquest-9SF PROMs (seeing prices, seeing to walk on uneven ground) were significantly associated. Conclusions: The eCAPS and Catquest-9SF questionnaires show some concordance with physician-deemed appropriateness, and more with prioritization. Binary conversions of PROM scales provide similar modelling, with minimal loss of explanatory power. As physician-deemed appropriateness and prioritization do not completely capture the patient perspective, PROMs may have a role in cataract surgery decision-making frameworks.