Two-year Outcomes of XEN Implantation with Minimal Bleb Needling.

Aim: Our study aims to report the 2 years outcomes of the XEN implant in a single unit, single surgeon setting with minimal bleb needling. Methods: A retrospective cohort study was conducted. Inclusion criteria were patients who underwent implantation with a XEN device between May 2016 and December 2017. This included patients who underwent both combined phacoemulsification and intraocular lens implantation alongside XEN implantation and those who underwent XEN implantation alone. Data gathered included basic demographic data, best-corrected visual acuity (LogMAR), intraocular pressure (IOP) in mm Hg, mean deviation from their visual field test, and the number of IOP-lowering medications they were on. This information was recorded for their preoperative visit, and then at 6, 12, 18 and 24 months postoperatively. The primary outcome assessed was a complete success when the patient was without glaucoma medications and had an IOP of 18 mm Hg or less, but more importantly, this also had to equate to a 20% reduction in IOP compared to baseline. Qualified success was defined as the same change in IOP but with medications. Surgical failure is defined as those who required additional glaucoma surgery or those who did not obtain an IOP of 18 mm Hg alongside a 20% reduction in IOP compared to baseline. Results: At 24 months follow-up 82.5% of patients were surgical successes. Complete surgical success was achieved in 27% of patients. Qualified surgical success was achieved in 55.6% of patients. Subgroup analysis of those undergoing XEN implantation on its own and those combined with phacoemulsification + IOL were similar. The rate of bleb needling was low at 4.5%. Complication rates were acceptable at 9.5%. Conclusion: It is possible to get good IOP control with minimal postoperative bleb needling in patients who have undergone XEN implantation. Similar success rates are found in those undergoing combined procedures. Clinical Significance: Bleb needling carries its own risks. Minimizing the number of bleb needling allows procedures to be reserved at a later date. Furthermore, our study shows that success rates are not affected by doing a combined procedure with phacoemulsification. How to cite this article: Ali ZC, Moshin N, Hakim MT, et al. Two-year Outcomes of XEN Implantation with Minimal Bleb Needling. J Curr Glaucoma Pract 2022;16(2):79-83.

Migration of XEN45 Implant: Findings, Mechanism, and Management.

AIM: The aim of this study is to report the mechanism of XEN migration and its management. BACKGROUND: Over the past decade, new less invasive surgical approaches for glaucoma have been devised and carried out successfully. One such technique is the use of the XEN gel stent. We present a rare and relatively unknown complication of XEN migration and present in detail the likely mechanism by which this occurs, and its subsequent management. CASE DESCRIPTION: A 73-year-old male with primary angle closure on maximal medical treatment presented with an intraocular pressure of 30 mm Hg in the left eye. The visual acuity was 6/5, iridocorneal angles were open in all four quadrants, and the cup disc ratio was 0.4. As phacoemulsification alone was unlikely to adequately lower intraocular pressures, the patient underwent combined phacoemulsification and XEN implantation. Although the patient had a good postoperative result with pressures lowered to 11 mm Hg, 4 months after the operation, the XEN was found to have migrated 4 mm into the anterior chamber, associated with a low-grade uveitis. The patient subsequently had the XEN explanted a new XEN inserted. Pressures lowered 1 month postoperatively to 14 mm Hg. CONCLUSION: XEN migration is likely due to a combination of mechanical and frictional forces. If the XEN is positioned such that more than 2 mm is in the subconjunctival space, the XEN is likely to be angled upward and, therefore, be more susceptible to these forces and undergo migration. CLINICAL SIGNIFICANCE: It is essential that XEN implants are correctly sited and that this is confirmed intraoperatively to prevent the need for further procedures. HOW TO CITE THIS ARTICLE: Ali ZC, Khoo DI, et al. Migration of XEN45 Implant: Findings, Mechanism, and Management. J Curr Glaucoma Pract 2019;13(2):79-81.

Perceptions and use of technology in older people with ophthalmic conditions.

Background: Technologies such as mobile applications are increasingly being developed for patients to help manage their clinical conditions. However there is a paucity of information confirming the capacity or willingness of older patients with ophthalmic complaints to engage with such computer applications. The aim of this paper is to assess the perception and use of a range of common computing technologies by older ophthalmic patients, in order to guide future ophthalmology-specific development and clinical use. Methods: Patients attending Manchester Royal Eye Hospital were surveyed with questions designed to measure their perceptions, attitudes and experiences of using technology.  Inclusion criteria included any patient aged 40 or over who attended the ophthalmology outpatients department. Results: A total of 300 patients completed the questionnaire. The male-to-female ratio was 128:169. The majority of patients owned predominantly mobile forms of technology such as tablets and smart phones. The most common uses of technology were for communicating with friends, watching television and gathering information. Patients aged over 80 had particular difficulty using technology and used it less regularly. Less than 10% overall stated eyesight as a reason for stopping using technology. Conclusions: Technology is used regularly by a large proportion of older ophthalmic patients, with numbers reducing significantly only in those aged 80 years or over. There appears to be potential for further medical use, though developers and clinicians should consider the perceptions and challenges highlighted through this survey.

Swept-source optical coherence tomography angiography features of sub-retinal fibrosis in neovascular age-related macular degeneration.

IMPORTANCE: The study highlights the role of optical coherence angiography in the management of patients with neovascular age-related macular degeneration (nAMD) who have developed sub-retinal fibrosis. BACKGROUND: Development of sub-retinal fibrosis in the context of nAMD is known to adversely affect visual function. The aim of this study is to assess structure and flow features obtained through swept-source optical coherence tomography angiography (OCTA) in patients with sub-retinal fibrosis and associate these with visual acuity (VA). DESIGN: Institutional retrospective cohort study. PARTICIPANTS: A total 39 eyes of 39 patients with nAMD with sub-retinal fibrosis imaged with OCTA were included in this study. METHODS: Patients underwent swept-source OCTA. Thickness of sub-retinal hyper-reflective material (SHRM) and presence and configuration of a choroidal neovascular membrane were recorded in each case. MAIN OUTCOME MEASURES: A univariate multiple regression was performed seeking associations between VA and structural and flow OCTA features. RESULTS: Average VA on the date of OCTA was 53 ± 22 ETDRS letters. Average thickness of centre-involving SHRM was 157 ± 73 µm. A choroidal neovascular membrane was detectable in 26 cases and not detectable in 13. VA was independently influenced by thickness of SHRM (P = 0.034) and presence of a detectable choroidal neovascular membrane (P = 0.02) on OCTA. CONCLUSIONS AND RELEVANCE: Poorer VA in patients with nAMD and sub-retinal fibrosis is associated with presence of a detectable neovascular membrane on OCTA. The role of OCTA to guide nuanced management decisions in this patient population may be significant.

Features of choroidal naevi on swept source optical coherence tomography angiography and structural reverse flow optical coherence tomography.

PURPOSE: The purpose of our study was to describe features of choroidal naevi as seen on swept source optical coherence tomography angiography (OCTA) and also on en face images derived from structural data from OCTA. METHODS: A prospective observational cohort study was carried out. Patients attending a specialised choroidal naevomelanocytic with known naevi were imaged with swept source OCTA. RESULTS: Seventy-one eyes of 70 patients were imaged. Forty-three patients and 44 eyes were included. Mean age was 57.7 years (SD 14.9), range 29-81 years. Male to female ratio was 20:23. On OCTA after manual segmentation, naevi could be seen in 47.6% of cases, whereas in the en face images, naevi could be clearly visualised in 79.5% of cases. In OCTA, the superficial and deep capillary plexuses appeared undisturbed as did the outer retinal layer appeared in all cases of flat naevi. In choroidal naevi with mild elevation, the outer retinal layer appeared more susceptible to projection artefacts from overlying retinal vasculature. The choriocapillaris layer showed a fading of the normal homogenous vascular mosaic corresponding to the area of the naevus. In the en face images, even the faintest and thinnest naevi could be visualised in striking detail, and naevi greater than 120 µm thickness appeared darker (p = 0.0034). CONCLUSIONS: OCTA presents characteristic changes in the choriocapillaris layers in cases of choroidal naevi. The association of naevus substance appearing darker with increasing thickness may offer a novel prognostic clue. En face structural OCT may allow accurate, detailed measurement of lateral dimensions which could be of value in the monitoring of suspicious naevi.

Use of a Neural Net to Model the Impact of Optical Coherence Tomography Abnormalities on Vision in Age-related Macular Degeneration.

PURPOSE: To develop a neural network for the estimation of visual acuity from optical coherence tomography (OCT) images of patients with neovascular age-related macular degeneration (AMD) and to demonstrate its use to model the impact of specific controlled OCT changes on vision. DESIGN: Artificial intelligence (neural network) study. METHODS: We assessed 1400 OCT scans of patients with neovascular AMD. Fifteen physical features for each eligible OCT, as well as patient age, were used as input data and corresponding recorded visual acuity as the target data to train, validate, and test a supervised neural network. We then applied this network to model the impact on acuity of defined OCT changes in subretinal fluid, subretinal hyperreflective material, and loss of external limiting membrane (ELM) integrity. RESULTS: A total of 1210 eligible OCT scans were analyzed, resulting in 1210 data points, which were each 16-dimensional. A 10-layer feed-forward neural network with 1 hidden layer of 10 neurons was trained to predict acuity and demonstrated a root mean square error of 8.2 letters for predicted compared to actual visual acuity and a mean regression coefficient of 0.85. A virtual model using this network demonstrated the relationship of visual acuity to specific, programmed changes in OCT characteristics. When ELM is intact, there is a shallow decline in acuity with increasing subretinal fluid but a much steeper decline with equivalent increasing subretinal hyperreflective material. When ELM is not intact, all visual acuities are reduced. Increasing subretinal hyperreflective material or subretinal fluid in this circumstance reduces vision further still, but with a smaller gradient than when ELM is intact. CONCLUSIONS: The supervised machine learning neural network developed is able to generate an estimated visual acuity value from OCT images in a population of patients with AMD. These findings should be of clinical and research interest in macular degeneration, for example in estimating visual prognosis or highlighting the importance of developing treatments targeting more visually destructive pathologies.