Optical coherence tomography angiography: a review of the current literature.

This narrative review presents a comprehensive examination of optical coherence tomography angiography (OCTA), a non-invasive retinal vascular imaging technology, as reported in the existing literature. Building on the coherence tomography principles of standard OCT, OCTA further delineates the retinal vascular system, thus offering an advanced alternative to conventional dye-based imaging. OCTA provides high-resolution visualisation of both the superficial and deep capillary networks, an achievement previously unattainable. However, image quality may be compromised by factors such as motion artefacts or media opacities, potentially limiting the utility of OCTA in certain patient cohorts. Despite these limitations, OCTA has various potential clinical applications in managing retinal and choroidal vascular diseases. Still, given its considerable cost implications relative to current modalities, further research is warranted to justify its broader application in clinical practice.

The Impact of the COVID-19 Pandemic and Lockdown on Macular Hole Surgery Provision and Surgical Outcomes: A Single-Centre Experience.

Purpose: We aimed to report the impact of the COVID-19 pandemic and related health policies and restrictions on the provision and efficacy of macular hole (MH) surgery. Methods: We carried out a retrospective cohort study. Two MH patient cohorts, those treated during the COVID-19 pandemic (12 months) and the pre-COVID-19 period (12 months before the lockdown) were reviewed and compared. Patient characteristics, time to consultation and surgery, MH size, baseline and postoperative visual acuity (VA) and failure rate were recorded and analysed. Results: A reduction of 43% in MH surgery occurred during the COVID-19 period (93 eyes vs. 53 eyes). Mean time to consultation and time to surgery increased significantly (52.7 days vs. 86.3 days, p < 0.01 and 51.3 days vs. 83.6 days, p = 0.01, respectively), while mean baseline and postoperative vision was significantly lower in the COVID-19 group (0.75 LogMAR vs. 0.63 LogMAR, p < 0.01 and 0.61 LogMAR vs. 0.44 LogMAR, p < 0.01, respectively). The median MH size was significantly larger in the COVID-19 group (296 µm vs. 365 µm, p = 0.016), and the failure rate increased from 7.6% to 15.4% (odds ratio 2.2 (95% CI: 0.72−6.8)). Conclusions: Our findings suggest the COVID-19 pandemic caused a significant reduction in MH surgery, increased waiting times and led to poorer surgical outcomes. For future pandemics, better strategies are required that allow semi-elective and elective surgery to continue in a timely fashion. Health providers should preserve the delivery of ophthalmological care, with enhanced encouragement to seek medical help for acute symptoms.

Surgical Management of Paediatric Aphakia in the Absence of Sufficient Capsular Support.

There are several available options for the demanding surgical correction of paediatric aphakia without sufficient capsular support. The literature suggests the implantation of a transscleral fixated posterior chamber-intraocular lens (PCIOL), an intrascleral fixated PCIOL, an iris-sutured intraocular lens (IOL), or an anterior chamber iris-claw IOL. We searched for reports on the management of paediatric aphakia in case of inadequate capsular support that delineated the diverse surgical approaches and their postoperative results. Analysis demonstrated that different complications can be encountered depending on IOL placement technique, such as suture rupture, IOL dislocation, secondary glaucoma, endophthalmitis, vitreous hemorrhage, and endothelial cell loss. However, it was shown that various IOL designs have similar visual outcomes. Taking into consideration the advantages and disadvantages of each surgical technique, ophthalmic surgeons can determine the safest and most efficient approach for paediatric aphakic patients.

Incidence of Clinically Significant Aniseikonia Following Encircling Scleral Buckle Surgery: An Evaluation of Refractive and Axial Length Changes Requiring Intervention.

To evaluate the incidence of symptomatic anisometropia and aniseikonia requiring intervention following surgery with combined pars plana vitrectomy (PPV) and broad 276 style encircling scleral buckle (ESB) for the repair of rhegmatogenous retinal detachments (RRD) and to report axial length (AL) and keratometry changes, a retrospective review of consecutive RRD patients treated with combined PPV and ESB between June 2016 until September 2019 was performed. All patients with symptomatic optically induced aniseikonia requiring additional interventions or surgical procedures including clear lens exchanges, secondary intraocular lens implants or contact lenses were documented. Keratometry and AL measurements were recorded for each eye and changes calculated. In total, 100 patients underwent combined PPV, ESB and endotamponade with mean age of 59.47 years (SD 11.49). AL was significantly increased (25.39 mm [SD 1.27] to 26.54 mm [SD 1.16], p = 0.0001), with a mean change of 1.15 mm (SD 0.67). Mean corneal astigmatism increased by -0.95 D (SD 0.51) in control eyes preoperatively and -1.33 (SD 0.87) postoperatively (p = 0.03). Over half of phakic patients (39/61; 64%) developed a visually significant cataract, subsequently undergoing surgery. Six of 100 patients developed symptomatic anisometropia with aniseikonia postoperatively (6%). Four proceeded with clear lens exchange despite absence of visually significant cataract (4%). Two of these initially trialled contact lenses (2%). One was intolerant, while the other decided to proceed with clear lens exchange for convenience. Only one patient (1%), being pseudophakic in both eyes, had persistent anisometropia/aniseikonia. AL and keratometry changes induced by encirclement with broad solid silicone rubber buckles are acceptable and similar to those reported previously using narrow encircling components, being unlikely to induce troublesome symptomatic anisometropia/aniseikonia. Many patients are phakic and develop visually significant cataracts, allowing correction of changes induced with the aim of visual restoration. A minority require more prolonged methods of visual rehabilitation, such as contact lens wear or clear lens exchanges. Caution and appropriate consent should be made in patients that are pseudophakic in both eyes at presentation.

First postoperative day review in eyes undergoing pars plana vitrectomy, encirclement and endotamponade to check intraocular pressure: Is it necessary?

PURPOSE: To assess the proportion of patients with raised intraocular pressure (IOP) (≥ 30 mmHg) on the first postoperative day following pars plana vitrectomy (PPV), encirclement and endotamponade and assess the number requiring alteration in management to address elevated IOP. To establish whether review on day one is required. METHODS: Retrospective case note review of consecutive patients who underwent 23-gauge PPV, 276-encirclement and endotamponade under the care of a single surgeon. All patients as standard received prophylactic anti-glaucoma medication post-surgery (eye drops) to take home but initiate only after day-one review. Statistical analysis was carried out using student t tests and Fisher's exact tests. RESULTS: Sixty-six patients were examined over a 2-year period. Mean day-one IOP was 22.2 mmHg (SD 7.3, 95% CI 20.4-24.0). Eleven patients (16.7%) had IOP ≥ 30 mmHg. Five patients (7.6%) had management changing decisions made at the day-one postoperative visit. Lens status, endotamponade, preoperative IOP, surgeon grade, cryopexy versus laser retinopexy or preoperative administration of once only 500 mg dose of intravenous acetazolamide did not influence IOP, with no significant difference between these subgroups. No cases of hypotony occurred. CONCLUSIONS: A significant minority of patients had elevation of IOP above 30 mmHg, a number of whom required treatment changes to address this. No preoperative risk factors were identified indicating those at risk of high IOP. It is important to identify these potentially harmful IOP elevations, and therefore day-one review is imperative and should be continued.

Lesson of the month 1: Seeing snowflakes.

Melanoma-associated retinopathy is a rare paraneoplastic complication of metastatic cutaneous malignant melanoma. It may present years after the original diagnosis of melanoma. We describe a patient with this condition who presented with persistent visual symptoms.

Vitrectomy in cases of nonaccidental injury.

Nonaccidental head injuries may present in several ways, requiring prompt recognition and management because of the risk of death or permanent neurologic and visual impairment. Dense amblyopia and high anisometropic myopia induced by prolonged occlusion of the macula by hemorrhage is a concern in these infants, although the prognosis also depends on the extent of associated brain injury. There are few reports of the visual and general outcome of children with a diagnosis of nonaccidental injury who have undergone vitrectomy. This report describes the outcome in six eyes of four patients diagnosed as having nonaccidental injury who underwent vitrectomy. The results are more favorable than in previous reports.

Apoptosis in proliferative vitreoretinopathy.

PURPOSE: To study the involvement of apoptosis using different apoptosis markers in PVR pathogenesis. METHODS: The presence of mRNA coding for Fas, Fas ligand (FasL), and TNF-related apoptosis inducing ligand (TRAIL) was investigated in vitreous samples from 46 consecutive patients-25 with PVR, 11 with retinal detachment (RD) not complicated by PVR, and 10 with macular hole (MH)-using RT-PCR. From previously examined vitreous samples, 21 PVR, 9 RD, and 10 MH were examined for their levels of TGF-beta2 protein with sandwich ELISA kits. Five epiretinal membranes excised from five patients with PVR were also examined for apoptotic cell death using the terminal deoxytransferase (TdT) mediated dUTP-biotin nick end labeling (TUNEL) technique. RESULTS: FAS mRNA was detected in 72% of patients with PVR, 55% of patients with RD and 20% of patients with MH. TRAIL mRNA was detected in 67% of patients with PVR, 89% of patients with RD, and 20% of patients with MH. FasL mRNA was detected in 20% of patients with PVR, 9% of patients with RD, and 10% of patients with MH. The median levels of Fas and TRAIL mRNA were significantly higher (P < 0.05) in patients with PVR than in those with MH hole but between patients with PVR and those with RD the difference was not significant (P > 0.05). A significant difference was detected between RD and MH for TRAIL mRNA levels (P = 0.008). For FasL, no significant difference between groups was found. TGF-beta2 was detected in all investigated vitreous samples. A significant difference was found between the PVR and MH groups (P = 0.001) and between the RD and MH groups (P = 0.004), but not between the PVR and RD groups (P < 0.05). The level of TGF-beta2 was significantly correlated to the level of TRAIL mRNA (r = 0.86), but no correlation was found between TGF-beta2 and Fas mRNA levels (r = 0.21). Four of five examined PVR epiretinal membranes showed positive staining for apoptotic cells using the TUNEL technique. CONCLUSIONS: Apoptosis is one of the mechanisms that is involved in PVR pathogenesis. Different apoptosis markers suggest different pathways occur in PVR, including Fas/FasL, TRAIL, and TGF-beta2 mediated processes.