Posterior Capsule Opacification: A Review of Experimental Studies

Posterior capsule opacification (PCO) is the most common complication of cataract surgery. It causes a gradual deterioration of visual acuity, which would otherwise improve after a successful procedure. Despite recent advances in ophthalmology, this complication has not been eradicated, and the incidence of PCO can be as high as 10%. This article reviews the literature concerning the pathomechanism of PCO and examines the biochemical pathways involved in its formation and methods to prevent this complication. We also review the reported tests performed in cell cultures under laboratory conditions and in experimental animal models and in ex vivo human lens capsules. Finally, we describe research involving human eyes in the clinical setting and pharmacological methods that may reduce the frequency of PCO. Due to the multifactorial etiology of PCO, in vitro studies make it possible to assess the factors contributing to its complications and search for new therapeutic targets. Not all pathways involved in cell proliferation, migration, and contraction of the lens capsule are reproducible in laboratory conditions; moreover, PCO in humans and laboratory animals may be additionally stimulated by various degrees of postoperative reactions depending on the course of surgery. Therefore, further studies are necessary

Impact of Three Waves of the COVID-19 Pandemic on the Rate of Elective Cataract Surgeries at a Tertiary Referral Center: A Polish Perspective

The aim of this study was to assess the effect of three waves of the COVID-19 pandemic on the number of elective cataract surgeries. A retrospective single-center consecutive case series study was performed. We included all 12,464 patients who received cataract surgery in the period between 1 January 2016 and 31 May 2021. Monthly numbers of cataract surgeries during the pandemic were compared with monthly numbers in the reference years 2016–2019. In the pandemic the number of cataract surgeries decreased by 53.4%. The monthly numbers during the first, second and third wave of the pandemic were 77.5%, 51.5% and 29.7% lower, respectively, compared with the reference level. No rebound effect was observed once the pandemic restrictions were eased. Simultaneous bilateral cataract surgeries (SBCS) constituted 6.5% of cataract procedures performed in April and May 2021 compared with 0.77% carried out between May 2019 and March 2021. While the pandemic-affected monthly numbers of cataract surgeries tend to increase recently, they are still below the prepandemic level. Patients should be encouraged to weigh the risks of COVID-19-related morbidity and mortality against the benefits of cataract surgery. Reorganization of the logistics of cataract services is advisable with consideration of SBCS as one of the options

The PreserFlo MicroShunt in the Context of Minimally Invasive Glaucoma Surgery: A Narrative Review

Recently, the quest for novel glaucoma surgical techniques and devices has been underway. Trabeculectomy remains the gold standard, but it requires the implantation of glaucoma drainage devices and frequent follow-ups, and it also carries a high risk of serious complications. The need for less invasive and safer procedures has led to the development of minimally invasive glaucoma surgery (MIGS), particularly for patients with mild–to–moderate disease. Among them, minimally invasive bleb surgery seems to be effective in classical glaucoma surgery, while maintaining MIGS benefits. The relatively new PreserFlo® MicroShunt (Santen, Osaka, Japan) is registered in Europe. It was released in 2019 for the treatment of patients with early–to–advanced open-angle glaucoma, where intraocular pressure (IOP) remains uncontrolled while on maximum tolerated medication and/or where glaucoma progression warrants surgery. This review focuses on the place of the PreserFlo MicroShunt, characterized by ab externo implantation, among MIGS procedures, discussing its advantages and disadvantages. The mechanisms of action, technical aspects, efficacy, and safety issues are summarized. The surgical technique, its efficacy, and safety profile are described, and directions for future studies are indicated. The PreserFlo MicroShunt ensures a high safety profile, minimal anatomical disruption, meaningful IOP-lowering effect, and ease of use for patients and physicians

Pros and Cons of Immediate Sequential Bilateral Cataract Surgery from a Patient Perspective: A Survey

The aim of the study was to analyze patients’ experiences with immediate sequential bilateral cataract surgery (ISBCS). An anonymous survey was sent by post to patients who underwent ISBCS between 1 May 2020 and 30 April 2022. A total of 195 participants completed the survey. Specifically, 94.6% of the respondents were satisfied with the possibility of having both eyes treated during one surgical procedure, 89.7% would choose ISBCS again if offered a choice, and 89.2% would recommend this procedure to their family members. ISBCS provided a subjective benefit for 84.6% of the respondents. The most commonly reported ISBCS-related problems were the necessity to sleep in a supine position (32.8%), inability to read shortly after the surgery (27.7%), having both eyes protected with a dressing (24.6%), and application of eyedrops to both eyes at the same time (17.4%). All patients were able to identify some pros of ISBCS, with the most common being single stay in the operating room (82.6%), lower number of visits to the clinic (62.6%), quick normalization of eyesight (61%), time savings for family members (54.9%), quick adjustment of reading glasses (32.3%), and economical aspects (23.6%). The perception of difficulties associated with ISBCS and the benefits offered by this procedure differed depending on patients’ gender, age, marital status, education, place of residence, occupational activity, level of care dependence, and everyday activities. Understanding patients’ opinions about ISBCS provides insight into the advantages and disadvantages of this procedure from a broader perspective

Quantitative Assessment of Choroidal Parameters in Patients with Various Types of Diabetic Macular Oedema: A Single-Centre Cross-Sectional Analysis

Diabetic macular oedema (DME) is an outcome of multiple, complex and not fully understood mechanisms. The aim of this study was to define the role of choroidopathy in the pathogenesis of various DME types. The retrospective cross-sectional single-centre study included 140 eyes from 105 patients with DME and 76 eyes from 52 non-diabetic controls. The eyes were stratified according to the type of DME: cystoid, diffuse, and with subretinal fluid. Optical coherence tomography-based choroidal parameters: thickness, volume, choroidal vascularity index (CVI), luminal area (LA), stromal area (SA), and total choroidal area (TCA) were compared. Eyes with DME, regardless of the type thereof, had lower choroidal thickness, volume, and CVI values than the controls. Further, the eyes with some specific DME types differed significantly from the controls in terms of LA and SA. While the eyes with various DME types did not differ significantly in terms of their choroidal thickness, volume and CVI, some between-group differences were found in LA, SA and TCA. Diabetic choroidopathy seems to play a role in the development of DME but is less likely involved in the pathogenesis of specific types thereof

Iridoschisis—A Systematic Review

Iridoschisis is a rare condition defined as a separation of the anterior iris stroma from the posterior stroma and muscle layers. In this paper, we review current data about the epidemiology, pathophysiology, clinical characteristics and differential diagnoses of this condition and discuss the specificity of surgical treatment of concomitant ocular diseases in iridoschisis patients. Iridoschisis may pose a challenge for both an ophthalmologist in an outpatient setting and an ophthalmic surgeon. Glaucoma, primarily angle-closure glaucoma, is the most often described condition concomitant to iridoschisis. Other ocular abnormalities found relatively often in iridoschisis patients include cataract, lens subluxation and corneal abnormalities. Special attention has been paid to potential complications of cataract surgery and prevention thereof. Beside addressing the practical aspects, we point to discrepancies and suggest topics for further investigation

XEN Glaucoma Implant for the Management of Glaucoma in Naïve Patients versus Patients with Previous Glaucoma Surgery

This retrospective study analyzed the surgical and refractive outcomes of a XEN Gel Implant (Allergan, Abbvie Company, Irvine, CA, USA) in naïve patients versus those with previous glaucoma surgery. We evaluated the efficacy of XEN implantation in 86 glaucoma patients during a long-term follow-up period. Patients were divided into two groups: naïve patients (Group 1) and patients with previous glaucoma surgery (Group 2). Eyes that received a XEN Gel Stent placement from December 2014 to October 2019 were included. Intraocular pressure (IOP) change, corrected distance visual acuity (CDVA), change in glaucoma medications, frequency of slit lamp revision procedures, and frequency of secondary glaucoma surgeries were the primary outcomes. In Group 1, the mean IOP before surgery was decreased significantly from 25.00 ± 7.52 mmHg to 16.83 ± 5.12 mmHg by the end of the study. In Group 2, the mean IOP decreased significantly from 25.35 ± 7.81 mmHg to 17.54 ± 5.34 mmHg. The mean IOP decrease from baseline was 29% in Group 1 and 27% in Group 2 (p = 0.567). There were no significant differences between the groups in the IOP baseline level, the final level, or the change between preoperative and final levels. The qualified success rate for Group 2 was 68.7% versus 76.5% for Group 1 for the initial procedure and 15.4% vs. 20.2%, respectively, for complete success rate (p > 0.05). However, at the end of the follow-up, more patients achieved an IOP < 18 mmHg in Group 1 than in Group 2. Despite the need for more anti-glaucoma medications, repeat XEN Gel implantation appears to show promising results in patients with previously failed anti-glaucoma procedures, owing to its minimal invasiveness

LC-MS-Based Metabolic Fingerprinting of Aqueous Humor

Aqueous humor (AH) is a transparent fluid which fills the anterior and posterior chambers of the eye. It supplies nutrients and removes metabolic waste from avascular tissues in the eye. Proper homeostasis of AH is required to maintain adequate intraocular pressure as well as optical and refractive properties of the eye. Application of metabolomics to study human AH may improve knowledge about the molecular mechanisms of eye diseases. Until now, global analysis of metabolites in AH has been mainly performed using NMR. Among the analytical platforms used in metabolomics, LC-MS allows for the highest metabolome coverage. The aim of this study was to develop a method for extraction and analysis of AH metabolites by LC-QTOF-MS. Different protocols for AH preparation were tested. The best results were obtained when one volume of AH was mixed with one volume of methanol : ethanol (1 : 1). In the final method, 2 µL of extracted sample was analyzed by LC-QTOF-MS. The method allowed for reproducible measurement of over 1000 metabolic features. Almost 250 metabolites were identified in AH and assigned to 47 metabolic pathways. This method is suitable to study the potential role of amino acids, lipids, oxidative stress, or microbial metabolites in development of ocular diseases