Vitreous substitutes and tamponades - A review of types, applications, and future directions.

Vitreous substitutes and tamponades occupy the vitreous cavity following vitrectomy in the management of various conditions such as retinal detachment, macular hole, and diabetic retinopathy. Such replacements can be for the short term (gases such as sulfur hexafluoride (SF6) and perfluoropropane (C3F8) or long term (such as silicone oils). Certain substitutes such as perfluorocarbon liquids are used only transiently during surgery as "a third hand" or rarely till a few days post surgery. Hydrogels and hyaluronan derivatives are among the newer vitreous substitutes that are showing promise for the future, albeit still under investigation. still being investigated for use as vitreous substitutes. These materials have properties similar to the natural vitreous and may offer advantages such as improved biocompatibility and biodegradability. Although vitreous substitutes are valuable tools in treating vitreoretinal conditions, they carry risks and potential complications such as cataract formation, glaucoma, and inflammation. The current communication extensively reviews the available literature on vitreous tamponades. It details the composition and properties of various vitreous substitutes and tamponades available for the clinician, highlighting the techniques of usage, indications, and limitations.

Idiopathic intracranial hypertension in two twin sisters.

Idiopathic intracranial hypertension (IIH) is a condition of unknown aetiology characterised by an increase in the intracranial pressure. Familial cases of IIH are rare and not well-understood. We present two monozygotic twins who developed IIH two years apart. The case involves two monozygotic female twins developing IIH in their 50s. They presented with a history of blurry vision and headaches. The diagnosis included the neurological, radiological and ophthalmological examination, excluding other causes. Both patients received treatment with acetazolamide, successfully resolving the papilloedema and restoring a normal visual field. This case highlights the occurrence of IIH among twins presenting at similar periods, emphasising the potential genetic influence. Clinicians should alert and educate the family regarding the risk factors and potential symptoms of this condition in the unlikely occurrence that other family members are affected.

Dry eye disease in astronauts: a narrative review.

Long-duration spaceflight can have adverse effects on human health. One of the most common ocular conditions experienced by astronauts is dry eye disease (DED). Symptoms of DED include feelings of eye irritation, eye strain, foreign body sensation and blurred vision. Over 30% of International Space Station expedition crew members reported irritation and foreign body sensation. We reviewed the current literature on the prevalence and mechanisms of DED in astronauts and its potential implications for long-duration spaceflight, including the influence of environmental factors, such as microgravity and fluid shift on tear film physiology in space. DED has negative effects on astronaut performance, which is why there is a need for further research into the pathophysiology and countermeasures. As an in-flight countermeasure, neurostimulation seems to be among the most promising options.

Gene expression signatures in conjunctival fornix aspirates of patients with dry eye disease associated with Meibomian gland dysfunction. A proof-of-concept study.

BACKGROUND: Meibomian gland dysfunction (MGD) is one of the most common conditions in ophthalmic practice and the most frequent cause of evaporative dry eye disease (DED). However, the immune mechanisms leading to this pathology are not fully understood and the diagnostic tests available are limited. Here, we used the nCounter technology to analyze immune gene expression in DED-MGD that can be used for developing diagnostic signatures for DED. METHODS: Conjunctival cell samples were obtained by aspiration from patients with DED-MGD (n = 27) and asymptomatic controls (n = 22). RNA was purified, converted to cDNA, preamplified and analyzed using the Gene Expression Human Immune V2 panel (NanoString), which includes 579 target and 15 housekeeping genes. A machine learning (ML) algorithm was applied to design a signature associated with DED-MGD. RESULTS: Forty-five immune genes were found upregulated in DED-MGD vs. controls, involved in eight signaling pathways, IFN I/II, MHC class I/II, immunometabolism, B cell receptor, T Cell receptor, and T helper-17 (Th-17) differentiation. Additionally, statistically significant correlations were found between 31 genes and clinical characteristics of the disease such as lid margin or tear osmolarity (Pearson's r < 0.05). ML analysis using a recursive feature elimination (RFE) algorithm selected a 4-gene mRNA signature that discriminated DED-MGD from control samples with an area under the ROC curve (AUC ROC) of 0.86 and an accuracy of 77.5%. CONCLUSIONS: Multiplexed mRNA analysis of conjunctival cells can be used to analyze immune gene expression patterns in patients with DED-MGD and to generate diagnostic signatures.

Dementia and cataract surgery in Australia and New Zealand.

BACKGROUND: Cataract surgery improves quality of life and reduces cognitive deterioration. OBJECTIVES: This paper discusses the health implications of low vision, commonly related to cataracts, in older adults. A recent publication reported that cataract surgery reduces the risk of dementia by 30% over 10 years. METHODS: We searched Medline from inception to January 2023. We also conducted backward and forward citation searches of included studies and set up alerts to identify studies published after the search date. We performed discussion groups with multidisciplinary experts. RESULTS: This article provides a broad description of the importance of vision for cognitive function. We discuss access to public-funded cataract surgery in Australia and New Zealand and how this impacts population benefits. CONCLUSIONS: We have evidence that cataract surgery can decrease the risk of dementia. This is an important topic that deserves recognition as part of an overall ageing response by policymakers and health professionals.

Prospective evaluation of intense pulsed light treatment for meibomian gland dysfunction and blepharitis due to ocular rosacea

Background: Ocular rosacea is a common skin condition leading to dry eye that is difficult to manage. Objectives: To estimate the efficacy and safety of a new intense pulsed light device, Thermaeye Plus, for meibomian gland dysfunction and blepharitis due to ocular rosacea. Materials & Methods: This prospective, longitudinal study included 74 eyes of 37 consecutive patients with ocular rosacea, with mean age of 45.6±11.7 years. Four consecutive sessions were undertaken, including14 flashes with 10 J/cm² on the periocular area and facial cheeks on Day 1, 14, 28, and 49. Clinical evaluation was based on: ocular surface disease index (OSDI) and symptom score questionnaires, quality of live and facial severity degree, non-invasive tear meniscus height, non-invasive tear break up time, corneal fluorescein staining and eyelid margin and meibomian gland assessment. Adverse effects on the eye and periocular area, and systemic complications were evaluated. Results: The OSDI questionnaire showed a decrease in symptoms, achieving normal values in 91.9% of patients. The symptom score showed amelioration, with the most significant changes relating to dryness, foreign body sensation, light sensitivity, and pain. Longitudinal analysis showed the most significant improvement between baseline at Day 1 and 49. All eyelid signs improved, most significantly for telangiectasia/vascularity and blepharitis, leading to a 78% clearance of facial rosacea and 81.1% reduction of flushing. In total, 100% of the patients reported an improvement in their quality of life after treatment and 94.6% a very significant improvement (p<0.001). Conclusion: These results demonstrate that Thermaeye Plus is an effective and safe treatment for ocular rosacea.

Real-World Experience with Brolucizumab in Wet Age-Related Macular Degeneration: The REBA Study.

The aim of the present study was to determine the efficacy and safety of intravitreal brolucizumab therapy for neovascular age-related macular degeneration (AMD) in the real-world setting. The REBA study (real-world experience with brolucizumab in wet AMD) was a retrospective, observational, multicentric study that included 78 consecutive patients (105 eyes), with neovascular AMD, who received brolucizumab therapy. Both treatment-naive and switch-therapy patients were included. Switch therapy was based either on fluid recurrence, fluid recalcitrance, or inability to extend beyond q4/q6. All relevant data were collected. The primary outcome measure was change in best-corrected visual acuity (BCVA) over time. Secondary outcome measures included determination of change in central subfield thickness (CST) and complications. The mean baseline BCVA was 49.4 ± 5.4 letters and 40 ± 3.2 letters, and corresponding mean BCVA gain was +11.9 ± 3.9 letters (p = 0.011) and +10.4 ± 4.8 letters (p = 0.014) in the treatment-naive and switch-therapy groups, respectively. The change in CST was significantly decreased in the treatment-naive (p = 0.021) and the switch-therapy (p = 0.013) groups. The mean follow-up was 10.4 months in both groups. One patient in the switch-therapy group developed vascular occlusion and another a macular hole after the fifth brolucizumab injection. Both patients recovered uneventfully. In conclusion, patients showed a very good anatomical and functional response to brolucizumab therapy in the real world, regardless of prior treatment status, until the end of the follow-up period. Two significant untoward events were noted.

Teleophthalmology in the post-coronavirus era.

173,766 New Zealanders suffer from visual impairment. The associated health-system costs are $523 million in total, or $3,008 per person. Yet eighty percent (80%) of blindness is avoidable if detected on time. Public health services have an increasing workload but are also limited by material and technical resources. Optometry practices continually increase referrals (up to 100% in one year) that cannot be solved on time, reducing the efficiency of the service. Teleophthalmology works by improving the efficiency of screening and monitoring and integrating eye healthcare and by decreasing referrals by up to 40%.

ENDOGENOUS ENDOPHTHALMITIS IN THE SETTING OF COVID-19 INFECTION: A Case Series.

PURPOSE: To describe endogenous endophthalmitis in the setting of COVID-19 pneumonia. METHODS: Patients recovering from COVID-19 pneumonia who presented to our department with any or all of the following complaints: pain, watering, redness, and decreased vision were identified. All relevant data were collected for analysis. RESULTS: Three patients with endogenous endophthalmitis were identified. All patients had been treated for COVID-19 pneumonia and therefore had received remdesivir and systemic steroids; 2 of the 3 patients received tocilizumab. All patients received vitreous biopsy, vitrectomy, and intraocular antibiotic injection. Patient 1 demonstrated Klebsiella pneumoniae in blood culture, K. pneumoniae and Escherichia coli in urine culture, and K. pneumoniae in vitreous fluid, whereas Patients 2 and 3 demonstrated Stenotrophomonas maltophilia and methicillin-resistant Staphylococcus aureus in the blood and nasopharyngeal culture, respectively. Correspondingly, the same organism was cultured from vitreous in Patients 2 and 3. The visual acuity at the last follow-up in Patients 1 to 3 was 20/100, 20/80, and 20/40, respectively. The probable source of infection was identified in each as renal calculi, dental caries, and the pharynx, respectively. Real-time polymerase chain reaction demonstrated the presence of Severe Acute Respiratory Syndrome Coronavirus 2 in the vitreous fluid of Patient 1. CONCLUSION: We report good outcomes of early intervention for endogenous endophthalmitis in the setting of COVID-19 infection. We also document the presence of SARS-CoV-2 in vitreous.

Correlation in acute CSCR between hyperreflectivity on the infrared image in optical coherence tomography and fluorescein angiography.

BACKGROUND: To determine the association between hyperreflective area identified on the reference image (en-face image) in spectral domain optical coherence tomography (SD-OCT) scan and the leak on fluorescein angiography in patients with acute treatment naive central serous chorioretinopathy (CSCR). METHODS: Retrospective, observational chart review. The reference image (en-face) image on SD OCT raster scan was examined for the presence of a hyperreflective spot and an attempt was made to correlate its location on the actual leak seen on FFA using anatomical landmarks as reference. Follow up was 6 months after CSCR resolution. Appropriate statistical analysis was made. RESULTS: Sixty-two patients (65 eyes; 49 males) with CSCR were identified of which 62/65 eyes (95.38%) showed the said correlation. The mean age was 31.24 years. The mean follow-up was 17.25 months. The mean BCVA at baseline was 0.28 logMAR. The mean final BCVA was 0.08. The hyperreflective spot noted on the infrared (reference) image correlated the most with the classic ink-blot leakage as well as the minimally enhancing/ill-defined leakage pattern. In 37/41 eyes, the area of hyperreflectivitiy correlated with the pigment epithelial detachment. The hyperreflective spot resolved in most patients who received photodynamic therapy but persisted in most patients who received eplerenone therapy. Persistent hyperreflectivity after subretinal fluid resolution appeared to correlate with persistent metamorphopsia and reduced contrast sensitivity in eyes with no subretinal fluid. CONCLUSION: We demonstrate an interesting correlation between the area of leak and the OCT reference image (en face) used to determine the level of the scan. SYNOPSIS: The study looks at the potential applicability of a correlation between leaking areas on fundus fluorescein angiography and a hyperreflective area on the infrared image in optical coherence tomography (OCT) in patients with central serous chorioretinopathy (CSCR).

Efficacy of a Novel Retrobulbar Extension Shunt to Rescue Eyes with Fibrotic Encapsulated Blebs and Uncontrolled Ocular Hypertension.

PURPOSE: Retrobulbar glaucoma shunts are large-bore fenestrated silicone stents that redirect aqueous humor into the retrobulbar space. They were designed to rescue failed standard tube shunts with fibrotic encapsulation in patients with intractable ocular hypertension. This article evaluates longer-term outcomes of a larger population undergoing retrobulbar aqueous redirection. METHODS: Outcomes of all retrobulbar shunts were placed among this progressive-entry surgical population over an 8-year interval. Implants were produced by New World Medical (NWM) in Rancho Cucamonga, California, and AJL in Bilbao, Spain. Mean and percentage IOP reduction and medications required were evaluated at annual intervals, along with pre-operative and final visual acuity. Significance of change was assessed by two-tailed paired t-test. Failure was designated as any eye requiring placement of another shunt or diode-cyclophotocoagulation. All data are included in this analysis regardless of outcome. RESULTS: Thirty-five retrobulbar shunts were implanted (18M, 17F; mean 54.3 years; mean follow-up 32.5 months). Short-term AJL shunt performance was comparable to that of the 26 NWM shunts, for which there was longer-term follow-up. Three shunts (9%) failed: Two eyes required diode at 6 months, one another standard shunt after > 2 years. Preoperative medications averaged 2.6, reduced to 0.4-0.75 medications at each annual assessment (P < 0.0001). IOP was substantially reduced (by 53-57% from mean baseline 29.9-32.5 mmHg to 16.4-18.4 mmHg; P < 0.0008) at every annual follow-up. Visual acuity remained stable (baseline mean VA 0.27, final VA 0.30; P = 0.68). CONCLUSION: Retrobulbar extension shunts can convert tube shunt failures, with high success rate, to eyes with IOP control comparable to successful primary filtration surgery.