BMJ Open Ophthalmology最新文献

Objective: Glaucoma is a common neurodegenerative disease resulting in irreversible blindness. This study investigates whether fucoxanthin can safeguard retinal ganglion cells (RGCs) by modulating Parkin-mediated mitophagy in experimental glaucoma.

Methods: An experimental glaucomatous model was induced in Sprague-Dawley rats via translimbal laser photocoagulation. Intraocular pressure (IOP) was monitored using a Tonolab tonometer. RGC survival was evaluated through FluoroGold labelling. Retinal and optic nerve samples were analysed at 3 days and 2 weeks post-IOP elevation for mitochondrial morphology and gene/protein expression using immunohistochemistry and molecular assays.

Results: Results demonstrated that mitophagy was acutely overactivated in the short term and impaired over the long term in ocular hypertensive rats. Fucoxanthin intravitreal administration enhanced RGC survival and Bcl-2 expression while reducing Bax and glial fibrillar acidic protein levels. During acute IOP elevation, fucoxanthin curtailed Parkin expression and mitophagosome formation, mitigating excessive mitophagy. Under prolonged IOP elevation, it elevated mitophagy-related proteins and restored mitophagy function, contributing to damaged mitochondrial clearance.

Conclusion: Fucoxanthin exerts neuroprotective effects in experimental glaucoma by modulating Parkin-mediated mitophagy. This highlights the therapeutic potential of maintaining mitophagy homeostasis for glaucoma treatment.

Aim: Investigate and characterise acute post-cataract fungal endophthalmitis pooled from the Endophthalmitis Management Study occurring within 6 weeks of primary surgery.

Methods: The fungal infection was confirmed through conventional and molecular microbiology work-ups and antifungal susceptibility testing. Clinical examination included measurement of distant vision and intraocular pressure, anterior segment photo documentation and inflammation score (IS) measurement. Per the microbiology report, the eyes were divided into culture-positive (C+), sequencing-positive (S+) and sequencing-positive-unidentified (U+) fungi. Clinical correlations and statistical comparisons were performed between these three cohorts.

Results: The study identified 21 patients with fungal endophthalmitis; it was 9.5% (21 of 220) of all acute post-cataract endophthalmitis in this study. Per the microbiology report, C+, S+ and U+ were 6, 9 and 6 patients, respectively. Fusarium and Aspergillus spp were the common fungi. The C+ fungi had higher presenting IS (p=0.023), shorter time to symptoms, worse presenting vision, corneal abscess (p=0.030) and higher probability of repeat intervention (p=0.042) than the other two groups. In the C+ group, the final vision of >20/400 was less (p=0.046) and phthisis bulbi was higher (p=0.010). All culturable fungi were resistant to amphotericin B and voriconazole.

Conclusion: There is a 10% probability of acute post-cataract fungal endophthalmitis in India. The eyes presenting with corneal abscesses carry a higher risk. The polymicrobial infections shown in this cohort should be interpreted cautiously since next-generation sequencing detects DNA from all organisms, including residual or low-abundance or non-viable organisms that traditional culture might miss. Despite this, the new molecular microbiology technology is necessary to confirm diagnosis and expedite appropriate treatment. Given multi-antifungal agent resistance, routine susceptibility testing must be considered.

Objective: Elevated oestrogen levels and pharmacotherapies targeting oestrogen receptors can reduce corneal biomechanical stability, and altered stromal collagenase activity has been identified as one the possible mechanisms. We wished to determine the impact of oestradiol and the selective tissue (o)estrogenic activity regulator (STEAR), tibolone, on corneal enzymatic digestion resistance.

Methods and analysis: Freshly prepared ex vivo porcine corneas (n=48) were divided into three groups. Group A corneas served as untreated controls. Group B corneas were incubated in 20 µmol/L oestradiol solution and group C corneas were incubated in 20 µmol/L oestradiol solution with 2.5 mg tibolone before digestion in 0.3% collagenase-A solution to assess digestion time until corneal button dissolution.

Results: Group A control corneas showed the strongest resistance to collagenase digestion (31.38±2.03 hours). Corneas from group B that were preconditioned with oestradiol showed significantly lower resistance to digestion than group A control corneas (27.25±1.84 hours, p<0.01). Group C corneas that had been pretreated with both oestradiol and tibolone showed the least resistance to digestion (22.38±2.47 hours), with significant differences to group B (p<0.01) and group A (p<0.01).

Conclusion: Oestradiol significantly reduces corneal enzymatic digestion resistance. When combined with the STEAR, tibolone, there is a further decrease in stromal enzymatic digestion resistance. These results suggest that high oestradiol levels could have a significant impact on corneal conditions characterised by elevated collagenase activity, such as corneal ectasias (eg, keratoconus) and infectious keratitis. Importantly, the employment of STEAR therapy, such as tibolone, may amplify the effects of oestradiol.

Purpose: To investigate alteration in pulsatile trabecular meshwork (TM) motion in normal tension glaucoma (NTG) compared with healthy controls and primary open-angle glaucoma (POAG) patients.

Methods: This cross-sectional study included 15 healthy individuals, 14 NTG patients and 15 POAG patients with asymmetric visual field defects (VFD). Eyes were categorised as mild-to-moderate VFD (GI) or severe VFD (GII). A custom-designed phase-sensitive optical coherence tomography system was used to assess TM motion in temporal and nasal regions. Parameters analysed included maximum velocity (MV) and cumulative displacement (CDisp).

Results: Mean deviation was comparable between NTG and POAG in GI eyes (p=0.944), and intraocular pressure post-treatment in POAG was similar to NTG (p=0.066). MV and CDisp in NTG were significantly lower than in healthy controls (p<0.001) but higher than in POAG (p<0.001). In POAG, temporal MV, nasal CDisp and temporal CDisp were significantly higher in GI than in GII eyes (p=0.002, 0.025 and 0.038). In NTG, no significant differences in MV or CDisp were observed between GI and GII eyes (p>0.05).

Conclusions: Pulsatile TM motion is reduced in NTG compared with healthy individuals but remains higher than in POAG. Unlike POAG, NTG shows no asymmetry in TM motion between eyes with varying VFD severity, suggesting additional factors beyond TM biomechanics contribute to NTG progression.

Objective: To investigate quantitative changes in iris blood flow after first-eye and second-eye cataract surgeries, and their correlation with increased pain in the second eye.

Methods and analysis: In this prospective study, 88 eyes of 44 participants who underwent uneventful cataract surgery were followed up at enrolment, 1 day before, and 1 day, 1 week and 1 month after each eye surgery. Iris blood flow was quantified by a swept-source optical coherence tomography angiography and intraoperative pain was evaluated. Participants were divided into three groups according to time intervals between two eye surgeries: ≥1 to <2 weeks (short interval), ≥2 to ≤4 weeks (medium interval) and greater than 4 weeks (long interval).

Results: The second eye experienced two significant increases in iris blood flow following cataract surgery: one after the first eye and the other after its own, with the latter being significantly higher than the increase observed in the operated eye after the first surgery (p<0.05). Additionally, the second eye showed higher iris blood flow density in the short interval group compared with the long and medium at specific time points (p<0.05). The bilateral pain index difference positively correlated with second eye iris blood flow density (p<0.05) and was significantly greater in the short interval group than the long interval group (p<0.05).

Conclusions: Iris blood flow increased in the second-operated eye post surgery compared with the first eye, which may correlate to second-eye pain. However, due to the variability in individual pain perception, a larger sample size is needed to prospectively validate our findings to improve their generalisability.

Trial registration number: NCT02182921.

Aim: To evaluate the effect of the corneal retrieval method on three outcome domains: donor consent rate, tissue quality and microbial contamination.

Methods: A systematic literature review was conducted using the Scopus, PubMed and Web of Science databases employing predefined search terms pertinent to corneal retrieval methods, consent rates, tissue quality and microbial contamination. Studies relevant to corneal donation and consent rates as well as reports comparing in situ corneal excision with whole-globe enucleation that evaluated at least one of the three primary outcome domains were included. This study adhered to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines.

Results: 12 out of 91 studies met the inclusion criteria. In situ corneal excision is associated with higher rates of consent from the family members of the deceased. Corneas harvested via in situ excision were of comparable tissue quality to those obtained from enucleation. Additionally, contamination rates were similar.

Conclusions: In situ excision of corneal tissue may provide a potential advantage in donor acceptance, while offering comparable tissue quality and microbial safety.

Objectives: To assess the influence of drainage retinotomy (DrR) on anatomical and visual outcomes of pars plana vitrectomy (PPV) for primary uncomplicated rhegmatogenous retinal detachment (RD), compared with drainage through pre-existing retinal break (PRB).

Methods and analysis: Retrospective study on patients treated with PPV for RD. Prospectively collected data were extracted from the Britain & Eire Association of Vitreoretinal Surgeons and European Society of Retina Specialists (EURETINA) RD database, including baseline features, surgical details, and anatomical and functional outcomes. Inclusion criteria were as follows: uncomplicated PPV, gas tamponade, drainage through DrR or PRB, surgeons with >100 cases recorded. Exclusion criteria were as follows: age <16, <2-month follow-up, ocular comorbidity, proliferative vitreoretinopathy ≥grade C, giant retinal tear, tamponade other than gas. Full propensity score matching resulted in matched groups to mitigate confounding bias. Subsequent multivariable linear regression was performed for postoperative best-corrected visual acuity (BCVA) as dependent variable, and Firth penalised logistic regression with DrR, single-surgery anatomical success (SSAS), epiretinal membrane (ERM) and macular fold as dependent dichotomised variables on matched data.

Results: Of 12 504 eyes extracted, 4175 were included. Of these, 3432 (82.2%) had PRB drainage (non-DrR group) and 743 (17.8%) a DrR (DrR group). Final median (IQR) BCVA was 0.18 (0.14-0.48) in the non-DrR group and 0.20 (0.18-0.48) in the DrR group (p=0.072). SSAS rate was 93.4% and 91% (OR 0.71 (95% CI 0.54 to 0.95)) and postoperative ERM rate 1.6% and 4.2% (OR 2.63 (95% CI 1.68 to 4.10)) in the non-DrR and DrR groups, respectively. On multivariable regression, DrR was associated with postoperative ERM (p=0.011), but not with final BCVA, SSAS and macular folds (p=0.633, 0.149 and 0.085, respectively).

Conclusion: Our study confirmed the association between DrR and increased risk of developing ERM; however, DrR does not appear to impact significantly on other outcomes.

Purpose: We aimed to develop and validate a prognostic scoring model for predicting poor visual outcomes in patients with open globe injury (OGI).

Design: A retrospective cohort study of patients with OGI from two teaching hospitals in Thailand.

Methods: 311 patients diagnosed with OGI between 2016 and 2023 were used to develop a multivariable logistic regression model predicting final visual acuity aimed at 6 months post-OGI. Visual outcomes were categorised into two groups using 20/200 as the cut-off for legal blindness. The model's performance was evaluated using receiver operating characteristic curve analysis. Internal validation was conducted with bootstrapping for 500 replications.

Results: 133 patients (42.77%) had visual acuity worse than 20/200 at the 6-month follow-up. The median follow-up time was 4.14 months, with an IQR of 3.00-11.74 months. Initial visual acuity (VA), relative afferent pupillary defect, rupture and eyelid injury were among the strongest predictors of visual outcome. Discrimination and calibration of the scoring model were satisfactory, with a C-statistic of 0.8671, a slope of 1 and a calibration-in-the-large of 0. Risk groups were created, categorised as mild, moderate and severe, with a C-statistic of 0.8094. The ORs for poor final VA (≤20/200) at 6 months were 1.51 (95% CI, 0.93 to 2.48) and 45.06 (95% CI, 11.20 to 387.94) in the moderate and severe risk groups, respectively.

Conclusions: Our prognostic model (revised Ocular Trauma Score) can be seamlessly used in emergency settings to predict visual outcomes in patients presenting with OGI. Presenting visual acuity (VA) is the strongest predictor. Interpretation should be made with caution due to several limitations, including the predominance of severe cases inherent to a referral-based setting, the relatively small sample size and the absence of paediatric patients. External validation of our model is needed.

Objective: To define sloping of the retina, a novel stereoscopic feature in primary open-angle glaucoma (POAG), and to evaluate its prevalence and associated risk factors in an African ancestry population.

Methods and analysis: Digital stereo disc images were graded for sloping by trained non-physician graders. We defined a sloping retina as one that slanted downward towards the disc margin instead of existing on the same plane as the disc margin. A 'sloping retina' approached the disc margin at an angle along at least one-third of the disc's circumference. The ocular and demographic risk factors of sloping were evaluated by univariable and multivariable logistic regression models.

Results: The prevalence of sloping in eyes with POAG was 22.0% (95% CI 20.6% to 23.4%). In a multivariable analysis, compared with eyes without sloping, eyes with sloping were less likely to have disc haemorrhages (p=0.03) and more likely to have a tilted disc (p<0.001), larger cup-to-disc ratio ((defined as 0.7-1), p=0.002), grey crescent (p=0.02), nasalisation of the vessels (p=0.01), moderate or deep cup depth (p<0.001) and conical cup shape (p<0.001). Sloping was not associated with any demographic characteristics in the multivariable analysis.

Conclusion: Associated with risk factors of advanced POAG, sloping presents as a novel feature that warrants further study to determine its mechanisms of development and prevalence in other study populations. Study limitations include: large difference in the number of eyes with and without sloping, potential morphological expressions of other phenotypes posing as sloping, impact of anatomical variability on grading, inherent biases when grading stereoscopic images and absence of a control or glaucoma suspect group. Future research into this phenotype in POAG patients might determine whether sloping retina is the result of or a precursor to glaucomatous damage, leading to a better understanding of POAG.

Background/aims: To describe the functional outcomes of patients with diabetic macular oedema (DME) non-responsive to bevacizumab switched to ranibizumab or aflibercept over 1 year and the demographic and anatomic predictors of these functional outcomes.

Methods: In a retrospective real-world cohort study, 76 consecutive patients with DME non-responsive to bevacizumab were reviewed at baseline and 12 months after switch to ranibizumab or aflibercept. Visual acuity (VA) and optical coherence tomography features such as central retinal thickness were assessed. Multiple logistic regression was performed to determine predictors for outcomes.

Results: From baseline to 1 year, the overall best-corrected VA improved by LogMAR 0.015±0.19 with no difference between patients who switched to ranibizumab or aflibercept (LogMAR 0.017±0.21 vs LogMAR 0.013±0.17, p=0.92). Ranibizumab patients had more reduction in central subfield thickness (CST) (390.13 µm vs 334.20 µm, p=0.033) than aflibercept patients. Baseline HbA1c (p=0.012) and number of bevacizumab injections (p=0.040) were significantly associated with gain in VA, while change in CST was a strong predictor of VA change (p<0.01). Aflibercept patients were more likely to gain vision after 6 months but not at 12 months.

Conclusions: In a real-world study, improvements in functional outcomes can still be gained after switching anti-vascular endothelial growth factor in bevacizumab non-responders. Both ranibizumab and aflibercept were comparable and effective treatments.