Immunological and inflammatory mechanisms in ocular allergy with special reference to vernal keratoconjunctivitis : clinical and experimental studies

Ocular allergy encompasses a wide range of conditions, most of which implicate IgE in the pathogenesis. In contrast to the benign nature of seasonal allergic conjunctivitis (SAC), the less common chronic eye diseases vernal and atopic keratoconjunctivitis (VKC and AKC) are severe and debilitating disorders. The factors that are responsible for the triggering and maintenance of these chronic diseases are largely unknown. The following objectives were pursued in this project: to characterise VKC in epidemiological and immunologic terms; to delineate the cellular infiltration and to determine the expression of mRNA for various cytokines in conjunctival biopsies from VKC patients with reference to atopic status; to investigate the role of the eosinophilic granulocyte in general ocular allergy by assessing cosinophil cationic protein (ECP) in tear fluid; to determine the kinetics of ECP release into tears after a single allergen provocation in sensitised volunteers with SAC; and finally, to explore the possible delaying effect of ECP in a corneal wound healing model in rabbits. In a cohort of VKC subjects, mostly children, only 60% of the cases were classed as atopic by conventional testing, i.e. presence of positive skin prick tests or RAST. An examination of specific IgE in tears did not reveal any additional atopic subjects. By retrieving information from a social database, it was found that VKC affects disproportionately high numbers of children of Asian or African origin. Since the majority of these children were born in Sweden, genetic rather than environmental factors should explain the unequal distribution of VKC among different ethnic groups. Expression of immunocytochemical markers and mRNA for cytokines were investigated in papillary tissue from atopic and non-atopic subjects with VKC. Salient differences with respect to the numbers of infiltrating cells and mRNA signals for cytokines pathognomonic for allergy: e.g. IgE cells, T-cells, mast cells, eosinophils, interleukin (IL)-5, and IL- 13 were found when disease and control samples were compared. In contrast, no differences were detectable between the atopic and non-atopic subjects with VKC. Non-atopic and atopic VKC thus share common immunological and inflammatory disease mechanisms that seem to be Th2-polarised. Tear samples from symptomatic patients with SAC, AKC, VKC, and healthy controls were analysed with respect to ECP levels. All three allergic conditions were associated with a significant ECP increase as compared with controls. Moreover, there was a significant correlation between symptom severity and ECP levels, particularly in VKC, substantiating the concept of eosinophil involvement in ocular allergic disease processes and a possible cause and effect relationship with keratopathy. ECP release into tears and its relationship to the acute and late phase reaction in a 72-hour time course in the conjunctiva was studied after relevant local allergen provocation in non-symptomatic subjects with SAC. Tear ECP was elevated in the late phase allergic reaction and was significantly correlated with symptoms at 24 hours after the challenge. To explore the possibility that ECP is instrumental in corneal disease in VKC, ECP was administered in eyes of rabbits that had been subjected to excimer laser operations to create standard size wounds. ECP significantly delayed the the process and was related to a changed cell distribution in the sliding epithelial sheets and a reduced expression of anti-apoptotic protein in keratocytes. ECP may thus be partially responsible for the keratopathy seen in chronic allergic eye disease

Risk factors for endophthalmitis after cataract surgery: Predictors for causative organisms and visual outcomes.

To investigate visual outcome, bacteriology, and time to diagnosis in groups identified as being at risk for endophthalmitis following cataract surgery

Postoperative Endophthalmitis in Immediate Sequential Bilateral Cataract Surgery : A Nationwide Registry Study

Purpose: To report the incidence of postoperative endophthalmitis (PE) after immediate sequential bilateral cataract surgery (ISBCS) in Sweden. Design: Retrospective cohort registry study. Participants: Patient data from 1 457 172 cataract extractions, including 1 364 934 unilateral surgeries and 92 238 ISBCSs. Methods: Endophthalmitis cases reported to the Swedish National Cataract Register (NCR) during a 16-year period (2002-2017) were analyzed in comparison to all control cases with regard to patient characteristics, surgical technique, and capsule complication. Main Outcome Measure: Incidence and determinants for PE in ISBCS compared with unilateral surgeries. Results: A total of 422 cases of PE were identified in 1 457 172 cataract extractions, yielding an overall incidence of 0.029% (95% confidence interval [CI], 0.0262-0.0317). For unilateral procedures, the rate was 0.0299% (95% CI, 0.0270-0.0328) or 408 cases in 1 364 934 operations, whereas that for ISBCS was 0.0152% (95% CI, 0.0072-0.0231) or 14 incidents in 92 238 operations (P = 0.01). In a logistic regression model including all cataract procedures, nonuse of intracameral (IC) antibiotics (ABs), capsule complication, age 85 years or more, male gender, and ocular comorbidity were found to be independent risk factors for PE. All these parameters were less frequent in ISBCS. Notwithstanding, in the same multivariate analysis, ISBCS in itself was associated with a significantly lower risk for PE. At follow-up, 5 of the 14 PE cases in the ISBCS cohort had a visual acuity (VA) of 20/200 or worse. Of these, one 93-year-old ISBCS patient developed bilateral infection. Conclusions: After ISBCS in Sweden, PE occurred once in 6600 surgeries. The risk of sustaining a final VA of 20/200 or less was 1 incident in 18 000 operated eyes. When counseling potential ISBCS patients about the risk of PE, it seems reasonable to state that the reported risk in the literature is lower than that with unilateral surgery but not negligible. Precautions remain necessary. (C) 2021 by the American Academy of Ophthalmology.Funding Agencies|Kronprinsessan Margaretas Arbetsnamnd for synskadade, KMA, Region Ostergotland; Swedish Association of Local Authorities and Regions</p

Visual acuity and intraocular pressure after surgical management of late in-the-bag dislocation of intraocular lenses. A single-centre prospective study

Objectives: To describe logarithm of the minimum angle of resolution (logMAR) best corrected visual acuity (BCVA) and intraocular pressure (IOP) after surgical management of late in-the-bag dislocation of the intraocular lens. Subjects/methods: In a single-centre prospective study, 165 consecutive cases having surgical correction for late in-the-bag-dislocation of intraocular lenses were analysed. One-year follow-up data of BCVA, IOP and a specially created composite variable designated “IOP issue” which considered IOP ≥ 23 mmHg, ongoing pressure reducing treatment and previous pressure reducing surgery were compared with baseline values. Logistic regression was used to investigate factors with a possible influence on the results. Results: The vast majority, 80% of patients, were operated with an anterior approach with repositioning of the present IOL. Remaining patients were managed with lens exchange via a posterior approach combined with a pars plana vitrectomy (PPV). Baseline BCVA values improved from 0.65 ± 0.48 to 0.32 ± 0.41 (p < 0.001), IOP decreased from 20.12 ± 8.4 to 18.44 ± 5.96 mmHg (p = 0.02) whereas the proportion of cases with a pressure issue remained unchanged, 47.3%, at the 1-year follow-up. Determinants for having a pressure issue at the 1-year follow-up were present a pressure issue at baseline and IOL repositioning with the anterior approach. Conclusions: Both surgical methods provided similar visual rehabilitation to other techniques described in the literature. However, subjects whose IOL was exchanged in combination with a PPV were at lower risk for an IOP issue at the follow-up

Changes in intraocular pressure after cataract surgery: Analysis of the Swedish National Cataract Register Data.

To analyze changes in intraocular pressure (IOP) after cataract surgery based on data from the Swedish National Cataract Register (NCR)

Endophthalmitis and severe blebitis following trabeculectomy. Epidemiology and risk factors; a single-centre retrospective study

Purpose: To study the epidemiology and risk factors of early-and late-onset postoperative endophthalmitis (PE) and severe blebitis following trabeculectomy. Methods: Retrospective, single-centre, observational study with a case-control design in part. Patients sustaining PE and severe blebitis following trabeculectomy or a combined trabeculectomy with a cataract extraction procedure performed from 1990 through 2008 and diagnosed from 1990 through 2012 were recorded at St Erik Eye Hospital. Incidence data were calculated with help from the hospital records. Notes data of cases and of six randomly selected but procedure matched control patients for each case were compared. Results: The joint rate of infection was 0.46% or 34 incidents in 7402 procedures. The frequency of early (occurring <6 weeks after surgery) onset PE was 0.19%, late PE was 0.19% and severe blebitis was 0.08%. Dominating aetiologies were staphylococci and streptococci. Overall, the infection severely impaired the visual function. Combined cataract and fistulating operations were less prone to develop late infections, p = 0.04, but no other decisive factors were identified in the case-control study. Data collection for all trabeculectomy surgeries from 1998 and onward identified an increased rate for late infection with the use of mitomycin C (MMC), 8 in 1171 surgeries or 0.7%, versus no such use, 0 case of late PE in 2136 surgeries, p < 0.001. Conclusions: Postoperative endophthalmitis is a devastating complication after trabeculectomy. The use of MMC increases the risk for delayed infection. Early PE after trabeculectomy is clearly more common than PE after cataract surgery. Developing efficacious prophylactic antibiotic regimens to reduce early PE after penetrating filtering procedures should be a major priority in ophthalmic surgery

Gender differences in biometry prediction error and intra-ocular lens power calculation formula

PurposeTo analyze changes over time in biometry prediction error (BPE) after cataract surgery with special reference to the impact of gender and the intra-ocular lens (IOL) calculation formula. MethodsAbout 65% of Swedish cataract surgery units participating in the outcome registration of the National Cataract Register (NCR) were included in this prospective register study. Data for planned and postoperative refraction and keratometry during the month of March 2004-2013 were analyzed, divided by gender. The newly introduced variables axial length and IOL calculation formula were analyzed for March 2013. Gender differences in BPE with correct sign (BPESign) and absolute biometry prediction error (BPEAbs) were compared for the Haigis' and Sanders-Retzlaff-Kraff T (SRK/T) formulas. ResultsThe BPEAbs decreased throughout the study period. In 2004-2006, the BPEAbs was larger in women than in men (p<0.05), but this difference disappeared from 2007. For 2004 through 2009, the mean BPESign was -0.1050.79D for women, but -0.003 +/- 0.73D for men. After 2009, this myopic error for women gradually diminished. The Haigis' formula performed better in women than the SRK/T formula (p<0.001); the SRK/T formula rendered a BPESign similar to that from 2004 to 2009 in women. Women had steeper corneas and shorter axial lengths than men (p<0.001). ConclusionThe myopic BPE in women - associated with steeper corneas and shorter axial lengths - is decreasing, possibly owing to an increased use of the Haigis' formula. Using the Haigis' formula to a higher extent can potentially further reduce the BPEs after cataract surgery

Three Learning Organizations in Cataract Surgery : The Example of Intracameral Antibiotic Injection

BACKGROUND: The recent systematic adoption of intracameral antibiotic injection during cataract surgery in Sweden, India, and the US serves as a model for the successful transitioning of local quality improvement initiatives to organization-wide implementation. Although the delivery of eye care in the 3 countries is distinctly organized with differing governances and technological infrastructure, each contains elements of a learning organization (ie, an organization that has adopted a culture of creating, acquiring, and transferring knowledge into practice through system-level and clinician-level change). METHODS: We describe a retrospective and organizational implementation study of intracameral antibiotic injection in Sweden, through the efforts of the National Cataract Registry; in the US by Kaiser Permanente; and in India by the Aravind Eye Hospital System. Leadership structure, training in problem solving, benchmarking, sharing of technical knowledge, and data and workforce engagement are compared. RESULTS: Each of the 3 organizations share the key elements of effective leadership, which values the exchange of ideas in the workforce, training and resourcing for change, and information management in the form of benchmarking and data sharing. In the case of intracameral antibiotic injection, a new technique was identified to improve quality and safety with a reduction in infections as evidence of the success of the programs. CONCLUSION: Committing to a culture of collective learning, and leveraging each stakeholder's personal investment, health-care systems may improve care delivery and set new benchmarks in quality and safety