Health economic evaluation of a nurse-assisted online eye screening in home healthcare to reduce avoidable vision impairment (iScreen): study protocol for a cluster randomized controlled trial.

BACKGROUND: Among older people undiagnosed and untreated vision impairment and blindness are common. The leading causes are uncorrected refractive errors and cataracts. Vision problems are associated with a lower quality of life, several health problems, and a higher chance of falling accidents and fractures. To eliminate avoidable vision impairment and blindness, targeted eye screening programs are recommended. Older patients, receiving home healthcare, have not yet been considered as a population at risk who could benefit from eye screening. METHODS: A cluster-randomized controlled trial will be conducted to investigate the cost-effectiveness and cost-utility of online nurse-assisted eye screening in home healthcare, compared to care as usual, in reducing avoidable vision impairment. A healthcare and societal perspective will be used. The study will be performed in collaboration with several home healthcare organizations in the Netherlands. The online eye screening consists of near and distance visual acuity, followed by an Amsler grading test. Measurements in both groups will take place at baseline and after 6 and 12 months of follow-up. A total of 240 participants will be recruited. Older men and women (65 +), who receive home-based nursing and are cognitively able to participate, will be included. The primary outcome will be the change of two lines or more on the Colenbrander-1 M visual acuity chart between baseline and 12-month follow-up. DISCUSSION: An eye screening for populations at risk contributes to the detection of undiagnosed and untreated vision impairment. This may reduce the health-related consequences of vision loss and the high economic burden associated with vision impairment. TRIAL REGISTRATION: ClinicalTrials.gov NCT06058637. Registered on 27 September 2023.

Cost-effectiveness of the ADVISE trial: An intraoperative OCT protocol in DMEK surgery.

The intraoperative optical coherence tomography (iOCT) is recently introduced in Descemet membrane endothelial keratoplasty (DMEK) surgery, which aims to increase clinical performance and surgery safety. However, the acquisition of this modality is a substantial investment. The objective of this paper is to report on the cost-effectiveness of an iOCT-protocol in DMEK surgery with the Advanced Visualization in Corneal Surgery Evaluation (ADVISE) trial. This cost-effectiveness analysis uses data 6 months postoperatively from the multicentre prospective randomized clinical ADVISE trial. Sixty-five patients were randomized to usual care (n = 33) or the iOCT-protocol (n = 32). Quality-Adjusted Life Years (EQ-5D-5L), Vision-related Quality of Life (NEI-VFQ-25) and self-administered resources questionnaires were administered. Main outcome is the incremental cost-effectiveness ratio (ICER) and sensitivity analyses. The iOCT protocol reports no statistical difference in ICER. For the usual care group compared with the iOCT protocol, respectively, the mean societal costs are €5027 compared with €4920 (Δ€107). The sensitivity analyses report the highest variability on time variables. This economic evaluation learned that there is no added value in quality of life or cost-effectiveness in using the iOCT protocol in DMEK surgery. The variability of cost variables depends on the characteristics of an eye clinic. The added value of iOCT could gain incrementally by increasing surgical efficiency, and aiding in surgical decision-making.

Allogeneic Serum Eye Drops: A Randomized Clinical Trial to Evaluate the Clinical Effectiveness of Two Drop Sizes.

INTRODUCTION: Allogeneic serum from blood donors is starting to be used to treat patients with dry eye disease (DED). However, the optimal dose is not known. We therefore aimed to evaluate the clinical efficaciousness and user-friendliness of micro-sized versus conventional-sized allogeneic serum eye drops (SEDs). METHODS: In a randomized trial, patients with DED first receive micro-sized SEDs (7 µl/unit) for 1 month, followed by a 1-month washout, before receiving conventional-sized SEDs (50 µl/unit) for 1 month; or vice versa. The primary endpoint was the Ocular Surface Disease Index (OSDI) score. Secondary endpoints were tear break-up time (TBT), tear production (TP), and presence of corneal punctate lesions (CP). The user-friendliness of both application systems was also compared. A linear mixed model for cross-over design was applied to compare both treatments. RESULTS: Forty-nine patients completed the trial. The mean OSDI score significantly improved from 52 ± 3 to 41 ± 3 for micro-sized SEDs, and from 54 ± 3 to 45 ± 3 for conventional-sized SEDs. Non-inferiority (margin = 6) of micro-sized SEDs was established. We demonstrate a significant improvement for TBT in case of conventional-sized SEDs and for CP in both treatment groups. TP trended towards an improvement in both treatment groups. The user-friendliness of the conventional drop system was significantly higher. CONCLUSIONS: For the first time, non-inferiority of micro-sized allogeneic SEDs was established. The beneficial effect of both SED volumes was similar as measured by the OSDI score. Although user-friendliness of the micro drop system was significantly lower, it is an attractive alternative as it saves valuable donor serum. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03539159).

Belgian Endothelial Surgical Transplant of the Cornea (BEST cornea) protocol: clinical and patient-reported outcomes of Ultra-Thin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK) versus Descemet Membrane Endothelial Keratoplasty (DMEK) - a multicentric, randomised, parallel group pragmatic trial in corneal endothelial decompensation.

OBJECTIVES: Corneal blindness is the third most frequent cause of blindness globally. Damage to the corneal endothelium is a leading indication for corneal transplantation, which is typically performed by lamellar endothelial keratoplasty. There are two conventional surgical techniques: Ultra-Thin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK) and Descemet Membrane Endothelial Keratoplasty (DMEK). The purpose of this study is to compare both techniques. METHODS AND ANALYSIS: The trial compares UT-DSAEK and DMEK in terms of clinical and patient reported outcomes using a pragmatic, parallel, multicentric, randomised controlled trial with 1:1 allocation with a sample size of 220 participants across 11 surgical centres. The primary outcome is the change in best-corrected visual acuity at 12 months. Secondary outcomes include corrected and uncorrected vision, refraction, proportion of high vision, quality of life (EQ-5D-5L and VFQ25), endothelial cell counts and corneal thickness at 3, 6 and 12 months follow-up appointments. Adverse events will also be compared 12 months postoperatively. ETHICS AND DISSEMINATION: The protocol was reviewed by ethical committees of 11 participating centres with the sponsor centre issuing the final definitive approval. The results will be disseminated at clinical conferences, by patient partner groups and open access in peer-reviewed journals. GOVERNANCE OF THE TRIAL: Both, trial management group and trial steering committee, are installed with representatives of all stakeholders involved including surgeons, corneal bankers, patients and external experts. TRIAL REGISTRATION NUMBER: NCT05436665.

The TeleTriageTeam, Offering Continuity of Personalized Care Through Telemedicine: Development and Evaluation.

BACKGROUND: The COVID-19 pandemic taught us how to rethink care delivery. It catalyzed creative solutions to amplify the potential of personnel and facilities. This paper presents and evaluates a promptly introduced triaging solution that evolved into a tool to tackle the ever-growing waiting lists at an academic ophthalmology department, the TeleTriageTeam (TTT). A team of undergraduate optometry students, tutor optometrists, and ophthalmologists collaborate to maintain continuity of eye care. In this ongoing project, we combine innovative interprofessional task allocation, teaching, and remote care delivery. OBJECTIVE: In this paper, we described a novel approach, the TTT; reported its clinical effectiveness and impact on waiting lists; and discussed its transformation to a sustainable method for delivering remote eye care. METHODS: Real-world clinical data of all patients assessed by the TTT between April 16, 2020, and December 31, 2021, are covered in this paper. Business data on waiting lists and patient portal access were collected from the capacity management team and IT department of our hospital. Interim analyses were performed at different time points during the project, and this study presents a synthesis of these analyses. RESULTS: A total of 3658 cases were assessed by the TTT. For approximately half (1789/3658, 48.91%) of the assessed cases, an alternative to a conventional face-to-face consultation was found. The waiting lists that had built up during the first months of the pandemic diminished and have been stable since the end of 2020, even during periods of imposed lockdown restrictions and reduced capacity. Patient portal access decreased with age, and patients who were invited to perform a remote, web-based eye test at home were on average younger than patients who were not invited. CONCLUSIONS: Our promptly introduced approach to remotely review cases and prioritize urgency has been successful in maintaining continuity of care and education throughout the pandemic and has evolved into a telemedicine service that is of great interest for future purposes, especially in the routine follow-up of patients with chronic diseases. TTT appears to be a potentially preferred practice in other clinics and medical specialties. The paradox is that judicious clinical decision-making based on remotely collected data is possible, only if we as caregivers are willing to change our routines and cognitions regarding face-to-face care delivery.

Efficacy of customized corneal crosslinking versus standard corneal crosslinking in patients with progressive keratoconus (C-CROSS study): study protocol for a randomized controlled trial.

BACKGROUND: Keratoconus is a degenerative disorder of the cornea leading to a protrusion and thinning with loss of visual acuity. The only treatment to halt the progression is corneal crosslinking (CXL), which uses riboflavin and UV-A light to stiffen the cornea. Recent ultra-structural examinations show that the disease is regional and does not affect the entire cornea. Treating only the affected zone with CXL could be as good as the standard CXL, that treats the entire cornea. METHODS: We set up a multicentre non-inferiority randomized controlled clinical trial comparing standard CXL (sCXL) and customized CXL (cCXL). Patients between 16 and 45 years old with progressive keratoconus were included. Progression is based on one or more of the following changes within 12 months: 1 dioptre (D) increase in keratometry (Kmax, K1, K2); or 10% decrease of corneal thickness; or 1 D increase in myopia or refractive astigmatism, requiring corneal crosslinking. DISCUSSION: The goal of this study is to evaluate whether the effectiveness of cCXL is non-inferior to sCXL in terms of flattening of the cornea and halting keratoconus progression. Treating only the affected zone could be beneficial for minimalizing the risk of damaging surrounding tissues and faster wound healing. Recent non-randomized studies suggest that a customized crosslinking protocol based on the tomography of the patient's cornea may stop the progression of keratoconus and result in flattening of the cornea. TRIAL REGISTRATION: This study was prospectively registered at ClinicalTrials.gov on August 31st, 2020, the identifier of the study is NCT04532788.

Introducing e-health technology to routine cataract care: patient perspectives on web-based eye test for postoperative telemonitoring.

PURPOSE: To explore cataract patients' experiences with an e-health tool for self-assessing visual function (ie, a web-based eye test), and to formulate recommendations for its successful adoption in routine cataract care. SETTING: Clinics in the Netherlands, Germany, and Austria. DESIGN: Mixed-methods study. METHODS: 22 participants were included in this study; in-depth interviews were conducted with 12. Questionnaires and in-depth semi-structured interviews were conducted alongside a multicenter randomized controlled trial evaluating the validity, safety and cost-effectiveness of remote care after cataract surgery (Cataract Online Refraction Evaluation, a Randomized Controlled Trial). Results were analyzed thematically. RESULTS: Participants reported positively about performing the web-based eye test at home. 4 overarching themes were identified in the interviews. First, participants were inventive in overcoming practical barriers encountered while conducting the test. Second, participants desired a clear presentation of test results and their meaning. Third, the ability to self-monitor visual function was appreciated. Fourth, most participants preferred to keep the option to contact their eyecare professional (ECP) postoperatively, especially when experiencing symptoms. Most would be satisfied with a phone consultation or an e-consult. Participants reported positive experiences with the web-based eye test. Barriers for successful adoption were identified, including insecurity about correctly performing the test, incomplete information on how to interpret test results, and a feeling that in-hospital assessments were superior to remote assessments. CONCLUSIONS: It is recommended to focus on building trust in remote eyecare delivery and that access to the ECP be retained when medically indicated or deemed necessary by the patient.

Evaluation of a visual acuity eHealth tool in patients with cataract.

PURPOSE: To validate the Easee web-based tool for the assessment of visual acuity in patients who underwent cataract surgery. SETTING: University Eye Clinic Maastricht, Maastricht, the Netherlands. DESIGN: Prospective method comparison study. METHODS: Subjects aged between 18 and 69 years who underwent cataract surgery on 1 or both eyes at the Maastricht University Medical Center+ were eligible to participate in this study. The uncorrected (UDVA) and corrected distance visual acuity (CDVA) assessments were performed using the web-based tool (index test) and conventional ETDRS and Snellen charts (reference tests). The outcomes of the different tests were expressed in logMAR, and a difference of <0.15 logMAR was considered clinically acceptable. RESULTS: 46 subjects with 75 operated eyes were included in this study. The difference of the UDVA between the web-based tool and ETDRS or Snellen was -0.05 ± 0.10 logMAR ( P < .001 [0.15; -0.26]) and -0.04 ± 0.15 logMAR ( P = .018 [0.24; -0.33]), respectively. For the CDVA, these differences were -0.04 ± 0.08 logMAR ( P < .001 [0.13; -0.21]) and -0.07 ± 0.10 logMAR ( P < .001 [0.13; -0.27]), respectively. The Pearson correlation coefficients between the web-based tool and ETDRS were maximally 0.94 and compared with Snellen 0.92. In total, 73% to 88% of the visual acuity measurement differences were within 0.15 logMAR. CONCLUSIONS: The web-based tool was validated for the assessment of visual acuity in patients who underwent cataract surgery and showed clinically acceptable outcomes in up to 88% of patients. Most of the participants had a positive attitude toward the web-based tool, which requires basic digital skills.

Video Grading of Descemet Membrane Endothelial Keratoplasty Surgery to Identify Surgeon Risk Factors for Graft Detachment and Rebubbling: A Post Hoc Observational Analysis of the Advanced Visualization In Corneal Surgery Evaluation Trial.

PURPOSE: The aim of this study was to explore video-graded intraoperative risk factors for graft detachment (GD) and rebubbling in Descemet membrane endothelial keratoplasty surgery. METHODS: A post hoc analysis of 65 eyes of 65 pseudophakic subjects with Fuchs endothelial dystrophy that underwent Descemet membrane endothelial keratoplasty surgery as part of the Advanced Visualization In Corneal Surgery Evaluation trial. All surgical recordings were assessed by 2 graders using a structured assessment form. A multinominal regression was performed to estimate the independent effect of video-graded intraoperative factors on the incidence of GD and rebubbling. Secondary outcomes are corrected distance visual acuity and endothelial cell density. RESULTS: In total, 33 GDs were recorded, of which 17 required rebubbling. No significant predictors for GD or rebubbling were identified. However, the results revealed 2 clinically relevant patterns. An unfavorable graft configuration (ie, wrinkled, tight scroll, or taco-shaped) and a gas-bubble size smaller than the graft diameter were associated with an increased risk of GD [odds ratio (OR) 2.5 and OR 2.26, respectively] and rebubbling (OR 2.0 and OR 2.60, respectively). Inversely, a larger gas-bubble size was associated with a reduced risk of GD (OR 0.37) and rebubbling (OR 0.36). At 3 and 6 months postoperatively, corrected distance visual acuity was poorer in subjects requiring a rebubbling and endothelial cell density loss was higher in subjects with a partial GD. CONCLUSIONS: Our analysis revealed that the gas-bubble size and graft shape/geometry seem to be relevant clinical factors for GD and rebubbling, whereas descemetorhexis difficulty, degree of graft manipulation, graft overlap, and surgical iridectomy were not associated with an increased risk.

The evaluation of an online nurse-assisted eye-screening tool in older adults receiving home healthcare.

PURPOSE: To investigate the agreement between an online nurse-assisted eye-screening tool and reference tests in older adults receiving home healthcare and to collect user experiences. METHODS: Older adults (65+) receiving home healthcare were included. Home healthcare nurses assisted in administering the eye-screening tool at participants' homes. Approximately 2 weeks later, a researcher administered reference tests at participants' homes. Experiences from participants and home healthcare nurses were collected. Agreement in outcomes (distance and near visual acuity, with the latter being measured using two different optotypes, and macular problems) between the eye-screening tool and reference clinical testing was compared. A difference of less than ±0.15 logMAR was considered acceptable. RESULTS: A total of 40 participants were included. Here, we describe the results for the right eye; results for the left eye were similar. The mean difference between the eye-screening tool and reference tests for distance visual acuity was 0.02 logMAR. The mean difference between the eye-screening tool and reference tests using two different optotypes for near visual acuity was 0.06 and 0.03 logMAR, respectively. The majority of the individual data points were within the ±0.15 logMAR threshold (75%, 51% and 58%, respectively). The agreement between tests for macular problems was 75%. Participants and home healthcare nurses were generally satisfied with the eye-screening tool, although remarks for further improvements were made. CONCLUSIONS: The eye-screening tool is promising for nurse-assisted eye screening in older adults receiving home healthcare, with the mostly satisfactory agreement. After implementing the eye-screening tool in practice, cost-effectiveness needs to be investigated.

Remote follow-up after cataract surgery (CORE-RCT): study protocol of a randomized controlled trial.

BACKGROUND: Cataract surgery has become one of the most performed surgical procedures worldwide. Postoperative management consists of routine clinical examinations to assess post-operative visual function and detect possible adverse events. Due to the low incidence of complications, the majority of clinic visits after cataract surgery are uneventful. Nonetheless, valuable time and hospital resources are consumed. We hypothesize that remote post-operative follow-up involving teleconsultations and self-assessments of visual function and health status, could be a valid alternative to face-to-face clinical examinations in selected patient groups. The practice of remote follow-up after cataract surgery has not yet been evaluated. The aim of this study is to investigate the validity, safety and cost-effectiveness of remote cataract surgery follow-up, and to report on the patients' experiences with remotely self-assessing visual function. METHODS: This study is a multicenter, open-label, randomized controlled trial. Patients planned for cataract surgery on both eyes, without ocular comorbidities, are eligible for participation. Participants will be allocated (1:1) into one of the two study groups: 'telemonitoring' or 'usual care'. Participants in the 'telemonitoring' group will perform in-home assessments after cataract surgery (remote web-based eye exams and digital questionnaires on their own devices). Participants in the 'usual care' group will have regular post-operative consultations, according to the study site's regular practice. Outcome measures include accuracy of the web-based eye exam for assessing visual acuity and refraction, patient-reported outcome measures (visual function and quality of life), adverse events, and cost aspects. DISCUSSION: Investigating remote follow-up after cataract surgery fits the current trends of digitization of health care. We believe that remote self-care can be a promising avenue to comply with the increasing demands of cataract care. This randomized controlled trial provides scientific evidence on this unmet need and delivers the desired insights on (cost)effectiveness of remote follow-up after cataract surgery. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04809402. Date of registration: March 22, 2021.

The Accuracy of a Web-Based Visual Acuity Self-assessment Tool Performed Independently by Eye Care Patients at Home: Method Comparison Study.

BACKGROUND:  Telehealth solutions can play an important role in increasing access to eye care. Web-based eye tests can enable individuals to self-assess their visual function remotely without the assistance of an eye care professional. A web-based tool for self-assessing visual acuity (VA) has previously been studied in controlled, supervised conditions. The accuracy of this tool when performed independently by patients in their home environment, using their own devices, has not yet been examined. OBJECTIVE:  The objective of this paper was to examine the accuracy of a web-based tool with respect to measuring VA in ophthalmic patients in their home environment, compared with a conventional in-hospital assessment using a Snellen chart (the gold standard). METHODS:  From April through September 2020, consecutive adult patients with uveitis at the University Medical Center Utrecht, the Netherlands, performed the web-based VA test at home (the index test) before their upcoming conventional VA assessment at the hospital (the reference test). The agreement between the 2 tests was assessed by the Bland-Altman analysis. Additional analyses were performed to investigate associations between clinical characteristics and the accuracy of the web-based test. RESULTS:  A total of 98 eyes in 59 patients were included in the study. The difference in VA between the index and reference tests was not significant, with a mean difference of 0.02 (SD 0.12) logMAR (P=.09) and 95% limits of agreement of -0.21 to 0.26 logMAR. The majority of the differences (77%) fell within the predetermined acceptable deviation limit of 0.15 logMAR. In addition, no patient characteristics or clinical parameters were found to significantly affect the accuracy of the web-based test. CONCLUSIONS:  This web-based test for measuring VA is a valid tool for remotely assessing VA, also when performed independently by patients at home. Implementation of validated web-based tools like this in the health care system may represent a valuable step forward in revolutionizing teleconsultations and can provide individual patients with the opportunity to self-monitor changes in VA. This is particularly relevant when the patient's access to ophthalmic care is limited. Future developments should focus on optimizing the testing conditions at home to reduce outliers.

Establishing a Biomarker for the Prediction of Short-Term Graft Detachment After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: The purpose of this study was to investigate the predictive value of pachymetry mapping 1 day after Descemet membrane endothelial keratoplasty (DMEK) as a biomarker for early graft detachment. METHODS: This was a post hoc analysis of 65 pseudophakic subjects with Fuchs endothelial dystrophy who underwent DMEK surgery between December 2018 and April 2021 as part of the Advanced Visualization In Corneal Surgery Evaluation international multicenter randomized controlled trial. One eye per patient was included. Preoperatively and 1 day postoperatively, patients underwent anterior segment optical coherence tomography imaging. Using a grid consisting of 25 zones (ie, pachymetry map), corneal thickness and presence of a graft detachment were mapped for each patient. Detachments of any size were considered, regardless of subsequent clinical interventions. Missing data were imputed and subsequently divided into a training and test set. Two prediction methods were evaluated: one model based on absolute corneal thickness and a regression model. RESULTS: A total of 65 eyes were included for analysis of which 33 developed any form of graft detachment. Preoperatively, no significant differences were observed between the groups ( P = 0.221). Corneal thickness in the corneal zones with a detached graft was significantly increased compared with corneal zones with an attached graft ( P < 0.001). The regression prediction model had an area under the curve of 0.87 (sensitivity: 0.79 and specificity: 0.75), whereas the absolute thickness cutoff model only reached 0.65. CONCLUSIONS: Pachymetry mapping 1 day after DMEK was predictive for early graft detachment, and the prediction model had a good to excellent performance. This aids in identifying patients at risk for graft detachment and subsequent tailored postoperative care.

A Guide to Direct (Peri)ocular Injuries Caused by Snakes: Systematic Review and Treatment Advice.

Ocular injuries caused by snakes are very rare, but damage can be severe. There is little evidence on the effective treatment of these injuries. The aim of this systematic review is to discuss all available literature and summarize existing experiences in a treatment advice. In January 2022, a search was performed in the PubMed database. Penetrative trauma by venomous snakebites constitute the most severe cases, and can require the evisceration of the eye. Nonvenomous snakes, mostly boas and pythons held in captivity, are also able to perforate the eye, though with a more favorable disease course. Chemical trauma by inoculation of venom occurs as well, and copious irrigation is advised in these cases. Detailed suggestions for ophthalmologic treatment are presented.

Automatic evaluation of graft orientation during Descemet membrane endothelial keratoplasty using intraoperative OCT.

Correct Descemet Membrane Endothelial Keratoplasty (DMEK) graft orientation is imperative for success of DMEK surgery, but intraoperative evaluation can be challenging. We present a method for automatic evaluation of the graft orientation in intraoperative optical coherence tomography (iOCT), exploiting the natural rolling behavior of the graft. The method encompasses a deep learning model for graft segmentation, post-processing to obtain a smooth line representation, and curvature calculations to determine graft orientation. For an independent test set of 100 iOCT-frames, the automatic method correctly identified graft orientation in 78 frames and obtained an area under the receiver operating characteristic curve (AUC) of 0.84. When we replaced the automatic segmentation with the manual masks, the AUC increased to 0.92, corresponding to an accuracy of 86%. In comparison, two corneal specialists correctly identified graft orientation in 90% and 91% of the iOCT-frames.

Bilateral posterior lamellar corneal transplant surgery in an infant of 17 weeks old: Surgical challenges and the added value of intraoperative optical coherence tomography.

This study aimed to describe the surgical challenges, management, and value of intraoperative optical coherence tomography in a case of a bilateral Descemet Stripping Automated Endothelial Keratoplasty corneal transplantation at 17 weeks of age for the treatment of severe posterior polymorphous corneal dystrophy resulting from a de novo mutation of the OVOL2-gene.

Clinical applications for intraoperative optical coherence tomography: a systematic review.

In this systematic review, we provide an overview of the current state of intraoperative optical coherence tomography (iOCT). As iOCT technology is increasingly utilized, its current clinical applications and potential uses warrant attention. Here, we categorize the findings of various studies by their respective fields, including the use of iOCT in vitreoretinal surgery, corneal surgery, glaucoma surgery, cataract surgery, and pediatric ophthalmology. The trend observed in recent decades towards performing minimally invasive ophthalmic surgery has caused practitioners to recognize the limitations of using a conventional surgical microscope for intraoperative visualization. Thus, the superior visualization provided by iOCT can improve the safety of these surgical techniques and promote the development of new minimally invasive ophthalmic surgeries. Landmark prospective studies found that iOCT can significantly affect surgical decision making and can cause a subsequent change in surgical strategy, and the use of iOCT has potential to improve surgical outcome. Despite these advantages, however, iOCT is still a relatively new technique, and beginning users of iOCT can encounter limitations that can preclude their reaching the full potential of iOCT and in this respect several improvements are needed.

Nationwide epidemiological approach to identify associations between keratoconus and immune-mediated diseases.

BACKGROUND: The aetiology of keratoconus (KC) remains poorly understood. KC has typically been described as a non-inflammatory disorder of the cornea. Nonetheless, there is increasing presumptive evidence for the role of the immune system in the pathogenesis of KC. AIM: To evaluate the association between KC and immune-mediated diseases on a population level. We hypothesise that KC is immune-mediated rather than a predominantly degenerative disease. METHODS: Data were obtained from the largest health insurance provider in the Netherlands. Dutch residents are obligatorily insured. The data contained all medical claims and sociodemographic characteristics from all KC patients plus all those data from a 1:6 age-matched and sex-matched control group. The primary outcome was the association between KC and immune-mediated diseases, as assessed by conditional logistic regression. RESULTS: Based on our analysis of 2051 KC cases and 12 306 matched controls, we identified novel associations between KC and Hashimoto's thyroiditis (OR=2.89; 95% CI: 1.41 to 5.94) and inflammatory skin conditions (OR=2.20; 95% CI: 1.37 to 3.53). We confirmed known associations between KC and atopic conditions, including allergic rash (OR=3.00; 95% CI: 1.03 to 8.79), asthma and bronchial hyperresponsiveness (OR=2.51; 95% CI: 1.63 to 3.84), and allergic rhinitis (OR=2.20; 95% CI: 1.39 to 3.49). CONCLUSION: Keratoconus appears positively associated with multiple immune-mediated diseases, which provides a population-based argument that systemic inflammatory responses may influence its onset. The identification of these particular diseases might shed light on potential comparable pathways through which this proinflammatory state is achieved, paving the way for pharmacological treatment strategies.

Pain mechanisms and management in corneal cross-linking: a review.

Though corneal collagen cross-linking (CXL) is an increasingly available and effective treatment for keratoconus, few reports have considered its impact on pain-related physiology in depth. This comprehensive narrative review summarises mechanisms underlying pain in CXL and clinical care possibilities, with the goal of future improvement in management of CXL-related pain. Postoperative pain associated with CXL is largely due to primary afferent nerve injury and, to a smaller extent, inflammation. Chronification of pain after CXL has not been reported, even as long-term nerve damage without regeneration following standard CXL treatment is frequently observed. The lack of pain chronification may be due to the minimally invasive nature of the procedure, with its rapidly recovering superficial corneal wound, and to the positive anti-inflammatory changes of the tear film that have been described after CXL. Different CXL approaches have been developed, with the transepithelial epithelial-on technique (epi-on) associated with less postsurgical pain than the gold standard, epithelial-off technique (epi-off). After the first few days, however, the difference in pain scores and need for analgesics between epi-on and epi-off disappear. Patients experience relatively high-intensity pain the first few days post-CXL, and many strategies for acute pain control following CXL have been studied. Currently, no method of pain management is considered superior or universally accepted. Acute pain following CXL is a recognised and clinically significant side effect, but few CXL studies have systematically investigated postoperative pain and its management. This review aims to improve patient pain outcomes following this increasingly common procedure.

Correction: The evaluation of a web-based tool for measuring the uncorrected visual acuity and refractive error in keratoconus eyes: A method comparison study.

[This corrects the article DOI: 10.1371/journal.pone.0256087.].