Background: To compare two swept-source optical coherence tomography (SS-OCT) biometers,IOLMaster 700 and ANTERION.Methods: This is a retrospective study. Biometric measurements of cataract patients performed between March and July 2021 in the Department of Ophthalmology, United Christian Hospital, Hong Kong, were reviewed. Patients scheduled for cataract surgery were measured with both SS-OCT devices on the same day.The following biometry parameters were compared: keratometry (K), total keratometry (TK), axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), white-to-white (WTW) and the predicted intraocular lens (IOL) power to achieve emmetropia. To assess the agreement between the devices, Bland-Altman analysis with 95% limits of agreement (LoA) were used.Results: In total, 92 eyes of 47 subjects were measured with both devices. There were statistically significant differences between the two biometers for most measurements (P<0.05) except for flat K, AL and IOL power when using the right eyes for analysis. For the left eyes, there were statistically significant differences in the measurements from the two biometers in all parameters except for flat and steep K. The ANTERION did not obtain ACD, AL and LT in 2 (2.17%), 1 (1.09%) and 5 cases (5.43%) respectively.Conclusions: The two biometers showed a clinically acceptable agreement in most parameters. Comparisons showed significant differences in most parameters but not clinically relevant except for the TK and WTW, and these two parameters should not be used interchangeably between the devices.
Background: A variety of experimental animal models are used in basic ophthalmological research to elucidate physiological mechanisms of vision and disease pathogenesis. The choice of animal model is based on the measurability of specific parameters or structures, the applicability of clinical measurement technologies, and the similarity to human eye function. Studies of eye pathology usually compare optical parameters between a healthy and altered state, so accurate baseline assessments are critical, but few reports have comprehensively examined the normal anatomical structures and physiological functions in these models.Methods: Three cynomolgus monkeys, six New Zealand rabbits, ten Sprague Dawley (SD) rats, and BALB/c mice were examined by fundus photography (FP), fundus fluorescein angiography (FFA), and optical coherence tomography (OCT).Results: Most retinal structures of cynomolgus monkey were anatomically similar to the corresponding human structures as revealed by FP, FFA, and OCT. New Zealand rabbits have large eyeballs, but they have large optic disc and myelinated retinal nerve fibers in their retinas, and the growth pattern of retinal vessels were also different to the human retinas. Unlike monkeys and rabbits, the retinal vessels of SD rats and BALB/c mice were widely distributed and clear. The OCT performance of them were similar with human beings except the macular.Conclusions: Monkey is a good model to study changes in retinal structure associated with fundus disease, rabbits are not suitable for studies on retinal vessel diseases and optic nerve diseases, and rats and mice are good models for retinal vascular diseases. These measures will help guide the choice of model and measurement technology and reduce the number of experimental animals required.
Background: Benign essential blepharospasm (BEB), aberrant facial nerve degeneration and hemifacial spasm (HFS) are all examples dystonia which, though not life-threatening, can have a significant impact on patient quality of life. The need for reliable self-rating surveys to monitor functional disability is fundamental. The Blepharospasm Disability Index (BSDI) is already a widely utilised and validated self-rating score for blepharospasm whilst the functional disability score (FDS) requires further validation. The principle aim of this study is to repeat validation of the FDS against the BSDI, which has been validated by several groups since its original description but only in patients with BEB.Methods: A randomised blinded prospective cohort study was conducted at a single unit on 38 patients with BEB, aberrant facial nerve degeneration and HFS. Patients were blinded to complete the FDS followed by the BSDI or the BSDI followed by the FDS with a 30-minute interval.Results: Both the FDS and BSDI were found to be reliable with high internal consistency and test-retest reliability. Both scales were also found to be moderately correlated with the Jankovic disease severity score.Conclusions: This study is the first to use the FDS as a rating scale in patients with HFS and aberrant facial nerve degeneration. It is also the first study to formally validate the FDS as an acceptable rating scale for patients with dystonia and in particular it provides validation for its use in patients with HFS and aberrant facial nerve degeneration.
Background and Objective: Ocular surface disease (OSD) is a common yet often overlooked consideration in the management of patients with glaucoma. Although there have been several review articles summarizing the relationship between glaucoma medications and OSD, there is a relative absence of such articles on the effects of glaucoma surgical treatments. Here, we present a comprehensive review of the literature regarding the relationship of glaucoma management and OSD, with an emphasis on surgical considerations.Methods: PubMed, Google Scholar, and Cochrane Review searches were performed using the following search terms: ocular surface, dry eye, minimally invasive glaucoma surgeries (MIGS), trabeculectomy,glaucoma medications. The titles and abstracts from those searches were screened for relevance to our review topics. Publications were included if the subjects included glaucoma patients, and if ocular surface outcomes were described. Non-English papers were excluded.
Key Content and Findings: Topical glaucoma medications frequently cause adverse effects on the ocular surface, both through direct action of the medications themselves as well as through toxicity from their associated preservatives. Optimization of the ocular surface may improve medication compliance rates.Traditional surgical treatments for glaucoma, such as trabeculectomy, can exacerbate OSD by disrupting the ocular surface but can also reduce the need for chronic medications. Optimization of ocular surface health is imperative in reducing trabeculectomy complication rates, while also potentially reducing the need for trabeculectomy in patients that are able to achieve intraocular pressure control through improved drop tolerability. The introduction of MIGS represents a promising alternative to existing therapies and has been shown to alleviate the overall medication burden. It would be reasonable to assume that decreasing the medication burden could reduce OSD prevalence and severity. However, more research is needed to directly assess the extent of improvement seen after MIGS.Conclusions: A comprehensive understanding of the importance of OSD in medical and surgical management of glaucoma is essential in optimizing patient care and improving outcomes.
Background and Objective: Limbal stem cell deficiency (LSCD) describes the clinical condition when there is dysfunction of the corneal epithelial stem/progenitor cells and the inability to sustain the normal homeostasis of the corneal epithelium. The limbal stem cells are located in a specialized area of the eye called the palisades of Vogt (POV). There have been significant advances in the diagnosis and management of LSCD over the past decade and this review focuses on the pathophysiology of LSCD, its clinical manifestations, diagnosis, and causes.Methods: Papers regarding LSCD were searched using PubMed to identify the current state of diagnosis and causes of LSCD published through to June 2022.
Key Content and Findings: LSCD is clinically demonstrated by a whorl-epitheliopathy, loss of the POV, and conjunctivalization of the cornea. The diagnosis of this condition is based on clinical examination and aided by the use of impression cytology, in vivo confocal microscopy, and anterior segment optical coherence tomography (asOCT). There are many causes of LSCD, but those which are most common include chemical injuries, aniridia, contact lens wear, and Stevens-Johnson syndrome (SJS).Conclusions: While this condition is most commonly encountered by corneal specialists, it is important that other ophthalmologists recognize the possibility of LSCD as it may arise in other co-morbid eye conditions.
The prevalence of diabetic retinopathy (DR) continues to increase in pregnant females; these individuals are also at a higher risk of disease progression. The lack of evidence regarding the safety and efficacy of current treatment options in pregnancy makes disease management particularly challenging.All pregnant women with diabetes should have a prenatal DR screening, as well as receive counseling regarding the progression and management of DR during pregnancy. Optimal blood glucose and blood pressure control should be encouraged. For patients with proliferative diabetic retinopathy (PDR) in the absence of visually significant diabetic macular edema (DME), panretinal photocoagulation (PRP) remains a safe and effective treatment option. Visually significant DME can be treated with focal laser if areas of focal leakage are identified in the macula on fluorescein angiogram, intravitreal steroids or anti-vascular endothelial growth factor (VEGF) agents, The theoretical risk of anti-VEGF agents to the fetus should be considered and the patients should be extensively counselled regarding the risks and benefits of initiating anti-VEGF therapy before initiating treatment. When the decision is made to treat with anti-VEGF agents, Ranibizumab should be the agent of choice. In conclusion, ophthalmologists should make treatment decisions in pregnant patients with DR on a case-by-case basis taking into consideration disease severity, risk of permanent threat to vision, gestational age, and patient preferences.
Background and Objective: Nearly 30 years have passed since limbal stem cell deficiency (LSCD) was first identified by pioneers and given clinical attention. LSCD remains a difficult disease to treat. It can potentially lead to blinding. At present, understanding of limbal stem cells (LSCs) has deepened and various treatment options for LSCD have been devised. The objective of this review is to summarize basic knowledge of LSCD and current treatment strategies.Methods: PubMed search was performed to find studies published in English on LSCs and LSCD including original reports and reviews. Literatures published from 1989 to 2022 were reviewed.
Key Content and Findings: LSCs are enigmatic stem cells for which no specific marker has been discovered yet. Although LSCD is not difficult to diagnose, it is still challenging to treat. An important advancement in the treatment of LSCD is the provision of guidelines for selecting systematic surgical treatment according to the patient’s condition. It is also encouraging that stem cell technologies are being actively investigated for their potential usefulness in the treatment of LSCD.Conclusions: Although various treatment options for LSCD have been developed, it should be kept in mind that the best chance of treatment for LSCD is in the early stage of the disease. Every effort should be made to preserve as many LSCs as possible in the early treatment of LSCD.
