Bonnie Nga Kwan Choy

Systematic review and meta-analysis on the efficacy of selective laser trabeculoplasty in open-angle glaucoma

Selective laser trabeculoplasty (SLT) is a relatively new type of laser used in treating open-angle glaucoma (OAG) and is reported to be equally efficacious to a first-line medication and argon laser trabeculoplasty (ALT). We summarize available evidence for considering SLT as an alternative treatment in OAG through systematic review and meta-analysis. Among OAG patients who range from newly diagnosed to those on maximally tolerated medical therapy, SLT results in a 6.9-35.9% intraocular pressure (IOP) reduction. Complications are rare and include an IOP spike requiring surgery, persistent macular edema, and corneal haze and thinning. Meta-analysis of randomized, controlled trials shows that SLT is non-inferior to ALT and medication in IOP reduction and also in achieving treatment success. Number of medications reduction is similar between SLT and ALT. More robust evidence is needed to determine its efficacy as a repeated procedure.

A case series of contact lens-assocaited Fusarium keratitis in Hong Kong.

To the Editor: We have read with interest the article ‘‘A case series of contact lens– associated Fusarium keratitis in Hong Kong’’ published by Srinivas K. Rao et al, and we would like to share our similar experience in managing such patients. Similar to Rao’s finding, our unit (Kowloon East cluster in Hong Kong) also observed an outbreak of Fusarium keratitis in our locality from spring/summer 2005 to autumn 2006. In the author’s series, 3 of 12 cases required corneal grafting and 2 of which failed graft at the end. On the contrary, the overall visual outcome in our case series of 14 cases (16 eyes) was good (87.5% with final best-corrected visual acuity 20/40 or better) with none of our patients required penetrating keratoplasty during the course of the infection. Because of the cumulating experience in treating Fusarium keratitis at that peak period, we vigilantly initiated antifungal agents as first-line treatment in 7 patients based on high clinical suspicion from history and clinical findings (topical 5% natamycin or topical 0.15% amphotericin B) so as not to miss any highly suspected cases. The good visual outcome might also be attributed to early commencement of antifungal agents in our population. We started antifungal agents based on microscopy showing fungal filaments before culture results were available during that peak season. The observed difference between the 2 populations might be attributed to the regional difference in the subjects. Similar to the author’s series, where 4 of their patients healed with antibacterials and did not receive topical or oral antifungals, we also observed some of our subjects whose infection resolved completely with antibacterials alone without the need for specific antifungal therapy. In 5 of our patients (36%), they were treated with topical antibacterial medications (typically with fortified ceftazidime 50 mg/mL and tobramycin 15 mg/mL) as first-line treatment for severe contact lens–related corneal infections before confirmation of specific pathogens with culture results. This might be explained by the fact that topical fluoroquinolones have been shown to have activity against Fusarium species, leading to resolution of Fusarium infection without the use of antifungal agents. We hope our experience, in conjunction with the author’s study, could contribute to better management of patients with contact lens–associated Fusarium keratitis.

Management of Primary Angle-Closure Glaucoma.

AbstractPrimary angle-closure glaucoma (PACG) is a progressive optic nerve degeneration and is defined as a glaucomatous optic neuropathy with associated characteristic enlargement of optic disc cupping and visual field loss that is secondary to ocular hypertension caused by closure of the drainage angle. Angle closure is caused by appositional approximation or adhesion between the iris and the trabecular meshwork. The main treatment strategy for PACG lies in the reduction of intraocular pressure, reopening of the closed angle, and possible prevention of further angle closure. There is no universally agreed best surgical treatment for PACG. Trabeculectomy, goniosynechialysis (GSL), glaucoma implant, and cyclodestructive procedures are effective surgical options. Each of them plays an important role in the management of PACG with its own pros and cons. Accumulating evidence is available to show the effectiveness of visually significant and visually nonsignificant cataract extraction in the treatment of PACG. Trabeculectomy and GSL are often combined with cataract extraction, which may offer additional pressure control benefits to patients with PACG. This review article will discuss laser peripheral iridotomy, argon laser peripheral iridoplasty, and surgeries such as GSL, phacoemulsification, and phaco plus glaucoma surgeries that lower intraocular pressure and also alter the anterior segment and/or drainage angle anatomy. Currently, glaucoma implants and cyclodestruction are mainly reserved for PACG patients who have failed previous filtering operations. Their role as initial surgical treatment for PACG will not be discussed.

Use of anti-vascular endothelial growth factor in the management of pterygium

The rising success of anti‐vascular endothelial growth factor (VEGF) therapies in ocular disease has stimulated the use of such treatments in the surgical management of pterygium. We reviewed the literature to better understand the safety and efficacy of the adjunctive role of anti‐VEGF treatments for pterygium excision. Without surgery, anti‐VEGF alone may favourably alter symptoms and vascularity, but does not cause pterygium regression. Some evidence supports the use of anti‐VEGF as an adjuvant therapy to surgery, especially when using a higher dose and a more frequent dosing regimen. Overall, anti‐VEGF is generally safe and well tolerated in patients with pterygium. Currently, the evidence does not conclusively support the use of anti‐VEGF in pterygium surgery. However, further research may guide unanswered questions regarding the interaction between VEGF and other factors responsible for pterygium growth. In addition, the optimal route and dosage of anti‐VEGF administration is not yet known.

Physical exercise and glaucoma: a review on the roles of physical exercise on intraocular pressure control, ocular blood flow regulation, neuroprotection and glaucoma-related mental health

The benefits of physical exercise on health and well‐being have been studied in a wide range of systemic and ocular diseases, including glaucoma, a progressive optic neuropathy characterized by accelerated apoptosis of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) and insufficient ocular perfusion have been postulated to be the two main theories in glaucoma development and progression. The effects of exercise in these two aspects have been demonstrated by numerous researches. A review in 2009 focusing on these two theories concluded that exercise results in transient IOP reduction but an inconsistent elevation in ocular perfusion. However, the majority of the studies had been conducted in healthy subjects. Over the past decade, technological advancement has brought forth new and more detailed evidence regarding the effects of exercise. Moreover, the neuroprotective effect of exercise by upregulation of neurotrophin and enhancement of mitochondrial function has been a focus of interest. Apart from visual impairment, the mental health issues in patients with glaucoma, which include anxiety and depression, should also be addressed. In this review, we mainly focus on publications from the recent years, so as to provide a comprehensive review on the impact of physical exercise on IOP, ocular perfusion, neuroprotection and mental health in patients with glaucoma.

Comparison of Tear Osmolarity in Rheumatoid Arthritis Patients With and Without Secondary Sjogren Syndrome

Purpose: To compare tear osmolarity (TO) and other dry eye parameters in rheumatoid arthritis (RA) patients with or without secondary Sjogren syndrome (sSS). Methods: Consecutive patients with RA were divided into a sSS group and no-sSS group using conventional diagnostic criteria by rheumatologists using symptomatology, Schirmer test score, and anti-Ro or anti-La autoantibody status. The TO, Ocular Surface Disease Index, dry eye disease (DED) parameters [such as tear breakup time (TBUT) and corneal staining score] and the systemic inflammatory markers [erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)] were compared. Correlation analyses between TO and the DED parameters and inflammatory markers were also performed. Results: A total of 42 cases with mean age 54.8 ± 12.3 were included, with 12 patients (29%) having sSS and 30 (71%) without sSS. TO was increased in both groups (329 ± 20 and 319 ± 25 mOsm/L, respectively), but no statistically significant difference was found between the 2 groups (P = 0.126). RA with sSS had significantly shorter TBUT, higher corneal staining score, and ESR CRP levels (P < 0.05). TO did not correlate with the Schirmer test score, but had significant positive correlations with age, corneal staining score, ESR, and CRP levels, and a significant negative correlation with TBUT. Conclusions: TO was increased in RA patients with or without sSS. There was no significant correlation between TO and the Schirmer test score, and the physician could not use TO to diagnose sSS. However, TO correlated well with both DED parameters (TBUT and corneal staining score) and systemic inflammatory markers (ESR and CRP).

A Case Report: Anti-Psychotic Agents Related Ocular Toxicity.

AbstractChlorpromazine is known to cause ocular pigmentary deposits. However, delayed presentation after cessation of chlorpromazine has not been reported. There are also no reports on whether newer generation of anti-psychotic agents contribute to ocular toxicity. We describe a case of ocular toxicity related to anti-psychotic agents. To the best of our knowledge, this is the first reported case of anterior segment pigmentary deposits associated with olanzapine use, 2 years after the cessation of chlorpromazine.We report a case of ocular toxicity in a patient with history of chlorpromazine usage of 100 mg per day for 13 years and subsequently switched to olanzapine 5 mg for 2 years. There were no signs of ocular toxicity while the patient was on chlorpromazine. However, when the patient switched to olanzapine, she developed the ocular side effect as described for chlorpromazine-induced ocular toxicity, with pigmentary depositions on both corneas and the anterior lens surface and decrease in vision.Olanzapine, a newer anti-psychotic agent, may play a role in the ocular pigmentary deposition, either directly causing pigmentary deposition itself or accentuating the effect of chlorpromazine as the 2 drugs act on the same receptors, although further studies are required to support this hypothesis. As patients with psychiatric conditions may not voluntarily complain of visual symptoms, ocular screening could be considered in these patients receiving chronic anti-psychotic treatment, so that any ocular toxicity could be diagnosed in a timely manner.

Effects of Riboflavin and Ultraviolet Illumination on the Biomechanical Properties of Conjunctiva

Purpose: Our experiment evaluated the biomechanical effects of riboflavin and ultraviolet A illumination, in terms of covalent bonding, permeability, and indentation rupture force, on excised cattle conjunctiva. Materials and Methods: Cattle conjunctiva was extracted and divided into the treatment group, which was soaked in riboflavin, followed by ultraviolet light illumination, and the control group. Samples were subsequently analysed on a Fourier transform infrared spectrum test to identify the presence of amide bonds, a permeability test to assess the diffusion of methylene blue across conjunctiva, and an indentation rupture force test. Results: The Fourier transform infrared spectrum test showed a significantly increased amide I band after treatment (p = 0.043), as well as in amide II, amide A, and amide B bands. The permeability test showed a reduced permeability to methylene blue after treatment (n = 25) compared to the control (n = 24; p = 0.03). The indentation rupture test showed a higher maximal rupture force in the treated samples (n = 10; p = 0.07). Conclusions: The study suggested that riboflavin and ultraviolet A illumination (commercially available as collagen crosslinking) strengthened cattle conjunctiva by increasing its amount of covalent bonds, reducing its permeability, and possibly improving its resistance to rupture. This is the first study in the collagen crosslinking literature on the biomechanical properties of conjunctival tissue.

Development and pilot-testing of patient decision aid for use among Chinese patients with primary open-angle glaucoma

Background A patient decision aid (PDA) is a tool for shared decision making (SDM), which emphasises patient empowerment. It is useful in chronic diseases and when there are multiple, no best single treatment option. Although SDM is prevalent in Western countries, its use is limited in Chinese societies, where the adoption of a paternalistic approach is strong. Here, we report the development, acceptance and pilot test results of a PDA targeted at Chinese patients with primary open-angle glaucoma (POAG). Methods We developed a PDA designed for use in Chinese patients with POAG. Recruited subjects were given our PDA. Baseline evaluation included decision conflict scale (DCS), validated glaucoma adherence questionnaires and glaucoma knowledge questionnaire. Subjects were briefed through the PDA and instructed to read it that day. Three to four weeks later, follow-up questionnaire as described above were conducted with the addition of acceptance questionnaires. Results Data from 65 subjects were available. The PDA was well received among subjects. DCS improved from 48.9±20.4 at baseline to 34.3±20.3 during follow-up, with P<0.01. Validated medication adherence questionnaires and knowledge showed improvement from baseline, which was statistically significant. Conclusions The use of PDA among Chinese subjects with POAG demonstrated positive reception and acceptance. Evaluation of its initial effects shows improvement in DCS, medication adherence and glaucoma knowledge. The implementation of SDM and PDA among Chinese subjects with POAG is encouraged. Future studies with randomised design and later evaluation time points can further reveal the impacts of PDA among Chinese subjects with POAG.

Suprachoroidal Hemorrhage with Delayed Rebleeding as the First Presentation of Bullous Pemphigoid Associated Acquired Hemophilia

We report a case of phacoemulsification conversion complicated by suprachoroidal haemorrhage (SCH) and delayed rebleeding at day 5 postoperation, as the first presentation of bullous pemphigoid associated acquired hemophilia. This association has been reported sparingly in the past, and almost exclusively only in hematology literature. To the best of our knowledge, this is the first case of delayed SCH rebleed presenting in a patient with previously undiagnosed Acquired Hemophilia reported. Although exceedingly rare, acquired hemophilia leads to drastic complications and has a high mortality rate. Advice to allow early recognition and prevention of complications is summarized.