Sector-Based Regression Strategies to Reduce Refractive Error-Associated Glaucoma Diagnostic Bias When Using OCT and OCT Angiography.

Purpose: This cross-sectional study aimed to investigate the sectoral variance of optical coherence tomography (OCT) and OCT angiography (OCTA) glaucoma diagnostic parameters across eyes with varying degrees of refractive error. Methods: Healthy participants, including individuals with axial ametropia, enrolled in the Hong Kong FAMILY cohort were imaged using the Avanti/AngioVue OCT/OCTA system. The OCT and OCTA parameters obtained include peripapillary nerve fiber layer thickness (NFLT), peripapillary nerve fiber layer plexus capillary density (NFLP-CD), and macular ganglion cell complex thickness (GCCT). Sectoral measurements of NFLT, NFLP-CD, and GCCT were based on sectors and hemispheres. Results: A total of 1339 eyes from 791 participants were stratified based on spherical equivalent refraction: high myopia (<-6 D), low myopia (-6 D to -1 D), emmetropia (-1 D to 1 D), and hyperopia (>1 D). Multivariable broken stick regression models, accounting for age, sex, and signal strength, showed that all NFLT sectors except temporally, the inferior GCCT hemisphere, and half of the NFLP-CD sectors were more affected by ametropia-related covariates than the corresponding global parameters. As expected, the false-positive rates in those sectors were elevated. Finally, sector-specific axial length (AL) and spherical equivalent (SE) adjustments helped reduce the elevated false-positive rates. Conclusions: The effect of optical magnification is even more prominent among sectors than the global parameters. AL- and SE-based adjustments should be individualized to each sector to mitigate this magnification bias effectively. Translational Relevance: Identifying sectoral differences among diagnostic parameters and adopting these sector-based adjustments into commercial OCT systems will hopefully reduce false-positive rates related to refractive error.

Regression-Based Strategies to Reduce Refractive Error-Associated Glaucoma Diagnostic Bias When Using OCT and OCT Angiography.

Purpose: The purpose of this study was to correct refractive error-associated bias in optical coherence tomography (OCT) and OCT angiography (OCTA) glaucoma diagnostic parameters. Methods: OCT and OCTA imaging were obtained from participants in the Hong Kong FAMILY cohort. The Avanti/AngioVue OCT/OCTA system was used to measure the peripapillary nerve fiber layer thickness (NFLT), peripapillary nerve fiber layer plexus capillary density (NFLP-CD), macular ganglion cell complex thickness (GCCT), and macular superficial vascular complex vascular density (SVC-VD). Healthy eyes, including ones with axial ametropia, were enrolled for analysis. Results: A total of 1346 eyes from 792 participants were divided into 4 subgroups: high myopia (<-6D), low myopia (-6D to -1D), emmetropia (-1D to 1D), and hyperopia (>1D). After accounting for age, sex, and signal strength, multivariable regression showed strong dependence in most models for NFLT, GCCT, and NFLP-CD on axial eye length (AL), spherical equivalent (SE) refraction, and apparent optic disc diameter (DD). Optical analysis indicated that AL-related transverse optical magnification variations predominated over anatomic variations and were responsible for these trends. Compared to the emmetropic group, the false positive rates were significantly (Chi-square test P < 0.003) elevated in both myopia groups for NFLT, NFLP-CD, and GCCT. Regression-based adjustment of these diagnostic parameters with AL or SE significantly (McNemar test P < 0.03) reduced the elevated false positive rates. Conclusions: Myopic eyes are biased to have lower NFLT, GCCT, and NFLP-CD measurements. AL- and SE-based adjustments were effective in mitigating this bias. Translational Relevance: Adoption of these adjustments into commercial OCT systems may reduce false positive rates related to refractive error.

Prevalence and Causes of Visual Impairment and Blindness among Adult Chinese in Hong Kong - The Hong Kong Eye Study.

PURPOSE: To investigate the prevalence, associations, and causes of visual impairment and blindness in the adult population of Hong Kong. METHODS: This cross-sectional population-based study included 2018 (870, 43% male) randomly selected adults with a mean age 52 ± 16 years (range 18-90 years) in Hong Kong. Each participant underwent comprehensive ophthalmic examinations. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) of each eye was recorded. Prevalence of visual impairment and blindness was calculated using both World Health Organization (WHO) and United States (US) definitions, based on BCVA and PVA. RESULTS: Visual acuity measurements were available for 1952 (96.8%) participants. The prevalence of visual impairment, based on BCVA value, using WHO and US definition, was 1.0 ± 0.1% and 2.7 ± 0.4%, respectively. The prevalence of visual impairment, based on PVA value, was 5.1 ± 0.5% and 14.0 ± 0.8%, using WHO and US definition, respectively. Multivariate analysis demonstrated the presence of visual impairment (PVA, WHO definition) increased significantly with older age (odds ratio 1.039, P < .001) and thinner central cornea thickness (odds ratio 0.994, P = .014), but not significantly associated with other socioeconomic, systemic or ocular parameters after adjusting for age and central corneal thickness. Under-correction of refractive error was the most common reason for presenting visual impairment. Causes of impaired BCVA were cataract (37%), age-related macular degeneration (26%), diabetic macular edema (11%), glaucoma (11%), epiretinal membrane (5%), and unknown (11%). CONCLUSION: The prevalence of visual impairment in Hong Kong increased significantly with older age and thinner central corneal thickness. The major causes for impairment were under-correction of refractive error, cataract, and age-related macular degeneration.

Exophthalmometry values in the Hong Kong Chinese adult population from a population-based study.

This study aims to establish the range of exophthalmometry values (EV) in the adult Hong Kong (HK) Chinese population, its relationship with various anthropometric parameters, and to compare it with the EV in different ethnic groups.About 1485 adult HK Chinese were drawn from a random sample from the community-based FAMILY Cohort. Participants were interviewed, and comprehensive ophthalmological assessments were conducted. EV was measured using the Hertel's exophthalmometer.EV of both eyes from 630 male (42.4%) and 855 female (57.6%) participants, mean age 54 ±â€Š17.2 and 52 ±â€Š16 respectively were analyzed. The mean EV were found to be 15.3 ±â€Š2.8 mm in the right eye, 15.2 ±â€Š2.9 mm in the left eye for men and 14.4 ±â€Š2.7 mm in the right eye, 14.3 ±â€Š2.7 mm in the left eye for women. There were no differences in the EV between right and left eyes (P > .05). Men had significantly higher EV than women (P < .05) and age was found to be negatively correlated to EV (P < .05). Body height (r = 0.20), weight (r = 0.25), waist (r = 0.11), hip circumference (r = 0.15), body mass index (r = 0.17), interpupillary distance (r = 0.54), and axial length (AL) (r = 0.20) were all found to have statistically significant positive correlations with EV (P < .01). Spherical equivalent was found to have statistically significant negative correlation with EV (P < .01).Our study provides normative data on EV in the HK Chinese population. Height, weight, interpupillary distance, waist, hip circumference, and AL had positive correlations with EV. Spherical equivalent had negative correlation with EV. There was no significant difference in EV between the right and left eye. Age and gender had significant effect on EV.

Macular Vessel Density Measured With Optical Coherence Tomography Angiography and Its Associations in a Large Population-Based Study.

Purpose: We investigate macular perfusion and the systemic and ocular associations in a population-based setting. Methods: In this cross-sectional study, 2018 adults residing in Hong Kong underwent detailed ophthalmic examinations after consenting to participate. Macular perfusion was measured with optical coherence tomography angiography (OCTA) using the split-spectrum amplitude decorrelation angiography algorithm. The parafoveal flow index and vessel area density were quantified using automated custom-built software. Results: Of the 2018 participants, the OCTA measurements were available for 1940, and 1631 (84.1%) had good quality scans. The right eyes of these 1631 participants (43.1% men) were included for final analysis. Mean age was 49.8 years (range, 18-92 years). Mean global macular vessel density was 47.3% and 55.1% for the superficial and deep retinal layers, respectively. In multivariate analysis, lower superficial vessel density remained significantly associated with lower signal strength index (SSI; P < 0.001, standardized ß = 0.607) and male sex (P < 0.001, ß = 0.162), and borderline associated with older age (P = 0.09, ß = -0.045) and longer axial length (AL; P = 0.09, ß = -0.037), while lower deep layer vessel density was significantly associated with lower SSI (P < 0.001, standardized ß = 0.667), longer AL (P < 0.001, ß = -0.097), and higher creatinine (P < 0.001, ß = -0.072). Conclusions: This large population-based study provided normative OCTA data of macular vessel density and demonstrated that a lower superficial retinal vessel density was significantly associated with lower SSI and male sex, while a lower deep layer retinal vessel density was significantly associated with lower SSI, longer AL, and higher level of creatinine. These associations must be considered when interpreting clinical quantitative OCTA data.

The practice patterns in the management of sebaceous carcinoma of the eyelid in the Asia Pacific region.

PURPOSE: To determine the practice patterns of ophthalmic plastic surgeons regarding the management of eyelid sebaceous carcinoma (SC). METHODS: An electronic survey was distributed to oculoplastic surgical colleagues in the Asia Pacific region requesting clinical information and treatment approaches to SC. RESULTS: The responses from 192 respondents from the Asia Pacific region was included and analyzed in this study. For initial diagnosis, most surgeons selected incisional biopsy (55%), followed by complete excision (35%). Initial workup was mainly by palpation of lymph nodes, chest X-ray, and computerized tomography scan (CT-scan) of the orbit. Conjunctival map biopsy was done in selected cases. Sentinel lymph node biopsy (SLNB) was done mainly for tumors larger than 10 mm. Management was mainly by surgical excision (5 mm margin) combined with adjuvant therapy in some cases, with radiotherapy being the most common. Margin status was determined most frequently by frozen section as evaluated by the pathologist (57%) followed by Mohs micrographic surgery (18%). Surveillance was based mainly on physical examination alone. CONCLUSION: The Asia Pacific oculoplastic surgeons prefer incisional biopsy for lesions suspicious of SC prior to definitive surgery. This is in contrast to survey results previously reported in other populations. Frozen section control (done by an oculoplastic surgeon with pathology support) is most commonly used for margin control and conjunctival map biopsies are done only in selected cases. Despite the potential benefits of SLNB, access and expertise in this area is currently lacking in the Asia Pacific region.

Retrospective review on the outcome and safety of transscleral diode laser cyclophotocoagulation in refractory glaucoma in Chinese patients.

PURPOSE: Transscleral cyclodiode laser cyclophotocoagulation (TSCP) is often reserved for treatment of refractory glaucoma. This retrospective study investigates the safety and efficacy of TSCP among the Chinese population. METHODS: A retrospective review was performed on electronic patient records of all patients receiving TSCP between years 2009 to year 2016. Patient demographics, indication for laser, success and response rate, change in intraocular pressure (IOP), number of treatment sessions, laser energy, glaucoma medication, visual acuity, pain symptoms and complication rate were documented. RESULTS: The study included 126 patients: 81 patients were male and 45 were female, and the mean age was 66.6 ± 14.3 years old and the mean follow-up was 22.7 ± 14.1 months. The mean number of treatment sessions was 1.5 ± 0.8. The success rate was 67.3%. The mean IOP before TSCP was 67 ± 38.6 mmHg and 22.8 ± 14.2 mmHg after TSCP, the mean IOP reduction was 38.4%, which was statistically significant (P value < 0.001, Wilcoxon signed rank test). The mean laser energy used per eye was 72.7 ± 56.6 and 49.2 ± 22.9 J per individual treatment session. The mean number of laser shots was 15.0 ± 6.1. 71% of patients were able to reduce their glaucoma medication after TSCP, (P value < 0.01, Wilcoxon signed rank test). 86.1% of patients had improvement in pain symptoms after TSCP. The overall complication rate was 7.1%. CONCLUSION: TSCP was found to be safe and effective among the Chinese population, with comparably low laser energy setting and complication rate. It was found to be most effective in treatment of glaucoma due to trauma, acute angle closure, uveitis and chronic angle closure.

Phacoemulsification cataract surgery in patients receiving novel oral anticoagulant medications.

INTRODUCTION: An increasing number of patients are taking novel oral anticoagulant (NOAC) medication, making perioperative management in phacoemulsification surgery an important issue. This study reports the haemorrhagic complications of NOAC in phacoemulsification surgery. DESIGN: Retrospective case study over a 4-year period. METHODS: Consecutive cases receiving NOAC during the time of phacoemulsification were reviewed. Patients were either advised to continue medications (continued group) or withhold medications before surgery (withheld group). MAIN OUTCOME MEASURES: Details including patient demographics, preoperative assessment, postoperative outcome and intraoperative, postoperative and systemic complications were recorded. RESULTS: A total of 20,100 cases of phacoemulsification were performed. Of which, 66 cases were found to be on NOAC (0.33%). This included 66 eyes of 53 patients, with 42 continued and 24 withheld medications before surgery. There was no statistically significant difference between the two groups in demographics, cataract risk factors, baseline renal function, clotting profile, type of NOAC, incision size, phacoemulsification energy, preoperative and postoperative visual acuity. There was also no significant difference in intraoperative, postoperative and systemic complications (p = 1.00 and 0.53, Fischer's exact test). None of the patients in the continued group had postoperative complications; two cases in the withheld group receiving retrobulbar anaesthesia had bruising and subconjunctival haemorrhage after resumption of NOAC (p = 0.13, Fischer's exact test). CONCLUSION: The present study found no difference in haemorrhagic complications between cases continuing and withholding NOAC during phacoemulsification. Nevertheless, the potential risks and benefits to continue or withhold NOAC perioperatively should be carefully considered via a multidisciplinary approach.

Combined pentagonal resection and inferior retractor plication in involutional entropion.

BACKGROUND: To describe the effectiveness of combined pentagonal resection and inferior retractor plication (PR + IRP) based on the Hill's procedure for the treatment of primary involutional lower eyelid entropion in the Chinese population. METHODS: This is a retrospective review of 52 eyelids of 46 patients who underwent PR + IRP for treatment of involutional entropion between May 2009 and May 2017. Patient demographics, presence of pre-operative laxity, post-operative outcome and presence of complications were all recorded from electronic patient records. RESULTS: A total of 52 eyelids of 46 patients received PR + IRP. None had recurrence of entropion, 1 (2.1%) had residual entropion, 2 eyelids (4.4%) had lower eyelid notching, 1 eyelid (2.2%) had infection and 1 eyelid (2.2%) had overcorrection. The overall success rate was 90.4%. CONCLUSION: Combined PR + IRP is an effective surgical procedure for primary involutional entropion with low recurrence rate. However, it may carry risk of eyelid notching post-operatively.

Randomized Crossover Study Showing Nurse-Led Same Day Review Replacing Next Day Review in Uneventful Phacoemulsification to Be Safe and Efficacious.

Purpose. To study whether nurse led same-day review (SDR) after uneventful phacoemulsification can replace next-day review (NDR) in terms of safety and efficacy. Setting. Patients are recruited from an ophthalmology outpatient clinic in Hong Kong. Design. A prospective, randomized crossover study conducted from November 2012 to 2014. Methods. Inclusion criteria include cataract surgery naïve patients undergoing phacoemulsification under local anaesthesia. All patients were seen by our ophthalmic nurse 2 hours after surgery. Before undergoing phacoemulsification of the first eye, patients were randomized to be reviewed on day 1 or 7 after surgery. Surgeons and reviewing doctors were blinded to patient allocation. For the patients' second eye surgery, group allocation will cross over. Primary outcome measures include visual improvement and patient satisfaction questionnaire. Other measures include cataract characteristics, surgical details, and complications. Statistical tests include paired t-test, Wilcoxon signed rank test, and Chi-square test. Results. 164 eyes from 82 patients were available. Visual improvement, satisfaction, and complications were comparable between both groups. Conclusions. A nurse led SDR can replace NDR in uneventful phacoemulsification in terms of safety and efficacy. Patient satisfaction is also comparable in the setting of Asian culture and when transportation is not a major concern.

Adjuvant therapy for the reduction of postoperative intra-abdominal adhesion formation.

BACKGROUND: To review currently available evidence on the use of adjuvant therapy to reduce the formation of postoperative intra-abdominal adhesions. METHODS: A search on Pubmed and the Cochrane library was undertaken using the keywords "abdominal", "adhesion", "postoperative", "prevention" and "reduction". Only randomised controlled trials, prospective non-randomised controlled studies and review articles published in the English language between 1990 and 2006 were included. RESULTS: Two prospective non-randomised controlled studies and 18 randomised controlled trials were included in this review. Adjuvant therapies reviewed included pharmacological agents (streptokinase, recombinant tissue plasminogen activator, vitamin E antioxidant molecules), and mechanical barriers (hyaluronic acid barriers, oxidised regenerated cellulose barriers, nanofibrous barriers and collagen foils). Hyaluronate/carboxymethylcellulose-based bioresorbable membrane (Seprafilm) appeared to be the most efficacious in reducing adhesion formation as well as decreasing the incidence of adhesion obstruction requiring reoperation in clinical studies. Drawbacks to the use of Seprafilm include high cost and complications such as haemorrhage and poor wound healing. CONCLUSIONS: Only a limited number of adjuvant treatment methods are currently available for the reduction of postoperative adhesions. Seprafilm has been proven to be the efficacious method to reduce adhesions. Investigations into the novel therapies are showing promising results in experimental studies and clinical studies before their wider application.