Topical and subconjunctival anesthesia versus topical anesthesia alone in patients with senile cataracts undergoing phacoemulsification: a double-blind randomized controlled trial

BACKGROUND

This study compared topical anesthesia to a combination of topical anesthesia and subconjunctival anesthesia for phacoemulsification.

METHODS

This double-blinded parallel placebo-controlled randomized trial involved senile cataract patients scheduled for phacoemulsification between May and December 2022. Patients were randomly assigned to receive either topical anesthesia with 0.5% tetracaine hydrochloride and subconjunctival balanced salt solution injection (Control group) or topical anesthesia and subconjunctival injection with 2% lidocaine (Lidocaine group). Baseline parameters, cataract grades, and various outcomes were recorded, including pain scores at specific time points, patient cooperation scores, requests for additional anesthesia, and complications. Statistical methods included Fisher's exact test, the t-test, ordinal logistic regression, and linear regression with robust standard errors.

RESULTS

In total, 176 patients were included in the study after excluding 33 patients. A significant reduction in immediate postoperative pain was achieved in the Lidocaine group (p < 0.001) and was maintained for 2 h (p = 0.011). Additionally, better cooperation was observed in this group (p = 0.038). However, patients in the Lidocaine group experienced more pain during the subconjunctival injection (p = 0.001) and a significant increase in subconjunctival hemorrhage related to the injection (p < 0.001). Despite this, the rates of surgical complications were comparable between the groups, and all phacoemulsification procedures were successfully completed using the assigned anesthetic technique.

CONCLUSIONS

The addition of subconjunctival lidocaine injection to topical anesthesia reduced postoperative pain and improved patient cooperation during phacoemulsification. However, the lidocaine injection was painful, and it carried a higher risk of spontaneous-relief subconjunctival hemorrhage.

TRIAL REGISTRATION

Trial Registration Number: TCTR20220804003, date of registration August 4, 2022, retrospectively registered.

Personalized Care in Eye Health: Exploring Opportunities, Challenges, and the Road Ahead for Chatbots

In modern eye care, the adoption of ophthalmology chatbots stands out as a pivotal technological progression. These digital assistants present numerous benefits, such as better access to vital information, heightened patient interaction, and streamlined triaging. Recent evaluations have highlighted their performance in both the triage of ophthalmology conditions and ophthalmology knowledge assessment, underscoring their potential and areas for improvement. However, assimilating these chatbots into the prevailing healthcare infrastructures brings challenges. These encompass ethical dilemmas, legal compliance, seamless integration with electronic health records (EHR), and fostering effective dialogue with medical professionals. Addressing these challenges necessitates the creation of bespoke standards and protocols for ophthalmology chatbots. The horizon for these chatbots is illuminated by advancements and anticipated innovations, poised to redefine the delivery of eye care. The synergy of artificial intelligence (AI) and machine learning (ML) with chatbots amplifies their diagnostic prowess. Additionally, their capability to adapt linguistically and culturally ensures they can cater to a global patient demographic. In this article, we explore in detail the utilization of chatbots in ophthalmology, examining their accuracy, reliability, data protection, security, transparency, potential algorithmic biases, and ethical considerations. We provide a comprehensive review of their roles in the triage of ophthalmology conditions and knowledge assessment, emphasizing their significance and future potential in the field.

Disagreement of Radial Peripapillary Capillary Density Among Four Optical Coherence Tomography Angiography Devices

Purpose

This prospective study evaluated the agreement among four optical coherence tomography angiography (OCTA) devices in the assessment of radial peripapillary capillary (RPC) density.

Methods

The study included 48 eyes of 48 subjects (14 healthy, 19 glaucomatous, and 15 non-glaucomatous optic neuropathy). Each participant was scanned using four OCTA devices in a random sequence: RTVue XR Avanti (RTVue), DRI OCT Triton (Triton), Revo NX 130 (Revo), and PLEX Elite 9000 (PlexE). All 6 × 6-mm grayscale OCTA images from each device were analyzed for RPC density using a customized algorithm. Agreement between each pair of devices was assessed using intraclass correlation coefficients (ICCs) and Bland-Altman plots.

Results

There was a poor correlation between devices in all comparisons (RTVue-Triton, ICC = 0.34; RTVue-Revo, ICC = 0.31; RTVue-PlexE, ICC = 0.28; Triton-Revo, ICC = 0.31; Triton-PlexE, ICC = 0.17; Revo-PlexE, ICC = 0.34). Significant proportional biases (P < 0.05) and wide limits of agreement with apparent constant biases were identified in all comparisons. The mean difference was greatest for the RTVue-Revo pair (-49.3%; 95% confidence interval [CI], -52.9 to -45.8) and smallest for the Triton-PlexE pair (-7.7%; 95% CI, -10.1 to -5.3).

Conclusions

The RPC densities obtained from each device had poor inter-device agreement and significant biases and cannot be used interchangeably.

Translational Relevance

RPC density obtained from different OCTA devices is not interchangeable; thus, the progression of optic neuropathy should be monitored using the same OCTA device.

Donut: Augmentation Technique for Enhancing The Efficacy of Glaucoma Suspect Screening

Glaucoma is the second most common cause of blindness. A glaucoma suspect has risk factors that increase the possibility of developing glaucoma. Evaluating a patient with suspected glaucoma is challenging. The "donut method" was developed in this study as an augmentation technique for obtaining high-quality fundus images for training ConvNeXt-Small model. Fundus images from GlauCUTU-DATA, labelled by randomizing at least 3 well-trained ophthalmologists (4 well-trained ophthalmologists in case of no majority agreement) with a unanimous agreement (3/3) and majority agreement (2/3), were used in the experiment. The experimental results from the proposed method showed the training model with the "donut method" increased the sensitivity of glaucoma suspects from 52.94% to 70.59% for the 3/3 data and increased the sensitivity of glaucoma suspects from 37.78% to 42.22% for the 2/3 data. This method enhanced the efficacy of classifying glaucoma suspects in both equalizing sensitivity and specificity sufficiently. Furthermore, three well-trained ophthalmologists agreed that the GradCAM++ heatmaps obtained from the training model using the proposed method highlighted the clinical criteria.Clinical relevance- The donut method for augmentation fundus images focuses on the optic nerve head region for enhancing efficacy of glaucoma suspect screening, and uses Grad-CAM++ to highlight the clinical criteria.

3-LbNets: Tri-Labeling Deep Convolutional Neural Network for the Automated Screening of Glaucoma, Glaucoma Suspect, and No Glaucoma in Fundus Images

Early detection of glaucoma, a widespread visual disease, can prevent vision loss. Unfortunately, ophthalmologists are scarce and clinical diagnosis requires much time and cost. Therefore, we developed a screening Tri-Labeling deep convolutional neural network (3-LbNets) to identify no glaucoma, glaucoma suspect, and glaucoma cases in global fundus images. 3-LbNets extracts important features from 3 different labeling modals and puts them into an artificial neural network (ANN) to find the final result. The method was effective, with an AUC of 98.66% for no glaucoma, 97.54% for glaucoma suspect, and 97.19% for glaucoma when analysing 206 fundus images evaluated with unanimous agreement from 3 well-trained ophthalmologists (3/3). When analysing 178 difficult to interpret fundus images (with majority agreement (2/3)), this method had an AUC of 80.80% for no glaucoma, 69.52% for glaucoma suspect, and 82.74% for glaucoma cases.Clinical relevance-This establishes a robust global fundus image screening network based on the ensemble method that can optimize glaucoma screening to alleviate the toll on those with glaucoma and prevent glaucoma suspects from developing the disease.

Assessment of Pain in Glaucoma Patients Undergoing Micropulse Transscleral Laser Therapy

Background: This study aimed to assess the pain experienced during micropulse transscleral laser therapy (MPTLT) and overnight thereafter and explore the factors associated with the pain. Methods: This prospective study included 100 eyes of 81 glaucoma patients undergoing MPTLT under retrobulbar anesthesia. All patients were asked to rate both types of pain using a numerical rating scale (NRS). The risk factors were explored using multivariable mixed-effects ordinal logistic regression. Results: The mean (SD) NRS pain score during the procedure was 3.57 (3.41) (range 0–10), which included no, mild, moderate, and severe pain in 30 (30%), 33 (33%), 17 (17%), and 20 (20%) eyes, respectively. The mean (SD) NRS score of overnight pain was 2.99 (2.28) (range 0–9), which included no, mild, moderate, and severe pain in 17 (17%), 59 (59%), 17 (17%), and 7 (7%) eyes, respectively. Twenty-seven (27%) eyes reported worse pain overnight than during the procedure. Increased age, initial intraocular pressure, and pain during the procedure were significantly associated with increased overnight pain (p < 0.05). Conclusions: Up to a fourth of eyes had worse pain after discharge. Older age, initial intraocular pressure, and pain during the procedure were risk factors for higher levels of overnight pain.

Incidence and Risk Factors for Retinopathy of Prematurity at a Rural Tertiary Hospital in Thailand

Purpose

To estimate the incidence and identify the factors affecting retinopathy of prematurity (ROP) in a rural tertiary hospital in Thailand.

Methods

This retrospective chart review included all infants screened for ROP. The study included all infants with gestational age (GA) ≤ 30 weeks or birth weight (BW) ≤ 1,500 gr or selected larger infants with an unstable clinical course. Retinal findings were classified according to the revised International Classification of ROP. Data were analyzed using univariate and multivariable logistic regression analyses.

Results

Of the 113 screened infants, the incidences of any ROP and ROP requiring intervention were 17.7% and 8.8%, respectively. In univariate analysis, lower GA, lighter BW, total days of supplemental oxygen, days of continuous positive airway pressure (CPAP), presence of apnea, and intraventricular hemorrhage (IVH) were associated with the development of any ROP. In the stepwise multivariable logistic regression analysis, lighter BW, male gender, and bronchopulmonary dysplasia (BPD) were significant risk factors for the development of any ROP. Lower GA and being either a twin or triplet were significant risk factors for ROP requiring intervention. However, no antenatal condition was identified as a risk factor for ROP.

Conclusion

The incidence of ROP in rural tertiary hospitals was relatively high as compared with previously published data from urban tertiary hospitals. Lighter BW, male gender, and BPD were significantly associated with the development of ROP in a local context. Epidemiological studies are necessary to prevent ophthalmic morbidities.

Efficacy of Selective Laser Trabeculoplasty in Primary Angle-closure Glaucoma after Peripheral Iridotomy

Aim

To evaluate the efficacy of selective laser trabeculoplasty (SLT) in Southeast Asian eyes with primary open-angle glaucoma (POAG) vs primary angle-closure glaucoma after peripheral iridotomy (PACG-PI).

Materials and methods

Records of glaucoma patients who underwent SLT and had a 24-month follow-up were reviewed. Pre- and post-treatment intraocular pressure (IOP), percentage of IOP reduction in POAG, and PACG-PI groups, and probability of failure were analyzed. SLT failure was defined as any eye that did not have IOP lower than 20% compared to the baseline or had an IOP higher than the baseline on two consecutive visits. Adding medication, repeating SLT, or surgical intervention to control IOP was also considered a failure.

Results

Sixty-three POAG and 12 PACG-PI eyes were eligible. The mean (standard deviation [SD]) age was 62.9 (10.2) years in POAG and 60.3 (6.2) years in PACG-PI. Mean (SD) prelaser IOP in POAG was 19.0 (4.4) mm Hg and 20.7 (4.7) mm Hg in PACG-PI. At 24 months post-SLT, mean (SD) IOP was 14.1 (4.7) mm Hg and 13.6 (2.0) mm Hg in POAG and PACG-PI, respectively. There was no significant difference in percentage of IOP reduction (22.8 ± 23.0% for POAG and 30.7 ± 19.5% for PACG-PI, p = 0.96), or failure probability (p = 0.10) between both groups.

Conclusion

The efficacy of SLT at 24 months was comparable between POAG and PACG-PI.

Clinical significance

Selective laser trabeculoplasty may be an option to further lower IOP in eyes with angle closure with visible trabecular meshwork (TM) after iridotomy, especially in highly pigmented eyes of Southeast Asians.

How to cite this article

Wongwuticomjon T, Chansangpetch S, Inobhas A, et al. Efficacy of Selective Laser Trabeculoplasty in Primary Angle-closure Glaucoma after Peripheral Iridotomy. J Curr Glaucoma Pract 2022;16(2):124-127.

Characteristics and long-term outcomes of childhood glaucoma: a retrospective-cohort study

Purpose: To evaluate the clinical characteristics and treatment outcomes of patients with childhood glaucoma.

Methods: We retrospectively reviewed the data of patients with childhood glaucoma who visited the glaucoma clinics at the Queen Sirikit National Institute of Child Health and the King Chulalongkorn Memorial Hospital between January 2008 and January 2018. The diagnosis was based on the Childhood Glaucoma Research Network classification. We recorded their clinical characteristics and requirement of any glaucoma interventions.

Results: A total of 691 eyes from 423 patients were included in this study. The patients predominantly comprised boys. The average follow-up duration was 71.3±63.8 months. The mean age at presentation was 3.9±4.4 years. Most patients presented with a high initial intraocular pressure (IOP). The average intial IOP of all patients was 28.5±11.2 mmHg. Glaucoma associated with non-acquired ocular anomalies (22.9%) was the most common subtype, followed by primary congenital glaucoma (20.8%). We recorded a family history of glaucoma in 6.4% of patients of the 234 patients with an available family history. Most patients had bilateral glaucoma (63.4%) and required at least one intervention (51.5%). The average IOP at the latest follow-up visit was 19.1±10.8 mmHg. All glaucoma types had significantly lower IOP, compared to that at their baselines (all p<0.001). Moreover, most patients had an unfavourable visual acuity (49.5%) at their latest visit.

Conclusions: Secondary glaucoma associated with non-acquired ocular anomalies is the most common subtype of glaucoma. The majority of patients had unfavourable visual outcomes. These real-world findings are fundamental to acquire a better understanding of childhood glaucoma.

GlauCUTU: Virtual Reality Visual Field Test

This study proposed a virtual reality (VR) head-mounted visual field (VF) test system, or also known as the GlauCUTU VF test, for a reaction time (RT) perimetry with moving visual stimuli that progressively increase in intensity. The test entailed 24-2 VF protocol and was examined on 2 study groups, controls with normal fields and subjects with glaucoma. To collect reaction times, participants were urged to respond to the stimulus by pressing on the clicker as fast as possible. Performance of the GlauCUTU VF test was compared to the gold standard Humphrey Visual Field Analyzer (HFA). The HFA showed a significant difference between the GlauCUTU and HFA with mean duration of 254.41 and 609, respectively [t(16) = 15.273, p<0.05]. Likewise, our system also effectively differentiated glaucomatous eyes from normal eyes for the left eye and right eye, respectively. When compared to the HFA, the GlauCUTU test produced a significantly shorter average test duration by 354 seconds which reduced test-induced eye fatigue. The portable and inexpensive GlauCUTU perimetry system proves to be a promising method for increasing accessibility to glaucoma screening.Clinical relevance- GlauCUTU, an automated head-mounted VR perimetry device for VF test, is portable, cost-effective, and suitable for low resource settings. Unlike the conventional HFA test, GlauCUTU VF test reports in terms of subjects RT which is reportedly higher in glaucoma patients.

Effectiveness of micropulse transscleral laser therapy in uncontrolled glaucoma secondary to ciliary body metastasis

Purpose

To report a case of ciliary body metastasis with uncontrolled glaucoma that was successfully treated with micropulse transscleral laser therapy (MPTLT).

Observations

A case of a 44-year-old female with uncontrolled glaucoma secondary to ciliary body metastasis from pulmonary adenocarcinoma. Antiglaucoma medications, intravitreal ranibizumab injection and local radiotherapy were ineffective in reducing her intraocular pressure (IOP) and ocular pain. MPTLT using a power setting of 2,000 mW, 31.3% duty cycle, and 140 seconds over 180 degrees demonstrated favorable IOP reduction (from 31 to 8 mmHg) on the first postoperative day without either ocular pain or postoperative complications. IOP remained controlled until she died from hemoperitoneum 18 days after hospital discharge.

Conclusions and importance

MPTLT can be a safe and effective procedure for IOP control in intraocular metastasis patients with uncontrolled glaucoma.

Displacement between anterior chamber width obtained by swept-source anterior segment optical coherence tomography and white-to-white distance

Purpose

To determine the relationship between the external limbal location, represented by white-to-white (WTW) distance, and the actual angle location, represented by spur-to-spur (STS) and angle-to-angle (ATA) distances.

Methods

166 eyes from 166 participants were imaged using CASIA2 anterior chamber optical coherence tomography (AS-OCT) and LenStar LS 900 optical biometer. The horizontal ATA and STS were measured using the swept-source Fourier-domain AS-OCT (CASIA2). The horizontal WTW was automatically measured using LenStar. The displacement lengths (DL) between WTW-STS and WTW-ATA were calculated. Bland-Altman plots and intraclass correlation were performed.

Results

The study showed that WTW has a positive correlation with STS (ICC = 0.82, p<0.001) and ATA (ICC = 0.82, p<0.001). The Bland-Altman analysis demonstrated that the mean difference of WTW-STS is 0.10 mm (95% CI 0.06 to 0.14 mm) with limits of agreement of -0.42 to 0.63 mm between WTW and STS, and the mean difference of WTW-ATA is 0.10 mm (95% CI 0.06 to 0.15 mm) with limits of agreement of -0.48 to 0.64 mm between WTW and ATA. Linear regression with adjustment showed that a WTW value greater than 12.07 mm is associated with a greater DL (WTW-STS DL ß 0.18, p = 0.003; WTW-ATA DL ß 0.14, p = 0.03).

Conclusions

Greater WTW was significantly associated with higher displacement of WTW from the two distances representing anterior chamber width. External limbal location may not accurately represent the actual angle location in eyes with larger WTW.

Characteristics and long-term outcomes of childhood glaucoma: a retrospective-cohort study

Purpose: To evaluate the clinical characteristics and treatment outcomes of patients with childhood glaucoma. Methods: We retrospectively reviewed the data of patients with childhood glaucoma who visited the glaucoma clinics at the Queen Sirikit National Institute of Child Health and the King Chulalongkorn Memorial Hospital between January 2008 and January 2018. The diagnosis was based on the Childhood Glaucoma Research Network classification. We recorded their clinical characteristics and requirement of any glaucoma interventions. Results: A total of 691 eyes from 423 patients were included in this study. The patients predominantly comprised boys. The average follow-up duration was 71.3±63.8 months. The mean age at presentation was 3.9±4.4 years. Most patients presented with a high initial intraocular pressure (IOP). The average intial IOP of all patients was 28.5±11.2 mmHg. Glaucoma associated with non-acquired ocular anomalies (22.9%) was the most common subtype, followed by primary congenital glaucoma (20.8%). We recorded a family history of glaucoma in 6.4% of patients of the 234 patients with an available family history. Most patients had bilateral glaucoma (63.4%) and required at least one intervention (51.5%). The average IOP at the latest follow-up visit was 19.1±10.8 mmHg. All glaucoma types had significantly lower IOP, compared to that at their baselines (all p<0.001). Moreover, most patients had an unfavourable visual acuity (49.5%) at their latest visit. Conclusions: Secondary glaucoma associated with non-acquired ocular anomalies is the most common subtype of glaucoma. The majority of patients had unfavourable visual outcomes. These real-world findings are fundamental to acquire a better understanding of childhood glaucoma.

Effect of oral statin use on mitomycin-C augmented trabeculectomy outcomes

Purpose

The effect of statins on wound healing is controversial, and their effect on trabeculectomy outcomes remains unclear. This study aimed to examine the relationship between oral statin use and trabeculectomy outcomes.

Methods

Medical records of patients who underwent primary mitomycin-C augmented trabeculectomy with 2 years of follow-up were reviewed. Pre- and postoperative intraocular pressures (IOP) and numbers of medications, subconjunctival 5-fluorouracil (5-FU) injections, and bleb-needling procedures were compared between statin users and nonusers. Failure was defined as an eye that failed to achieve a 20% lowering of IOP from baseline or had an IOP > 21 mm Hg, as well as an eye that required further surgical intervention, developed hypotony, or had no light perception visual acuity.

Results

In total, 158 subjects were enrolled, with 47 eyes from statin users and 111 eyes from statin nonusers. The 24-month cumulative probability of failure was 78.7% for statin users and 60.4% for nonusers (P = .013). Cox proportional-hazards modeling showed a significantly higher hazard risk in statin users (adjusted hazard ratio 1.61, P = .026). There were no significant between-group differences in mean IOPs or number of medications (both P > .05) at 24 months. Multivariable Poisson regression analysis that statin use was associated with increased numbers of 5-FU injections (P = .014) and bleb-needling procedures (P = .031).

Conclusions

This study demonstrated that oral statin use was associated with higher rates of trabeculectomy failure and increased numbers of 5-FU injections and bleb-needling procedures.

Ethnicity-Specific Database Improves the Diagnostic Ability of Peripapillary Retinal Nerve Fiber Layer Thickness to Detect Glaucoma

PURPOSE

To determine the changes in optical coherence tomography (OCT) color probability codes and diagnostic ability for peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell complex (GCC) analysis after applying Chinese and white subjects normative databases.

DESIGN

Cross-sectional study.

METHODS

This study enrolled 219 healthy eyes (108 white and 111 Chinese patients) to construct an ethnicity-specific normative database for pRNFL and macular GCC thickness, which was tested then in 180 eyes with or without glaucoma (102 white and 78 Chinese patients). The percent of change of color probability codes were evaluated after applying the original built-in and the ethnicity-specific normative databases, respectively. Sensitivity and specificity were calculated to evaluate the change in diagnostic ability to detect glaucoma.

RESULTS

Healthy white subjects had a thinner pRNFL than Chinese subjects in the overall average thickness as well as the superior, inferior, and temporal quadrants (P < .001). Macular GCC did not differ between ethnicities. After applying an ethnicity-specific normative database, the percent of pRNFL abnormal color code labels decreased significantly for the overall average thickness in the white subjects. This resulted in a significant increase in the specificity to detect glaucoma in the white population (P < .001). No significant changes were seen when applying an ethnicity-specific normative database for macular GCC thickness.

CONCLUSIONS

After applying an ethnicity-specific normative database, the percent of pRNFL abnormal color codes decreased significantly, improving the specificity to detect glaucoma in the white population. These findings suggest there may be utility in having ethnicity-specific normative databases for pRNFL thickness.

Literature Review of Surgical Treatment in Idiopathic Full-Thickness Macular Hole

Purpose

To summarize current surgical techniques for treating primary macular holes (MHs).

Methods

We reviewed publications detailing surgical approaches to primary MHs, briefly described their protocols, and outlined their results.

Results

Currently, the technique for primary MH repair is pars plana vitrectomy, removing the posterior cortical vitreous, stripping the epiretinal membranes, and ending with intraocular gas tamponade. The evident benefit of peeling off the internal limiting membrane (ILM) was clearly shown for MHs at stages 2 to 4 by achieving an anatomical closure rate of >90%, even in large MH up to 650 µm. Newer MH surgical techniques include modification of ILM flap techniques, placing an autologous scaffolding of tissue within the hole, and cell therapy has shown to increase the closure rate of large and chronic macular holes, resulting in modest functional improvement in complicated MHs.

Conclusion

Since the turn of the century, the success rate of modern macular surgery has increased, even for large and chronic MHs. There seems to be no limit to novel concepts in MH surgery, which range from anatomical closure to those proposing natural restoration of visual function via stem cell therapy.

Intraocular pressure elevation associated with blood in Schlemm's canal after strabismus surgery

Purpose

To report a case of increased intraocular pressure (IOP) associated with blood in Schlemm's canal following strabismus surgery.

Observations

A 43-year-old female presented with acquired comitant esotropia. The patient had undergone an uneventful bilateral medial rectus recession and right lateral rectus resection operation under general anesthesia. Routine post-operative follow-up at day 3 detected a marked chemosis at the temporal side of the conjunctiva, an elevated IOP of 30 mmHg, and the presence of blood in Schlemm's canal in the temporal angle of the right eye. Episcleral venous outflow impairment was hypothesized to be the cause of secondary ocular hypertension in this patient. IOP was controlled with anti-glaucoma drops. Conjunctival chemosis, IOP, and blood in Schlemm's canal gradually decreased, and all topical medications were ceased at 11 weeks after the surgery.

Conclusion and importance

An IOP elevation can be an early complication after strabismus surgery. The presence of blood in Schlemm's canal suggests that the cause is impairment of episcleral venous flow. Although the episode can be transient, this report underlines the importance of IOP examination during the early post-operative period.

Automated Glaucoma Screening from Retinal Fundus Image Using Deep Learning

Glaucoma is the second leading cause of blindness worldwide. This paper proposes an automated glaucoma screening method using retinal fundus images via the ensemble technique to fuse the results of different classification networks and the result of each classification network was fed as an input to a simple artificial neural network (ANN) to obtain the final result. Three public datasets, i.e., ORIGA-650, RIM-ONE R3, and DRISHTI-GS were used for training and evaluating the performance of the proposed network. The experimental results showed that the proposed network outperformed other state-of-art glaucoma screening algorithms with AUC of 0.94. Our proposed algorithms showed promising potential as a medical support system for glaucoma screening especially in low resource countries.

Anterior Segment Parameters of Filipino-Americans Compared to Chinese-Americans and Caucasian Americans Using Anterior Segment Optical Coherence Tomography

Purpose

We compare anterior segment characteristics of Filipino- versus Chinese- and Caucasian-Americans to describe the differences in risk factors among each ethnic group.

Methods

A cross-sectional study was conducted among Filipino, Chinese, and Caucasian subjects without glaucoma who underwent a standardized set of ocular examinations and anterior segment optical coherence tomography (Visante ASOCT) imaging. Zhongshan Angle Assessment Program (ZAAP) 4 was used for ASOCT image analysis. The following quantitative parameters wereobtained from ZAAP: (1) angle opening distance (AOD500, AOD750), angle recess area at 750 μm (ARA), and trabecular-iris space area at 500 and 750 μm (TISA500, TISA750); (2) iris parameters, including iris thickness at 750 μm from the scleral spur (IT750), iris area (IArea), iris curvature or convexity (ICurv), and pupil diameter; 3) anterior chamber parameters; and (4) lens vault.

Results

The Filipino (122 eyes), Chinese (121 eyes), and Caucasian (111 eyes) subject groups were similar in terms of demographic and clinical characteristics. We reported pairwise comparisons of Filipino parameter values to Chinese or Caucasian values, represented as B-coefficients and P values. In multivariate analysis, Filipinos had narrower angles than Caucasians (AOD750, TISA 500, TISA 750, ARA, P < 0.001). Filipinos had thicker and more convex irises than Caucasians (IT750, IT 2000, ICurv P < 0.003). Angle and iris parameters were similar overall for Filipino and Chinese.

Conclusions

Filipinos appear to have more convex and thicker irises, smaller lens vault and narrower angles compared to Caucasians. Filipino eyes closely resembled Chinese eyes with similar iris and angle parameters.

Translational Relevance

The anatomic angle parameters of Filipinos may contribute to angle closure risk among this population, thus ASOCT and thorough angle analysis is recommended in this population.

How to Predict Intraocular Pressure Reduction after Cataract Surgery? A Prospective Study

Purpose/Aim: To evaluate the best formula to predict intraocular pressure (IOP) reduction after cataract surgery. Materials and methods: In this prospective longitudinal study, we included consecutive patients with or without glaucoma, either with open or with narrow angles but without peripheral anterior synechiae, who underwent phacoemulsification. Clinical factors and anterior segment parameters measured with optical biometry and optical coherence tomography were evaluated as preoperative predictors for IOP reduction at 6 months postoperatively. To find the best combinations of predictors, model selection was conducted using least absolute selection and shrinkage operator regression with cross-validation. Results: A total of 156 eyes from 109 patients were enrolled. The mean age of the patients was 74.89 (±8.54) years and the average preoperative IOP was 15.6 (±3.68) mmHg with 0.7 (range 0-4) glaucoma medications. The mean IOP reduction after phaco was 3.1 (±2.49) mmHg at postoperative month 6. After multivariate analysis, preoperative IOP (β = 0.49 [0.4-0.59] P < .0001), gonioscopy score (β = -0.14 [-0.23 to -0.06] P = .0001), anterior chamber depth (β = -0.85 [-1.64 to -0.07] P = 0.033), lens thickness (LT) (β = 0.87 [0.12-1.62] P = .024), and angle open distance 750 (β = -2.2 [-3.96 to -0.44] P = 0.014) were associated with IOP reduction. The best formula to correlate with IOP reduction was -4.76 + (0.46 × preoperative IOP) - (0.42 × LT) - (0.1 × gonioscopy score) - (0.66 × glaucoma status). Conclusion: Different formulas were developed and were able to improve the predictive value of the preoperative IOP. When used in combination, these formulas may help the clinician to know how much IOP reduction to expect after cataract surgery at 6 months postoperatively.

Case report of eyelid schwannoma: A rare presentation in a child

Purpose

To report a rare case of solitary eyelid schwannoma in a Thai child without clinical manifestation of neurofibromatosis.

Observations

A 9-year-old Thai boy presented with an isolated painless mass on the left lower eyelid. The mass had gradually grown for 2 years. He denied a history of trauma or previous eyelid surgery. A clinical examination revealed no clinical features of neurofibromatosis. The provisional diagnosis at that time was a sebaceous cyst. However, excisional biopsy showed an encapsulated tumor characterized by interlaced spindle-celled fasciculi with focal palisading of nuclei arranging in Antoni A and Antoni B patterns. The immunocytochemistry was strongly positive for S-100 protein reaction. The diagnosis of schwannoma was made, with no recurrence at.

Conclusions and importance

Schwannoma of the eyelid is extremely rare in children, accounting for less than 0.1% of all eyelid tumors. Combined with clinical features, histopathologic and immunohistochemical analyses emphasize the disease entities. These findings may extend the knowledge on experiences of schwannoma in children.

Comparison of Anterior Segment Optical Coherence Tomography Parameters Among Vietnamese, Chinese, and Whites

PURPOSE

To evaluate the difference in anterior segment optical coherence tomography (AS-OCT) parameters among ethnic Vietnamese, Chinese, and whites.

DESIGN

Cross-sectional study.

METHODS

We prospectively recruited phakic nonglaucomatous participants (based on intraocular pressure < 21 mm Hg, normal optic nerve head and retinal nerve fiber, and cup-to-disc ratio < 0.6) of 3 ethnic groups-Vietnamese, Chinese, and white. AS-OCT parameters including angle (angle opening distance, trabecular-iris space area, and angle recess area), iris (iris thickness, iris area, and iris curvature [Icurv]), and anterior chamber parameters (anterior chamber depth, width [ACW], area, and lens vault [LV]) were obtained. A linear regression model with adjustment for age, sex, axial length, and pupillary diameter was used for analysis. Subgroup analysis was performed in closed- and open-angle subgroups, which were defined in eyes with gonioscopically visible posterior trabecular meshwork for less than 2 quadrants (closed) and equal to or more than 2 quadrants (open).

RESULTS

Data were obtained from 126 Vietnamese, 124 Chinese, and 112 white participants. Mean (standard deviation) age of participants was 60.2 (11.8) years. Among overall subjects, Vietnamese had significantly smaller values in all angle and anterior chamber parameters than Chinese and white subjects (all P ≤ .001) except LV. Vietnamese had significantly higher Icurv than Chinese (B -0.065, P < .001) and white subjects (B -0.073, P < .001). In the open-angle subgroup, Vietnamese had significantly smaller angle and anterior chamber dimensions (P ≤ .001) and thicker iris (P < .001) than whites, whereas there was no significant difference in all parameters compared to Chinese except for smaller ACW in Vietnamese (P < .001). In the closed-angle subgroup, Vietnamese possessed smaller angle, smaller anterior chamber dimensions, and higher Icurv than Chinese and white subjects (P < .001). Vietnamese had significantly greater LV compared to Chinese (B -204.8, P = .001).

CONCLUSION

Vietnamese subjects had more of the anatomic characteristics associated with risk for angle closure, including small anterior chamber dimension, high iris curvature, and high lens vault, compared to the other 2 ethnicities.

Efficacy of Cataract Surgery With Trabecular Microbypass Stent Implantation in Combined-Mechanism Angle Closure Glaucoma Patients

PURPOSE

To evaluate the effectiveness of trabecular microbypass stent (iStent) implantation in combined mechanism glaucoma (CMG).

DESIGN

Retrospective cohort study.

METHODS

We reviewed the medical charts of patients with the following scenarios: (1) primary open-angle glaucoma (POAG) undergoing phacoemulsification (PE), (2) POAG undergoing PE with iStent (POAG-PE/iStent), (3) CMG undergoing PE (CMG-PE), and (4) CMG undergoing PE with iStent (CMG-PE/iStent). CMG was defined as narrow-angle glaucoma patients whose angle had opened after iridotomy. Linear mixed-effects models were performed to determine the effect of iStent on postoperative 1-year success rate (intraocular pressure [IOP] ≤ 18 without medication), IOP, and number of medications.

RESULTS

Data from 301 eyes were available. The number of eyes (subjects) was 61 (45) in the POAG-PE, 60 (50) in POAG-PE/iStent, 93 (76) in CMG-PE, and 87 (70) in CMG-PE/iStent group. Success criteria were achieved in 13.1% for POAG-PE, 33.3% for POAG-PE/iStent (POAG-PE vs POAG-PE/iStent B 3.01; P < .001), 37.6% for CMG-PE, and 43.7% for CMG-PE/iStent (CMG-PE vs CMG-PE/iStent B 2.25; P < .001). There was no difference in the IOP between POAG-PE and POAG-PE/iStent, and between CMG-PE and CMG-PE/iStent. The iStent significantly reduced number of medications in the POAG (B -0.70; P < .001) and CMG group (B -0.52; P < .001). Comparing the effect of iStent on POAG and CMG, the analysis showed similar iStent efficacy in terms of the success rate, IOP, and number of medications (P > .05).

CONCLUSIONS

Combined PE/iStent significantly increased success rate and reduced number of medications in CMG patients compared to PE alone. The effects of iStent were comparable between POAG and CMG groups.

Agreement of Anterior Segment Parameters Obtained From Swept-Source Fourier-Domain and Time-Domain Anterior Segment Optical Coherence Tomography

Purpose

To assess the interdevice agreement between swept-source Fourier-domain and time-domain anterior segment optical coherence tomography (AS-OCT).

Methods

Fifty-three eyes from 41 subjects underwent CASIA2 and Visante OCT imaging. One hundred eighty–degree axis images were measured with the built-in two-dimensional analysis software for the swept-source Fourier-domain AS-OCT (CASIA2) and a customized program for the time-domain AS-OCT (Visante OCT). In both devices, we examined the angle opening distance (AOD), trabecular iris space area (TISA), angle recess area (ARA), anterior chamber depth (ACD), anterior chamber width (ACW), and lens vault (LV). Bland-Altman plots and intraclass correlation (ICC) were performed. Orthogonal linear regression assessed any proportional bias.

Results

ICC showed strong correlation for LV (0.925) and ACD (0.992) and moderate agreement for ACW (0.801). ICC suggested good agreement for all angle parameters (0.771–0.878) except temporal AOD500 (0.743) and ARA750 (nasal 0.481; temporal 0.481). There was a proportional bias in nasal ARA750 (slope 2.44, 95% confidence interval [CI]: 1.95–3.18), temporal ARA750 (slope 2.57, 95% CI: 2.04–3.40), and nasal TISA500 (slope 1.30, 95% CI: 1.12–1.54). Bland-Altman plots demonstrated in all measured parameters a minimal mean difference between the two devices (−0.089 to 0.063); however, evidence of constant bias was found in nasal AOD250, nasal AOD500, nasal AOD750, nasal ARA750, temporal AOD500, temporal AOD750, temporal ARA750, and ACD. Among the parameters with constant biases, CASIA2 tends to give the larger numbers.

Conclusions

Both devices had generally good agreement. However, there were proportional and constant biases in most angle parameters. Thus, it is not recommended that values be used interchangeably.

Factors related to hypertensive phase after glaucoma drainage device implantation

Background

The aim of the study was to evaluate factors related to hypertensive phase (HP) after glaucoma drainage device (GDD) implantation.

Patients and methods

Retrospective charts review of glaucoma patients who underwent GDD implantation and completed 12 months of follow-up at King Chulalongkorn Memorial Hospital since 2004 was performed. Patients were divided into two groups according to the presence or absence of HP. The data were analyzed for factors associated with HP. The surgical outcomes including surgical failure, post-operative visual acuity (VA), post-operative number of medications, post-operative intraocular pressure (IOP), and post-operative complication were compared between the two groups.

Results

Seventy-two patients were included. Most were diagnosed with secondary glaucoma (N=51, 70.8%), and Baerveldt was the most implanted GDD (N=49, 68.1%). Mean ± SD of IOP was significantly lower: 27.1±9.6 mmHg at pre-operation and 13.7±59 mmHg at 12-month follow-up (p<0.001). HP was identified in 38/72 patients (52.8%, 95% CI 40.7-64.7). Risk factor of HP was pre-operative VA equal or better than 20/70 (p=0.021, OR 7.5; 95% CI 1.4-41.4). Presence of underlying heart disease (patients in this group had taken anti-platelets) was found as a protective factor for HP (p=0.027, OR 0.06; 95% CI 0.00-0.72). It was speculated that the anti-inflammatory effect of the anti-platelets, particularly aspirin, may be responsible for controlling inflammation and retarding fibrosis formation around drainage implants. Failure rate at 12 months was 24/72 (33%). There was no difference in all surgical outcomes between the two groups. Survival analysis also showed no significant difference between HP and non-HP group.

Conclusion

HP commonly occurred after GDD implantation. Pre-operative VA was a risk factor for the development of HP, whereas presence of underlying heart disease was a protective factor. No association between HP and surgical outcomes was identified.

Optical Coherence Tomography Angiography in Glaucoma Care

PURPOSE

To provide the reader with information on the principal techniques of optical coherence tomography angiography (OCTA); the current literature on OCTA reproducibility; its applications to glaucoma detection and monitoring of progression; and the role of OCTA in the assessment of the vascular component in glaucoma pathogenesis.

METHODS

A literature review of the pertinent publications for the OCTA in relation to the development, techniques, and its use in glaucoma was carried out.

RESULTS

Rapid improvements in optical coherence tomography (OCT) technology have allowed for enhancement of both image resolution and scanning speed, and the development of vascular assessment modality. OCTA is the non-invasive in vivo imaging of the vasculature located within the retina and optic nerve head area. The principle of OCTA is to use the variations in OCT signals caused by moving particles as the contrast mechanism for imaging of flow. Several algorithms which aim to maximize the contrast signal and minimize the noise have been developed including the phase-based techniques, intensity-based techniques (e.g., split-spectrum amplitude decorrelation angiography (SSADA)), and complex-based techniques (e.g., optical microangiography (OMAG)). With its reliable technique, high image resolution, and current availability, OCTA has been widely used in the assessment of posterior segment diseases including glaucoma in which ocular perfusion dysfunction has been proposed as a pathophysiological mechanism.

CONCLUSION

OCTA may enhance our knowledge of glaucoma pathogenesis and offer an improvement in our ability to detect glaucomatous change.

Anterior Segment Imaging for Angle Closure

PURPOSE

To summarize the role of anterior segment imaging (AS-imaging) in angle closure diagnosis and management, and the possible advantages over the current standard of gonioscopy.

DESIGN

Literature review and perspective.

METHODS

Review of the pertinent publications with interpretation and perspective in relation to the use of AS-imaging in angle closure assessment focusing on anterior segment optical coherence tomography and ultrasound biomicroscopy.

RESULTS

Several limitations have been encountered with the reference standard of gonioscopy for angle assessment. AS-imaging has been shown to have performance in angle closure detection compared to gonioscopy. Also, imaging has greater reproducibility and serves as better documentation for long-term follow-up than conventional gonioscopy. The qualitative and quantitative information obtained from AS-imaging enables better understanding of the underlying mechanisms of angle closure and provides useful parameters for risk assessment and possible prediction of the response to laser and surgical intervention. The latest technologies-including 3-dimensional imaging-have allowed for the assessment of the angle that simulates the gonioscopic view. These advantages suggest that AS-imaging has a potential to be a reference standard for the diagnosis and monitoring of angle closure disease in the future.

CONCLUSIONS

Although gonioscopy remains the primary method of angle assessment, AS-imaging has an increasing role in angle closure screening and management. The test should be integrated into clinical practice as an adjunctive tool for angle assessment. It is arguable that AS-imaging should be considered first-line screening for patients at risk for angle closure.

Consensus recommendations for trabecular meshwork cell isolation, characterization and culture

Cultured trabecular meshwork (TM) cells are a valuable model system to study the cellular mechanisms involved in the regulation of conventional outflow resistance and thus intraocular pressure; and their dysfunction resulting in ocular hypertension. In this review, we describe the standard procedures used for the isolation of TM cells from several animal species including humans, and the methods used to validate their identity. Having a set of standard practices for TM cells will increase the scientific rigor when used as a model, and enable other researchers to replicate and build upon previous findings.

Use of Nd:YAG laser to recanalize occluded Cypass Micro-Stent in the early post-operative period

Purpose

To report the first case of Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser use to recanalize a CyPass occluded with a clot in the early postoperative follow-up.

Observations

A 66 year-old woman with primary open angle glaucoma and cataract received combined cataract surgery plus CyPass in the right eye. Surgery was uneventful, however, there was a small amount of hyphema related to bleeding around the site of Cypass insertion. Intraocular pressure (IOP) was between 6 and 7 mmHg in the first week on no glaucoma medications. At the second postoperative week, IOP jumped to 30 mmHg and a clot was observed obstructing the CyPass lumen. We disrupted the clot with a single shot from a Nd:YAG laser. Twenty minutes after the laser, the IOP was 8 mmHg. CyPass was recanalized without complications. IOP was 11 mmHg at 1 month postoperatively with timolol 0.5% twice a day.

Conclusions and importance

It is important to perform gonioscopy to evaluate for CyPass obstruction in cases of IOP spike. Nd:YAG laser may be a useful approach to recanalize the CyPass in the early postoperative follow-up.

Comparison of Anterior Segment Parameters among Koreans, Chinese, and White Persons

PURPOSE

To evaluate anterior segment (AS) parameters obtained by AS OCT within an urban Korean population and to compare them with measurements seen in Chinese and white participants.

DESIGN

Prospective, cross-sectional, clinic-based study.

PARTICIPANTS

Three gender- and age-matched cohorts of Korean, Chinese, and white participants recruited from general ophthalmology clinics in urban academic hospital settings.

METHODS

Anterior segment OCT (Visante OCT; Carl Zeiss Meditec, Dublin, CA) was used to image the AS of all participants. Customized software was used to calculate AS parameters.

MAIN OUTCOME MEASURES

Five angle parameters (AOD₅₀₀, AOD₇₅₀, TISA₅₀₀, TISA₇₅₀, ARA), 5 iris parameters (IT₇₅₀, IT₂₀₀₀, ITCM, Iarea, Icurv), and 5 anterior chamber parameters (ACD, ACW, ACA, ACV, LV) were compared. Anterior vault (AV), relative AV, and relative LV were also calculated. These parameters were compared across all cohorts using a Kruskal-Wallis test. General linear models were built to assess pairwise comparison between Korean and Chinese and between Korean and white cohorts. Two-sided P values less than 0.05 were considered statistically significant. We also considered Bonferroni correction to control family-wise type 1 error (ɑ_FW = 0.05 / 18 = 0.003).

RESULTS

The study included 132, 124, and 112 participants in the Korean, Chinese, and white cohorts, respectively. Korean participants showed AS parameters similar to those of Chinese participants, with the exception of having a smaller average ACW and a larger average IT₂₀₀₀. Compared with white persons, Koreans showed smaller angle parameters (trabecular-iris space area measured at 500 μm and 750 μm from the SS and angle recess area), anterior chamber parameters (ACD, ACW, ACA, ACV), and thicker irises (iris thickness measured at 750 μm and 2000 μm from the SS, maximum IT at the middle one third of the iris). The Korean cohort also was noted to show a smaller average LV compared with both Chinese and white cohorts.

CONCLUSIONS

The Korean cohort demonstrated smaller average LV and relative LV.

Impact of Myopia on Corneal Biomechanics in Glaucoma and Nonglaucoma Patients

Purpose

We evaluated the impact of myopia on corneal biomechanical properties in primary open-angle glaucoma (POAG) and nonglaucoma patients, and the effect of modification of glaucoma on myopic eyes.

Methods

This cross-sectional study included 66 POAG eyes (33 myopia, 33 nonmyopia) and 66 normal eyes (33 myopia, 33 nonmyopia). Seven corneal biomechanical parameters were measured by ultra-high-speed Scheimpflug imaging, including corneal deformation amplitude (CDA), inward/outward corneal applanation length (ICA, OCA), inward/outward corneal velocity (ICV, OCV), radius, and peak distance (PD).

Results

Mean age (SD) of the 65 male (49%) and 67 female (51%) patients was 59 (9.82) years. Myopia was associated with significantly higher CDA (adjusted effect = 0.104, P = 0.001) and lower OCV (adjusted effect = -0.105, P < 0.001) in the POAG group. Within the nonglaucoma group, myopic eyes had a significantly lower OCV (adjusted effect = -0.086, P < 0.001) and higher CDA (adjusted effect = 0.079, P = 0.001). All parameters except PD suggested that glaucoma modified the effect of myopia on corneal biomechanics. Percentage differences in the adjusted myopic effect between POAG and nonglaucoma patients was 31.65, 27.27, 31.65, 50.00, 22.09, and 60.49 for CDA, ICA, OCA, ICV, OCV, and radius, respectively.

Conclusions

Myopia had a significant impact on corneal biomechanical properties in the POAG and nonglaucoma groups. The differences in corneal biomechanical parameters suggest that myopia is correlated with significantly lower ocular rigidity. POAG may enhance the effects of myopia on most of these parameters.

Case report: atypical presentation of Mycobacterium tuberculosis uveitis preceding nodular scleritis

Background

Intraocular tuberculosis is uncommon and has various clinical presentations. Lack of specific clinical clues can make the diagnosis challenging. The purpose of this study is to report a clinical presentation of tuberculous iridocyclitis that mimics phacolytic glaucoma and has a distinctive inflammatory deposit in the inner side of the cornea. This report is the first to describe the progression of tuberculous iridocyclitis to nodular scleritis without evidence for extraocular tuberculous infection.

Case presentation

A 78-year-old, immunocompetent woman presented with subacute intraocular inflammation with high intraocular pressure, mimicking phacolytic glaucoma. Distinct pigment keratic precipitates were noted on the first visit. Even though the cataract extraction was uneventful and adequate anti-inflammatory drugs were given, the inflammation did not subside as expected. Seven weeks later, she developed two scleral abscesses, which were subsequently explored for microbiological investigation. The smears of the pus revealed positive acid-fast bacilli stain and PCR for Mycobacterium tuberculosis complex. Eventually, the pus culture grew Mycobacterium tuberculosis. Anti-tuberculosis medications were prescribed. After 1 month of treatment, the abscesses were cured. However, her visual acuity did not improve at the last visit.

Conclusions

This case revealed an unusual presentation and untreated course of tuberculosis iridocyclitis. Pattern of keratic precipitates may indicate the presence of tuberculosis.

Original article. Repeatability assessment of the New Numbers Contrast Sensitivity Chart

Background: The validity and agreement of the New Numbers Contrast Sensitivity Chart with the original Mars chart have been found to be good. The two charts can be used interchangeably; however, evidence of the repeatability of the new chart remains to be sought. This study was to assess the repeatability of the New Numbers Contrast Sensitivity Chart.

Objectives: We assessed the repeatability of the Numbers Contrast Sensitivity Chart.

Methods: Two hundred subjects from the ophthalmic clinic of the King Chulalongkorn Memorial Hospital, who were able to communicate and read Arabic numerals were recruited. The contrast sensitivity (CS) scores were collected by reading the same Numbers Contrast Sensitivity Chart in the same environment with each eye and both eyes ten minutes apart. The repeatability of the CS score was assessed by Bland-Altman plot analysis.

Results: The visual acuity of subjects with variety in diagnoses ranged from 20/480 to 20/20. The mean differences were -0.006, -0.008, -0.002 log CS and the coefficients of repeatability were 0.155, 0.141, and 0.093 for the right eye, left eye, and both eyes, respectively. The plots showed a narrow range of 95% limit of agreement, which were (+0.146, -0.159) in the right eye, (+0.130, -0.147) in the left eye, and (+0.089, -0.093) in both eyes.

Conclusions: The New Numbers Contrast Sensitivity Chart has good repeatability. With proven good validity and repeatability, this easy and convenient numbers chart is beneficial for practical use in a clinical setting where English is not used as the primary language.