Improved accuracy of spectral-domain optical coherence tomography and optical coherence tomography angiography for monitoring myopic macular neovascularisation activity

BACKGROUND/AIMS

To evaluate the diagnostic accuracy of spectral-domain optical coherence tomography (SD OCT) combined with OCT angiography (OCTA) for myopic myopic macular neovascularisation (MNV) activity.

METHODS

Both eyes of patients with myopic MNV diagnosed with fluorescein angiography (FA), SD OCT and OCTA were assessed by unmasked investigators. The images were deidentified and randomised before graded by masked investigators, who determined the presence of active myopic MNV by using SD OCT together with OCTA without FA and by FA alone, respectively. The findings of masked investigators were compared with unmasked investigators.

RESULTS

213 eyes of 110 patients comprising 499 imaging episodes were eligible for grading. For diagnosing new-onset myopic MNV without FA, combined use of SD OCT and OCTA had a sensitivity of 0.94, specificity of 0.84 and area under the curve (AUC) of 0.92. FA had a sensitivity of 0.52 (p<0.01), specificity of 0.80 (p=0.38) and AUC of 0.66 (p<0.01). For recurrent myopic MNV, the combination of SD OCT and OCTA had a sensitivity of 0.98, specificity of 0.78 and AUC of 0.88. FA had a sensitivity of 0.50 (p=0.04), specificity of 0.76 (p=0.85) and AUC of 0.63 (p=0.01). Myopic traction maculopathy was more frequently associated with recurrent myopic MNV (p<0.01).

CONCLUSION

SD OCT with dense volumetric scan was highly sensitive for diagnosing myopic MNV. The addition of OCTA improved the diagnostic specificity without FA. Monitoring of the longitudinal changes on SD OCT and judicious use of FA is a reliable surveillance strategy for myopic MNV.

Emerging Roles of cGAS-STING Signaling in Mediating Ocular Inflammation

Cyclic GMP-AMP (cGAMP) synthase (cGAS), a sensor of cytosolic DNA, recognizes cytoplasmic nucleic acids to activate the innate immune responses via generation of the second messenger cGAMP and subsequent activation of the stimulator of interferon genes (STINGs). The cGAS-STING signaling has multiple immunologic and physiological functions in all human vital organs. It mediates protective innate immune defense against DNA-containing pathogen infection, confers intrinsic antitumor immunity via detecting tumor-derived DNA, and gives rise to autoimmune and inflammatory diseases upon aberrant activation by cytosolic leakage of self-genomic and mitochondrial DNA. Disruptions in these functions are associated with the pathophysiology of various immunologic and neurodegenerative diseases. Recent evidence indicates important roles of the cGAS-STING signaling in mediating inflammatory responses in ocular inflammatory and inflammation-associated diseases, such as keratitis, diabetic retinopathy, age-related macular degeneration, and uveitis. In this review, we summarize the recently emerging evidence of cGAS-STING signaling in mediating ocular inflammatory responses and affecting pathogenesis of these complex eye diseases. We attempt to provide insightful perspectives on future directions of investigating cGAS-STING signaling in ocular inflammation. Understanding how cGAS-STING signaling is modulated to mediate ocular inflammatory responses would allow future development of novel therapeutic strategies to treat ocular inflammation and autoimmunity.

Recent Advances in Clinical Applications of Imaging in Retinal Diseases

Many diseases that cause visual impairment, as well as systemic conditions, manifest in the posterior segment of the eye. With the advent of high-speed, high-resolution, reliable, and noninvasive imaging techniques, ophthalmologists are becoming more dependent on ocular imaging for disease diagnosis, classification, and management in clinical practice. There are rapid advances on the indications of multimodal retinal imaging techniques, including the application of ultra-widefield fundus angiography, fundus autofluorescence, optical coherence tomography, as well as optical coherence tomography angiography. This review summarizes and highlights the clinical applications, latest indications, and interpretations of multimodal imaging in age-related macular degeneration, polypoidal choroidal vasculopathy, diabetic macular edema, central serous chorioretinopathy, diabetic retinopathy, retinal vein occlusion, and uveitis.

Optimizing treatment for diabetic macular edema during cataract surgery

Diabetic macular edema (DME) causes visual impairment in diabetic retinopathy (DR). Diabetes mellitus is a global epidemic and diabetic individuals are at risk of developing DR. Approximately 1 in 10 diabetic patients suffers from DME, which is the commonest cause of vision-threatening DR at primary-care screening. Furthermore, diabetes predisposes to a higher frequency and a younger onset of cataract, which further threatens vision in DME patients. Although cataract extraction is an effective cure, vision may still deteriorate following cataract surgery due to DME progression or recurrence, of which the risks are significantly higher than for patients without concurrent or previous history of DME at the time of operation. The management of pre-existing DME with visually significant cataract is a clinical conundrum. Deferring cataract surgery until DME is adequately treated is not ideal because of prolonged visual impairment and maturation of cataract jeopardizing surgical safety and monitoring of DR. On the other hand, the progression or recurrence of DME following prompt cataract surgery is a profound disappointment for patients and ophthalmic surgeons who had high expectations for postoperative visual improvement. Prescription of perioperative anti-inflammatory eye drops is effective in lowering the risk of new-onset DME after cataract surgery. However, management of concurrent DME at the time of cataract surgery is much more challenging because DME is unlikely to resolve spontaneously even with the aid of anti-inflammatory non-steroidal or steroid eye drops. A number of clinical trials using intravitreal injection of corticosteroids and anti-vascular endothelial growth factor (anti-VEGF) as first-line therapy have demonstrated safety and efficacy to treat DME. These drugs have also been administered perioperatively for the prevention of DME worsening in patients undergoing cataract surgery. This article reviews the scientific evidence to guide ophthalmologists on the efficacy and safety of various therapies for managing patients with DME who are particularly vulnerable to cataract surgery-induced inflammation, which disintegrates the blood-retinal barrier and egression of fluid in macular edema.

Epigallocatechin-3-Gallate Protects Trabecular Meshwork Cells from Endoplasmic Reticulum Stress

Primary open-angle glaucoma (POAG) is the most common form of glaucoma, for which elevated intraocular pressure (IOP) is a major risk factor. IOP is mainly regulated by dynamic balance of aqueous humor (AH) production and outflow via the conventional trabecular meshwork/Schlemm's canal (TM/SC) pathway. Dysfunctions of TM cells due to endoplasmic reticulum (ER) stress have been demonstrated to increase the resistance of AH outflow, resulting in IOP elevation. Epigallocatechin-3-gallate (EGCG), the most abundant polyphenolic component in green tea, has been shown to alleviate ER stress in several diseases while its potential roles in alleviating ER stress in TM cells have not been determined. In this study, we investigate the mitigation of tunicamycin-induced ER stress in TM cells by EGCG. MTT assay was used to measure the cell viability of human TM (HTM) cells and primary porcine TM (PTM) cells. ER stress levels in both HTM cells and primary PTM cells were detected by quantitative real-time PCR. The primary PTM cells isolated from porcine TM tissues were characterized by immunostaining. We found that 40 μM and 80 μM EGCG pretreatment substantially promoted HTM cell survival under 3 μM tunicamycin-induced ER stress. Pretreatment of 40 μM EGCG markedly reduced the expression of ER stress markers ATF4, HSPA5, and DDIT3, evoked by 3 μM tunicamycin in HTM cells. Furthermore, 40 μM EGCG pretreatment significantly decreased the expressions of ATF4, HSPA5, and DDIT3 at the mRNA level induced by 3 μM tunicamycin and improved cell viability in primary PTM cells. Our results show that EGCG is capable of protecting TM cells from ER stress. EGCG provides a promising therapeutic option for POAG treatment.

Post-translational modifications on the retinoblastoma protein

The retinoblastoma protein (pRb) functions as a cell cycle regulator controlling G1 to S phase transition and plays critical roles in tumour suppression. It is frequently inactivated in various tumours. The functions of pRb are tightly regulated, where post-translational modifications (PTMs) play crucial roles, including phosphorylation, ubiquitination, SUMOylation, acetylation and methylation. Most PTMs on pRb are reversible and can be detected in non-cancerous cells, playing an important role in cell cycle regulation, cell survival and differentiation. Conversely, altered PTMs on pRb can give rise to anomalies in cell proliferation and tumourigenesis. In this review, we first summarize recent findings pertinent to how individual PTMs impinge on pRb functions. As many of these PTMs on pRb were published as individual articles, we also provide insights on the coordination, either collaborations and/or competitions, of the same or different types of PTMs on pRb. Having a better understanding of how pRb is post-translationally modulated should pave the way for developing novel and specific therapeutic strategies to treat various human diseases.

Optical Coherence Tomography Angiography Compared with Multimodal Imaging for Diagnosing Neovascular Central Serous Chorioretinopathy

PURPOSE

To assess the diagnostic accuracy of optical coherence tomography angiography (OCTA) compared with multimodal imaging for choroidal neovascularization (CNV) in central serous chorioretinopathy (CSC) eyes and to determine the features that predicted CNV.

DESIGN

Prospective cross-sectional study.

METHODS

Consecutive CSC patients were recruited from retina clinic. The reference standard for CNV was determined by interpretation of multimodal imaging with OCTA, structural OCT line scan, fluorescein angiography (FA), indocyanine green angiography (ICGA), ultra-widefield fundus photography and fundus autofluorescence (FAF). Two independent masked graders examined OCTA without FA and ICGA to diagnose CNV. Univariate and multivariate analyses were performed to evaluate factors associated with CNV.

RESULTS

CNV was detected in 69 eyes in 64 out of 277 CSC patients according to reference standard. The two masked graders who examined OCTA had sensitivity of 81.2% (95% Confidence Interval [CI], 71.9%-90.4%) and 78.3% (95% CI, 68.5%-88.0%), specificity of 97.3% (95% CI, 95.9%-98.8%) and 96.2% (95% CI, 94.5%-98.0%), positive predictive values of 82.4% (95% CI, 73.3%-91.4%) and 76.1% (95% CI, 66.1%-86.0%), and negative predictive values of 97.1% (95% CI, 95.6%-98.7%) and 96.7% (95% CI, 95.0%-98.3%). Their mean area under the receiver operating characteristic curve (AUC) was 0.88 with good agreement (Kappa coefficient 0.80 [95% CI, 0.72-0.89]). Flat irregular pigment epithelial detachment on structural OCT, neovascular network on OCTA and ill-defined late leakage on FA significantly correlated with CNV in CSC from multiple regression (P < 0.001, P < 0.001 and P = 0.005, respectively).

CONCLUSIONS

There is discordance between OCTA and multimodal imaging in diagnosing CNV in CSC. This study demonstrated the caveats in OCTA interpretation, such as small extrafoveal lesions and retinal pigment epithelial alterations. Comprehensive interpretation of OCTA with dye angiography and structural OCT is recommended.

Visualising the choriocapillaris: Histology, imaging modalities and clinical research - A review

The choriocapillaris plays a considerable role in the normal physiology of the eye as well as in various diseases. Assessing the changes in the choriocapillaris can therefore provide important information about normal ageing and pathogenesis of visual impairment, and even some systemic diseases. In vivo imaging of the choriocapillaris has evolved from non-depth resolved, dye-based angiography to advanced, high-resolution optical coherence tomography angiography (OCTA). However, the intricate microvascular networks within the choriocapillaris are still beyond the resolving limits of most OCTA instruments. Knowledge of histology, meticulous image acquisition methods, recognition of artefact and post-acquisition processing techniques are necessary for optimising OCTA choriocapillaris images. Qualitative and quantitative analyses of the choriocapillaris provide clinical information in age-related macular degeneration (AMD), diabetic retinopathy (DR), pathologic myopia and central serous chorioretinopathy (CSC). Furthermore, studies have revealed choriocapillaris changes in posterior uveitis that are correlated with treatment outcome and have important prognostic significance. In addition to retinal diseases, choriocapillaris changes have been observed in systemic vascular diseases and complications associated with pregnancy.

Genetic associations of central serous chorioretinopathy: a systematic review and meta-analysis

AIMS

To identify single-nucleotide polymorphisms (SNPs) associated with central serous chorioretinopathy (CSCR) by a systematic review and meta-analysis, and to compare the association profiles between CSCR, neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV).

METHODS

We searched the EMBASE, PubMed and Web of Science for genetic studies of CSCR from the starting dates of the databases to 12 September 2020. We then performed meta-analyses on all SNPs reported by more than two studies and calculated the pooled OR and 95% CIs. We also conducted sensitivity analysis and adopted the funnel plot to assess potential publication bias.

RESULTS

Totally 415 publications were reviewed, among them 10 were eligible for meta-analysis. We found 10 SNPs that have been reported at least twice. Meta-analysis and sensitivity analysis confirmed significant associations between CSCR and six SNPs in three genes, namely age-related maculopathy susceptibility 2 (ARMS2) (rs10490924, OR=1.37; p=0.00064), complement factor H (CFH) (rs800292, OR=1.44; p=7.80×10^-5; rs1061170, OR=1.34; p=0.0028; rs1329428, OR=1.40; p=0.012; and rs2284664, OR=1.36; p=0.0089) and tumour necrosis factor receptor superfamily, member 10a (TNFRSF10A) (rs13278062, OR=1.34; p=1.44×10^-15). Among them, only TNFRSF10A rs13278062 showed the same trend of effect on CSCR, nAMD and PCV, while the SNPs in ARMS2 and CFH showed opposite trends in the SNP associations.

CONCLUSIONS

This study confirmed the associations of ARMS2, CFH and TNFRSF10A with CSCR, and revealed that ARMS2, CFH and TNFRSF10A may affect different phenotypic expressions of CSCR, nAMD and PCV.

Comorbidity of dementia and age-related macular degeneration calls for clinical awareness: a meta-analysis

AIM

To determine the association between dementia and age-related macular degeneration (AMD) using meta-analysis.

METHODS

We searched in the MEDLINE, EMBASE, Web of Knowledge, PsycInfo and Cochrane database of systematic reviews for studies published from March 1959 to March 2018. We included cross-sectional, case-control and cohort studies that evaluated the association of dementia/Alzheimer's disease (AD) with AMD (as outcome) and the association of AMD with dementia/AD (as outcome). Studies that compared cognitive functions between AMD and controls were also included. The summary outcomes, namely odds ratio (OR), relative risk, mean differences and corresponding 95% CIs, were estimated using random effects models. We performed sensitivity analysis based on study quality and individual study effect to control for potential biases.

RESULTS

Among 2159 citation records, we identified 21 studies consisting of 7 876 499 study subjects for meta-analysis. Patients with dementia (p_adjusted≤0.017, OR≥1.24, I²≤9%) or AD (p=0.001, OR_unadjusted=2.22, I²=50%) were at risk for AMD, particularly for late AMD (p_adjusted<0.001, OR=1.37, I²=0). AMD was also significantly associated with increased risk of AD/cognitive impairment (p_adjusted=0.037, OR=2.42, I²=38%). Moreover, patients with AMD had poorer cognitive functions when compared with controls, including Mini-Mental State Examination (p<0.001, I²≤79%) and Trail Making Test A (p<0.001, I²=0). Sensitivity analysis and Egger's test indicated our results were less likely biased.

CONCLUSIONS

A significant association between dementia/AD and AMD calls for greater clinical awareness. The cost-effectiveness of routine screening for the other condition in patients with primary diagnosis of dementia/AD or AMD requires further study.

Impact of virtual reality simulation on learning barriers of phacoemulsification perceived by residents

Objective

To identify residents’ perceived barriers to learning phacoemulsification surgical procedures and to evaluate whether virtual reality simulation training changed these perceptions.

Design

The ophthalmology residents undertook a simulation phacoemulsification course and proficiency assessment on the Eyesi system using the previously validated training modules of intracapsular navigation, anti-tremor, capsulorrhexis, and cracking/chopping. A cross-sectional, multicenter survey on the perceived difficulties in performing phacoemulsification tasks on patients, based on the validated International Council of Ophthalmology’s Ophthalmology Surgical Competency Assessment Rubric (ICO-OSCAR), using a 5-point Likert scale (1 = least and 5 = most difficulty), was conducted among residents with or without prior simulation training. Mann–Whitney U tests were carried out to compare the mean scores, and multivariate regression analyses were performed to evaluate the association of lower scores with the following potential predictors: 1) higher level trainee, 2) can complete phacoemulsification most of the time (>90%) without supervisor’s intervention, and 3) prior simulation training.

Setting

The study was conducted in ophthalmology residency training programs in five regional hospitals in Hong Kong.

Results

Of the 22 residents, 19 responded (86.3%), of which 13 (68.4%) had completed simulation training. Nucleus cracking/chopping was ranked highest in difficulty by all respondents followed by capsulorrhexis completion and nucleus rotation/manipulation. Respondents with prior simulation training had significantly lower difficulty scores on these three tasks (nucleus cracking/chopping 3.85 vs 4.75, P = 0.03; capsulorrhexis completion 3.31 vs 4.40, P = 0.02; and nucleus rotation/manipulation 3.00 vs 4.75, P = 0.01). In multivariate analyses, simulation training was significantly associated with lower difficulty scores on these three tasks.

Conclusion

Residents who had completed Eyesi simulation training had higher confidence in performing the most difficult tasks perceived during phacoemulsification.

Association of antenatal steroid and risk of retinopathy of prematurity: a systematic review and meta-analysis

Background

Retinopathy of prematurity (ROP) is one of the leading causes of childhood blindness. Use of antenatal steroid can reduce neonatal morbidity and mortality in preterm births, but its effect on ROP remained controversial. We aim to determine the association between antenatal steroid and risk of ROP by a systematic review and meta-analysis.

Methods

Reported studies on the association between antenatal steroid and risk of ROP or severe ROP were identified from MEDLINE and Embase databases from their inception to November 2016. Outcome measures were ORs with 95% CIs. Extracted data were pooled using a random-effect model or fixed-effect model where appropriate. Heterogeneity was assessed, and sensitivity analysis was performed.

Results

A total of 434 relevant studies were identified, and 28 studies were eligible for the meta-analysis, involving 20 731 neonates with 4202 cases of ROP. Among the 28 studies included, 13 studies provided data evaluating the association between antenatal steroid use and severe ROP, involving 4999 neonates with 792 cases of severe ROP. Antenatal steroid administration was associated with a reduced risk of ROP development (ORunadjusted=0.82, 95% CI 0.68 to 0.98; ORadjusted=0.67, 95% CI 0.47 to 0.94) and progression to severe ROP (ORunadjusted=0.58, 95% CI 0.40 to 0.86).

Conclusion

Antenatal steroid administration is associated with a reduced risk of ROP development and progression to severe ROP. Our results strengthened the indications of antenatal steroid therapy to high-risk mothers giving preterm births, especially in low-income and middle-income countries where antenatal steroid are not yet widely used.

Classification of Exudative Age-Related Macular Degeneration With Pachyvessels on En Face Swept-Source Optical Coherence Tomography

Purpose

The purpose of this study was to classify exudative maculopathy by the presence of pachyvessels on en face swept-source optical coherence tomography (SSOCT).

Methods

Consecutive patients with signs of exudative maculopathy underwent SSOCT, fluorescein and indocyanine green angiography (ICGA), ultra-widefield fundus color photography, and autofluorescence examinations. Images were analyzed in a masked fashion by two sets of four examiners in different sessions: (1) the presence of pachyvessels in en face OCT and (2) features of exudative maculopathy in conventional imaging modalities. Quantitative data obtained were subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI), which was the ratio of choroidal vessels lumen area to a specified choroidal area from binarized cross-sectional OCT scans.

Results

Pachyvessels was observed in 38 (52.1%) of 73 eyes. The pachyvessels group was associated with younger age (69.1 ± 9.4 years, odds ratio [OR] = 0.95, 95% confidence interval [95% CI] = 0.90-0.97, P = 0.04), presence of polypoidal lesions (OR = 3.27, 95% CI = 1.24-8.62, P = 0.01), increased SFCT (OR = 1.08, 95% CI = 1.02-1.14, P < 0.01), and increased CVI (65.4 ± 5.3, OR = 1.12, 95% CI = 1.02-1.23, P = 0.01). In multivariate regression, CVI significantly correlated with pachyvessels (OR = 1.24, 95% CI = 1.03-1.55, P = 0.04).

Conclusions

Exudative maculopathy could be classified based on differences in choroidal vasculature morphology. Current results implied that choroidal hemodynamics may be relevant to variable natural history and treatment response in neovascular AMD and polypoidal choroidal vasculopathy.

Atrophy of retinal inner layers is associated with poor vision after endophthalmitis: a spectral domain optical coherence tomography study

PurposeTo investigate the retinal structural changes in endophthalmitis and their association with visual outcome.Patients and methodsForty-five eyes of 45 patients diagnosed with endophthalmitis were included. Spectral domain optical coherence tomography (SD-OCT) was performed after inflammation was controlled. The relationship between SD-OCT features and best-corrected visual acuity (BCVA) at the last follow-up was analyzed.ResultsThe structural changes included inner segment ellipsoid (ISe) disruption (49%), atrophy of retinal inner layers (24%), epimacular membrane (24%), and macular edema (24%). BCVA was worse in patients with ISe disruption (P=0.005) and retinal inner layers' atrophy (P=0.004) compared with those without. There was no significant difference of BCVA between the patients with and without epimacular membrane, or intraretinal cysts. Multivariate regression showed that atrophy of retinal inner layers (b=0.41±0.17, P=0.022) was the only independent factor associated with BCVA.ConclusionAtrophy of retinal inner layers is associated with visual impairment in endophthalmitis, despite successful management.

Reduced Macular Vascular Density in Myopic Eyes

BACKGROUND

Morphological changes of the vasculature system in patients with myopia have been observed by Doppler ultrasound and fundus fluorescein angiography (FFA); however, these studies have limitations. Doppler ultrasound provides low-resolution images which are mainly obtained from visualized large vessels, and FFA is an invasive examination. Optic coherence tomography (OCT) angiography is a noninvasive, high-resolution measurement for vascular density. The purpose of this study was to investigate the change of vascular density in myopic eyes using OCT angiography.

METHODS

This cross-sectional study includes a total of 91 eyes from 47 participants including control, moderate, and high myopia that were evaluated by OCT angiography. Patients with myopia were recruited from the Refractive Department, Shenzhen Aier Eye Hospital, from August 5, 2015 to April 1, 2016. Emmetropic eyes were from healthy volunteers. The vascular density at macula and optic disc regions, ganglion cell complex (GCC) thickness, and retinal nerve fiber layer (RNFL) thickness were measured. Their relationships with axial length (AL) and refractive error were analyzed. One-way analysis of variance (ANOVA), Pearson's correlation, and generalized estimating equation were used for statistical analysis.

RESULTS

Both superficial and deep macular vascular density were highest in control (25.64% ± 3.76% and 37.12% ± 3.66%, respectively), then in moderate myopia (21.15% ± 5.33% and 35.35% ± 5.50%, respectively), and lowest in high myopia group (19.64% ± 3.87% and 32.81% ± 6.29%, respectively) (F = 13.74 and 4.57, respectively; both P < 0.001). Both superficial (β = -0.850 and 0.460, respectively) and deep (β = -0.766 and 0.396, respectively) macular vascular density were associated with AL and spherical equivalent (all P < 0.001). Superficial macular vascular density was associated with GCC thickness (β = 0.244, P = 0.040), independent of spherical equivalent. The vascular density in optic disc region had no difference among the three groups, and it was not associated with AL, spherical equivalent, or RNFL thickness.

CONCLUSION

Our results suggested that with the increase of myopia, the vascular density decreased in macular region, but not in optic disc region.

Risk factors for endophthalmitis requiring evisceration or enucleation

Endophthalmitis has devastating sequelae resulting in blindness and even loss of eyeball. Although the prognosis of endophthalmitis has much improved with the advances of antibiotics and vitreoretinal surgery, of the number of patients that required evisceration or enucleation is still significant. We retrospectively reviewed the charts of 210 eyes of 210 patients with endophthalmitis andcompared the group that required evisceration or enucleation with those that received salvaging therapies. Regression analysis was used to identify the risk factors for evisceration or enucleation. Thirty eyes (14.3%) underwent enucleation or evisceration. The group of eviscerated or enucleated eyes were older (58.7 vs. 42.2 years, p < 0.001), had more women (56.7% vs. 22.2%, p = 0.003), had poorer initial visual acuity (2.79 vs. 2.10 LogMAR, p < 0.001), and had longer duration before intervention (18.03 vs. 5.74 days, p = 0.031). The most common primary indications for endophthalmitis were infections from corneal ulcer (50.0% vs. 4.4%, p < 0.001) andfrom endogenous source (23.3% vs. 5.6%, p < 0.001). Less common indications were trauma (26.7% vs. 67.8%, p < 0.001) and postoperative (6.7% vs. 22.2%, p = 0.049) endophthalmitis. After adjusting for confounding factors, corneal ulcer-related endophthalmitis, endogenous endophthalmitis and initial visual acuity were the independent risk factors for evisceration or enucleation.

Advances of optical coherence tomography in myopia and pathologic myopia

The natural course of high-axial myopia is variable and the development of pathologic myopia is not fully understood. Advancements in optical coherence tomography (OCT) technology have revealed peculiar intraocular structures in highly myopic eyes and unprecedented pathologies that cause visual impairment. New OCT findings include posterior precortical vitreous pocket and precursor stages of posterior vitreous detachment; peripapillary intrachoroidal cavitation; morphological patterns of scleral inner curvature and dome-shaped macula. Swept source OCT is capable of imaging deeper layers in the posterior pole for investigation of optic nerve pits, stretched and thinned lamina cribrosa, elongated dural attachment at posterior scleral canal, and enlargement of retrobulbar subarachnoid spaces. This has therefore enabled further evaluation of various visual field defects in high myopia and the pathogenesis of glaucomatous optic neuropathy. OCT has many potential clinical uses in managing visual impairing conditions in pathologic myopia. Understanding how retinal nerve fibers are redistributed in axial elongation will allow the development of auto-segmentation software for diagnosis and monitoring progression of glaucoma. OCT is indispensable in the diagnosis of various conditions associated with myopic traction maculopathy and monitoring of post-surgical outcomes. In addition, OCT is commonly used in the multimodal imaging assessment of myopic choroidal neovascularization. Biometry and topography of the retinal layers and choroid will soon be validated for the classification of myopic maculopathy for utilization in epidemiological studies as well as clinical trials.

Bevacizumab for neovascular age-related macular degeneration in Chinese patients in a clinical setting

AIM

To determine the outcome of non-investigational treatment with intravitreal bevacizumab (IVB) in neovascular age-related macular degeneration (AMD) patients.

METHODS

Retrospective chart review of 81 eyes with neovascular AMD followed-up for at least 12mo and received 3-monthly loading IVB injections. Re-treat was based upon the individual clinician's judgment. Best-corrected visual acuity (BCVA) and optical coherence tomography measurements of central foveal thickness outcomes were evaluated at 12, 24mo.

RESULTS

Eighty-one eyes (of 75 patients) completed 12mo of follow-up and 44 eyes (of 41 patients) completed 24mo of follow-up. The mean baseline logMAR BCVA significantly improved from 0.94±0.69 to 0.85±0.68 at 12mo (P<0.001) and from 0.91±0.65 to 0.85±0.60 (P=0.004) at 24mo. The proportion of eyes that lost <15 logMAR letters at 12mo was 90.1% and at 24mo was 81.8%. IVB was effective in improving visual acuity in both treatment naïve and previous photodynamic therapy (PDT)-treated subgroups. Treatment naive patients required significantly fewer injections than patients with prior PDT. Multiple regression analysis identified that poorer baseline visual acuity was associated with greater improvement in visual acuity (P=0.015).

CONCLUSION

Fewer injections in clinical practice may result in suboptimal visual outcomes compared with clinical trials of IVB in neovascular AMD patients. Poor baseline visual acuity and prior PDT treatment may also improve vision after IVB. The safety and durability of effect was maintained at 24mo.

Endoscopic-assisted retrieval of retained lacrimal stent material in congenital nasolacrimal duct obstruction without dacryocystorhinostomy

We report a 3-year-old child with history of congenital nasolacrimal duct obstruction who failed lacrimal probing and underwent bicanalicular intubation. Removal of stent from the superior punctum was unsuccessful and it was trapped in the lacrimal sac. We performed endonasal endoscopic-assisted retrieval of retained stent material without necessitating dacryocystorhinostomy (DCR). There was no recurrence of infection and nasolacrimal duct obstruction symptoms during 6 months of follow-up.

Techniques to minimize skin incision scar for external dacryocystorhinostomy

Although there has been a narrowing in the gap in successful functional outcomes between external and endonasal DCR, external DCR is still being frequently performed when cost, availability of additional surgical instruments and visual systems, surgeon's experience and preference are concerned. Nonetheless, skin incisions at the lateral nasal sidewall of the lower eyelid inevitably leave cutaneous scars. The purpose of this review is to evaluate the outcomes of current modified surgical practices that prevent a conspicuous scar in external DCR.

Safe excision of a large overhanging cystic bleb following autologous blood injection and compression suture

Here, we report a large, overhanging cystic bleb that compromised vision and induced a foreign body sensation in a patient who underwent a trabeculectomy surgery with anti-metabolite therapy 4 years prior. Ultrasound biomicroscopy revealed multiple loculations with thin septa inside the bleb and a high risk of damage to the bleb was anticipated with a straight forward surgical excision. We injected autologous blood and placed a compression suture 6 weeks prior to surgical excision of the overhanging portion of the bleb. The operation was successful in preserving excellent bleb function, restoring visual acuity, and alleviating symptoms in our patient with up to 9 months of follow-up.

Clinicopathological survey of 23 patients with lacrimal fossa lesions in Hong Kong

AIM

To survey the clinicopathological correlations of lacrimal fossa lesions in the Hong Kong population.

METHODS

A total of 23 patients with lacrimal fossa lesions were identified radiologically. The mean age at the time of diagnosis was 52 year-old. The medical records of patients diagnosed with lacrimal fossa lesions and subsequently underwent radiological investigations were collected and reviewed retrospectively throughout a six years period from 2000 to 2006 from three regional hospitals (Tung Wah Eastern Hospital, Pamela Youde Nethersole Eastern Hospital and Queen Mary Hospital) belonging to the Hong Kong Mega Cluster. Patient demographics, presenting signs and symptoms, imaging modalities, pathological reports and subsequent management were recorded.

RESULTS

The most common initial presenting symptom was upper lid swelling (83%) followed by proptosis (13%). 19 patients (83%) had benign lacrimal fossa lesion and 4 patients (17%) had malignancy. Three of the malignancies were lymphomas and one was adenoid cystic carcinoma.

CONCLUSION

Age is an important factor in considering the differential diagnosis of lacrimal fossa lesion. Lymphoproliferative diseases have the highest incidence in patients over 60 years of age while inflammatory lesions are more common in younger patients in Hong Kong.