COMPARING FUNCTIONAL AND VASCULAR LAYER OUTCOMES OF LASER PHOTOCOAGULATION VERSUS SUBTHRESHOLD MICROPULSE LASER FOR DIABETIC MACULAR EDEMA: An OCT-Angiography Study.

PURPOSE: To compare the efficacy of conventional laser and subthreshold micropulse laser (SML) in treating diabetic macular edema in terms of functional outcomes and changes in quantitative metrics for the retinal capillary and choriocapillary vascular layers. METHODS: Fifty-two eyes from 52 patients with treatment-naive, clinically significant macular edema were randomly assigned to the conventional laser group or SML group in a 1:1 ratio. Best-corrected visual acuity, central macular thickness (CMT), and optical coherence tomography angiography scans were measured at baseline, 1, 3, and 6 months after treatment. RESULTS: The SML group showed rapid visual recovery, improving from baseline of 0.320 ± 0.31 logarithm of the minimum angle of resolution (20/42 Snellen) to 0.270 ± 0.22 logarithm of the minimum angle of resolution (20/37 Snellen) at 1 month ( P = 0.038) and had significant improvements in CMT at 6-month post-treatment (353.88-301.00 µ m, P = 0.005). Statistically significant changes were detected across all optical coherence tomography angiography metrics, including vessel density, vessel length density, vessel diameter index, and fractal dimension, at 6 months for both groups in the deep capillary plexus and choriocapillary plexus. CONCLUSION: Subthreshold micropulse laser resulted in early visual recovery and sustained macular thickness improvement in the treatment of diabetic macular edema. Microvascular perfusion parameters, including vessel density, vessel length density, and fractal dimension, improved in the deep capillary plexus and choriocapillary plexus for both treatment groups at 6 months post-treatment.

COVID-19 reduced scleral buckling training in fellows and shifted young ophthalmologists' preference toward vitrectomy: An Asia-Pacific survey.

BACKGROUND: To assess rhegmatogenous retinal detachment (RRD) surgery trends and training among young ophthalmologists (YOs, vitreoretinal fellows or attendings/consultants with ≤10 years of independent practice) and the impact of the COVID-19 pandemic. METHODS: An anonymous online survey was completed by 117 YOs in the Asia-Pacific regarding their RRD surgery experiences in 2021-2022. RESULTS: To achieve a 90% probability of surgical competency, 91 vitrectomy and 34 scleral buckling (SB) completions during fellowship were needed. In total, 49 (41.9%) YOs had fellowship affected by COVID-19. In the COVID versus pre-COVID era, however, the volume of SB completions per fellowship year decreased significantly (median [IQR] 3.3 [1.5, 9] vs. 13 [6.5, 23]; p < 0.001) and was lower than the required volume to achieve competency. YOs were less confident in conducting SB versus vitrectomy (3.5 ± 1.1 vs. 4.2 ± 0.8, p < 0.001), and they reported a decrease in the proportion of SB (-3.1%, p = 0.047) and an increase in the proportion of vitrectomy (+4.8%, p < 0.001) after the pandemic outbreak. Apart from RRD clinical characteristics, surgical confidence is among the main factors that affect surgical method decisions. During the pandemic, more YOs may have avoided SB due to the need for general anaesthesia, leading to longer surgical time and risk of viral transmission during intubation/extubation. CONCLUSIONS: SB surgical exposure is suboptimal in most fellowship programs in the 11 Asia-Pacific countries/regions we surveyed and further declined during the COVID-19 pandemic. YOs are less confident in performing SB, leading to a trend toward primary vitrectomy since the COVID-19 outbreak.

The clinical presentation and treatment outcomes of ocular tuberculosis: a 5-year experience in an endemic area.

PURPOSE: To report the clinical presentations of ocular tuberculosis infection (OTB) and the treatment regimen and outcome in an endemic area. METHODS: This is a retrospective case series of patients with presumed OTB treated in a tertiary teaching hospital in Hong Kong in 2014-2019. RESULTS: Among the nineteen patients recruited, the most common clinical presentation of OTB was retinal vasculitis (42.1%), followed by scleritis, intermediate uveitis, and choroidal tuberculoma (15.8% respectively). 94.7% and 94.4% of the subjects were treated with ATT and steroid, respectively, and 31.6% were put on systemic immunosuppressant prior to the initiation of ATT. Apart from those suffering from intermediate uveitis, most demonstrated good clinical response within 8 weeks of ATT initiation. CONCLUSION: Ocular involvement of TB has been increasingly recognized, especially in endemic regions like Hong Kong. High index of suspicion is recommended for OTB in typical clinical phenotypes or recurrent/resistant ocular inflammation unresponsive to conventional therapy. TB retinal vasculitis was the most common presentation of OTB in this study and OTB generally requires treatment with either regional or systemic steroid together with ATT.

ONE-YEAR RESULTS OF HALF- VERSUS STANDARD-DOSE PHOTODYNAMIC THERAPY COMBINED WITH RANIBIZUMAB FOR POLYPOIDAL CHOROIDAL VASCULOPATHY.

PURPOSE: To explore the efficacy of half-dose verteporfin photodynamic therapy (hd-PDT) and standard-dose photodynamic therapy (sd-PDT), when combined with ranibizumab in the treatment of polypoidal choroidal vasculopathy. METHODS: Subjects were allocated to either the hd-PDT arm or the sd-PDT arm. All subjects received an injection of ranibizumab and PDT treatment (dosage according to allocation) at baseline. Subjects were followed up monthly for 12 months, and re-treatment were given at each visit if criteria were met. RESULTS: There were 26 subjects in the hd-PDT arm and 32 in the sd-PDT arm. Overall mean age was 69.3 ± 9.4 years. Baseline demographics and ocular features did not differ significantly between the two arms. Improvement in vision and reduction in central retinal thickness were similar between the two arms. When presenting, visual acuity was better than 20/50 (logarithm of the minimum angle of resolution 0.4), or when there were three or less polyps angiogram, those treated with hd-PDT tended to perform better than those treated with sd-PDT. CONCLUSION: In general, hd-PDT was able to produce similar results as sd-PDT. Subgroup analysis revealed superior results with hd-PDT when baseline vision was 20/50 or better, or when there were three or less polyps on indocyanine green angiography.

Repeated intraocular crystallization of ganciclovir in one eye after bilateral intravitreal injections: a case report.

BACKGROUND: Cytomegalovirus (CMV) retinitis is an opportunistic infection that primarily affects immunocompromised individuals. Intravitreal ganciclovir injection monotherapy or in combination with systemic anti-CMV therapy are effective treatments for CMV retinitis. Crystallization of ganciclovir after intravitreal injection is extremely rare. Only two cases had been reported in literature. Crystallization in only one eye after bilateral injections had not been reported before. We hereby report a case of intraocular ganciclovir crystallization in one eye after bilateral intravitreal injections, and repeated crystallization in the same eye after repeated injections. CASE PRESENTATION: A 79-year-old patient had bilateral cytomegalovirus retinitis and received bilateral intravitreal ganciclovir injections of 2.5 mg in 0.05 ml sterile water. Fundus examination after injection showed formation of needle-shaped, golden-yellow crystals in the vitreous of right eye but not in left eye. The crystals dissolved spontaneously. Repeated bilateral intravitreal ganciclovir injections 4 days later resulted in repeated crystallization of ganciclovir in right eye but not in left eye. The crystals dissolved spontaneously and completely after 5 minutes. Visual acuity remained unchanged and intraocular pressure was normal. CONCLUSIONS: Intraocular ganciclovir crystallization could occur after intravitreal injections. It is important to perform fundus examination after injection. The crystals may dissolve rapidly and vitrectomy may not be necessary. Our case suggested intraocular ganciclovir crystallization is an idiosyncratic phenomenon, subjects to distinctive intraocular environment which could be different between two eyes of the same patient. The susceptible intraocular environment could be persistent leading to repeated crystallization.

Serial Spectral-Domain Optical Coherence Tomography Findings in Acute Retinal Pigment Epitheliitis and the Correlation to Visual Acuity.

PURPOSE: To evaluate the features of acute retinal pigment epitheliitis (ARPE) at onset and in the course of recovery by serial spectral-domain optical coherence tomography (SD OCT) and the correlation to visual acuity (VA). DESIGN: Retrospective cohort study. PARTICIPANTS: Consecutive patients with ARPE. METHODS: A review of medical records was performed. MAIN OUTCOME MEASURES: Integrity of SD OCT retinal bands at onset and in the course of disease, time required to achieve each retinal band restoration, corresponding VA change, and final VA. RESULTS: Four patients were included. Initial SD OCT showed a dome-shaped hyper-reflective lesion at the photoreceptor outer segment layer disrupting the ellipsoid zone (EZ) and interdigitation zone (IZ) (100%). In the early phase, there was also upward displacement of the external limiting membrane (ELM) and mild transient thickening of the retinal pigment epithelium (RPE)/Bruch's complex (Bc). Acute retinal pigment epitheliitis resolved in a sequence of (1) a decrease in height of SD OCT hyper-reflective lesion and the upwardly displaced ELM returning to its normal position with irregularity; (2) complete disappearance of the hyper-reflective lesion; (3) restoration of ELM; (4) restoration of EZ; and (5) restoration of IZ. The average time to restore ELM, EZ, and IZ was 4.3±5.2, 7.3±7.2, and 12.5±12.4 weeks, respectively, and the corresponding logarithm of the minimum angles of resolution (logMAR) VAs were 0.24±0.23, 0.09±0.07, and 0.05±0.06, respectively. Visual acuity improved when IZ was restored. CONCLUSIONS: Early SD OCT revealed an inflammatory lesion in the photoreceptor outer segment layer displacing ELM. The RPE was involved only mildly and transiently. Recovery occurred in a sequence of ELM, EZ, and IZ restoration, and VA improved when the IZ was restored. These features suggested that the IZ (i.e., the contact between photoreceptors and RPE) is the primary site of inflammation in ARPE.

A simple modification to the 25-gauge trocar and cannula system for retinopathy of prematurity related lens-sparing vitrectomy.

BACKGROUND: Recently, 25-gauge vitrectomy has become more popular. However, most still perform the surgery in pediatric patients without the use of the trocars and cannulas as in adult vitrectomies. METHODS: We described a simple modification using adult 25-gauge cannulas and 270-silicone watzke sleeves, enabling these instruments to be used in pediatric cases. The sleeve is cut into segments of 2 mm in length, and then introduced up the shaft of the 25-gauge trocar. One is introduced first, and a second one is introduced on top of the first one. This secures the two sleeves on the shaft of the trocar, such that they act as a spacer. The effective shaft of the trocar was then reduced to 2 mm in length. RESULTS: This method enabled successful surgery in two cases. CONCLUSIONS: This allows the adaptation of the standard 25-gauge system for pediatric cases with only the slightest modification needed.

Successful treatment of intraocular post-transplant lymphoproliferative disorder with intravenous rituximab.

We reported a rare case of intraocular post-transplant lymphoproliferative disorder (PTLD) arising in a 3-year-old liver transplant recipient who had a prior history of systemic PTLD. The first PTLD entered remission after treatment with intravenous rituximab and withdrawal of immunosuppressants. One year after remission, she presented with granulomatous uveitis and iris nodules in the right eye. Iris biopsy confirmed recurrence of intraocular PTLD, which resolved completely after a second course of intravenous rituximab.

1-year results of combined half-dose photodynamic therapy and ranibizumab for polypoidal choroidal vasculopathy.

BACKGROUND: To evaluate the efficacy and safety of half-dose photodynamic therapy (PDT combined with ranibizumab for polypoidal choroidal vasculopathy (PCV). PCV is commonly treated with a combination of anti-vascular endothelial growth factor and standard-dose photodynamic therapy (PDT). Choroidal ischemia and visual loss can be resulted from the standard-dose PDT. Half-dose PDT has proved to produce similar results and safety profile in treating central serous chorioretinopathy. Half-dose PDT may offer an alternative for PCV cases where the damage to choroidal vasculature maybe less. Here, we report the efficacy of treating PCV cases with combination of ranibizumab and half-dose PDT. METHODS: In this prospective, non-comparative, interventional case series, 19 treatment-naive eyes were treated with combined half-dose PDT and ranibizumab. All subjects were followed up for 12 months with measurement of best-corrected visual acuity (BCVA), central foveal thickness (CFT) by optical coherence tomography. Indocyanine green angiogram (ICG) was performed every 3-monthly, and subjects assessed in terms of polyp regression rates, changes in vision and central foveal thickness, need to repeat half-dose PDT. Subgroup analysis was performed based on ICG features. RESULTS: The mean logMAR BCVA improved from 0.64 at baseline to 0.41 at 12 months. The mean CFT improved from 459.6 mum at baseline to 384.2 mum at 12 months. The difference between baseline BCVA and CFT and that at 12 months were statistically significant (both P = 0.03). Polyp regression rate after one half-dose PDT was 42.1 %. This was 61.5 % in the polyp-only group, while that in the branching-vascular-network (BVN) group was 0 % (P = < 0.01). CONCLUSION: Half-dose PDT combined with intravitreal ranibizumab was able to induce high polyp regression rate in PCV cases that had one single polyp.

Acute postoperative endophthalmitis after cataract operation: result of early vitrectomy within 24 hours of presentation.

OBJECTIVES: To evaluate result of early pars plana vitrectomy (PPV) within 24 hours of presentation for acute postoperative endophthalmitis after cataract operation, and to determine factors that predict visual outcome. METHODS: Consecutive patients who developed acute postoperative endophthalmitis within 6 weeks after cataract operation were reviewed. Patients were divided into two groups for analysis: (1) those receiving PPV within 24 hours of presentation (early PPV group), and (2) those receiving initial intravitreal antibiotics only without PPV within 24 hours of presentation (IVA group). RESULTS: Out of 41,411 cataract operations, 22 eyes developed acute postoperative endophthalmitis. Presenting VA was hand-movement or worse in 72.7%. The most common organisms were Staphylococcus (40.9%), Streptococcus (13.6%) and Enterococcus (13.6%). 22.7% of eyes had good final VA ≥ 20/30 and 27.3% had poor final VA < 20/400. Early PPV group had significantly lower rate of requiring additional treatments to control infection (25% versus 80%, P = 0.030), higher rate of retinal detachment (25% versus 0%, P = 0.221) and similar final logMAR VA (1.08 ± 1.08 versus 0.80 ± 0.80, P = 0.489) compared to IVA. Multivariate linear regression analysis showed that worse final VA was significantly associated with Streptococcus (ß = 1.92, P = 0.007) and retinal detachment (ß = 1.72, P = 0.005) but not with early PPV (P = 0.225). CONCLUSION: Early PPV was superior to initial intravitreal antibiotics alone as it required fewer additional treatments to control infection. Visual outcome was similar between early PPV and initial intravitreal antibiotics alone despite high number of poor presenting VA of light-perception in early PPV group. Streptococcal infection and retinal detachment were major poor prognostic factors for vision.

Rise in intraocular pressure with elevator travel in post-vitrectomy patients.

To evaluate the impact of elevator travel on intraocular pressure after vitreoretinal surgery with gas tamponade. Patients undergoing pars plana vitreoretinal surgery with and without gas insertion were recruited on post-operative day 1. All intraocular pressures were measured three times by Tono-Pen AVIA (Reichert, USA) on the fourth floor and, after rapid ascent in an elevator, on the 12th floor of the hospital. All patients were observed and asked for any symptoms of pain or nausea for at least 15 min. In this study, 54 patients were recruited. Twenty-seven patients underwent vitreoretinal procedures with gas insertion, while 27 patients without gas insertion acted as controls. The mean age of patients was 60.9 years. The mean changes in intraocular pressure of the patients with gas insertion (+ 1.39 mmHg) were greater than those without gas insertion (- 0.43 mmHg) and statistically significantly different (95% CI 1.17-2.48, P < 0.0001). Patients undergoing vitreoretinal surgery with gas insertion had statistically significant intraocular pressure rise even with 8-floor ascent in the immediate post-operative period. Further studies are needed to evaluate the change in intraocular pressure with a larger range of altitudes and different gases.

Prediction model to predict type 1 retinopathy of prematurity using gestational age and birth weight (PW-ROP).

PURPOSE: To develop a prediction model for type 1 retinopathy of prematurity (ROP) from an Asian population. METHODS: This retrospective cohort study included 1043 premature infants who had ROP screening in a tertiary hospital in Hong Kong from year 2006 to 2018. The ROP prediction model was developed by multivariate logistic regression analyses on type 1 ROP. The cut-off value and the corresponding sensitivity and specificity were determined by receiver operating characteristic curve analysis. A validation group of 353 infants collected from another tertiary hospital in another region of Hong Kong from year 2014 to 2017 was used for external validation. RESULTS: There were 1043 infants in the study group. The median gestational age (GA) was 30 weeks and 1 day and median birth weight (BW) was 1286 g. The prediction model required only GA and BW as parameters (prematurity-birth weight ROP (PW-ROP)). The area under curve value was 0.902. The sensitivity and specificity were 87.4% and 79.3%, respectively. Type 1 ROP developed in 0.9%, 17.4% and 50% of infants with PW-ROP scores<0, between 0 and <300, and ≥300 respectively (p<0.001). On external validation, our prediction model correctly predicted 95.8% of type 1 ROP (sensitivity=95.8%, specificity=74.8%) in the validation group. CONCLUSION: The PW-ROP model is a simple model which could predict type 1 ROP with high sensitivity and specificity. Incorporating this model to ROP examination would help identify infants at risk for ROP treatment.

The inner segment/outer segment junction: what have we learnt so far?

PURPOSE OF REVIEW: The advancement of optical coherence tomography has improved the resolution of in-vivo images of the retina. This has led to a wealth of novel knowledge regarding the microstructures of the photoreceptor layer and its relationship with visual functions under different pathological diseases. RECENT FINDINGS: Identification of the hyperreflective lines in the photoreceptor layer has been made possible by spectral domain optical coherence tomography. The inner segment/outer segment junction, external limiting membrane, cone outer segment tips, and the retinal pigment epithelium were thought to be the origins of the four hyperreflective lines seen in the photoreceptor layer. Integrity of these lines has been linked with visual functions in various retinopathies, and has been suggested to carry prognostic implications. Recovery of initially interrupted lines has been documented following successful treatment. SUMMARY: Identification of these hyperreflective lines may have clinical implications as visual function was found to correlate closely with their integrity. Restoration of these lines may indicate treatment response and potential visual recovery.

Safety review of anti-VEGF therapy in patients with myopic choroidal neovascularization.

INTRODUCTION: Anti-angiogenesis therapy with intravitreal anti-VEGF agents is now the standard-of-care treatment for myopic choroidal neovascularization (CNV). AREAS COVERED: We provide a critical review of the safety of all the anti-VEGF agents currently used for treating myopic CNV including ranibizumab, aflibercept, conbercept, bevacizumab, and ziv-aflibercept. EXPERT OPINION: Anti-VEGF therapy for myopic CNV with the currently available anti-VEGF drugs generally have favorable safety outcomes in the short-term. Nonetheless, ocular adverse events following anti-VEGF therapy for myopic CNV may develop and these include worsening or new development of myopic traction maculopathy, increased risk of retinal detachment, and progression of chorioretinal atrophy. Clinicians should be aware of these potential complications and evaluate them before and after anti-VEGF therapy.

Applications of Multimodal Imaging in Central Serous Chorioretinopathy Evaluation.

Central serous chorioretinopathy (CSCR) is a macular disease characterized by serous retinal detachment commonly involving the macular region. CSCR has a wide spectrum of clinical presentations. Although a significant proportion of CSCR cases are self-limiting, patients can suffer from persistent or recurrent disease, sometimes complicated with choroidal neovascularization, resulting in permanent visual loss. Multimodal imaging, including fluorescein angiography, indocyanine green angiography, fundus autofluorescence, and optical coherence tomography, has advanced the diagnosis and classification of CSCR cases. Evolution of new imaging techniques including optical coherence tomography angiography, wide-field imaging, and en face reconstruction imaging has also contributed to better understandings of the pathophysiology of CSCR. This review article summarizes the features of multimodal imaging for CSCR and discusses the application of such features in evaluating the disease.

Fundus Autofluorescence and Optical Coherence Tomography Characteristics in Different Stages of Central Serous Chorioretinopathy.

OBJECTIVE: To describe the morphological changes on fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SD-OCT) imaging at different chronicity of central serous chorioretinopathy (CSC). METHODS: This cross-sectional study included patients with CSC of different chronicity. Changes in FAF scans and morphological changes on SD-OCT were evaluated and compared at different stages of CSC. RESULTS: Sixty-nine patients were enrolled in the study, with a mean age of 52.1 ± 11.8 years. A distinct hypoautofluorescence (AF) pattern was observed at the leakage point in acute CSC (100%). The leakage site was indistinguishable in 48% of the patients with late-chronic CSC. The majority of acute CSC patients showed hyper-AF in the area of serous retinal detachment (SRD), which persisted in the early-chronic stage of CSC. In late-chronic CSC, many cases of hypo-AF (22.2%) and mixed-pattern AF (14.8%) were observed. SD-OCT revealed evolving features of retinal pigment epithelium (RPE) abnormalities in a time-dependent manner: from peaked PEDs in acute CSC to low-lying PEDs in early-chronic CSC and, eventually, flat, irregular PEDs in late-chronic CSC. The average thickness of the photoreceptor layer (inner and outer segment; IS/OS) was 79 µm in the acute group and 55.2 µm in the chronic group. The photoreceptor layer (IS/OS) height was positively associated with visual acuity (p=0.002). CONCLUSION: Different stages of CSC present different patterns on FAF and SD-OCT imaging. Chronicity of CSC can be estimated using specific features in these images. Photoreceptor layer (IS/OS) height acts as a good and objective predictor of visual outcomes in CSC patients.

The Contemporary Role of Photodynamic Therapy in the Treatment of Pachychoroid Diseases.

Recent advances in retinal imaging technology have improved our understanding in the pathogenesis and evolvement of various chorioretinal diseases. Central serous chorioretinopathy and polypoidal choroidal vasculopathy are now recognized to belong to the same spectrum of disorders known as pachychoroid diseases. Pachychoroid diseases have similar pathogenesis pathway and common characteristics of thickened choroid, dilated outer choroidal vessels, and thinning of choriocapillaris. More disease entities have been identified to belong to this disease spectrum. Photodynamic therapy can induce choroidal hypoperfusion, remodeling of abnormal choroidal vessels, and reduction of choroidal congestion. It is known to be an effective treatment for chronic central serous chorioretinopathy and polypoidal choroidal vasculopathy. Many new studies are being performed to investigate its efficacy in other pachychoroid diseases. In this review, we provided an overview of the rationale, efficacy, and treatment strategies of photodynamic therapy in different pachychoroid diseases and discussed its role in the management along with other treatment modalities with most updated clinical evidence.