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.

Choroidal structures in polypoidal choroidal vasculopathy, neovascular age-related maculopathy, and healthy eyes determined by binarization of swept source optical coherence tomographic images.

PURPOSE: To evaluate quantitatively the choroidal vascularity in polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (AMD) patients compared to healthy controls. METHODS: All eyes underwent swept source optical coherence tomography (OCT), and choroidal images were binarized into blood vessels lumen and stroma. The choroidal vascular index (CVI) was defined as the ratio of luminal area (LA) over total choroidal area of the subfoveal region with a width of 1500 µm. RESULTS: The study included 73 patients with neovascular AMD or PCV with mean ± standard deviation (SD) age of 71.8 ± 9.3 years, which was older than the mean age of 65.1 ± 10.8 years of 72 healthy eyes from control group (p < 0.01). The 44 PCV eyes had significantly higher mean SFCT of 214.23 ± 95.21 µm than neovascular AMD eyes (172.74 ± 96.48 µm, p = 0.03) and greater luminal area (0.23 ± 0.09 mm2 vs. 0.19 ± 0.08 mm2, p = 0.05). After adjusting for age, axial length, and gender in multivariate regression analysis, the SFCT of PCV and neovascular AMD eyes were not significantly different from healthy eyes (195.55 ± 93.11 µm), but the CVI of both PCV (64.94 ± 5.43%, p = 0.01) and neovascular AMD (62.54 ± 5.57%, p = <0.01) were significantly lower than control (68.53 ± 5.91%). CONCLUSION: Despite physiological changes of choroidal vasculature due to aging, the choroidal morphology is different in PCV, neovascular AMD and healthy eyes, which has implication on disease pathogenesis.

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.

New loci and coding variants confer risk for age-related macular degeneration in East Asians.

Age-related macular degeneration (AMD) is a major cause of blindness, but presents differently in Europeans and Asians. Here, we perform a genome-wide and exome-wide association study on 2,119 patients with exudative AMD and 5,691 controls, with independent replication in 4,226 patients and 10,289 controls, all of East Asian descent, as part of The Genetics of AMD in Asians (GAMA) Consortium. We find a strong association between CETP Asp442Gly (rs2303790), an East Asian-specific mutation, and increased risk of AMD (odds ratio (OR)=1.70, P=5.60 × 10(-22)). The AMD risk allele (442Gly), known to protect from coronary heart disease, increases HDL cholesterol levels by 0.17 mmol l(-1) (P=5.82 × 10(-21)) in East Asians (n=7,102). We also identify three novel AMD loci: C6orf223 Ala231Ala (OR=0.78, P=6.19 × 10(-18)), SLC44A4 Asp47Val (OR=1.27, P=1.08 × 10(-11)) and FGD6 Gln257Arg (OR=0.87, P=2.85 × 10(-8)). Our findings suggest that some of the genetic loci conferring AMD susceptibility in East Asians are shared with Europeans, yet AMD in East Asians may also have a distinct genetic signature.

A case of dengue maculopathy with spontaneous recovery.

PURPOSE: To report a case of dengue maculopathy, which resolved spontaneously without treatment. METHODS: A 25-year-old female patient with good past health was admitted to a general hospital in Hong Kong with fever of unknown origin after traveling to Indonesia. Based on the clinical features and a positive real-time polymerase chain reaction for dengue virus type 1, she was diagnosed with dengue fever. The patient developed dengue macu-lopathy mainly affecting the vision of her left eye. Abnormalities on a multifocal electro-retinogram showed bilateral involvement. RESULTS: As there is no proven treatment for dengue maculopathy, the patient opted for observation. Her vision returned to normal within 3 weeks. CONCLUSION: Dengue maculopathy can cause severe visual loss and may resolve without treatment.

Primary 23-gauge transconjunctival sutureless vitrectomy for rhegmatogenous retinal detachment.

PURPOSE: To describe the results of primary 23-gauge transconjunctival sutureless vitrectomy for rhegmatogenous retinal detachment (RRD). METHODS: In a prospective case series, 24 eyes of 24 consecutive patients with RRD underwent primary 23-gauge transconjunctival pars plana vitrectomy with intraocular gas tamponade. Postoperative follow-up ranged from 6 months to 16 months. RESULTS: Fifteen eyes (62.5%) had multiple breaks. Seven eyes (29.2%) had inferior breaks. Other complications included giant tear in one eye, peripheral choroidal detachment in one eye, and concomitant macular holes in two eyes. The primary anatomical success rate was 91.7%. The mean postoperative visual acuity at postoperative month 3 improved from 20/41 to 20/25 (P = 0.111) and from 20/735 to 20/56 (P < 0.0001) in macula-on and macula-off cases, respectively. One patient (4.2%) had hypotony on postoperative day 1. No patients developed choroidal detachments. No sutures were used in any of the sclerotomy sites. Of the patients, 87.5% reported no or mild foreign body sensation, whereas 79.1% reported no or mild pain on the first postoperative day. CONCLUSIONS: Twenty-three-gauge transconjunctival sutureless vitrectomy appears to be a feasible option in treating RRD in selected cases, with the potential benefit of reducing postoperative ocular irritation.

Effect of indocyanine green and illumination on gene expression in human retinal pigment epithelial cells.

PURPOSE: To investigate the biological effects of indocyanine green (ICG) and acute illumination on human retinal pigment epithelial (RPE) cells. METHODS: Three concentrations (0, 0.25, and 2.5 mg/mL) of ICG were applied to ARPE19 cells for 1 minute. After isotonic rinsing, the cells were irradiated with a light beam with a wavelength spectrum from 400 to 800 nm and an output of 1850 lumens for 15 minutes. The cells were collected at timed intervals for the investigation of cell death and expression of stress-response genes by reverse transcription-polymerase chain reaction, immunofluorescence, and Western blot analysis. RESULTS: After ICG incubation, photoreactive changes were observed in the RPE cells. A reduction in cellular viability and considerable shrinkage of the cells were observed. The expressions of the apoptosis-related genes p53 and bax and the cell cycle arrest protein p21 were upregulated in cells treated with both ICG and light. Of the early-response genes, the expression of c-fos was specifically enhanced by light, with additive effects from the presence of ICG. Such stimulatory effects on these gene expressions were greater at 2.5 mg/mL than at 0.25 mg/mL ICG. CONCLUSIONS: ICG in the presence of acute illumination can elicit cell-cycle arrest and even apoptosis in RPE cells. The establishment of a safety level in the application of ICG in the region of 0.25 mg/mL is recommended.