Chi Wai Tsang

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.

Results of high‐density silicone oil as a tamponade agent in macular hole retinal detachment in patients with high myopia

Background: To evaluate the use of high-density silicone oil (HDSO) as a tamponade agent for retinal detachment secondary to myopic macular hole. Methods: 12 eyes of 12 patients with macular hole retinal detachment underwent pars plana vitrectomy, internal limiting membrane peeling and HDSO tamponade. No posturing was required postoperatively and HDSO was removed 3–4 months later. Outcome measures included macular hole closure and retinal attachment rates, best-corrected visual acuity (BCVA), and intraoperative and postoperative complications. Results: The mean age of the patients was 67.8 years and the mean spherical equivalent refractive error was −13.4 diopters. After the removal of HDSO, 10 (83%) eyes had macular hole closure with retinal reattachment without any tamponade. One eye had retinal reattachment after re-operation and the other refused further surgery. At the last follow-up, the median BCVA improved from 20/800 to 20/600 (p = 0.046). A transient increase in intraocular pressure was observed in 5 (42%) eyes and one eye each developed mild oil emulsification and transient peripheral choroidal detachment. None of the eyes was found to have severe intraocular inflammation postoperatively. Conclusions: HDSO seemed to be an effective tamponade agent for myopic macular hole retinal detachment. Further prospective controlled studies seem warranted.

Decreasing efficacy of repeated intravitreal triamcinolone injections in diabetic macular oedema.

Background/aim: Intravitreal triamcinolone (IVTA) results in transient improvements in diabetic macular oedema (DMO), necessitating repeated injections. The authors report a case series of 10 eyes of 10 patients with DMO, who received a repeat injection of 4 mg IVTA, at least 26 weeks after the first injection of the same dose. Method: Pre-injection and at 2, 4, 9, and 17 weeks post-injection, best corrected visual acuity (BCVA) and central foveal thickness (CFT) on optical coherence tomography, after the first and repeat injections, were compared using paired t test. Side effects were monitored. Results: BCVA, CFT, intraocular pressure (IOP), and cataract scores were not significantly different before initial and repeat injections (given at 32.5 (SD 3.5) weeks after the first injection). Transient improvements of BCVA and CFT were achieved after both injections. However, after the repeat injection, the BCVA was significantly worse at all time points (p<0.05) and so were the best achieved CFT and the CFT at 4 weeks post-injection (p = 0.034 and 0.011 respectively), compared with the initial injection. Post-injection maximum IOPs and increase in cataract scores were not significantly different between the two injections. Conclusion: A repeat injection of 4 mg of IVTA may not be as effective as an initial injection for the treatment of DMO.

Prevalence and mechanism of appositional angle closure in acute primary angle closure after iridotomy.

Purpose:  A prospective observational case series to assess the prevalence of appositional angle closure in darkness among iridotomized Chinese eyes after acute primary angle closure (APAC) with the use of both clinical methods and ultrasound biomicroscopy.

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.

Fornix‐based trabeculectomy using the ‘anchoring’ corneal suture technique

Aim: To assess the safety and efficacy of fornix‐based trabeculectomy with the ‘anchoring’ corneal suture technique in Chinese patients.

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.

Vitrectomy with and without scleral buckle for inferior retinal detachment.

In the article presented by Wickham and associates,1 the authors compared vitrectomy and gas for treating inferior break retinal detachments with vitrectomy, gas and scleral buckle. The study showed no significant difference in the final outcome between the two groups. While vitrectomy and gas for inferior break retinal detachments appears promising, there are several issues that we would like to raise. Firstly, the surgery was performed by a registrar, fellow, or consultant. These surgeons may have varying degrees of experience and the inconsistency may affect the rate of successful surgical outcome. Secondly, additional tears were treated with cryotherapy …

Review of Small Gauge Vitrectomy: Progress and Innovations

Purpose. To summarise the surgical advances and evolution of small gauge vitrectomy and discuss its principles and application in modern vitreoretinal surgery. The advent of microincisional vitrectomy systems (MIVS) has created a paradigm shift away from twenty-gauge vitrectomy systems, which have been the gold standard in the surgical management of vitreoretinal diseases for over thirty years. Advances in biomedical engineering and surgical techniques have overcome the technical hurdles of shifting to smaller gauge instrumentation and sutureless surgery, improving surgical capabilities and expanding the indications for MIVS.