Timothy Yy Lai

Epiretinal membrane surgery with or without internal limiting membrane peeling

Background:  The purpose of the present paper was to evaluate the visual outcome and recurrence rate of epiretinal membrane (ERM) formation following vitreoretinal surgery with and without internal limiting membrane (ILM) peel.

Peripheral and posterior pole retinal lesions in association with high myopia: a cross-sectional community-based study in Hong Kong.

PurposeTo evaluate the prevalence and factors associated with posterior pole and peripheral retinal lesions in Chinese subjects with high myopia.MethodsThree hundred and thirty-seven asymptomatic adults with high myopia of refractive error ⩽−6 D were examined in a cross-sectional community-based study. All subjects underwent cycloplegic refraction, ultrasound biometry and dilated fundal examination. Statistical analysis was performed to assess factors associated with the presence of posterior pole and peripheral retinal lesions.ResultsThe mean age of the 337 subjects was 36.0 years and the mean spherical equivalent refractive error was −10.2 D. Thirty-eight eyes (11.3%, 95% CI=8.1–15.2%) were found to have one or more posterior pole lesions and subjects with posterior pole lesion had significantly older age, longer axial length and higher degree of myopia (all P<0.001) compared with subjects without posterior pole lesion. After controlling for axial length, both the severity of refractive error and older age were significantly associated with the presence of posterior pole lesion (both P<0.001). For peripheral retinal lesions, 189 eyes (56.1%, 95% CI=50.6–61.5%) were found to have one or more peripheral retinal lesions. The presence of peripheral retinal lesion was associated with younger age and higher degree of refractive error (P=0.046 and 0.002, respectively).ConclusionPosterior pole and peripheral retinal degenerative lesions were found in a considerable proportion of subjects with high myopia. As some of these retinal lesions might predispose to visual impairment, highly myopic individuals should be educated on the symptoms of various eye conditions and seek care immediately if symptoms arise.

Phacoemulsification with intravitreal triamcinolone in patients with cataract and coexisting diabetic macular oedema: a 6-month prospective pilot study

AimsTo assess the safety and efficacy of phacoemulsification with intravitreal triamcinolone (ivTA) injection in diabetics with cataract and clinically significant macular oedema (CSMO).MethodsA total of 19 eyes of 15 consecutive diabetic patients with cataract and CSMO were prospectively recruited. Patients underwent phacoemulsification and intraocular lens implantation with 4 mg ivTA injection at completion of surgery. Patients were followed up on day 1, then weekly for 1 month, and thereafter monthly until 6 months postoperatively. Best corrected visual acuity (BCVA), central macular thickness (CMT) measured by optical coherence tomography, and adverse events were recorded.ResultsIn total, 17 eyes completed 6 months of follow-up. In all, 58.8% showed improvement in BCVA of ⩾2 lines, with statistically significant improvement in mean Snellen BCVA of 2.4 lines at 6 months. The peak BCVA was achieved at 4 months. The mean CMT decreased from a baseline of 449 μm to a minimum of 321±148 μm (28.5% reduction) achieved at 2 months, with statistically significant reduction at all postoperative time intervals until 6 months. Of 17 eyes, 4 (23.5%) developed transiently elevated intraocular pressure that normalised by 6 months in all but one patient. No injection- or surgery-related complications were encountered.ConclusionsPhacoemulsification with concurrent 4 mg ivTA injection appears to be a safe option for managing diabetics with cataract and CSMO. However, large-scaled randomised controlled trials are necessary for delineating the relative contributions of cataract removal and CMT reduction to visual improvement. Moreover, the transient effect on CMT may warrant further studies to determine optimal timing and dosage of further ivTA injections.

Ophthalmic manifestations and risk factors for mortality of HIV patients in the post‐highly active anti‐retroviral therapy era

Background:  To evaluate the ophthalmic manifestations and risk factors for mortality in HIV patients in the post‐highly active anti‐retrovirus therapy (HAART) era.

Pars plana vitrectomy in the management of retained intravitreal lens fragments after cataract surgery

Purpose: To assess the outcome of patients who underwent pars plana vitrectomy for retained lens fragments after cataract surgery.

Extensive submacular haemorrhage in polypoidal choroidal vasculopathy managed by sequential gas displacement and photodynamic therapy: a pilot study of one‐year follow up

Background:  Polypoidal choroidal vasculopathy (PCV) with peculiar vascular lesions presents frequently as recurrent submacular haemorrhage. The best treatment is still not certain. It is the authors’ objective to evaluate the 1‐year safety and efficacy of photodynamic therapy (PDT) using verteporfin for persistent macular PCV after pneumatic displacement of the massive submacular haemorrhage with intravitreal perfluoropropane (C3F8).

Photoreceptor inner segment ellipsoid band integrity on spectral domain optical coherence tomography

Spectral domain optical coherence tomography cross-sectional imaging of the macula has conventionally been resolved into four bands. However, some doubts were raised regarding authentication of the existence of these bands. Recently, a number of studies have suggested that the second band appeared to originate from the inner segment ellipsoids of the foveal cone photoreceptors, and therefore the previously called inner segment-outer segment junction is now referred to as inner segment ellipsoidband. Photoreceptor dysfunction may be a significant predictor of visual acuity in a spectrum of surgical and medical retinal diseases. This review aims to provide an overview and summarizes the role of the photoreceptor inner segment ellipsoid band in the management and prognostication of various vitreoretinal diseases.

A prospective study on trypan blue capsule staining under air vs under viscoelastic

AimTo compare the safety and effectiveness of trypan blue capsule staining under air vsunder viscoelastic.MethodsA total of 52 consecutive patients planned for phacoemulsification of white mature cataract were randomly assigned to trypan blue staining under air or under viscoelastic. Perioperative changes in best-corrected visual acuity (BCVA), central corneal thickness (CCT), and endothelial cell density (ECD) were compared between the two groups. The differences in operating and phacoemulsification times, staining pattern, and complications between the two groups were also recorded.ResultsPhacoemulsification of white mature cataract was performed in 50 (96%) eyes. The median preoperative BCVA was hand movement. No significant differences in the baseline characteristics were found between the two groups. At 3 months after phacoemulsification, the median BCVA improved to 0.8. The mean CCT returned to preoperative level by 1 month postoperatively and the mean ECD loss was 11.9% 3 months postoperatively. No significant differences in median BCVA, mean phacoemulsification and operation times, mean CCT, and mean ECD were found between the two groups.ConclusionsTrypan blue staining of the anterior lens capsule under air or under viscoelastic were similarly effective and safe methods for the phacoemulsification of white mature cataract.

Long-term results of oral valganciclovir for treatment of anterior segment inflammation secondary to cytomegalovirus infection

Background The purpose of this study was to assess the efficacy of oral valganciclovir in the treatment of anterior segment inflammation caused by cytomegalovirus (CMV) infection. Methods Consecutive patients with anterior segment inflammation due to CMV causing anterior uveitis or corneal endotheliitis treated with oral valganciclovir were reviewed. Diagnosis of CMV infection was confirmed by polymerase chain reaction of the aqueous aspirate prior to commencement of oral valganciclovir. All patients were treated with an oral loading dose of 900 mg valganciclovir twice daily for at least 2 weeks, followed by an additional 450 mg valganciclovir twice-daily maintenance therapy. Changes in visual acuity, intraocular pressure (IOP), use of antiglaucomatous eye drops, and recurrence were analyzed. Results Thirteen eyes of 11 patients were followed for a mean of 17.2 months. Two patients had bilateral corneal endotheliitis. All eyes had absence of anterior segment inflammation within 3 weeks after treatment. Following treatment, the mean logMAR visual acuity improved significantly from 0.58 at baseline to 0.37 at the last follow-up (P = 0.048). The mean IOP and number of antiglaucomatous eye drops also decreased significantly (P = 0.021 and P = 0.004, respectively). Five (38.5%) eyes had recurrence of anterior uveitis after valganciclovir was stopped and required retreatment with oral valganciclovir. Conclusion Oral valganciclovir appeared to be effective in controlling CMV anterior uveitis, resulting in visual improvement and IOP reduction following control of inflammation. However, despite the initial clinical response in all cases, recurrence after cessation of oral valganciclovir could occur.

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.