W.-M. Chan

Combined photodynamic therapy and intravitreal triamcinolone injection for the treatment of subfoveal choroidal neovascularisation in age related macular degeneration: a comparative study

Aim: To evaluate the outcomes of combined intravitreal triamcinolone (IVTA) and photodynamic therapy (PDT) with verteporfin in the treatment of subfoveal choroidal neovascularisation (CNV) caused by age related macular degeneration (AMD). Methods: 48 eyes from 48 patients with subfoveal CNV caused by AMD were prospective recruited, with 24 eyes treated with combined PDT with IVTA and compared with a control group of 24 eyes which received PDT monotherapy. In the combined treatment group, IVTA was performed immediately after PDT as an outpatient procedure. The mean number of treatments, mean logMAR best corrected visual acuity (BCVA), mean line of visual acuity changes, and proportion of patients without moderate visual loss at 1 year were compared between the combined and monotherapy groups. Results: At 1 year the logMAR BCVA for the PDT with IVTA group changed from 0.88 to 0.95 (p = 0.32 compared with baseline), whereas the logMAR BCVA for the monotherapy group reduced from 0.74 to 1.09 (p<0.001 compared with baseline). A significantly higher proportion of patients who had PDT with IVTA did not develop moderate visual loss at 1 year compared with the monotherapy group (70.8% and 33.3% respectively, p = 0.009). Eyes which had combined treatment had significantly fewer lines lost compared with monotherapy alone (0.7 and 3.5 lines respectively, p = 0.015). Subgroup analysis showed that PDT with IVTA is effective in preventing visual loss in both predominately classic and occult CNV groups. The mean number of treatments for the combined and monotherapy groups was 1.5 and 1.96 respectively (p = 0.076). Conclusions: Combined PDT with IVTA appeared more effective statistically at 12 months for stabilisation of vision (<3 logMAR lines change) compared with PDT monotherapy. Further randomised control trials might be justified to conclude the efficacy of PDT with IVTA.

Choroidal neovascularisation in pathological myopia: an update in management

Choroidal neovascularisation (CNV) secondary to pathological myopia is an important cause of significant visual impairment in young and middle aged adults globally and is particularly prevalent in Asian populations. In the past few years, there have been rapid advancements in the different treatments for myopic CNV. The purpose of this perspective is to give an overview of the natural history of myopic CNV and the various treatment options including laser photocoagulation, photodynamic therapy, submacular surgery, and macular translocation surgery. Future directions in the management of myopic CNV are also discussed.

Visual acuity and quality of life outcomes in cataract surgery patients in Hong Kong

Background: Visual acuity, visual functioning, and vision related quality of life outcomes after cataract surgery were assessed in a population based study in a suburban area of Hong Kong. Methods: A cluster sampling design was used to select apartment buildings within housing estates for enumeration. All enumerated residents 60 years of age or over were invited for an eye examination and visual acuity measurement at a site within each estate. Visual functioning (VF) and vision related quality of life (QOL) questionnaires were administered to interview subjects who had undergone cataract surgery and to unoperated people with presenting visual acuity less than 6/60 in either eye, and a sample of those with normal visual acuity. Results: 36.6% of the 310 cataract operated individuals had presenting visual acuity 6/18 or better in both eyes, and 40.0% when measured by pinhole. 4.5% were blind, with presenting visual acuity less than 6/60 in both eyes. Of operated eyes, 59.6% presented with visual acuity 6/18 or better. 11.2% of the operated eyes were blind with vision less than 6/60. Visual acuity outcomes 6/18 or better were marginally associated with surgery in private versus public hospitals. Lens status (pseudophakic versus aphakic) and surgical period (within the most recent 3 years versus before) were not significantly related to vision outcomes. Mean VF and QOL scores decreased consistently with decreasing vision status. Spearman correlation with vision status was 0.420 for VF scores and 0.313 for QOL scores. Among VF/QOL subscales, correlation was strongest for visual perception (r = 0.447) among VF subscales and weakest for self care (r = 0.171) among QOL subscales. Regression adjusted VF and QOL total scores for cataract operated individuals were slightly lower than for those of visually comparable unoperated individuals (p<0.05). Conclusions: Cataract operations in Hong Kong did not consistently produce good presenting visual acuity outcomes, suggesting that postoperative monitoring would be useful to minimise visual impairment in this population. Although vision outcomes were consistently correlated with all VF/QOL subscale scores, there was a differential impact with VF subscales usually being affected more by reduced acuity than the more general QOL subscales.

Photodynamic therapy with verteporfin for juxtafoveal choroidal neovascularization secondary to pathologic myopia-1-year results of a prospective series

PurposeTo study the efficacy of photodynamic therapy (PDT) with verteporfin in the treatment of juxtafoveal choroidal neovascularization (CNV) secondary to pathologic myopia.MethodsProspective, open label, two-centre, noncomparative, interventional case series. Consecutive patients with juxtafoveal CNV associated with pathologic myopia were recruited and treated with a standard regimen of PDT with verteporfin. Patients were being followed up every 3-monthly and retreatment was considered when there was evidence of angiographic leakage. Outcome measures included changes in the mean best-corrected visual acuity (BCVA) at the 1-year follow-up when compared with the baseline, the proportion of patients who had stable (within 1 line) and improved visions.ResultsA total of 11 eyes from 11 patients with juxtafoveal CNV secondary to pathologic myopia were recruited and all completed the 1-year follow-up. The mean age at presentation was 44.8 years. The refractive error ranged from −6.0 to −15.0 D (±SD was −9.55±3.04 D). The logMAR BCVA improved from 0.57 to 0.39 at the 1-year follow-up (Wilcoxon signed-ranks test, P=0.027). The mean improvement was 1.8 lines. Five eyes (45.4%) had BCVA improved by ⩾3 lines. None of the treated patients had visual loss of ⩾1 line. The mean number of treatments over the 12-month study period was 2.3 sessions.ConclusionsThe results are encouraging, especially on considering the low retreatment rate, stable or improved BCVA in all treated eyes, and consistently good safety profile. Juxtafoveal myopic CNV may be an expanded indication for PDT with verteporfin.

Multifocal electroretinogram demonstrated macular toxicity associated with ethambutol related optic neuropathy

Ethambutol is an effective drug in the first line treatment for tuberculosis but its use may be associated with ocular toxicity.1 Toxic optic neuropathy is the most important ocular side effect and is related to the dose and duration of treatment.2 It is usually bilateral and both central and peripheral types of optic neuropathy have been described. The central type involves the papillomacular bundle and results in decreased visual acuity, caecocentral scotoma, and blue-yellow colour vision loss, whereas the peripheral type causes peripheral visual field loss, especially bitemporal defects with sparing of visual acuity and red-green colour vision impairment.3 In additional to the optic nerve toxicity, studies have also demonstrated that ethambutol may also be toxic at the retinal level.4–6 We report a patient with ethambutol related toxic optic neuropathy associated with bilateral macular toxicity as demonstrated by multifocal electroretinogram (mfERG). To our knowledge, evaluation …

In vivo measurements of macular and nerve fibre layer thickness in retinal arterial occlusion.

AimTo investigate the structure–function relationship in patients with retinal arterial occlusion by measuring the macular and the peripapillary retinal nerve fibre layer (RNFL) thickness and the visual sensitivity.MethodsThis is an observational case series with three patients with central retinal arterial occlusion (CRAO) and two patients with branch retinal arterial occlusion (BRAO). The macular/peripapillary RNFL thickness and the visual field were measured with Stratus optical coherence tomography (OCT) and Humphrey visual field analyzer, respectively, at least 1 year after the diagnosis of CRAO or BRAO.ResultsThe macular thickness, in particular the inner retinal layer, and the peripapillary RNFL thickness were reduced in patients with retinal arterial occlusion. The decrease in the macular and the peripapillary RNFL thickness corresponded to the sites of retinal arterial occlusion with diffuse and segmental thinning found in CRAO and BRAO, respectively. Visual field defects were found in the corresponding locations of macular and RNFL thinning, and closely correlated with the degree of the structural damage.ConclusionsStructural damages in terms of reduction in the macular and peripapillary RNFL thickness were evident in patients with retinal arterial occlusion. A close structure–function correlation was found and a worse functional outcome is associated with a more extensive thinning of the macula and RNFL. OCT measurements of the macular/peripapillary RNFL thickness provide useful indicators to reflect the severity of the disease in retinal arterial occlusion and serve as a new paradigm to study and monitor the disease longitudinally.

An infected hydrogel buckle with Corynebacterium pseudotuberculosis.

Scleral buckling is still the most common procedure to repair a rhematogenous retinal detachment. Acute or chronic infection of scleral explant is rare but well recognised serious postoperative complication threatening the eye and jeopardising the retinal attachment and visual outcome. They may present acutely as painful red eye with purulent discharge or chronically with extrusion of the explants. The reported incidence varies between 0.5% and 5.6%.1 Surgical technique, different synthetic materials of scleral explants, duration of surgery, size, and position of buckle affect the rate of infection. In the largest retrospective review of 757 patients with episcleral buckle for rhegmatogenous retinal detachment, Roldan-Pallares and associates had reported 1.3% patients requiring removal of the implant with the commonest seen in silicone sponge (9%) and the least common encountered in hydrogel implant (1.3%).2 Smiddy et al have studied 45 cases of scleral buckling infection and identified coagulase …

A novel missense RP1 mutation in retinitis pigmentosa.

AimsMore than 20 mutations associated with retinitis pigmentosa (RP) have been identified in the retinitis pigmentosa 1 (RP1) gene, all of them leading to the production of a truncated protein without 50–70% of the C-terminal of the RP1 protein. RP1 was recently found to be a microtubule-associated protein (MAP) and responsible for the organisation of the photoreceptor outer segment. The N-terminal doublecortin (DCX) domain of RP1 is essential for its function. But how the C-terminal of the protein affects its function is still not known. This study aims to get a better understanding of the RP1 gene by mutation screening on RP patients.MethodsPeripheral blood was taken from 72 RP patients. Together with 101 RP patients and 190 control subjects previously reported, mutation screening was performed by polymerase chain reaction (PCR) and direct sequencing. Statistical analysis was performed using SPSS.ResultsTwo novel missense sequence changes, D984G and C727W, and one novel variant, 6492T>G, at the 3′ untranslated region were found. They were not found in 190 control subjects. D984G causes RP. It creates two possible N-myristoylation sites according to PROSITE. C727W does not segregate with RP in the family. It abolishes an N-myristoylation site. R872H, a previously reported polymorphism, was predominantly present in control subjects (P=0.001).ConclusionsOur results suggest that disruption of the C-terminal of RP1 may be associated with the development of RP, and the possible involvement of the RP1 polypeptide downstream of its DCX domain in normal RP1 function.

Rapid development of severe toxic retinopathy associated with continuous intravenous deferoxamine infusion

Deferoxamine mesylate is a chelating agent used in the treatment of iron overload in patients requiring regular transfusions. Deferoxamine is most commonly administered as a slow subcutaneous infusion but continuous intravenous infusion may be required for treating life threatening cardiac complications due to iron overload.1 Toxic retinopathy is one of the complications associated with deferoxamine, in which different manifestations including pigmentary retinopathy, bull’s eye maculopathy, and vitelliform maculopathy have been described.2–,8 We report a patient who had rapid development of irreversible diffuse pigmentary retinopathy with severe visual loss while receiving continuous intravenous deferoxamine infusion. A 17 year old β thalassaemic patient was referred for ophthalmic assessment with recent onset of colour vision impairment 4 months after commencement of continuous intravenous deferoxamine infusion. He had been on subcutaneous deferoxamine for …

The Moral Judgments of Chinese Students

Abstract The Defining Issues Test (DIT) was translated into Chinese and administered to 84 male and 84 female Chinese subjects in Hong Kong. No significant sex differences in all of the stage scores derived from DIT ratings and rankings were found. In addition, the Pearson correlation matrix of Stage 2 through 6 scores for the females but not for the males approximated a simplex-like pattern. The unrotated factor loadings of the Principal Components Analysis for the female subjects provided clear support to the claim of an ordered sequence of Kohlbergs stages measured by the DIT. The factor loadings on the higher stages (4, 5, and 6), however, were less discriminating and consistent in the male factor pattern.