Quality of cementation in conventional versus minimally invasive total knee arthroplasty.

PURPOSE: To review the immediate postoperative radiographs of 108 patients following conventional or minimally invasive total knee arthroplasty (TKA) to assess the quality of cementation in terms of cement voids and retained cement. METHODS: Records of 20 male and 88 female consecutive patients aged 50 to 83 (mean, 67.5) years who underwent conventional TKA (n=56) or computer-assisted minimally invasive TKA (n=52) for osteoarthritis by a single senior surgeon were reviewed. Immediate postoperative radiographs were assessed by a single blinded assessor for the quality of cementation in terms of cement void and retained cement in different zones of the femoral, tibial, and patellar components along the prosthesis-bone interface using the Knee Society total knee arthroplasty roentgenographic evaluation and scoring system. RESULTS: The 2 groups were comparable in terms of baseline demographics as well as cement void and retained cement on the femoral, tibial, and patellar components, except that in the minimally invasive group, cement void beneath the anterior flange of the femoral component was wider (0.32 vs. 0 mm, p=0.001), and retained cement in the posterior or lateral aspects of the tibial component was more common (50.0% vs. 28.6%, p=0.018). CONCLUSION: Minimally invasive TKA resulted in a wider cement void beneath the anterior flange of the femoral component and a higher rate of retained cement around the tibial component.

Preclinical safety evaluation of subretinal AAV2.sFlt-1 in non-human primates.

We report on the long-term safety of AAV2.sFlt-1 (a recombinant adeno-associated virus serotype 2 carrying the soluble form of the Flt-1 receptor) injection into the subretinal space of non-human primates. Levels of sFlt-1 protein were significantly higher (P<0.05) in the vitreous of four out of five AAV2.sFlt-1-injected eyes. There was no evidence of damage to the eyes of animals that received subretinal injections of AAV2.sFlt-1; ocular examination showed no anterior chamber flare, normal fundus and electroretinography responses equivalent to those observed before treatment. Notably, immunological analysis demonstrated that gene therapy involving subretinal injection of AAV2.sFlt-1 does not elicit cell-mediated immunity. Biodistribution analysis showed that AAV2.sFlt-1 could be detected only in the eye and not in the other organs tested. These data indicate that gene therapy with subretinal AAV2.sFlt-1 is safe and well tolerated, and therefore promising for the long-term treatment of neovascular diseases of the eye.

Factors affecting the predictability of SRK II in patients with normal axial length undergoing phacoemulsification surgery.

INTRODUCTION: This study aims to evaluate the factors affecting the accuracy of biometry assessment using the SRK II formula in predicting the refractive outcome after uneventful cataract surgery by phacoemulsification for eyes within the normal range of axial lengths. METHODS: A retrospective review of 100 consecutive cases of uncomplicated phacoemulsification surgery performed by two surgeons from January to September 2005 in a single centre was done. Eyes with axial length greater than or equal to 22.5 mm and less than 24.5 mm were included in the study. The error of prediction was calculated by actual postoperative refractive error minus the refraction target. A comparison was made between the low predictability (prediction error more than 0.50 dioptres [D]) and high predictability (prediction error less than or equal to 0.50 D) groups of eyes. Statistical analysis was performed. RESULTS: A total of 267 case notes were reviewed, of which 100 met the inclusion criteria. The mean age was 68.3 years, with a mean keratometric reading of 43.94 +/- 1.27 D and mean axial length of 23.38 +/- 0.51 mm. The mean IOL power used was 21.77 +/- 1.50 D. The mean error was +0.25 +/- 0.67 (range -1.58 to +1.80) D, with the standard error of mean 0.669. 45 percent of the patients were within 0.5 D of the predicted refractive error and 83 percent were within 1.0 D. There was no difference in preoperative corneal astigmatism, mean keratometry, axial length, age or gender of the patient, laterality of the operated eye and intraocular lens power between the low and high predictability groups. There was a negative correlation between the axial length and prediction error. CONCLUSION: SRK II is reliable in the prediction of the refractive outcome in normal axial length eyes. The findings in our study are comparable to those found in previous studies. We found a negative correlation between axial length and prediction error, even within the range of normal axial length eyes.

Argon laser photocoagulation for the treatment of polypoidal choroidal vasculopathy.

AIM: To evaluate the efficacy of conventional argon laser for the treatment of serosanguineous maculopathy secondary to polypoidal choroidal vasculopathy (PCV). METHODS: A retrospective audit of patients who had argon laser photocoagulation to angiographically determined polypoidal lesions and subsequently followed up at 1, 3, 6, and 12 months post treatment. RESULTS: Twenty-one eyes (75%) had stable or improved vision at 12 months. Twenty-three eyes had extrafoveal, two eyes had juxtafoveal, and three eyes had subfoveal polyps. In the extrafoveal group, 18 eyes (78%) had stable or improved vision at 12 months. Eighteen eyes (64.3%) showed clinical or angiographic resolution of maculopathy. Three eyes (10.7%) had recurrence of polyps subfoveally, three eyes (10.7%) had subsequent choroidal neovascularisation, and four eyes (14.3%) had persistent leakage with neurosensory detachment. CONCLUSION: In our study, 18 of the 23 eyes which had extrafoveal polyps had stable or improved best-corrected visual acuity and showed complete resolution of maculopathy at 12 months follow-up. Argon laser photocoagulation would appear to be most beneficial for extrafoveal PCV. However, in view of the retrospective nature of this study, the true efficacy of argon laser treatment would have to be evaluated with a larger, prospective and randomised controlled trial.

Giant retinal tear management: an Asian experience.

PURPOSE: To report the management of giant retinal tears (GRT). METHODS: Retrospective review of all patients who underwent surgery for GRT with at least 6 months follow-up. RESULTS: A total of 124 patients with 128 eyes were managed for GRT between 1991 and 2005. Of them, 99 eyes of 96 patients with at least 6 months follow-up were reviewed (mean follow-up 63.38 months). There were 113 men and the mean age was 39.6 years (8-72 years). Myopia was present in 81 eyes (63.3%) with mean myopia -7.56 dioptres sphere, DS (-1.00 to -27.00 DS). All eyes underwent pars plana vitrectomy. Scleral buckling was done in 90 eyes (70.3%) and lens removal in 49 of 95 phakic eyes (51.2%). Total 84 eyes (84.8%) were re-attached at 6 months after vitrectomy. This was achieved with one surgery in 71 eyes (71.7%). The mean number of surgeries for reattachment was 1.19 surgeries. At 6 months, 41 eyes (41.4%) regained 20/40 or better vision. A total of 47 vitreoretinal pathologies were seen in the fellow eyes of the 124 patients, including 4 with GRTs. CONCLUSION: Surgical success for GRT can be achieved with good visual outcome in 84.8% after a mean of 1.19 surgeries. The fellow eyes are however at risk of pathologies and should be followed-up in the long term.

Photodynamic therapy with verteporfin for polypoidal choroidal vasculopathy.

BACKGROUND: To describe the efficacy of photodynamic therapy (PDT) with verteporfin for the treatment of polypoidal choroidal vasculopathy (PCV). METHODS: This is a retrospective interventional case series of 41 eyes of 40 patients with angiographic evidence of PCV, which had PDT with verteporfin. Pre-treatment best-corrected visual acuity (BCVA) was measured and patients were followed up for at least 12 months with BCVA recorded at each visit. RESULTS: The mean follow-up time was 23.7 months. Seven of 10 eyes (70%) with juxtafoveal lesions and 17 of 31 eyes (54.8%) with subfoveal lesions had stable or improved vision (loss of

Patients' expectation and experience of visual sensations during phacoemulsification under topical anaesthesia.

PURPOSE: To describe what patients expect to see and the visual sensations they actually experience during phacoemulsification under topical anaesthesia. We also sought to determine if patients find their intraoperative visual experience frightening and the factors associated with this. MATERIALS AND METHODS: Ninety-eight patients who underwent phacoemulsification and intraocular lens implantation under topical anaesthesia were interviewed preoperatively on what they expected to see with their operated eye during surgery and again postoperatively on what they actually saw. No patient received counselling about possible intraoperative visual sensations. A logistic (multivariate) regression model was used for statistical analysis. RESULTS: Preoperatively, 36 patients (36.7%) expected at least light perception, 38 (38.8%) expected no light perception, and 24 (24.5%) were unsure what to expect. Some patients also expected a variety of different visual sensations. Postoperatively, all patients (100%) reported seeing light intraoperatively and many experienced various other visual sensations. Nineteen patients (19.4%) found their visual experience frightening. The following factors were statistically associated with a frightening visual experience: preoperative anxiety, previous cataract surgery in the fellow eye, experiencing an intraoperative increase in clarity, not seeing movement intraoperatively, and not knowing what to expect. CONCLUSIONS: The majority of patients in this study either expected that they would see nothing at all during the surgery or were unsure of what to expect. All patients subsequently saw at least some light, and many perceived various other visual sensations that were frightening to nearly one in five patients. Preoperative counselling should inform about possible intraoperative visual experience.

Age-related macular degeneration: what's new.

INTRODUCTION: Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the developed western world, accounting for approximately 50% of all cases of registered blindness. The rising prevalence of this disease in Asia seems to parallel the same trend in the developed world. Because of the socio-economic impact of this disorder, much attention has been paid to elucidating the underlying pathogenic mechanisms, as well as seeking alternative forms of treatment. This review discusses the latest advances in AMD diagnosis, treatment and prophylaxis. METHODS: Medline search with emphasis on randomised controlled clinical trials and large case-control series. Only articles cited on the Index Medicus were included in this review. RESULTS: Recent advances in the diagnosis and treatment of AMD include conventional argon laser photocoagulation, photodynamic therapy (PDT), radiation therapy, surgical options and gene therapy. CONCLUSIONS: There have been numerous advances in the management of AMD and exciting new research applications have emerged. The introduction of exciting new modalities, such as PDT, has revolutionised the approach to treating CNVM and their effects on central vision. However, there has been no breakthrough in achieving satisfactory outcomes with the available techniques for treating occult neovascular lesions. As results of large prospective randomised clinical trials evaluating new treatment alternatives become available, a treatment algorithm for neovascular AMD will emerge that best minimises visual loss and may even result in visual improvement.

Purtscher-like retinopathy after retrobulbar injection.

Purtscher-like retinopathy occurred in a 46-year-old Chinese male who received 5 mL of 2% lignocaine, retrobulbar injection, and underwent pterygium excision with conjunctiva graft. The visual acuity improved spontaneously from 20/120 on the first postoperative day to 20/20 within 8 weeks. The disc swelling, veinous tortuosity, retinal whitening, and hemorrhage resolved with time. However, relative afferent papillary defect and an arcuate visual field deficit persisted. The mechanisms of this Purtscher-like retinopathy are postulated.

Retinal detachment in Chinese, Malay and Indian residents in Singapore: a comparative study on risk factors, clinical presentation and surgical outcomes.

PURPOSE: To evaluate the risk factors, clinical presentation and surgical outcomes of retinal detachment (RD) among Chinese, Malay and Indian residents in Singapore. METHODS: A retrospective descriptive study from January 1995 to December 1998. All RD operations performed at a tertiary ophthalmic center in Singapore were initially identified from a computerized audit database. Case records data of all Malay and Indian patients as well as a 10% randomized sample of Chinese patients were retrieved and analyzed. Tractional and exudative RD's were excluded. RESULTS: Of the Singapore residents who had a RD operation over the 4-year period, 597 (89.6%) were Chinese, 47 (7.1%) were Malays and 22 (3.3%) were Indians. The age (mean: 46.1 +/- 15.5 years), gender distribution (70.5% males) and presenting visual acuities were similar in the 3 races. The most common site of the retinal break(s) was the superotemporal retina (44.9%), followed by the inferotemporal retina (15.3%). Chinese patients were more likely to have multiple or indeterminate breaks (p = 0.09) and macula-on RD (p = 0.04), compared to Malays and Indians. The distribution of known risk factors (myopia, lattice degeneration, prior cataract surgery and prior ocular trauma) was similar between the three races. The majority of patients required a scleral buckling operation either in isolation (71.3%), or in combination with vitrectomy (19.4%), and only 10 (7.8%) had vitrectomies without buckles. At 6 months postoperatively, anatomical success (defined as an attached retina on ocular examination) and functional success (defined as visual acuities of 6/60 or better) were achieved in 108 (94.7%) and 62 patients (54.4%), respectively, with no significant racial variation seen. The overall rate of redetachment after the initial operation was low (9.3%). CONCLUSION: Variation in risk factors, clinical presentations and postoperative outcomes of retinal detachment appears to be minimal among Chinese, Malays and Indians in Singapore.

Perfluorocarbon liquids (perfluorodecalin) in vitreoretinal surgery--a local experience.

A low viscosity perfluorocarbon liquid (perfluorodecalin) known commercially as DKLine was used intraoperatively as a temporary vitreous substitute in 20 patients undergoing vitrectomy surgery for a variety of complicated vitreoretinal conditions. The indications for its use included giant retinal tears (9), proliferative vitreoretinopathies (2), dislocated lenses (2), dislocated posterior chamber implant (1), endophthalmitis with retinal detachment (2), traction retinal detachment (1), pseudophakic retinal detachment (2) and exudative retinal detachment (1). In all cases with retinal detachment, perfluorodecalin was successful in flattening the retina intraoperatively. It was also successful in permitting the safe removal of dislocated lenses that were lying on the retina. In all except four cases, removal of perfluorodecalin was complete. We observed no toxic effects from remnant bubbles of perfluorocarbon in the eye.

Choroidal melanoma: a report of three cases.

Choroidal melanoma is extremely rare in our population. We report three cases with varied presentations. Two patients presented late with secondary lens induced and neovascular glaucoma, and one patient had early presentation of metamorphosia. We would like to emphasise the importance of an ultrasound scan before any intraocular surgery where the view of the fundus is obscured by an opaque ocular media. A proper ultrasound diagnosis avoids unnecessary surgery which could cause tumour dissemination. Two cases were enucleated and one was managed conservatively.