Robert F. Lam

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.

The Effect of Parental History of Myopia on Children’s Eye Size and Growth: Results of a Longitudinal Study

PURPOSE To evaluate the effect of parental myopia on eye size and growth in Chinese children. METHODS A school-based, cross-sectional survey was performed in Chinese children 5 to 16 years of age. A longitudinal cohort study was conducted 1 year later. The effects of parental myopia, parental education level, and near work performed by the child on the refractive error and ocular biometry of the child were assessed. RESULTS There were 7560 children enrolled in the initial study (response rate: 76.3%). One year later, 4468 children (response rate: 75.9%) in the original cohort (with the exception of those who had completed primary schooling) were evaluated, to determine eye growth. Although children with a stronger parental history of myopia tended to be less hyperopic before the onset of myopia (spherical equivalent refraction [SER] = 0.43 D, 0.67 D, and 0.68 D in children with two, one, and no myopic parents respectively; P = 0.007), the axial lengths did not follow the same pattern (axial length [AL] = 23.11, 23.07, and 23.15 mm; P = 0.429). Eye growth and myopic shift in refraction occurred more rapidly among children with a stronger parental history of myopia (annual AL growth/myopia progression = 0.37 mm/-0.22 D, 0.26 mm/-0.07 D, and 0.20 mm/-0.02 D in children with two, one, and no myopic parents, respectively; P < 0.001). CONCLUSIONS Ocular biometric data in Chinese children suggest that parental history of myopia influences the growth rate of the eye, rather than its size before the onset of myopia, as previously reported in Caucasian children. Further longitudinal studies involving children of different ethnicities are warranted.

Quality of Reporting of Key Methodological Items of Randomized Controlled Trials in Clinical Ophthalmic Journals

Purpose: To evaluate the reporting quality of key methodological items in randomized controlled trials (RCTs) in four general clinical ophthalmology journals.Methods: The reporting of 11 key methodological items in RCTs published in American Journal of Ophthalmology, Archives of Ophthalmology, British Journal of Ophthalmology and Ophthalmology in the year 2005 was assessed. Results : Sixty-seven eligible RCTs were assessed and the mean number of items reported was 6.3 per RCT. No significant difference in the mean number of items reported was found between the four journals (P = 0.20). The most frequently reported item was ethics approval and informed consent (97.0%), followed by masking status (85.1%), description of withdrawals (76.1%), adverse events (73.1%), and intention-to-treat analysis (71.6%). Details on sequence generation, randomization restriction, allocation concealment, allocation implementation, patient flow diagrams, and sample size calculation were reported in < 50% of the RCTs assessed. Both sample size and page length of the RCTs correlated with the number of methodological items reported (P = 0.024 and P = 0.008, respectively). Conclusions: Similar to other specialties, rooms for improvement exist in the reporting of key methodological items of RCTs in clinical ophthalmic journals. Stricter adoption of the CONSORT statement might enhance the reporting quality of RCTs in ophthalmic journals.

Retinal Redetachment after Silicone Oil Removal in Proliferative Vitreoretinopathy: A Prognostic Factor Analysis

PURPOSE To determine the prognostic factors associated with retinal redetachment after 1300-centistokes silicone oil removal in rhegmatogenous retinal detachments (RDs) associated with grade C proliferative vitreoretinopathy (PVR). DESIGN Nonrandomized, retrospective, comparative interventional trial. METHODS One hundred and forty-seven eyes with RD and grade C PVR treated with silicone oil tamponade, with subsequent silicone oil removal, in an institutional setting. Main outcome measures included anatomic success, defined as complete retinal attachment after silicone oil removal, and best-corrected visual acuity (BCVA) after silicone oil removal. RESULTS Silicone oil was removed after a mean tamponade period of 12.4+/-9.8 months. The mean follow-up after silicone oil removal was 22.1+/-18.7 months (range, 6.0 to 71.0 months). The retina remained attached in 120 eyes after oil removal. The overall anatomic success rate was 81.6%+/-3.2%. Logistic regression showed that an increased number of previous unsuccessful RD surgeries (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.19 to 0.80; P=.010) and longer axial lengths (OR, 0.42; 95% CI, 0.15 to 0.87; P=.032) were associated with a lower anatomic success rate. Previous vitrectomy, previous scleral buckling procedure, 12% perfluoropropane-air exchange immediately after silicone oil removal, and duration of silicone oil tamponade were not statistically associated with the anatomic success rate. Anatomic success was associated with a significantly better BCVA (1.169+/-0.475 vs 1.520+/-0.381 logarithm of the minimum angle of resolution; P<.001). CONCLUSIONS The number of previous surgeries and axial length, rather than the nature of the previous surgical procedures, were significant prognostic factors for anatomic success after silicone oil removal.

Macular pigment optical density in a Chinese sample.

Purpose: Extensive efforts have been devoted to determining the macular pigment optical density (MPOD) in Caucasian subjects. Unfortunately, no such data in ethnic groups with naturally dark irises are currently available. In this study, we report the values in a sample of Chinese subjects. Methods: The MPOD was measured psychophysically using a densitometer at 0.25°, 0.50°, 1.00°, and 2.00° eccentricity from the foveal center in 92 Chinese subjects. Results: The spatial profile for the averaged MPOD was approximately exponential in form and showed a decline with age (r = −0.23). Subjects aged below 60 years had significantly higher averaged MPOD than those aged 60 years or above. Significant gender differences, in favor of males, were also found in the middle-age groups. Conclusions: Our study reports for the first time the MPOD in a Chinese population. Baseline information on MPOD would aid future research in preventive measures against age-related macular degeneration.

Retained presumed intraocular cotton fiber after cataract operation: Long-term follow-up with in vivo confocal microscopy

PURPOSE: To evaluate the long‐term clinical outcomes in eyes with retained presumed intraocular cotton fibers after cataract surgery. SETTING: Hong Kong Eye Hospital, Hong Kong, The Peoples Republic of China. METHODS: A retrospective review of 19 eyes with retained presumed intraocular cotton fibers after cataract surgery was performed. Outcome measures were fiber‐related complications. In vivo confocal microscopy was performed in eyes with entrapped cotton fibers at the wound site. RESULTS: The duration of retained presumed cotton fibers ranged from 5 to 110 months (mean 42.3 months). No complications were noted in any of these eyes, including endophthalmitis, persistent uveitis, or corneal endothelial cell loss. In vivo confocal microscopy in eyes with entrapped fibers at the wound site showed normal corneal endothelium morphology with no keratocyte activation or inflammatory response. CONCLUSIONS: Retained presumed fibers after cataract operations are more common than anticipated. In contrast to other organic foreign bodies, these retained fibers appear to be well tolerated. Conservative treatment can be adopted for these fibers as these pose minimal toxicity to the eye.

Vitrectomy for Diabetic Macular Edema with and without Internal Limiting Membrane Removal

ischemia, however, could only be diagnosed by fundus fl uorescent angiography. We would be grateful if the authors let us know whether they had excluded the presence of macular ischemia in these already ischemic retinas. Secondly, for a valid head-to-head comparison to be made, the study should also include a documentation of potential confounders that may affect the visual and anatomical outcomes. Information including the duration of diabetic edema, the number of previous laser treatments and the time since the last focal/grid laser treatment would be helpful in allowing the reader to better evaluate the results of the study. Lastly, it would be important to exclude type II error in this ‘negative’ study (i.e. no statistically signifi cant difference between the two treatment groups). Were there any In the article by Yamamoto et al. [1] , the authors concluded that vitrectomy in eyes with diabetic macular edema without internal limiting membrane (ILM) removal was as effective in reducing the retinal thickness and improving the visual acuity as in eyes with ILM removal. There were several issues that raised our interest. Firstly, there were more proliferative diabetic retinopathy (PDR) than non-PDR eyes in either group of the study. A recent article by Mason et al. [2] in which vitrectomy was performed for PDR eyes found that preand postoperative iris neovascularization, postoperative macular ischemia and postoperative vitreous hemorrhage were signifi cant prognostic factors for negative visual outcomes. The authors have documented no cases of iris neovascularization and vitreous hemorrhage in their series. Macular Received: August 26, 2005 Accepted: September 16, 2005

Sub-Tenon's block versus topical anaesthesia for cataract surgery.

We read with great interest the article by Ruschen et al comparing patient satisfaction during cataract surgery with sub-Tenon’s block (STB) versus topical anaesthesia (TOP).1 The authors concluded that in the setting of day case cataract surgery, patients reported significantly higher satisfaction scores with STB than TOP. We would like to raise two issues for discussion. Firstly, the lower satisfaction score in the TOP group may only reflect a suboptimal TOP that was given in the current study and may not be generalisable to other …

Cystoid macular oedema with trypan blue use

We read with interest the article by Gouws et al 1 on the apparent increased incidence of cystoid macular oedema (CMO) in phacoemulsification patients when trypan blue was used to stain the anterior capsule. Trypan blue has been commonly used in both anterior and posterior segment surgeries.2–4 If trypan blue does cause macular toxicity, its risks should theoretically be higher when used in posterior segment surgeries. However, studies on the use of trypan blue, both in the anterior2,3 …