[Empirical study on nano-fluorouracil-coated intraocular lens inhibiting posterior capsule opacification]

OBJECTIVE

To prepare nano-fluorouracil-coated intraocular lens (IOL) and to investigate its effect and feasibility of inhibiting posterior capsule opacification (PCO) of rabbit.

METHODS

Nano-fluorouracil is cross linked with IOL with the technology of energy-loaded particle beam. Forty New Zealand white rabbits were medially divided into 2 groups named group A and B randomly. All the crystalline lens of the left eyes were emulsified and evacuated of by the same operator, and then different treatment in different groups. In group A, the control group, the Polymethylmethacrylate (PMMA) IOLs were implanted. In group B, the nano-fluorouracil-coated IOLs were implanted. Slit-lamp-micrographscopy, histopathologyscopy and electron-microscopy were performed when 4 weeks after the operations.

RESULTS

The incidence rate and severity degree of PCO in control group is higher than the other group. The inflammatory reaction of anterior segment of the left eyes were remarkably occurred in group A. While almost no inflammatory reaction of anterior segment of the left eyes occurred in group B.

CONCLUSIONS

With implanting nano-fluorouracil-coated IOLs after phacoemulsification and evacuation of the crystalline lens can inhibit PCO actively and have slight toxic reaction and damage in the eyes.

Efficacy and tolerability of latanoprost compared to dorzolamide combined with timolol in the treatment of patients with elevated intraocular pressure: a meta-analysis of randomized, controlled trials

OBJECTIVE

The aim of this study was to evaluate the efficacy and tolerability of latanoprost, compared with the combination of dorzolamide and timolol, in the treatment of patients with elevated intraocular pressure (IOP).

METHODS

Pertinent randomized, controlled trials were identified through systematic searches of the Cochrane Library, PubMed, EMBASE, Chinese Biomedicine Database, and internet searches of meeting abstracts and the manufacturers' databases. The main efficacy measures were the IOP reduction (IOPR), including diurnal mean IOPR, and 10:00 IOPR. The main tolerability measure was withdrawal due to adverse events and individual adverse events.

RESULTS

Fourteen (14) studies involving 2149 patients were included in the meta-analysis. Latanoprost was significantly more effective in lowering diurnal mean IOP than combined dorzolamide and timolol in patients with IOP insufficiently controlled by timolol alone, with a weighted mean difference (WMD) for the diurnal mean IOPR% of 3.12 (95% confidence interval, 0.47-5.78) at 3 months, and latanoprost was as effective as the combination of dorzolamide and timolol in patients without baseline timolol treatment. The combination of dorzolamide and timolol was associated with numerically greater reductions in 10:00 IOP, compared with latanoprost in patients with or without timolol treatment at baseline: only the result in patients with baseline timolol treatment at 1 month was statistically significant (WMD -4.14: range, -5.78 to -2.50). The combination of dorzolamide and timolol was less tolerated than latanoprost, with pooled relative risk for withdrawals due to adverse events being 0.34 (range, 0.13-0.84).

CONCLUSIONS

Latanoprost was associated with significantly greater efficacy in lowering diurnal mean IOP than combined dorzolamide and timolol in patients with IOP insufficiently controlled by timolol alone, and latanoprost was as effective as combined dorzolamide and timolol in patients without baseline timolol treatment. The combination of dorzolamide and timolol was less tolerated than latanoprost.

Krypton yellow laser for the treatment of macular hole in high myopia without retinal detachment

PURPOSE

To evaluate the prophylactic effect of krypton yellow laser for the treatment of macular holes in high myopic eyes in order to reduce the risk of retinal detachment.

METHODS

Twenty-seven eyes of 27 patients with high myopia and macular holes were randomly assigned to two groups. Fifteen patients (group A, 15 eyes) were subject to laser photocoagulation around the hole margin along with an oral placebo (vitamin B1), while 12 patients (group B, 12 eyes) were only given the oral placebo (vitamin B1). The incident rate of retinal detachment due to macular hole and the mean best-corrected visual acuity of the two groups before and after treatment were measured. The data were statistically tested by X2 test and Student's t test.

RESULTS

The incident rates of retina1 detachment in group A and group B were 20%(3/15) and 58.3%(7/12), respectively (X2=4.201, P0.05). The mean BCVA of group B on the initial examination was 24/200, while the mean BCVA at the final follow-up was 30/200 (P>0.05). No significant difference in initial visual acuity (P>0.05) or final visual acuity (P>0.05) was found between the two groups.

CONCLUSION

Krypton yellow laser photocoagulation could reduce the incidence of retinal detachment due to a macular hole in high myopia with acceptable functional results in this study.

Transconjunctival orbitotomy for orbital cavernous hemangiomas

BACKGROUND

Orbital cavernous hemangiomas, particularly those within the retrobulbar space, are approached by neurosurgeons as well as by ophthalmic surgeons. Several surgical techniques have been applied over the past decades. Less traumatic approaches in this functionally and cosmetically important region are desirable. We describe a transconjunctival approach in 39 patients with orbital cavernous hemangiomas.

METHODS

Thirty-nine patients with orbital cavernous hemangiomas were treated with transconjunctival orbitotomy. The clinical and radiologic characteristics of orbital cavernous hemangiomas were analyzed in the course of their appropriate treatment.

RESULTS

In all patients, cavernous hemangiomas were just behind the globe or were compressing it. Computed tomography and magnetic resonance imaging showed orbital cavernous hemangiomas as round, well-defined intraconal masses. In 37 cases, the tumors were removed intact, and only 1 patient suffered permanent vision loss as a result of intraoperative hemorrhage. In the other 2 cases, the tumor fragments were incompletely removed. Visual acuity increased in 6 of the 9 cases with primary visual impairment. Thirty-two patients with primary proptosis were resolved completely. Six patients with visual field defect were also improved.

INTERPRETATION

Retrobulbar intraconal cavernous hemangiomas can be removed successfully through a transconjunctival approach. However, if the tumor is close to, or touching, the orbital apex, adhering tightly to retrobulbar tissue, or combined with large draining veins, operation through other approaches must be considered.

Intraocular pressure and endothelium cell counts after cataract surgery with chitosan and sodium hyaluronate (Healon GV): 3-year follow-up results of a randomised clinical trial

INTRODUCTION

The purpose of this study was to evaluate the long-term effects of chitosan 0.1% and sodium hyaluronate 1.4% (Healon GV(R); Advanced Medical Optics, Santa Ana, CA, USA) on intraocular pressure (IOP) and endothelial cell loss.

METHODS

This randomised study comprised 140 eyes of 140 patients with age-related cataracts undergoing phacoemulsification followed by posterior chamber intraocular lens (IOL) implantation; 70 received chitosan 0.1%, and 70 received sodium hyaluronate 1.4%. The IOP was measured with standard Goldman applanation tonometry pre-operatively and 1 day, 1 week, 1 month, 3 months, 1 year and 3 years postoperatively. Endothelial cell counts were performed pre-operatively and 1 week, 1 month, 3 months, 1 year and 3 years postoperatively using a Pro/Koester WFSCM contact endothelial microscope.

RESULTS

There were no significant differences found in postoperative IOP levels among the chitosan and sodium hyaluronate groups (P>0.05). No significant differences were found in postoperative mean endothelial cell counts at all time points between the chitosan and sodium hyaluronate groups (P>0.05).

CONCLUSION

Chitosan has the same effects as sodium hyaluronate on IOP and endothelium cells counts after cataract surgery and IOL implantation, and therefore may be an alternative ophthalmic viscoelastic device.

Prophylactic use of timolol maleate to prevent intraocular pressure elevation after Nd-YAG laser posterior capsulotomy

PURPOSE

To evaluate the effective prophylaxis of topical 0.5% timolol maleate for the intraocular pressure rise following Nd-YAG laser posterior capsulotomy.

METHODS

A total of 190 eyes of 184 patients who underwent Nd-YAG laser posterior capsulotomy were randomly assigned to pre-treatment with either topical application of 0.5% timolol maleate (treatment group) or nothing (control group).

RESULTS

The mean intraocular pressure (IOP) of the treatment group was 14.8+/-3.0 mmHg before capsulotomy and 15.7+/-3.4 mmHg after capsulotomy (P>0.05), whereas IOP was 15.1+/-3.3 mmHg and 17. 2+/-4.3 mmHg (P<0.05) for the control group. There was no statistically significant difference between the two groups with regard to mean IOP before capsulotomy (P>0.05), but a statistically significant difference was seen between the two groups after capsulotomy (P<0.05). Six of 91 eyes (6.6%, two with aphakia) in the treatment group had an IOP elevation greater than 6 mmHg compared with 14 of 99 eyes (14.1%, eight with aphakia) in the control group (P<0.01).

CONCLUSION

Pre-treatment with a topical application of 0.5% timolol maleate is effective in preventing IOP elevation after Nd-YAG laser posterior capsulotomy.

Efficacy of different intraocular lens materials and optic edge designs in preventing posterior capsular opacification: a meta-analysis

PURPOSE

To evaluate the efficacy of different intraocular lens (IOL) materials and optic edge designs in preventing posterior capsular opacification (PCO).

DESIGN

Systematic review and meta-analysis.

METHODS

Pertinent studies were selected through an electronic search of the Cochrane Library, MEDLINE, and Embase. The randomized controlled trials meeting the predefined criteria were reviewed systematically by meta-analysis. The treatment effects were measured as risk difference, and the pooled estimates were computed according to a random effect model.

RESULTS

In total, 23 randomized controlled trials were included in the present meta-analysis. The pooled risk differences of Nd:YAG laser capsulotomy rates were -24% (95% confidence interval [CI], -29% to -20%) comparing acrylic with polymethylmethacrylate (PMMA) lenses; -9% (95% CI, -17% to -1%) comparing silicone with PMMA lenses; 14% (95% CI, -8% to 36%) comparing hydrogel with PMMA lenses; 4% (95% CI, -2% to 10%) comparing silicone with acrylic lenses; 19% (95% CI, 8% to 30%) comparing hydrogel with acrylic lenses; and 28% (95% CI, 10% to 46%) comparing hydrogel with silicone lenses. The pooled risk differences of PCO rates were -39% (95% CI, -47% to -31%) comparing acrylic with PMMA lenses; -14% (95% CI, -29% to 0%) comparing silicone with acrylic lenses; 56% (95% CI, 36% to 75%) comparing hydrogel with acrylic lenses; and 48% (95% CI, 31% to 64%) comparing hydrogel with silicone lenses. When comparing sharp with rounded-edge designs, pooled risk differences of capsulotomy rates were -47% (95% CI, -77% to -17%) in PMMA lenses, -22% (95% CI, -47% to 2%) in acrylic lenses, and -9% (95% CI, -17% to 0%) in silicone lenses; pooled risk differences of PCO rates were -28% (95% CI, -50% to -7%) in acrylic lenses and -37% (95% CI, -46% to -27%) in silicone lenses.

CONCLUSIONS

The rates of PCO and Nd:YAG laser capsulotomy may be influenced by different IOL biomaterials and optic edge designs. The lenses made by acrylic and silicone and those with sharp optic edges are superior in lowering the rates of PCO and laser capsulotomy.

[Effect of phacoemulsification versus extracapsular extraction on visual acuity: a meta-analysis]

OBJECTIVE

To examine the efficacy of phacoemulsification (Phaco) versus extracapsular extraction (ECCE) on visual acuity.

METHODS

9 cases related with Phaco and ECCE were retrieved from PubMED and Chinese biomedical data base. The combinability of the studies was assessed in terms of clinical and statistical criteria. Treatment effect was measured as risk difference between phacoemulsification and extracapsular extraction. Pooled estimates were analyzed with computer according to a random-effects model.

RESULTS

A total of 1192 patients were included in 9 trials. The pooled risk differences of visual acuity 0.5 or better after surgery one week or 3 month were 24% (95% CI is 10% - 37%), 20% (95% CI is 14% - 25%) respectively. The complications extracapsular extraction rates (36.8%) of phacoemulsification was lower than extracapsular extraction (62.1%).

CONCLUSIONS

Phacoemulsification is a safer and reliable surgery for restoration of visual acuity in patients with cataract, and is superior to extracapsular cataract extraction.