Vincent Y. W. Lee

Phacoemulsification time and power requirements in phaco chop and divide and conquer nucleofractis techniques.

Purpose: To evaluate the differences in phaco time and power required between the divide and conquer and phaco chop nucleofractis techniques. Setting: Department of Ophthalmology, Central Middlesex Hospital, London, United Kingdom. Methods: A retrospective pilot study of 125 patients was followed by a prospective randomized study of 117 patients comparing the phaco chop with divide and conquer techniques in terms of phaco time (minutes), phaco power (%), equivalent phaco time (calculated time required if 100% power had been used throughout), intraoperative and postoperative complications, and postoperative visual acuity. Results: In the pilot study, mean phaco time in the phaco chop group was 1.4 minutes ± 0.09 (SD) and in the divide and conquer group, 3.4 ± 0.1 minutes (P < .0001). Mean equivalent phaco time was also less in the phaco chop group (0.39 ± 0.03 minutes) than in the divide and conquer group (0.98 ± 0.08 minutes) (P < .0001). In the prospective study, phaco chop required significantly less phaco time (1.2 ± 0.1 minutes) than divide and conquer (2.4 ± 0.1 minutes) (P < .0001), less phaco power (25.3% ± 1.2% versus 35.1% ± 1.2%) (P < .0001), and less equivalent phaco time (0.29 ± 0.02 minutes versus 0.84 ± 0.05 minutes) (P < .0001). The operating time was shorter in the phaco chop group. There were no differences in complications and postoperative visual acuity. Conclusions: This study showed a significant advantage of the phaco chop over the divide and conquer technique in phaco power and duration. Phaco chop also required less operative time and intraocular manipulation without an apparent increase in intraoperative or postoperative complications.

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.

Microhook capsule stabilization for phacoemulsification in eyes with pseudoexfoliation-syndrome-induced lens instability

Cataract extraction in eyes with pseudoexfoliation syndrome is known to result in a high incidence of intraoperative and postoperative complications. Lens instability--phacodonesis--is often present and may lead to zonular rupture, capsule tears, and vitreous loss. We describe the use of microhook iris retractors to stretch and fixate the capsulorhexis relative to the sclera, which stabilizes the capsular bag and facilitates safe phacoemulsification in eyes with pseudoexfoliation-syndrome-induced lens instability. Results of this technique in 8 eyes are reported.

Ocular-hypertensive response and corneal endothelial changes after intravitreal triamcinolone injections in Chinese subjects: a 6-month follow-up study

PurposeTo assess the intraocular pressure (IOP) and corneal endothelial changes, over a 6-month period, after a single injection of intravitreal triamcinolone (ivTA) in Chinese patients.MethodsA total of 43 eyes of 43 consecutive Chinese patients with various macular diseases received a single bolus injection of 4 mg ivTA, of which, 14 eyes with significant cataracts underwent simultaneous phacoemulsification and primary intraocular lens implantation. IOP was measured preoperatively and weekly in the first month, and then monthly until 6 months postinjection. Specular microscopy was performed on 24 of the 29 eyes without simultaneous cataract surgery, preoperatively and at months 1, 3, and 6.ResultsAll patients completed 6 months of follow-up. Nine out of 43 (20.9%) eyes had IOP >21 mmHg. Their mean maximum IOP was 29.2 mmHg (range 23.0–37.0), necessitating the use of 2.0 types of topical antiglaucomatous medications on average. The IOP elevation occurred at a mean of 5.2 weeks (range 1–17) postinjection. All IOPs returned to normal, without additional antiglaucomatous medications, by 6 months. There was no statistically significant difference (paired t-test, P<0.05) in the corneal endothelial cell count and other specular microscopy parameters up to 6 months after the injections.ConclusionA single 4 mg bolus injection of ivTA appeared to have no harmful effects on the corneal endothelium. IvTA caused transient IOP elevations in 20.9% of Chinese patients, similar to that observed in Caucasians. As the IOP rise can occur as early as 1 week after the injection, early monitoring will help its early detection and prevent optic nerve damage.

Screening for visual impairment in elderly patients with hip fracture: validating a simple bedside test

Screening for visual impairment in elderly patients with hip fracture: validating a simple bedside test

Interactive Expressions of HtrA1 and VEGF in Human Vitreous Humors and Fetal RPE Cells

PURPOSE High-temperature requirement factor A1 (HtrA1) is associated with exudative age-related macular degeneration, an angiogenic retinal disease related to vascular endothelial growth factor (VEGF). This study investigates the interactive relationship between the expressions of HtrA1 and VEGF. METHODS; The vitreous humor levels of HtrA1, VEGF, and pigment epithelium-derived factor were determined in 55 unrelated Han Chinese patients who underwent ocular surgeries. Expressions of HTRA1 and VEGFA were studied interactively and under stress conditions in primary human fetal retinal pigment epithelial (RPE) cells to evaluate their regulations. RESULTS Vitreous levels of HtrA1 were significantly associated with that of VEGF in vitreous samples from all patients (Pearsons correlation coefficient test, r = 0.650, P = 7.91 × 10(-8)) and from patients with retinal detachment (r = 0.835, P = 2.14 × 10(-7)). On stress induction, HTRA1 and VEGFA were upregulated in human fetal RPE cells treated by tunicamycin and dithiothreitol, but reduced after treatment by MG132. However, HtrA1 and VEGF did not regulate each other in their expressions. CONCLUSIONS This study revealed an association between HtrA1 and VEGF in human vitreous humors and RPE cells. They are both related to stress and inflammatory conditions.

Decompression retinopathy following laser peripheral iridoplasty for acute primary angle-closure.

Decompression retinopathy following laser peripheral iridoplasty for acute primary angle-closure

Randomized controlled trial on the safety of intracameral cephalosporins in cataract surgery.

Objective: To compare the safety profiles of intracameral cephalosporins in cataract surgery. Patients and methods: In this controlled trial, 129 patients were randomized to one of four groups to receive 1 mg of one of three cephalosporins – cefazolin, cefuroxime, or ceftazidime, or normal saline – given intracamerally during cataract surgery. Central endothelial cell density (ECD) and retinal center point thickness (CPT) were determined by specular microscopy and ocular coherence tomography, respectively, before and at 3 months after surgery. Results: There were no statistical significant differences in the changes of ECD and CPT between eyes receiving intracameral cephalosporin and control. Conclusion: The use of intracameral cefazolin, cefuroxime, or ceftazidime (1 mg in 0.1-mL solution) at the time of cataract surgery had no significant effect on ECD and CPT postoperatively.

Multiport-illumination-system-assisted phacoemulsification in eyes with dense vitreous hemorrhage during combined cataract and vitreous surgery

&NA; We describe the use of a multiport illumination system to enhance the red reflex during combined phacoemulsification and pars plana vitrectomy in 10 patients with cataract and vitreous hemorrhage. This method improves illumination and visualization of the lens structures and the instruments, which may reduce the risk of complication. To our knowledge, this approach has not been reported.

Intravitreal dexamethasone for diabetic macular edema: a pilot study.

BACKGROUND AND OBJECTIVE To determine the response and safety profile of intravitreal dexamethasone in treating diabetic macular edema. PATIENTS AND METHODS In this prospective pilot study, 12 eyes of 12 patients with diabetic macular edema were randomized to receive a single injection of 0.4 mg (n = 6) or 0.8 mg (n = 6) of intravitreal dexamethasone. The outcome measures were changes in best-corrected visual acuity and central foveal thickness on optical coherence tomography. Side effects were monitored. RESULTS The 3-month results were reported. In both dosage groups, there were transient improvements in best-corrected visual acuity and central foveal thickness, but the changes were not significant at any time point (best-corrected visual acuity: P > or = 0.14; central foveal thickness: P > or = .08). No significant side effects were observed, except one eye developed a peak intraocular pressure of greater than 21 mm Hg. CONCLUSION A single injection of intravitreal dexamethasone (0.4 or 0.8 mg) did not have significant beneficial effects on diabetic macular edema within 3 months from injection in this small pilot study.