Pia Easter Leon

Stroke dynamics and frequency of 3 phacoemulsification machines

PURPOSE: To measure the working frequency and the stroke dynamics of the phaco tip of 3 phacoemulsification machines. SETTING: University Eye Clinic of Trieste, Italy. DESIGN: Experimental study. METHODS: A video wet fixture was assembled to measure the working frequency using a micro camera and a micropulsed strobe‐light system. A different video wet fixture was created to measure tip displacement as vectorial movement at different phaco powers using a microscopic video apparatus. RESULTS: The working frequency of the Infiniti Ozil machine was 43.0 kHz in longitudinal mode and 31.6 kHz in torsional mode. The frequency of the Whitestar Signature machine was 29.0 kHz in longitudinal mode and 38.0 kHz with the Ellips FX handpiece. The Stellaris machine had a frequency of 28.8 kHz. The longitudinal stroke of the 3 machines at different phaco powers was statistically significantly different. The Stellaris machine had the highest stroke extent (139 μm). The lateral movement of the Infiniti Ozil and Whitestar Signature machines differed significantly. No movement on the y‐axis was observed for the Infiniti Ozil machine in torsional mode. The elliptical path of the Ellips FX handpiece had different x and y components at different phaco powers. CONCLUSIONS: The 3 phaco machines performed differently in terms of working frequency and stroke dynamics. The knowledge of the peculiar lateral and elliptical path strokes of Infiniti and Whitestar Signature machines may allow the surgeon to fully use these features for lens removal. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Correction of low corneal astigmatism in cataract surgery.

AIM To evaluate and compare aspheric toric intraocular lens (IOL) implantation and aspheric monofocal IOL implantation with limbal relaxing incisions (LRI) to manage low corneal astigmatism (1.0-2.0 D) in cataract surgery. METHODS A prospective randomized comparative clinical study was performed. There were randomly recruited 102 eyes (102 patients) with cataracts associated with corneal astigmatism and divided into two groups. The first group received toric IOL implantation and the second one monofocal IOL implantation with peripheral corneal relaxing incisions. Outcomes considered were: visual acuity, postoperative residual astigmatism, endothelial cell count, the need for spectacles, and patient satisfaction. To determine the postoperative toric axis, all patients who underwent the toric IOL implantation were further evaluated using an OPD Scan III (Nidek Co, Japan). Follow-up lasted 6mo. RESULTS The mean uncorrected distance visual acuity (UCVA) and the best corrected visual acuity (BCVA) demonstrated statistically significant improvement after surgery in both groups. At the end of the follow-up the UCVA was statistically better in the patients with toric IOL implants compared to those patients who underwent implantation of monofocal IOL plus LRI. The mean residual refractive astigmatism was of 0.4 D for the toric IOL group and 1.1 D for the LRI group (P<0.01). No difference was observed in the postoperative endothelial cell count between the two groups. CONCLUSION The two surgical procedures demonstrated a significant decrease in refractive astigmatism. Toric IOL implantation was more effective and predictable compared to the limbal relaxing incision.

Combined therapy with bevacizumab and photodynamic therapy for myopic choroidal neovascularization: A one-year follow-up controlled study

AIM To evaluate the efficacy and safety of a combined treatment for myopic choroidal neovascularization (CNV) using photodynamic therapy (PDT) and intravitreal bevacizumab and to compare it with intravitreal bevacizumab monotherapy. METHODS Thirty-four eyes with angiographic evidence of myopic CNV were randomly divided into two groups: 17 were treated with one intravitreal bevacizumab injection (1.25 mg) and low-fluence-rate PDT within seven days of the injection (Group A). The other 17 received monotherapy with bevacizumab injections (Group B). Clinical evidence of complications, best corrected visual acuity (BCVA) and fluorescein leakage were evaluated. BCVA and optical coherence tomography (OCT) were evaluated monthly. The timepoints follow-up was established at 6 and 12mo. All patients were retreated following a PRN protocol. RESULTS A total of 34 eyes of 34 patients (26 women and 8 men) with a mean age of 62.35 years were included. In Group A (17 eyes) the mean BCVA increased from 0.55±0.13 logMAR before the treatment to 0.40±0.09 logMAR at the 12mo follow-up (P<0.01). In Group B (17 eyes) the mean BCVA increased from 0.60±0.11 logMAR before the treatment to 0.55±0.12 logMAR at the 12mo follow-up (P<0.01). There was no statistically significant difference between the two groups in terms of LogMar visual acuity. In Group A the mean number of combined treatments was 1.8±0.11 per patient; in Group B the mean number of intravitreal bevacizumab injections was 3.1±0.08 per patient. The number of treatments was significantly fewer in Group A (P<0.01). No local or systemic side effects occurred among any of the patients treated in this study. CONCLUSION The combination of anti-angiogenic injections and PDT appears to be a safe and effective option for myopic CNV treatment and allows for a significant reduction of intravitreal injections.

An evaluation of intraoperative and postoperative outcomes of torsional mode versus longitudinal ultrasound mode phacoemulsification: a Meta-analysis

AIM To evaluate and compare the intraoperative parameters and postoperative outcomes of torsional mode and longitudinal mode of phacoemulsification. METHODS Pertinent studies were identified by a computerized MEDLINE search from January 2002 to September 2013. The Meta-analysis is composed of two parts. In the first part the intraoperative parameters were considered: ultrasound time (UST) and cumulative dissipated energy (CDE). The intraoperative values were also distinctly considered for two categories (moderate and hard cataract group) depending on the nuclear opacity grade. In the second part of the study the postoperative outcomes as the best corrected visual acuity (BCVA) and the endothelial cell loss (ECL) were taken in consideration. RESULTS The UST and CDE values proved statistically significant in support of torsional mode for both moderate and hard cataract group. The analysis of BCVA did not present statistically significant difference between the two surgical modalities. The ECL count was statistically significant in support of torsional mode (P<0.001). CONCLUSION The Meta-analysis shows the superiority of the torsional mode for intraoperative parameters (UST, CDE) and postoperative ECL outcomes.

Spontaneous or secondary to intravitreal injections of anti-angiogenic agents retinal pigment epithelial tears in age-related macular degeneration

AIM To evaluate the visual function evolution of retinal pigment epithelial (RPE) tears in patients with age-related macular degeneration (AMD) according to type of occurrence [spontaneous or secondary to anti-vascular endothelial growth factor (anti-VEGF) injection] and the topographic location of the tear after a two-year follow-up period. METHODS A total of 15 eyes of 14 patients with RPE tears in exudative AMD were analyzed retrospectively at the University Eye Clinic of Trieste. Inclusion criteria were: patient age of 50 or older with AMD and RPE tears both spontaneous occurring or post anti-VEGF treatment. Screening included: careful medical history, complete ophthalmological examination, fluorescein angiography (FA), indocyanine green angiography (ICG), autofluorescence and infrared imaging and optical coherence tomography (OCT). Patients were evaluated every month for visual acuity (VA), fundus examination and OCT. Other data reported were: presence of PED, number of injections before the tear, location of the lesion. RESULTS Mean follow-up was 24wk (SD±4wk). A total of 15 eyes were studied for RPE tear. In 6 cases (40%), the RPE tears occurred within two years of anti-VEGF injections the others occurred spontaneously. In 13 cases (86.6%), the RPE tear was associated with pigment epithelial detachment (PED). In 7 cases (46.6%), the RPE tear occurred in the central area of the retina and involved the fovea. Two lesions were found in the parafoveal region, six in the extra-macular area. In all cases visual acuity decreased at the end of the follow-up period (P<0.01) independently of the type or the topographical location of the lesion. CONCLUSION RPE tear occurs in exudative AMD as a spontaneous complication or in relation to anti-VEGF injections. Visual acuity decreased significantly and gradually in the follow-up period in all cases. No correlation was found between visual loss and the type of onset or the topographic location of the tears.

Role of the phaco tip surface.

Role of the phaco tip surface In his article reporting the results of a new prototype phacoemulsification tipwith internal grooves (threaded tip), Watanabe showed that the threaded tip can amplify the cavitation effect and that intensification of cavitation gives a higher phacoemulsification effect. We have also investigated the role of the phaco tip whenultrasound (US) energywith anultra-speedvideo recording system is applied by analyzing the stroke motion and the surface constitution before and after surgery. Based on our data and the frames of the videos, we assume that the shape of the phaco tip correlates to sections where the deterioration effect of cavitation is seen. This suggests that generation of the turbulence waves also depends on the tip design. In 2005, we described a technique for visualizing fluid turbulence and cavitation created by a US phaco tip and suggested that cavitation was involved in fragmentation of the nucleus. The study by Zacharias indicates that there is no relationship between cavitation and phacoemulsification power; moreover, he found that cavitation does not improve cutting function.Watanabe often references Zacharias’work, often to support his own work, but attempts to contradict it if we consider the conclusion expressed above. Another consideration to evaluate is related to the fact that grooves create more cavitation. This is not a positive and safe result if the tissue damage effect and the dispersion of metal fragments in the anterior chamber are considered.Clinical studies show that cavitationmayplay a role in decreasing endothelial cells. Theapplicationof high-intensityUS energy in the aqueous media can generate acoustic cavitation with the concomitant generation of free radicals and sonoluminescence, aphenomenon inwhichelectronically excited species cause the emission of a light flash. It can also cause localized high pressure and temperature elevation. All these factors can cause tissue damage. Nevertheless, we strongly believe that the grooves, as designed by Watanabe, provide traction and mechanical adherence that could give the user a feeling of less chatter and can improve gripping capacity. In conclusion, we consider Watanabe’s study interesting and innovative and think that future studies should consider the potential role of the change of the tip surface to increase the gripping adherence and to reduce the chattering effect of the phaco tip.

Unilateral Optic Neuritis: A Rare Complication after Measles-Mumps-Rubella Vaccination in a 30-Year-Old Woman.

Purpose. To report a case of unilateral optic neuritis following Measles-Mumps-Rubella (MMR) vaccination. Methods. A 30-year-old female developed unilateral optic neuritis five days after a Measles-Mumps-Rubella (MMR) booster vaccination. The patient displayed unilateral involvement, with severe visual loss. However, visual acuity improved significantly after four days of intravenous steroid therapy with 500 mg/day of methylprednisolone. Conclusions. Optic neuritis is one of the rare complications associated with the mumps, measles, and rubella vaccine. It may be a toxic reaction to the nonviral component of the vaccine, but the exact etiology is unknown. Postvaccination neuritis is generally bilateral and usually affects children. In adults, unilateral optic neuritis is usually correlated with multiple sclerosis (MS).