André Maia

Fluid dynamics in three 25-gauge vitrectomy systems: principles for use in vitreoretinal surgery.

Purpose:  To compare infusion and extrusion fluid volumes with three 25‐gauge vitrectomy systems.

INTRAVITREAL INJECTIONS OF ZIV-AFLIBERCEPT FOR DIABETIC MACULAR EDEMA: A Pilot Study.

Purpose: Diabetic macular edema is the leading cause of blindness in young adults in developed countries. Beyond metabolic control, several therapies have been studied such as laser treatment and intravitreal injections of corticosteroids or anti–vascular endothelial growth factor drugs. In terms of public health the long-term treatment with the current available drugs is very expensive and new therapies with the same or better effect should be investigated. This study sought to evaluate the efficacy and safety of intravitreal injections of ziv-aflibercept for the treatment of diabetic macular edema. Methods: Seven consecutive patients with diabetic macular edema were enrolled. A complete examination, including full-field electroretinography, visual acuity, central retinal thickness, and evaluation of systemic and ocular complications, was performed before and at 24 weeks after intravitreal injections of ziv-aflibercept. The seven patients were submitted to six consecutive intravitreal injections of ziv-aflibercept with a 4-week interval. Results: No significant differences were found in the amplitude or implicit time of any electroretinography component after intravitreal injections of ziv-aflibercept, and no systemic or ocular complication was observed. The improvement of visual acuity was significant at 24 weeks (P < 0.05). The central retinal thickness significantly decreased during the course of 24 weeks. Conclusion: Intravitreal injections of ziv-aflibercept seem to be a safe and effective treatment option for diabetic macular edema.

Intravitreal Injection of Ziv-Aflibercept in Patient With Refractory Age-Related Macular Degeneration

The results of a patient with exudative age-related macular degeneration who received an intravitreal injection of ziv-aflibercept (Zaltrap; Sanofi-Aventis, Paris, France) in the right eye are described. A complete ocular examination as well as color fundus photography, optical coherence tomography, fluorescein angiography, microperimetry, full-field electroretinography, and multifocal electroretinography were performed and repeated 1 month later. The patient experienced subjective and objective improvement of visual acuity with a decrease in intraretinal and subretinal fluid. Microperimetric improvement also occurred. Electroretinographic changes were noted from baseline to the 30-day follow-up. No adverse events were observed at any time point. Ziv-aflibercept demonstrated short-term safety and efficacy after intravitreal administration for neovascular macular degeneration.

Structure-function correlations in glaucoma using matrix and standard automated perimetry versus time-domain and spectral-domain OCT devices.

PURPOSE We examined the structure-function relationship between two perimetric tests, the frequency doubling technology (FDT) matrix and standard automated perimetry (SAP), and two optical coherence tomography (OCT) devices (time-domain and spectral-domain). METHODS This cross-sectional study included 97 eyes from 29 healthy individuals, and 68 individuals with early, moderate, or advanced primary open-angle glaucoma. The correlations between overall and sectorial parameters of retinal nerve fiber layer thickness (RNFL) measured with Stratus and Spectralis OCT, and the visual field sensitivity obtained with FDT matrix and SAP were assessed. The relationship also was evaluated using a previously described linear model. RESULTS The correlation coefficients for the threshold sensitivity measured with SAP and Stratus OCT ranged from 0.44 to 0.79, and those for Spectralis OCT ranged from 0.30 to 0.75. Regarding FDT matrix, the correlation ranged from 0.40 to 0.79 with Stratus OCT and from 0.39 to 0.79 with Spectralis OCT. Stronger correlations were found in the overall measurements and the arcuate sectors for both visual fields and OCT devices. A linear relationship was observed between FDT matrix sensitivity and the OCT devices. The previously described linear model fit the data from SAP and the OCT devices well, particularly in the inferotemporal sector. CONCLUSIONS The FDT matrix and SAP visual sensitivities were related strongly to the RNFL thickness measured with the Stratus and Spectralis OCT devices, particularly in the overall and arcuate sectors.

Perspective on Fluid and Solid Dynamics in Different Pars Plana Vitrectomy Systems

PURPOSE To summarize current concepts and recent data from the literature about different vitrectomy machines and small-gauge systems based on physical laws. DESIGN Interpretive essay. METHODS Review and synthesis of selected recent literature with interpretation and perspective. RESULTS Pars plana vitrectomy can be performed with a wide variety of treatment strategies, for multiple diseases, and with different materials (solids and fluids). We discuss a variety of machines and system settings (peristaltic pump, duty cycle, aspiration, and infusion controls) targeting safer and the most effective surgery with detailed explanations of the physical properties. CONCLUSIONS Effective management of new surgical strategies is based on recognizing and addressing various physical characteristics in disease and ocular settings. Although the properties of machine are expanding, the long-term efficacy and safety of most new approaches have yet to be established in controlled clinical trials.

Ultrasound biomicroscopy in recently postoperative 23-gauge transconjunctival vitrectomy sutureless self-sealing sclerotomy.

Purpose: To evaluate the ultrasound biomicroscopy (UBM) images of recent postoperative 23-gauge vitrectomy using single- and 2-step techniques. Methods: Twelve consecutive eyes were randomized and submitted to 23-gauge sutureless transconjunctival vitrectomy surgery divided in 2 groups: 1) using a beveled trocar to insert the microcannula (single step) and 2) using a stiletto blade to perform first a tunnel incision and then insert the microcannula (2 steps). All patients underwent 3-port vitrectomy with a straight angled incision of 20° to 30°. Ultrasound biomicroscopy examination was performed after 8 days to 10 days of surgery to locate and document the sclerotomy sites. Results: All patients had at least two diameters of the incision measured, and all wounds were constructed obliquely. Single-step sclerotomy mean size was 375.40 μm ± 83.70 μm (range, 280.4–695 μm) and coefficient of variation (CV) was 0.21. Two-step sclerotomy mean size was 315.5 μm ± 56.8 μm (range, 253.2–362.5 μm; CV = 0.26; P = 0.556). Two patients had an intraocular 5,000 centistokes silicone oil injection, one for each group. Only in the single-step incision was silicone oil observed in the wound. Conclusion: Twenty-three-gauge single- and two-step sclerotomies showed no statistical difference in site diameter at UBM. Postoperative UBM examination allowed the evaluation of the wound architecture. A large sample size comparing both surgical techniques should provide a statistical difference.

Effect of lens status in the surgical success of 23-gauge primary vitrectomy for the management of rhegmatogenous retinal detachment: the Pan American Collaborative Retina Study (PACORES) group results.

Purpose: To determine the effects of lens status on the success rate of primary pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment using either perfluoropropane gas (C3F8) or silicone oil (SO) tamponade. Methods: A retrospective chart analysis was made of 97 eyes from 92 patients with rhegmatogenous retinal detachment with no proliferative vitreoretinopathy that were treated with primary 23-gauge PPV. Eyes included in this were phakic (n = 28), pseudophakic (n = 41), or phakic eyes subject to simultaneous phacoemulsification, intraocular lens implantation, and PPV during primary rhegmatogenous retinal detachment repair (n = 28). Tamponade at the end of PPV was with either C3F8 (n = 65) or SO (n = 32). Success was defined as retinal reattachment at 1 year follow-up after a single procedure in eyes submitted to C3F8 injection; in eyes treated with SO injection, the success rate was defined as retina reattached 1 year after oil removal. Statistical comparisons were made between groups using chi-square, Fishers exact test, Kruskal–Wallis, Mann–Whitney, and multivariate analysis. All eyes were operated by 2 experienced retina surgeons and had a minimum follow-up of 12 months. Results: The vitreoretinal redetachment rate in eyes subjected to C3F8 tamponade was significantly higher (28.6%) for phakic eyes (P = 0.011) compared with pseudophakic or phakic eyes that underwent to phacoemulsification and intraocular lens implantation (4.5%). Eyes in which SO was used at the end of the surgical procedure demonstrated a similar trend of higher reoperation rates in phakic eyes (28.6%) compared with pseudophakic or phakic eyes (8%) subjected to phacoemulsification and intraocular lens implantation; however, no statistically significant difference was observed (P = 0.201). No statistically significant differences were found between groups in relation to the number of tears (P = 0.863) and their location (inferior: P = 0.189, superior: P = 0.708, nasal: P = 0.756, and temporal: P = 0.08). Conclusion: The success rates of primary 23-gauge PPV with either C3F8 or SO tamponade in pseudophakic eyes with rhegmatogenous retinal detachment was higher than the same procedure performed in phakic eyes. Still, the retrospective and limited data presented is too preliminary to suggest or recommend that practitioners perform simultaneous combined cataract surgery with retinal detachment and requires further studies in a larger and prospective design to confirm these present findings.

Clinical And Electrophysiological Evaluation After Intravitreal Ziv-aflibercept For Exudative Age-related Macular Degeneration

Purpose: To evaluate the 6-month safety and efficacy of ziv-aflibercept intravitreal injections for treating exudative age-related macular degeneration. Methods: Fifteen patients with unilateral exudative age-related macular degeneration were enrolled. The best-corrected visual acuity was measured and spectral domain optical coherence tomography was performed at baseline and monthly. Full-field electroretinography and multifocal electroretinography were obtained at baseline and 4, 13, and 26 weeks after the first injection. All patients received three monthly intravitreal injections of ziv-aflibercept (1.25 mg) followed by as-needed treatment. Results: Between baseline and 26 weeks, the mean logMAR best-corrected visual acuity improved (P = 0.00408) from 0.93 ± 0.4 (20/200) to 0.82 ± 0.5 (20/160) logarithm of the minimum angle of resolution, respectively; the central retinal thickness decreased significantly (P = 0.0007) from 490.3 ± 155.1 microns to 327.9 ± 101.5 microns; the mean total macular volume decreased significantly (P < 0.0001) from 9.51 ± 1.36 mm3 to 8.08 ± 1.34 mm3, and the a-wave implicit time increased, with no differences in the other full-field electroretinography parameters. The average multifocal electroretinography macular responses within the first central 15° showed significantly (P < 0.05) increased P1 amplitudes at 26 weeks. No systemic or ocular complications developed. Conclusion: Intravitreal ziv-aflibercept significantly improved the best-corrected visual acuity, multifocal electroretinography amplitudes, central retinal thickness, and total macular volume from baseline to 26 weeks. No retinal toxicity on full-field electroretinography or adverse events occurred during the follow-up period.

Heavy Silicone Oil as a Long-Term Endotamponade Agent for Complicated Retinal Detachments

We retrospectively evaluated a heavy silicone oil (HSO) as a long-term intraocular endotamponade agent to treat complicated RD by inferior PVR in 25 eyes of 25 patients. Patients underwent PPV and injection of Oxane HD as an internal tamponade agent. A comparison of preoperative and postoperative BCVA at month 1, month 6, and last visit was made in the group in which HSO was removed and in the group in which HSO was not removed. Statistical calculations were performed using the Wilcoxon test. The HSO was removed from 11 patients after a mean of 26.55 ± 21.38 months. The HSO remained inside the vitreous cavity in 14 eyes due to a high chance of PVR recurrence (mean follow-up period, 11.07 ± 7.44 months). Anatomic success was achieved in 92%. The BCVA in the group, in which HSO was not removed, improved significantly during the first 6 months. Among the patients who had the oil removed, there was improvement in BCVA after 1 month. Oil emulsification was the most common adverse effect in 52% of eyes. HSO is an effective tamponade in complex rhegmatogenous and tractional RD complicated by PVR. HSO can remain in the eye for long periods with relative tolerability and safety.

SUPRACHOROIDAL BUCKLING FOR THE MANAGEMENT OF RHEGMATOGENOUS RETINAL DETACHMENTS SECONDARY TO PERIPHERAL RETINAL BREAKS.

Purpose: To evaluate functional and anatomical outcomes of eyes undergoing suprachoroidal buckling for the management of peripheral retinal breaks in rhegmatogenous retinal detachment. Methods: Retrospective cohort study of 41 eyes of 41 patients undergoing suprachoroidal buckling for the management of rhegmatogenous retinal detachment secondary to single or multiple retinal breaks. Suprachoroidal indentation was achieved through the introduction of filler material using a 23-gauge (23-G) olive-tipped, suprachoroidal cannula. This allowed for the creation of a suprachoroidal dome and chorio-retinal apposition. Healon5 (Abbott Medical Optics) was used as filler material in all eyes. Combined 25-G vitrectomy was performed in 5 eyes. Cryopexy and laserpexy were used in 37 and 4 eyes, respectively. Results: Mean visual acuity gain was the primary outcome measure. Final retinal reattachment rate, single-surgery reattachment rate, and complications were secondary outcome measures. Mean best-corrected distance visual acuity improved from 20/1,100 to 20/42. Single surgery reattachment rate was 92.7% (38/41 eyes). Final retinal reattachment was achieved in all 41 eyes (100%). There was no statistically significant difference in visual acuity gain or anatomical reattachment in terms of retinal break quadrant or extent. No major complications were observed. Two localized suprachoroidal hemorrhages occurred at the entry site for the cannula. These resolved without further intervention. Conclusion: Suprachoroidal buckling using a specially designed cannula is a safe and effective procedure for the management of rhegmatogenous retinal detachment secondary to peripheral retinal breaks.