Intraoperative bleeding during vitrectomy for diabetic tractional retinal detachment with versus without preoperative intravitreal bevacizumab (IBeTra study)

Aims: To compare the amount of intraoperative intraocular bleeding in patients with diabetes with macula-involving tractional retinal detachment (TRD) undergoing pars plana vitrectomy (PPV) with and without preoperative intravitreal bevacizumab (IVB) injection. Methods: An institutional study was carried out with consecutive patients with diabetic retinopathy and macula-involving TRD of recent (3 months) onset who were randomly assigned to PPV only (PPV group) or PPV combined with one IVB (1.5 mg/0.06 ml) injection 2 weeks prior to surgery (bevacizumab (BEV)/PPV group). All patients underwent 23-gauge PPV 3 weeks after baseline. The main outcome measure was erythrocyte count in the fluid retrieved from the vitrectomy cassette using a Neubauer counting chamber. Results: The study included 20 patients. The mean erythrocyte count was 14865x10(3) (SD 19332x10(3); median 4500x10(3)) cells in the BEV/PPV group, and 176240x10(3) (SD 108375x10(3); median 166600x10(3)) cells in the PPV group. The mean erythrocyte count was significantly lower in the BEV/PPV group than in the PPV group (p < 0.0001). No major adverse events were identified. Conclusion: Preoperative IVB injection was associated with reduced intraocular bleeding during 23-gauge PPV for diabetic macula-involving TRD. Further studies are needed to confirm our preliminary findings.

Neuroprotective effects of oral lamotrigine administration on rabbit retinas after pars plana vitrectomy and silicone oil injection

Purpose: To investigate potential retinal neuroprotective effects of oral lamotrigine in rabbits after pars plana vitrectomy (PPV) and intravitreal silicone oil injection (SOI). Methods: Twelve New Zealand rabbits (weight, 2.0-2.5 kg) underwent PPV with SOI on the right eye. For 30 days postoperatively, 6 rabbits received a daily oral dose of lamotrigine (25 mg/kg), and 6 rabbits received a daily oral dose of water. The animals were killed 30 days after surgery. All retinas were processed histologically, immunostained using glial fibrillary acidic protein (GFAP), and analyzed by fluorescence microscopy. Retina sections from all groups were analyzed by TUNEL for the presence of apoptosis and stained with hematoxylin-eosin for morphologic analysis and retina cell density measurements in each layer using a Zeiss Axiophot microscope and KS 400 software. Results: Retinas from water-operated eyes showed a significant decrease in cell density associated with cell death compared with retinas from water-control eyes; cell density was reduced by 56% in the outer nuclear layer (ONL), 49% in the inner nuclear layer (INL), and 64% in the ganglion cell layer (GCL). Lamotrigine-operated retinas showed a reduction in cell death when compared with water-operated retinas; cell death was reduced by 52% in the ONL, 25% in the INL, and 56% in the GCL. Water-operated retinas showed TUNEL-positive cells and GFAP immunofluorescence throughout Muller cell processes; lamotrigine-operated retinas showed no TUNEL-positive cells and decreased GFAP staining when compared with water-operated retinas. Conclusions: PPV with SOI was associated with apoptosis of retinal cells and activation of glial cells in rabbit eyes. Oral lamotrigine administration provided protection against these effects.

Preretinal partial pressure of oxygen gradients before and after experimental pars plana vitrectomy.

PURPOSE: To evaluate preretinal partial pressure of oxygen (PO2) gradients before and after experimental pars plana vitrectomy. METHODS: Arteriolar, venous, and intervascular preretinal PO2 gradients were recorded in 7 minipigs during slow withdrawal of oxygen-sensitive microelectrodes (10-μm tip diameter) from the vitreoretinal interface to 2 mm into the vitreous cavity. Recordings were repeated after pars plana vitrectomy and balanced salt solution (BSS) intraocular perfusion. RESULTS: Arteriolar, venous, and intervascular preretinal PO2 at the vitreoretinal interface were 62.3 ± 13.8, 22.5 ± 3.3, and 17.0 ± 7.5 mmHg, respectively, before vitrectomy; 97.7 ± 19.9, 40.0 ± 21.9, and 56.3 ± 28.4 mmHg, respectively, immediately after vitrectomy; and 59.0 ± 27.4, 25.2 ± 3.0, and 21.5 ± 4.5 mmHg, respectively, 2½ hours after interruption of BSS perfusion. PO2 2 mm from the vitreoretinal interface was 28.4 ± 3.6 mmHg before vitrectomy; 151.8 ± 4.5 mmHg immediately after vitrectomy; and 34.8 ± 4.1 mmHg 2½ hours after interruption of BSS perfusion. PO2 gradients were still present after vitrectomy, with the same patterns as before vitrectomy. CONCLUSION: Preretinal PO2 gradients are not eliminated after pars plana vitrectomy. During BSS perfusion, vitreous cavity PO2 is very high. Interruption of BSS perfusion evokes progressive equilibration of vitreous cavity PO2 with concomitant progressive return of preretinal PO2 gradients to their previtrectomy patterns. This indicates that preretinal diffusion of oxygen is not altered after vitrectomy. The beneficial effect of vitrectomy in ischemic retinal diseases or macular edema may be related to other mechanisms, such as increased oxygen convection currents or removal of growth factors and cytokines secreted in the vitreous.

Traitement du décollement de rétine du pseudophaque: étude rétrospective comparant la vitrectomie sans indentation au traitement ab-externo [Vitrectomy without scleral buckle versus ab-externo approach for pseudophakic retinal detachment: comparative retrospective study].

PURPOSE: Retinal detachment (RD) is a major complication of cataract surgery, which can be treated by either primary vitrectomy without indentation or the scleral buckling procedure. The aim of this study is to compare the results of these two techniques for the treatment of pseudophakic RD. PATIENTS AND METHODS: The charts of 40 patients (40 eyes) treated with scleral buckling for a primary pseudophakic RD were retrospectively studied and compared to the charts of 32 patients (32 eyes) treated with primary vitrectomy without scleral buckle during the same period by the same surgeons. To obtain comparable samples, patients with giant retinal tears, vitreous hemorrhage, and severe preoperative proliferative vitreoretinopathy (PVR) were not included. Minimal follow-up was 6 months. RESULTS: The primary success rate was 84% in the vitrectomy group and 82.5% in the ab-externo group. Final anatomical success was observed in 100% of cases in the vitrectomy group and in 95% of cases in the ab-externo group. Final visual acuity was 0.5 or better in 44% of cases in the vitrectomy group and 37.5% in the ab-externo group. The duration of the surgery was significantly lower in the ab-externo group, whereas the hospital stay tended to be lower in the vitrectomy group. In the vitrectomy group, postoperative PVR developed in 3 eyes and new or undetected breaks were responsible for failure of the initial procedure in 2 eyes. CONCLUSION: Primary vitrectomy appears to be as effective as scleral buckling procedures for the treatment of pseudophakic RD.

Anatomic and functional outcome after 23-gauge sutureless transconjunctival vitrectomy, peeling and intravitreal triamcinolone for idiopathic macular epiretinal membranes

Purpose:To report the functional, anatomic outcome and safety profile of 23-gauge pars plana vitrectomy (PPV) combined with peeling and intravitreal injection of triamcinolone acetonide (TA) in eyes with idiopathic epiretinal membranes (ERM). Methods:Retrospective, nonrandomized study of consecutive patients who underwent 23-gauge transconjunctival sutureless PPV with subsequent membrane peeling and intravitreal TA injection for an idiopathic ERM. All patients were operated between February 2007 and February 2008 at the Jules Gonin University Eye Hospital. The minimum follow-up was 6-months. Results:Thirty-nine eyes of 39 patients were included. The mean follow-up was 7 months (SD: 2.2, range: 6-15 months). Twenty-two (56%) eyes were pseudophakic and 17 (44%) were phakic at the time of surgery. Mean preoperative intraocular pressure (IOP) was 14 mmHg (SD: 3.5). At the final follow-up mean IOP was 14.5 (SD: 2.7) that did not differ significantly from the IOP at baseline (P: 0.14- 2-tailed t test). Five patients (13%) needed temporary topical anti-glaucoma treatment.Mean preoperative BCVA was 0.28 decimal equivalent (logMAR 0.54, SD: 0.2, range: 1.0 - 0.2). and improved significantly (P <0.0001, 2-tailed t test) to a mean of 0.6 decimal equivalent (logMAR 0.22, SD: 0.16, range: 0.6 - 0) at the final follow-up. The visual acuity improved by a mean of 3.2 lines (SD 2.1, range 0- 8). Twenty-nine patients (74%) demonstrated a gain of 3 or more lines.Mean central macular thickness (CMT) was 456 µm (SD: 77) at the baseline that reduced significantly (P <0.0001, 2-tailed t test) at the final follow-up to 327µm (SD: 79). Average CMT reduction was 131µm (SD: 77, range: 36- 380 µm). A subgroup analysis of 15 selected cases that had CMT measurement 1 week after surgery demonstrated that 84% of the total final reduction in CMT occurred during the first week. Conclusions:23-gauge sutureless transconjunctival vitrectomy with the concomitant administration of intravitreal TA is a safe and effective technique for the treatment of idiopathic ERM and may speed up anatomical recovery.

Anatomic and functional outcome after 23-gauge vitrectomy, peeling, and intravitreal triamcinolone for idiopathic macular epiretinal membrane.

PURPOSE: To report both the functional and anatomic outcome and safety profile of 23-gauge pars plana vitrectomy combined with membrane peeling and intravitreal injection of triamcinolone acetonide in eyes with idiopathic macular epiretinal membranes. METHODS: Retrospective study of 39 consecutive patients who underwent 23-gauge transconjunctival sutureless vitrectomy, membrane peeling, and intravitreal triamcinolone acetonide injection for an idiopathic macular epiretinal membrane between February 2007 and February 2008. Minimum follow-up was 6 months. RESULTS: Thirty-nine eyes of 39 patients were included in the study. The mean follow-up was 7 +/- 2.2 months (range, 6-15 months). Twenty-two eyes (56%) were pseudophakic and 17 (44%) were phakic at the time of surgery. Five of the phakic eyes (29.4%) had worsening of cataracts during the follow-up period. Mean preoperative intraocular pressure was 14 +/- 3.5 mmHg. At the final follow-up, mean intraocular pressure was 14.5 +/- 2.7 mmHg, which did not differ significantly from the intraocular pressure at baseline (P = 0.14, two-tailed t-test). Five (13%) patients needed topical antiglaucoma treatment. Mean preoperative best-corrected visual acuity (BCVA) was 0.28 decimal equivalent (20/71 Snellen equivalent; logarithm of the minimum angle of resolution 0.54 +/- 0.2, range: 1.0-0.2) and improved significantly (P < 0.0001, two-tailed t-test) to a mean of 0.6 decimal equivalent (20/33 Snellen equivalent; logarithm of the minimum angle of resolution 0.22 +/- 0.16, range: 0.6-0) at the final follow-up. The BCVA improved by a mean of 3.2 +/- 2.1 lines (range: 0-8). Twenty-nine patients (74%) demonstrated a gain of > or =3 lines. Mean central macular thickness was 456 +/- 77 microm (mean +/- SD) at baseline, which was significantly reduced at the final follow-up to 327 +/- 79 microm (mean +/- SD; P < 0.0001, two-tailed t-test). Average central macular thickness reduction was 131 +/- 77 microm (mean +/- SD; range: 36-380 microm). A subgroup analysis of 15 selected cases, which had central macular thickness and BCVA measurements after the first postoperative week, demonstrated that 84% of the total final reduction in central macular thickness and 84% of the total final improvement in BCVA occurred already during the first postoperative week. CONCLUSION: Twenty-three-gauge sutureless transconjunctival vitrectomy is a safe and effective technique for the treatment of idiopathic macular epiretinal membranes. The concomitant administration of intravitreal triamcinolone acetonide after pars plana vitrectomy may speed up and improve the anatomic and functional outcome.

Pseudophakic Retinal Detachment Surgery by 23 G Vitrectomy using Slit-Lamp and Non-Contact 90 D Lens.

Background: The purpose of this study is to report the anatomic and functional results of primary 23 G vitrectomy using slit-lamp and non-contact 90 D lens for the treatment of pseudophakic rhegmatogenous retinal detachment. Patients and Methods: Pseudophakic eyes were operated by 23 G vitrectomy using slit-lamp and non-contact 90 D lens, internal subretinal fluid drainage, cryopexy and internal gas tamponade. The preoperative and postoperative characteristics were analysed. Main outcome measures were anatomic success rates after initial surgical intervention and after reoperation for primary failures, visual outcome at the last follow-up visit, and complications. Results: 46 pseudophakic eyes were included in this retrospective study (October 2013- January 2014). In 40 cases, sulfur hexafluoride 23 % gastamponade was used, silicone oil in 6 cases (13 %). The retina was reattached successfully after a single surgery in 44 eyes (96 %). Recurrence of retinal detachment occurred in 2 eyes. Final anatomic reattachment was obtained in 100 % after a second operation. Silicone oil was removed in all eyes. Visual acuity improved significantly from logMAR 0 (IQR 0 - 0.9) to logMAR 0 (IQR 0 - 0.2) (p < 0.005). Conclusions: Primary 23 G vitrectomy using slit-lamp and non contact 90 D lens for the treatment of pseudophakic rhegmatogenous retinal detachment provides a high anatomic and functional success rate and is associated with few complications.

Preretinal partial pressure of oxygen gradients before and after experimental pars plana vitrectomy.

PURPOSE: To evaluate preretinal partial pressure of oxygen (PO2) gradients before and after experimental pars plana vitrectomy. METHODS: Arteriolar, venous, and intervascular preretinal PO2 gradients were recorded in 7 minipigs during slow withdrawal of oxygen-sensitive microelectrodes (10-μm tip diameter) from the vitreoretinal interface to 2 mm into the vitreous cavity. Recordings were repeated after pars plana vitrectomy and balanced salt solution (BSS) intraocular perfusion. RESULTS: Arteriolar, venous, and intervascular preretinal PO2 at the vitreoretinal interface were 62.3 ± 13.8, 22.5 ± 3.3, and 17.0 ± 7.5 mmHg, respectively, before vitrectomy; 97.7 ± 19.9, 40.0 ± 21.9, and 56.3 ± 28.4 mmHg, respectively, immediately after vitrectomy; and 59.0 ± 27.4, 25.2 ± 3.0, and 21.5 ± 4.5 mmHg, respectively, 2½ hours after interruption of BSS perfusion. PO2 2 mm from the vitreoretinal interface was 28.4 ± 3.6 mmHg before vitrectomy; 151.8 ± 4.5 mmHg immediately after vitrectomy; and 34.8 ± 4.1 mmHg 2½ hours after interruption of BSS perfusion. PO2 gradients were still present after vitrectomy, with the same patterns as before vitrectomy. CONCLUSION: Preretinal PO2 gradients are not eliminated after pars plana vitrectomy. During BSS perfusion, vitreous cavity PO2 is very high. Interruption of BSS perfusion evokes progressive equilibration of vitreous cavity PO2 with concomitant progressive return of preretinal PO2 gradients to their previtrectomy patterns. This indicates that preretinal diffusion of oxygen is not altered after vitrectomy. The beneficial effect of vitrectomy in ischemic retinal diseases or macular edema may be related to other mechanisms, such as increased oxygen convection currents or removal of growth factors and cytokines secreted in the vitreous.

Anti-inflammatory efficacy of a single posterior subtenon injection of triamcinolone acetonide versus prednisolone acetate 1% eyedrops after pars plana vitrectomy

Purpose: To compare the safety and anti-inflammatory efficacy of a single posterior subtenon injection of triamcinolone acetonide (TA) with prednisolone acetate 1% eyedrops after pars plana vitrectomy (PPV).Methods: the study included 40 consecutive phakic eyes of 40 patients undergoing PPV for non-clearing vitreous haemorrhage with attached retina (verified by echography), epiretinal membrane or macular hole. At the end of the surgical procedure, eyes were randomized to receive either a single posterior subtenon injection of TA (40 mg in 1 ml) plus sham eyedrops (prednisolone acetate 1% vehicle) postoperatively (group TA), or a posterior subtenon sham injection (1 ml balanced salt solution) plus prednisolone acetate 1% eyedrops postoperatively (group ED).Results: There was no difference in the severity of anterior chamber cell and flare between the two groups at any time-point during the study period (p > 0.05). Separate within-group analysis revealed a significant decrease in anterior chamber cell and flare from postoperative day 1 to postoperative days 7, 14 and 28 in both groups (p < 0.05). There was no difference in pain, photophobia, conjunctival erythema, ciliary flush or chemosis scores between the two groups at any time-point during the study period (p > 0.05). Steroid-induced intraocular hypertension was not observed in either group.Conclusions: A single posterior subtenon injection of TA can be as effective and safe as a 4-week regimen of prednisolone acetate 1% eyedrops in controlling intraocular inflammation after PPV.

Intraoperative bleeding during vitrectomy for diabetic tractional retinal detachment with versus without preoperative intravitreal bevacizumab (IBeTra study)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

EVALUATION OF MICROBIAL GROWTH ON SINGLE-USE VITRECTOMY PROBES REPROCESSED IN HEALTHCARE PRACTICE

The aim of this study was to evaluate the microbial growth on single-use vitrectomy probes reprocessed in healthcare practice. We investigated nine vitrectomy probes that had been reused and reprocessed using different methods. The samples were sectioned, individually, in portions of 3.5 cm, totaling 979 sampling units (extensions, connectors and vitrectomy cutters), which were inoculated in culture medium and incubated at 37 C for 14 days. The results showed microbial growth on 57 (5.8%) sample units, 25 of which had been sterilized using ethylene oxide, 16 by hydrogen peroxide plasma, and 16 by low-temperature steam and formaldehyde. Seventeen microbial species were identified. The most prevalent were: Micrococcus spp., coagulase-negative Staphylococcus, Pseudomonas spp., and Bacillus subtilis. The reuse of single-use vitrectomy probes was shown to be unsafe, therefore this practice is not recommended.

Intraocular pressure changes following 20G pars-plana vitrectomy

To observe the excursions of short-term intraocular pressure (IOP) after 20-G pars-plana vitrectomy (ppV).