Vitreous Reflux Research Articles

Effect of Prophylactic Medication and Influence of Vitreous Reflux in Pressure Rise after Intravitreal Injections of Anti-VEGF Drugs

To assess the efficacy of a hypotensive prophylactic medication in preventing intraocular pressure (IOP) changes after intravitreal injections, and the effect of occurrence of vitreous reflux on the variation of IOP. A total of 141 intravitreal injections of anti-vascular endothelial growth factor drugs (0.05 mL) were randomly distributed into 2 groups: in group 1 (n = 77), no prophylactic IOP-lowering medication was used; in group 2 (n = 64), a fixed combination of brimonidine and timolol was instilled 5 minutes before the injection. The IOP was measured before and 1, 15, and 30 minutes after the injection. The presence of vitreous reflux was recorded. Despite significantly reducing the IOP by ~3 mm Hg, prophylactic medication did not prevent a transient IOP rise. A total of 22.7% of injections showed vitreous reflux, and those patients experienced much lower initial spikes. Indeed, only 6.5% out of 77 injections above 30 mm Hg within 1 minute after injection showed vitreous reflux. Only one case showed an IOP >30 mm Hg at 15 minutes, and none at 30 minutes postinjection. The IOP normalization rates over time were similar in all groups within 15 minutes. Prophylactic medication instilled 5 minutes before the injection was not effective in preventing a pressure rise after intravitreal injections. Vitreous reflux decreased significantly the spike figures compared to injections with no reflux.

Intravitreal chemotherapy: Indications and results

AbstractThe presence of active vitreous seeding following state‐of‐the‐art conservative treatment of intraocular retinoblastoma leads in the vast majority of cases to either external beam irradiation (EBR) and/or enucleation. Intravitreal chemotherapy (IVC) is theoretically the best route for delivering the highest vitreous concentration of a chemotherapeutic drug, over intravenous, periocular and ophthalmic artery chemotherapy. This makes IVC the best candidate for treatment of diffuse vitreous disease in eyes with retinoblastoma, but it has remained highly controversial, as considered an invasive procedure associated with the risk of tumor exteriorization. We retrospectively reviewed all consecutive patients with vitreous disease found eligible and then treated by intravitreal injections of melphalan. IVC was performed every 7 to 10 days up to 8 injections of Melphalan (20‐30 g) per event, using a novel injection technique characterized by the prevention of vitreous reflux and sterilization of the needle track. The results appear promising in terms of safety (with no evidence of exteriorization), and efficacy with unprecedented salvage rate over 85%. Control of vitreous seeding was achieved without EBR in all cases.

Comparing the Effects of Three Different Intravitreal Injection Techniques on Vitreous Reflux and Intraocular Pressure

To compare the effects of straight, oblique, and double-plane tunnel scleral intravitreal injection techniques, on short-term intraocular pressure (IOP) changes, occurrence of vitreous reflux (VR), and/or other complications. A total of 105 patients were included in this prospective study. Patients were assigned randomly to one of the straight injection group (SI; n=35), oblique injection group (OI; n=35), or double-plane tunnel injection group (DPTI; n=35). The occurrence of VR and preinjection and postinjection IOP at 2 and 6 h were compared between groups, and complications were assessed. The mean patient age was 71.1±6.6 years (range 58 to 86 years; 50 women and 55 men). In the SI, OI, and DPTI groups, VR occurred in 18 (51.4%), 12 (34.3%), and 6 patients (17.1%), respectively. Mean preinjection IOPs were 15.4, 14.8, and 15.6 mmHg, and changed to 17.3, 18.0, and 20.0 mmHg at the second hour, and 15.7, 16.2, and 16.1 mmHg at the sixth hour, respectively. No significant differences among the groups were found in terms of complications such as transient mild uveitis or subconjunctival hemorrhage. Double-plane tunnel injection prevents VR from the injection site and has no additional complications than other techniques.

Effect of the Honan Intraocular Pressure Reducer to Prevent Vitreous Reflux after Intravitreal Bevacizumab Injection

To evaluate the effect of the Honan intraocular pressure reducer (HIPR) on vitreous reflux during intravitreal (IVT) injection. Prospective, comparative, controlled, investigator-blinded, randomized clinical study. Sixty eyes of 60 patients who underwent IVT injection were allocated into 2 groups with or without using the HIPR. Vitreous reflux was estimated by measuring largest diameter of the conjunctival bleb formed after IVT injection. Preoperative intraocular pressure (IOP) before and after application of the HIPR and IOP immediately postoperatively and 3 and 10 minutes postoperatively were evaluated. The mean amount of vitreous reflux was significantly less with the HIPR than without the HIPR (1.46±1.04 mm vs 2.61±1.37 mm; p<0.001). The preoperative IOP was significantly lower with the HIPR than without the HIPR (11.62±4.04 mmHg vs 16.26±3.86 mmHg; p=0.026). The 3-minute postoperative IOP was 31.34±3.16 mmHg with the HIPR and 32.61±5.62 mmHg without the HIPR (no statistical significance; p=0.345). The HIPR prevents vitreous reflux after IVT through a reduction in the preoperative IOP. However, the HIPR appears not to affect the postoperative course of transient IOP elevation.

Effect of the Honan intraocular pressure reducer on intraocular pressure increase following intravitreal injection using the tunneled scleral technique

To determine the effect of the Honan intraocular pressure reducer (HIPR) on the rise in intraocular pressure (IOP) after an intravitreal injection using a tunneled scleral incision. This was a prospective, comparative, controlled, non-randomized clinical study. Sixty eyes of 60 patients who received intravitreal injections with the tunneled scleral technique were allocated into two groups, one with and one without application of the HIPR. The pre-operative IOP both before and after application of the HIPR, and the IOP immediately postoperative, and at 3 and 10 min postoperatively were evaluated. The vitreous reflux was estimated by measuring the large diameter of the sub-conjunctival bleb formed after intravitreal injection. The pre-operative IOP in the HIPR group was significantly lower than that in the non-HIPR group following application of the HIPR. The immediate postoperative IOP was significantly lower in the HIPR group than in the non-HIPR group. The IOP at 10 min postoperatively was lower in the HIPR group than in the non-HIPR group. There was no difference in the amount of vitreous reflux between the HIPR and the non-HIPR groups. The use of the HIPR reduces the IOP after an intravitreal injection using the tunneled scleral technique. However, the HIPR does not appear to affect a reduction in the vitreous reflux.

Immediate intraocular pressure rise after intravitreal injection of ranibizumab and two doses of triamcinolone acetonide.

To evaluate prospectively immediate intraocular pressure (IOP) changes after the intravitreal injection of ranibizumab, 2 and 4mg triamcinolone acetonide. Patients who underwent intravitreal injection of 0.1mL (4mg) triamcinolone acetonide (TA, Group T4), 0.05mL (2mg) TA (Group T2) and 0.05mL (0.5mg) ranibizumab (Group R) comprised the study population. Overall, 229 eyes of 205 patients were injected. Fifty-four eyes (23.6%) were in Group T4, 69 eyes (30.1%) in Group T2 and 106 eyes (46.3%) in Group R. If IOP was less than 26mmHg immediately after the injection no further measurement was performed. If IOP was ≥26mmHg, IOP was remeasured till the reading was below 26mmHg at 5, 15 and 30 minutes. Immediately after the injection, the IOP of 28 eyes (51.9%) in Group T4, 22 eyes (31.9%) in Group T2 and 51 eyes (48.1%) in Group R were over 25mmHg. At 30 minutes, IOP of one eye (1.9%) in group T4, two eyes (2.9%) in group T2 and two eyes (1.9 %) in Group R were over 25mmHg. Immediate post-injection IOP was significantly higher in Group T4 and Group R when compared to Group T2 (P<0.001 and P<0.001, respectively). IOP was significantly higher in eyes without vitreous reflux when compared to those with vitreous reflux in all groups (P<0.001). IOP may remarkably increase immediately after the intravitreal injection of 2 or 4mg triamcinolone acetonide, and 0.5mg ranibizumab. Absence of vitreous reflux is the most important predicting factor for immediate IOP rise after the injection.

Does lens status affect the course of early intraocular pressure and anterior chamber changes after intravitreal injection?

This study aimed to observe changes in anterior chamber parameters and the course of intraocular pressure (IOP) after injection of 0.1 ml intravitreal triamcinolone acetonide (TA) and to determine differences between phakic and pseudophakic eyes without vitreous reflux. A prospective observational clinical trial was conducted with 89 patients who received an intravitreal injection of TA and did not display vitreous reflux. Intraocular pressure measurements were made before injection and at 3, 10, 20, 30 and 40 mins after injection. Pentacam measurements were made before injection and at 5, 15, 30 and 45 mins after injection. Anterior chamber depth (ACD) and anterior chamber volume (ACV) were significantly greater in pseudophakic eyes than in phakic eyes at all measurement time-points (p < 0.001). There was a decrease in both ACD and ACV at 5 mins after injection, and a gradual increase to normal values was observed at 15, 30 and 45 mins after injection in all study eyes. Compared with pre-injection measurements, changes in ACD and ACV were statistically significant at each time-point in both phakic and pseudophakic eyes (p < 0.001). A significant increase in IOP within 3 mins of injection was observed in both groups and a more rapid decrease 10 mins after injection was observed in pseudophakic eyes. The differences in IOP between phakic and pseudophakic eyes at all measurement time-points, except baseline and 3 mins after injection, were statistically significant (p < 0.001). Intraocular pressure < 30 mmHg and < 24 mmHg was recorded in all pseudophakic eyes at 10 and 20 mins after intravitreal injection, respectively. Following intravitreal injection of 0.1 ml TA, without vitreous reflux, IOP decreased to safe levels more quickly in pseudophakic eyes than in phakic eyes. Although there were more pronounced changes in anterior chamber parameters in pseudophakic eyes, these changes were reversible without any residual clinical significance.

TUNNELLED VERSUS STRAIGHT INTRAVITREAL INJECTION

To compare tunnelled scleral intravitreal injection with straight scleral intravitreal injection concerning short-term intraocular pressure (IOP) changes, occurrence and amount of vitreous reflux, and patient discomfort. Sixty patients were randomly allocated to two groups (tunnelled intravitreal injection and straight intravitreal injection). IOP was measured before and directly (<1 minute) after the injection of 0.05 mL of an antivascular endothelial growth factor agent and then every 5 minutes until IOP was <30 mmHg. Occurrence and amount of vitreous reflux were recorded. Patient discomfort during injection was assessed with a Wong-Baker faces pain rating scale. IOP (mmHg +/- SD) increased significantly directly after injection to 35.97 +/- 8.13 (tunnelled intravitreal injection) and 30.19 +/- 12.14 (straight intravitreal injection). These pressure spikes differed significantly between both groups (P = 0.01, mean difference: -7.11). Five minutes after injection, there was no significant difference in IOP increase between the groups. All IOP measurements were <30 mmHg after 15 minutes. Occurrence and amount of vitreous reflux were significantly higher with straight intravitreal injection. There was no significant difference in Wong-Baker faces pain rating scale score between both groups. Tunnelled intravitreal injection seems to be the technique of choice for low-volume intravitreal injection (0.05 mL). There is neither a difference in patient discomfort nor a difference in IOP increase 5 minutes after injection between both groups. Significantly less vitreous reflux with tunnelled intravitreal injection should lead to less postinjectional drug loss.

Short-term Course of Intraocular Pressure after Intravitreal Injection of Triamcinolone Acetonide

To describe the natural history of intraocular pressure (IOP) within the first 30 minutes after intravitreal injection of triamcinolone acetonide (TA). Prospective, interventional, consecutive case series. Thirty-eight consecutive patients who met inclusion and exclusion criteria and underwent intravitreal injection of 0.1 ml (4 mg) of TA were studied. Intraocular pressure was measured by Goldmann applanation tonometry at baseline; immediately after injection; and at 2, 5, 10, 20, and 30 minutes after injection. Intraocular pressure measurements at baseline; immediately after intravitreal injection; and 2, 5, 10, 20, and 30 minutes after injection, and percentage of patients with IOP < or = 24 mmHg at 30 minutes. Patients who did not experience vitreous reflux (30/38 [78.9%]) at the site of injection had a significant initial elevation of IOP that rapidly normalized. Patients who experienced vitreous reflux (8/38 [21.1%]) at the site of injection had either no change in IOP or a small drop in IOP that rapidly normalized. The IOP measured in millimeters of mercury immediately after injection (45.9 [no reflux], 12.6 [reflux]), 2 minutes after injection (39.9 [no reflux], 13.5 [reflux]), 5 minutes after injection (33.3 [no reflux], 13.8 [reflux]), 10 minutes after injection (26.4 [no reflux], 15.1 [reflux]), and 20 minutes after injection (21.8 [no reflux], 15.0 [reflux]) showed a statistically significant difference between the 2 groups. The difference in IOP between the 2 groups was not significant at baseline or 30 minutes after injection. At 30 minutes, 90% (95% confidence interval, 85.8%-95.2%) of patients without vitreous reflux had an IOP < 24 mmHg. Patients undergoing intravitreal injection of TA with no vitreous reflux have a risk of short-term elevation of IOP that rapidly normalizes over 30 minutes. In patients with vitreous reflux after the injection, the IOP declines immediately after injection and rapidly normalizes over 10 minutes.