Short-term impact of intravitreal ranibizumab injection on axial ocular dimension and intraocular pressure

Immediate Rise in Intraocular Pressure After First-Time Intravitreal Injection of Bevacizumab

Objective This study aims to report an immediate change in intraocular pressure (IOP) after the first injection of bevacizumab. Materials and methods An interventional case series was carried out at Isra Postgraduate Institute of Ophthalmology, Al-Ibrahim Eye Hospital, Karachi, from November 2018 to April 2020. All patients with various chorioretinal diseases requiring anti-VEGF treatment were included in the study. Patients with a history of previous anti-VEGF or steroid injections and personal or family history of glaucoma were excluded. Bevacizumab in a dose of 1.25 mg (0.05 ml) was injected intravitreally under topical anesthesia maintaining sterile aseptic conditions in the operating room. IOP was checked one hour prior to the injection, and hourly monitoring of it was continued for the next six hours. Data were analyzed using SPSS Statistics to compare the mean IOP readings before and after injection. Results A total of 191 eyes of 147 patients were included in the study. Among them, 92 (62.58%) were male and 55 (37.41%) were female with a mean age of 45.5 ± 8.8 years. The mean pre-injection IOP was measured as 12.12 ± 2.11 mmHg. The frequency of IOP elevation of ˃ 21 mmHg was observed in 169 (88.5%) eyes at five minutes, 104 (54.5%) eyes at 30 minutes, 33 (17.3%) eyes at one hour, and 16 (8.4%) eyes at two hours. The raised mean post-operative IOP was 30.44 ± 6.53 mmHg at five minutes, 26.27 ± 4.65 mmHg at 30 minutes, 26.12 ± 3.31 mmHg at one hour, and 25.63 ± 3.03 mmHg at two hours. The IOP reduced to pre-injection value at three hours measuring 12.12 ± 2.11 mmHg and continued to stay at that level for the next three hours. Conclusions The majority of the eyes receiving first-time intravitreal bevacizumab injection showed a significant increase in IOP level within five minutes to two hours post-injection.

Effect of quadrant switch on ıntraocular pressure change in ıntravitreal aflibercept or ranibizumab ınjection applications

OBJECTIVE

To evaluate the effect of injection quadrant switch on the intraocular pressure (IOP) change in intravitreal aflibercept or ranibizumab applications.

METHODS

123 eyes of 123 patients who received intravitreal injection (IVE) into the superotemporal quadrant at least 10 times for age-related macular degeneration or diabetic macular edema have been recruited. The demographic data, lens status, IOP values (preoperative, postoperative 0th min, and postoperative 30th min), and amount of vitreous reflux (VR) following IVE have been recorded. Next IVE application was performed into the inferotemporal quadrant of the patient, which had never been injected before.

RESULTS

The mean IOP value at postoperative 0th min was 50.24 ± 7.66 mmHg after injections into the superotemporal quadrant and was 34.85 ± 4.96 mmHg after injections into the inferotemporal quadrant. No significant difference was observed between the preoperative and postoperative 30th min-IOP values (p > 0.05), while a significant difference was found between the postoperative 0th min-IOP values among quadrants (p < 0.001). VR was significantly higher in applications into the inferotemporal quadrant than those into the superotemporal quadrant (p < 0.001).

CONCLUSION

One of the most principal factors affecting the postoperative short-term IOP increase is the amount of VR, and this amount decreases the IOP following an IVE. The high amount of VR produced in the quadrant where the injection was applied for the first time caused a low-level IOP, while the low amount of VR formed in the quadrant where the repeated injections were applied caused a higher IOP.

Anterior chamber changes assessment by Scheimpflug analysis after intravitreal dexamethasone implantation

PURPOSE

To evaluate structural changes in the anterior chamber and intraocular pressure (IOP) changes following intravitreal dexamethasone implantation.

METHODS

Forty-two eyes of 42 patients that received intravitreal dexamethasone implant for the management of macular edema secondary to diabetic retinopathy or branch retinal vein occlusion (BRVO) were included in the study. IOP was measured by Goldmann applanation tonometry. Anterior chamber depth (ACD) and iridocorneal angle (ICA) was measured by a Scheimflug camera (Sirius, CSO, Italy) the day before the injection of the dexamethasone implant and on postoperative day 1, first week, and first month.

RESULTS

Mean IOP was 15.14 ± 2.77 mmHg before the procedure and, 15.67 ± 3.70 mmHg, 15.86 ± 3.11 mmHg, 16.21 ± 2.75 mmHg on day 1, first week, and first month following intravitreal dexamethasone implantation, respectively. Mean ICA and ACD were significantly higher in pseudophakic eyes compared to phakic eyes. However, there was no statistically significant change in ICA before and after the procedure (on postoperative day 1, first week, and first month) among both phakic and pseudophakic patients (p = 0.783). Similarly, ACD remained unchanged after the procedure (on postoperative day 1, first week, and first month) compared to the initial measurement (p = 0.802).

CONCLUSION

This study confirmed that there was an increase in IOP. However, these changes were not accompanied with a change in ACD or ICA.

The effects of intravitreal injections on intraocular pressure and retinal nerve fiber layer: a systematic review and meta-analysis

The number of eye diseases treated with intravitreal injections is increasing. Obviously, an injection of fluid into the eye results in an increase of intraocular pressure (IOP), the main risk factor for glaucoma. However, the effect of these repeated IOP increases on the eye is unclear. Therefore, we performed a systematic review with meta-analyses. PubMed, Embase and Clinical Trials Registries were searched for articles investigating the relationship between intravitreal injections (anti-vascular endothelial growth factor [anti-VEGF] or steroids) and either IOP, retinal nerve fiber layer (RNFL)-thickness and glaucoma. Multiple meta-analyses were performed, combining data on intravitreal injection of anti-VEGF medication and dexamethasone implants. A total of 74 articles were eligible for meta-analyses. The short-term effect of an intravitreal injection of anti-VEGF showed a statistically significant increase in IOP. One day after injection of anti-VEGF, however, IOP was significantly lower than baseline. The long-term time-intervals showed no significant difference in IOP. After intravitreal injection of a dexamethasone implant, IOP was significantly higher than baseline 1 month post-injection. RNFL-thickness was significantly reduced 6 and 12 months post-injection of anti-VEGF, as well as at end of follow up. Caution is advised when using intravitreal medication, especially when treating patients with advanced glaucoma; in these cases, prophylactic IOP-lowering medication may be considered.

Hypotensive efficacy of topical brimonidine for intraocular pressure spikes following intravitreal injections of antivascular endothelial growth factor agents: a randomised crossover trial

PURPOSE

To determine the effect of topical brimonidine tartrate prophylaxis on intraocular pressure (IOP) spikes following intravitreal injection of antivascular endothelial growth factor (anti-VEGF) agents.

METHODS

This is a randomised crossover trial of consecutive non-glaucomatous eyes receiving intravitreal anti-VEGF injections between December 2016 and July 2017. All eyes were randomly assigned to no prophylaxis or topical brimonidine tartrate 0.15 % administered 20 min prior to injection in one of two consecutive visits. Measurements of IOP were obtained immediately (T0), 10 min (T10) and 20 min (T20) after injection during the visits with and without prophylaxis.

RESULTS

Among the 58 eyes of 55 patients (116 visits), the mean (SD) age was 74.3 (11.6), and 62% were female. The mean baseline IOP was 15.3 (2.3) mm Hg (range: 11-20). On average, the immediate postinjection IOP during the visit without prophylaxis was 41.6 (12) mm Hg (range: 17-81). Compared with no prophylaxis, the visit with preadministered topical brimonidine tartrate had a lower IOP at T0 (p<0.001), T10 (p=0.001) and T20 (p=0.043), and a smaller proportion of eyes with IOP elevation of greater than 20 mm Hg from preinjection (p=0.002) and IOP greater than 50 mm Hg at T0 (p=0.036). Without prophylaxis, two eyes (two patients) had an IOP of greater than 70 mm Hg at T0 and thus underwent anterior chamber paracentesis.

CONCLUSION

Topical brimonidine tartrate prophylaxis for intravitreal injection of anti-VEGF agents effectively reduces IOP spikes in non-glaucomatous eyes and may be easily incorporated into ophthalmologists' current practice.

TRIAL REGISTRATION NUMBER

NCT03513172.

[Structural changes in the ocular anterior segment against elevation of intraocular pressure after repeated intravitreal injections]

Numerous studies have demonstrated the efficacy of anti-VEGF medications for exudative (wet) age-related macular degeneration (AMD). Significant IOP elevation is one of the side effects of anti-VEGF intravitreal injection.

PURPOSE

To study the changes in the parameters of anterior segment of the eyeball against acute IOP elevation after repeated intravitreal injections (IVI) of anti-VEGF medication.

MATERIAL AND METHODS

The study was conducted on a random sample of 45 patients (45 eyes) diagnosed with exudative (wet) form of AMD. All patients received two 0.05 ml intravitreal injections of ranibizumab with one-month interval. Measurements of IOP were performed with rebound tonometer Icare-Pro (ICare, Finland) before intravitreal injection, then one minute, 30 minutes and 3 hours after. The parameters of the ocular anterior segment, namely thickness and optical density of the cornea, volume and angle of the anterior chamber were evaluated by Scheimpflug imaging (Pentacam HR, Oculus, Germany) before IVI, and 15 minutes after.

RESULTS

Statistically significant (p<0.05) elevation of IOP to 40 mm Hg (confidence interval 32-48 mm Hg) was recorded one minute after injecting 0.05 mL of ranibizumab solution into the vitreous cavity with IOP having the tendency for gradual normalization. When measured 15 minutes after IVI, the following parameters of the ocular anterior segment structures had reliably changed in the setting of elevated IOP: corneal thickness had increased to 27 µm (confidence interval 14-38 µm), corneal optical density - to 16.7 (confidence interval 10.4-19.5). No significant changes of either volume or angle of anterior chamber were revealed. Comparative analysis showed no significant changes of parameters after the 1^st and the 2^nd IVI.

CONCLUSION

The revealed changes were transient in nature and did not require any corrections since all parameters returned to baseline after each injection.

The acute and chronic effects of intravitreal anti-vascular endothelial growth factor injections on intraocular pressure: A review

The acute and chronic effects of repeated intravitreal antivascular endothelial growth factor (VEGF) injections on intraocular pressure have not been fully characterized, and the development of sustained ocular hypertension could adversely affect patients who are at risk of glaucomatous optic neuropathy. As expected, volume-driven, acute ocular hypertension immediately follows intravitreal injection, but this pressure elevation is generally transient and well tolerated. Several medications have been investigated to limit acute ocular hypertension following anti-VEGF therapy, but the benefits of pretreatment are not conclusive. Chronic, sustained ocular hypertension, distinct from the short-term acute ocular hypertension after each injection, has also been associated with repeated intravitreal anti-VEGF injections. Risk factors for chronic ocular hypertension include the total number of injections, a greater frequency of injection, and preexisting glaucoma. Proposed mechanisms for chronic ocular hypertension include microparticle obstruction, toxic or inflammatory effects on trabecular meshwork, as well as alterations in outflow facility by anti-VEGF agents. Although limiting anti-VEGF therapy could minimize the risk of both acute and chronic ocular hypertension, foregoing anti-VEGF therapy risks progression of various macular diseases with resulting permanent central vision loss. While definitive evidence of damage to the retinal nerve fiber layer is lacking, patients receiving repeated injections should be monitored for ocular hypertension and patients in whom sustained ocular hypertension subsequently developed should be periodically monitored for glaucomatous changes with optic nerve optical coherence tomography and static visual fields.

Effects of intravitreal injection of bevacizumab with or without anterior chamber paracentesis on intraocular pressure and peripapillary retinal nerve fiber layer thickness: a prospective study

PURPOSE

To investigate the effects of intravitreal injection of bevacizumab (IVB) with or without anterior chamber paracentesis on intraocular pressure (IOP) and peripapillary retinal nerve fiber layer (PRNFL) thickness.

METHODS

In this prospective randomized clinical trial, 90 eyes with center involving diabetic macular edema or wet type age-related macular degeneration (AMD) were randomly assigned to receive IVB either without (group A) or with (group B) anterior chamber paracentesis. IOP was measured before and within 2 min, 30 min, 24 hours and 3 months after injections. Peripapillary spectral-domain optical coherence tomography (SD-OCT) was performed before and 3 months after injections.

RESULTS

Mean IOP changes 2 minutes, 30 minutes, 24 hours, and 3 months after injections were 26.4 ± 5.7 mmHg (P < 0.001), 6.5 ± 6.3 mmHg (P < 0.001), 0.2 ± 2.9 mmHg (P > 0.99) and 0.5 ± 2.4 mmHg (P > 0.99) in group A and -1.3 ± 2.4 mmHg (P < 0.001), -3.2 ± 1.8 mmHg (P < 0.001), -3.1 ± 1.8 mmHg (P < 0.001) and -1.8 ± 2.2 mmHg (P < 0.001) in group B, respectively Mean baseline average PRNFL thickness was 85.3±5.6 μm and 85.6 ± 5 μm in groups A and B respectively. Mean PRNFL thickness changes after 3 month was -2 ± 2 μm (P < 0.001) in group A and 0 ± 2 μm (P = 0.101) in group B. Mean PRNFL thickness in group A decreased more than group B (P < 0.001).

CONCLUSION

Conventional method of IVB injection was associated with acute IOP rise and significant PRNFL loss 3 months after injection. Anterior chamber paracentesis prevents acute IOP rise and PRNFL loss.

Anterior segment changes on ultrasound biomicroscopy after intravitreal anti vascular endothelial growth factor injection

BACKGROUND

Intravitreal injections are standard of care today and have the potential to change the anatomy of the anterior segment of the eye. This research was undertaken to evaluate the changes in anterior segment anatomy after intravitreal anti vascular endothelial growth factor (anti VEGF) injections.

METHODS

We conducted a prospective interventional case series at a quaternary care center where patients undergoing intravitreal injection had pre and post injection ultrasound biomicroscopy (UBM) and intraocular pressure (IOP) measurement after intravitreal anti VEGF injection of 0.05 ml volume.

RESULTS

75 eyes of 75 patients as per inclusion criteria were studied. A transient rise in IOP post intravitreal injection was found immediately after the injection. The mean rise from baseline was 17 mmHg immediately after injection and IOP returned to normal within 30 min in all cases. Angle measurement done as per established techniques revealed no significant changes in the angles and anterior chamber.

CONCLUSION

Intravitreal anti VEGF injections had no readily apparent short term concerns. IOP rise was transient and no case was found to have IOP high enough to cause concern for interruption of the optic nerve perfusion or statistically significant narrowing of the anterior chamber angle.

Estimation of ocular volume from axial length

BACKGROUND/AIMS

To determine which biometric parameters provide optimum predictive power for ocular volume.

METHODS

Sixty-seven adult subjects were scanned with a Siemens 3-T MRI scanner. Mean spherical error (MSE) (D) was measured with a Shin-Nippon autorefractor and a Zeiss IOLMaster used to measure (mm) axial length (AL), anterior chamber depth (ACD) and corneal radius (CR). Total ocular volume (TOV) was calculated from T2-weighted MRIs (voxel size 1.0 mm(3)) using an automatic voxel counting and shading algorithm. Each MR slice was subsequently edited manually in the axial, sagittal and coronal plane, the latter enabling location of the posterior pole of the crystalline lens and partitioning of TOV into anterior (AV) and posterior volume (PV) regions.

RESULTS

Mean values (±SD) for MSE (D), AL (mm), ACD (mm) and CR (mm) were -2.62±3.83, 24.51±1.47, 3.55±0.34 and 7.75±0.28, respectively. Mean values (±SD) for TOV, AV and PV (mm(3)) were 8168.21±1141.86, 1099.40±139.24 and 7068.82±1134.05, respectively. TOV showed significant correlation with MSE, AL, PV (all p<0.001), CR (p=0.043) and ACD (p=0.024). Bar CR, the correlations were shown to be wholly attributable to variation in PV. Multiple linear regression indicated that the combination of AL and CR provided optimum R(2) values of 79.4% for TOV.

CONCLUSION

Clinically useful estimations of ocular volume can be obtained from measurement of AL and CR.

The link between intravitreal antivascular endothelial growth factor injections and glaucoma

PURPOSE OF REVIEW

To summarize the reports of both transient and sustained elevation in intraocular pressure (IOP) associated with intravitreal injections of antivascular endothelial growth factor (anti-VEGF) agents and to review the possible mechanisms for these findings.

RECENT FINDINGS

Transient elevation in IOP is common after intravitreal injection of anti-VEGF agents. Sustained IOP elevation is less commonly seen but can require medical and/or surgical intervention. The mechanism for sustained IOP elevation is not well understood but has been attributed to trabecular meshwork injury from repeated injections, a potential toxic or inflammatory reaction after exposure to the biologic agents and/or vehicle, or mechanical blockade of the trabecular meshwork by protein aggregates or contaminant particles associated with packaging and injection techniques, among other potential causes.

SUMMARY

Intravitreal anti-VEGF injections are commonly used to treat neovascular diseases of the eye. Although they have a favorable side-effect profile, their use can be associated with both transient and sustained elevation in IOP. Further research is necessary to determine the cause of these findings.