Comparing the effects of three different intravitreal injection techniques on vitreous reflux and intraocular pressure

Clinical Features Associated with Acute Elevated Intraocular Pressure After Intravitreal Anti-VEGF Injections

Purpose

To study the effects of intravitreal injection (IVI) of anti-VEGF (vascular endothelial growth factor) agents on intraocular pressure (IOP) and find associations with acute pressure spikes.

Methods

This was a three-month, prospective study of patients receiving outpatient IVI of anti-VEGF agents for diabetic retinopathy (DR), age-related macular degeneration (AMD), and retinal vein occlusion (RVO) at the Acuity Eye Group Medical Centers. IOP was measured pre- and post-injection at 10-minute intervals up to 50 minutes after injection with a handheld tonometer. Patients with an IOP greater than 35 mmHg at 30 minutes received an anterior chamber paracentesis (ACP), while patients below 35 mmHg were monitored without intervention.

Results

A total of 617 patients (51% female, 49% male) received IVI for DR (n = 199), AMD (n = 355), and RVO (n = 63). ACP was performed in 17 patients. Average pre-injection IOP was 16 ± 4 compared to 24 ± 7 mmHg for the non-ACP vs ACP group, respectively (mean ± standard deviation), p < 0.0001. IOP returned to baseline in 98% of patients at 50 minutes. A diagnosis of glaucoma and glaucoma suspect was more prevalent in the ACP group compared to the non-ACP group, 82.3% vs 14.2% and 17.6% vs 9.0%, respectively, p < 0.0001 and p > 0.05. Patients with a pre-injection IOP >25 mmHg and a history of glaucoma had a 58.3% rate of ACP. A 31-gauge needle had a higher mean increase in IOP from baseline compared to 30-gauge needle, p < 0.0001.

Conclusion

IOP spikes are most significant in the first 10 minutes after IVI but typically resolve within the first hour. However, utilizing a smaller 31-gauge IVI in patients with a glaucoma history and pre-injection IOP >25 mmHg may be associated with significant IOP spikes lasting longer than 30 minutes.

Intraocular nano-microscale drug delivery systems for glaucoma treatment: design strategies and recent progress

Glaucoma is a leading cause of irreversible visual impairment and blindness, affecting over 76.0 million people worldwide in 2020, with a predicted increase to 111.8 million by 2040. Hypotensive eye drops remain the gold standard for glaucoma treatment, while inadequate patient adherence to medication regimens and poor bioavailability of drugs to target tissues are major obstacles to effective treatment outcomes. Nano/micro-pharmaceuticals, with diverse spectra and abilities, may represent a hope of removing these obstacles. This review describes a set of intraocular nano/micro drug delivery systems involved in glaucoma treatment. Particularly, it investigates the structures, properties, and preclinical evidence supporting the use of these systems in glaucoma, followed by discussing the route of administration, the design of systems, and factors affecting in vivo performance. Finally, it concludes by highlighting the emerging notion as an attractive approach to address the unmet needs for managing glaucoma.

"The effect of two different intravitreal injection techniques on frequency of vitreous reflux and on treatment response in neovascular AMD patients"

PURPOSE

To determine the effect of two distinct intravitreal injection (IVI) techniques on the frequency of vitreous reflux (VR) and on treatment response at cumulative dosages in neovascular age-related macular degeneration (nAMD) patients.

PATIENTS AND METHODS

Ninety-three eyes of 93 nAMD patients were included in the study. IVI was performed in 47 eyes using the straight technique (ST) and 46 eyes with the tunneled technique (TT). Patients received three loading doses of intravitreal bevacizumab, and substantial VR was noted for each IVI. Central (CMT), 1mm (MT1), and 3mm (MT3) macular thicknesses were measured before and after treatment. VR frequency and treatment response were compared in both groups, and correlation analysis was performed.

RESULTS

Post-treatment VR was seen in 91 of 141 IVI with the ST and 33 of 138 IVI with the TT. The decrease in CMT, MT1, and MT3 after treatment with the ST was 121.4±92.5μm, 65.3±50.6μm, 28.8±30.8μm, respectively, and with the TT was 114.0±97.5μm, 67.8±72.6μm, and 27.1±31.4μm, respectively. The ST substantially increased the rate of VR compared to the TT (P<0.001), whereas the decrease in CMT, MT1, and MT3 did not vary significantly (P>0.05). There was no correlation between VR rate and decreases in CMT, MT1, or MT3 (P>0.05).

CONCLUSIONS

According to our findings, the ST resulted in a higher frequency of VR than the TT, but VR did not affect the treatment response, despite multiple doses. Complication rates were negligible with both approaches. As a result, it appears that practitioners may use either IVI approach.

B-SCAN ULTRASONOGRAPHY OF VITREOUS DYNAMICS DURING INTRAVITREAL ADMINISTRATION OF ANTIANGIOGENICS

PURPOSE

To study the distribution of angiogenesis inhibitors (anti-Vascular Endothelial Growth Factor) injected into the vitreous cavity by means of simultaneous ultrasonography.

METHODS

Three hundred and thirty-two B-scan ultrasound sequences of 121 eyes from 95 patients were recorded simultaneously to the intravitreal anti-Vascular Endothelial Growth Factor administration. The dynamics of the injected substance and the presence of reflux were studied, associating them with the presence/absence of total posterior vitreous detachment.

RESULTS

Three well-defined patterns were distinguished. Pattern A: the medication penetrates the vitreous in a linear manner until reaching the retina (3.6%, n = 12). Pattern B: the medication adopts a globular shape and then moves down reaching the retrohyaloid space (37%, n = 123). Pattern C: the medication remains in a globular form (54%, n = 180). The pattern was not identified in 17 (5.1%) injections. Pattern A was only observed in vitrectomized eyes. The reflux (7.8%) was exclusive in eyes showing a C pattern. A relationship (P < 0.001) was observed between the presence/absence of total posterior vitreous detachment, the patterns, and the presence of reflux.

CONCLUSION

This study document for the first time the behavior of antiangiogenic medication injected into the vitreous cavity and how its distribution and the presence of reflux is conditioned by the previous state of the vitreous body.

Evaluation of intraocular pressure change and anterior segment parameters after intravitreal bevacizumab injection - Cannula size matters

PURPOSE:

To determine the changes in intraocular pressure (IOP) and anterior chamber parameters following intravitreal bevacizumab injection with different sizes of cannulas.

METHODS:

This clinical trial was conducted with 70 eyes of 70 patients who received an intravitreal injection of bevacizumab with 26 G (Group 1) or 30 G (Group 2) needle. Preinjection and postinjection 30^th-min IOP and pentacam measurements were obtained. Anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), corneal volume (CV), and iridocorneal angle (ICA) measurements were evaluated in pentacam.

RESULTS:

Preinjection mean IOP values in Group 1 and 2 were 14.7 ± 3.29 mm Hg and 15.1 ± 2.87 mm Hg, respectively. Postinjection mean IOP in Group 1 was 16.8 ± 6.24 mm Hg and in Group 2 was 20.3 ± 3.66 mm Hg. Postinjection mean IOP values were significantly higher than preinjection values in both groups (Group 1 P < 0.005 and Group 2 P < 0.001). IOP change was significantly higher in Group 2 after injection (P < 0.05). In both groups, the change in IOP found to be more significant in phakic eyes than pseudophakic eyes (Group 1 P < 0.001, Group 2 P < 0.001). CCT and CV were significantly higher in both groups 30 min after the injection than preinjection (Group 1 and Group 2; P < 0.01). In Group 2 ACD, ACV and ICA values were significantly lower than preinjection values (P < 0.05).

CONCLUSION:

Needle bore size is an important parameter that influences anterior segment parameters and IOP change in the intravitreal injection. IOP rise and anterior segment changes are more prominent with a thinner cannula.

Comparison between two intravitreal injection techniques with respect to fluid reflux, intraocular pressure, and therapeutic effect

CONTEXT:

Effect of fluid reflux on intraocular pressure (IOP) and therapeutic benefits.

AIMS:

The aim of this study is to compare two intravitreal injection techniques in terms of fluid reflux, short-term IOP changes, and therapeutic effect.

SETTINGS AND DESIGN:

A prospective, double-blinded, randomized interventional study.

SUBJECTS AND METHODS:

Sixty eyes were randomly allocated to two groups (direct intravitreal injection technique and oblique intravitreal injection technique). IOP was measured before and immediately after the injection of 0.1 ml comprising of bevacizumab (1.25 mg/0.05 ml) and dexamethasone (0.2 mg/0.05 ml) and then at 30 min after the injection. Occurrence and amount of vitreous reflux were recorded. Best-corrected visual acuity (BCVA) and central macular thickness (CMT) were assessed preinjection and 6 weeks postinjection.

RESULTS:

IOP (mmHg ± standard deviation) increased significantly immediately after injection to 24.30 ± 3.02 (direct intravitreal injection) and 31.50 ± 3.49 (oblique intravitreal injection). These pressure rise differed significantly between both groups (mean difference: 7.2, P < 0.0001). Thirty minutes after injection, there was no significant difference in IOP increase between the groups. Occurrence and amount of fluid reflux were significantly higher with direct intravitreal injection. There was no significant difference in BCVA and CMT outcome between both groups.

CONCLUSIONS:

Direct intravitreal injection technique has lower rise in IOP and higher incidence of fluid reflux than the oblique intravitreal technique. Fluid reflux does not cause a therapeutic compromise in terms of BCVA or CMT changes, so the reflux fluid must be the vitreous not the drug. Thus, direct injection technique seems to be the preferred technique.

Extraocular, periocular, and intraocular routes for sustained drug delivery for glaucoma

Although once daily anti-glaucoma drug therapy is a current clinical reality, most therapies require multiple dosing and there is an unmet need to develop convenient, safe, and effective sustained release drug delivery systems for long-term treatment to improve patient adherence and outcomes. One of the first sustained release drug delivery systems was approved for the reduction of intraocular pressure in glaucoma patients. It is a polymeric reservoir-type insert delivery system, Ocusert™, placed under the eyelid and on the ocular surface for zero-order drug release over one week. The insert, marketed in two strengths, released pilocarpine on the eye surface. While many clinicians appreciated this drug product, it was eventually discontinued. No similar sustained release non-invasive drug delivery system has made it to the market to date for treating glaucoma. Drug delivery systems under development include punctal plugs, ring-type systems, contact lenses, implants, microspheres, nanospheres, gels, and other depot systems placed in the extraocular, periocular, or intraocular regions including intracameral, supraciliary, and intravitreal spaces. This article discusses the advantages and disadvantages of the various routes of administration and delivery systems for sustained glaucoma therapy. It also provides the reader with some examples and discussion of drug delivery systems that could potentially be applied for glaucoma treatment. Interestingly, one intracamerally injected implant, Durysta™, was approved recently for sustained intraocular pressure reduction. However, long-term acceptance of such devices has yet to be established. The ultimate success of the delivery system will depend on efficacy relative to eye drop dosing, safety, reimbursement options, and patient acceptance. Cautious development efforts are warranted considering prior failed approaches for sustained glaucoma drug delivery. Neuroprotective approaches for glaucoma therapy including cell, gene, protein, and drug-combination therapies, mostly administered intravitreally, are also rapidly progressing towards assessment in humans.

Reflux, Intraocular Pressure Variation and Pain Following Intravitreal Ranibizumab Injections Using 30-Gauge or 32-Gauge Needles for Patients With Retinal Pathologies: A Randomized Clinical Trial

PURPOSE

To compare reflux, intraocular pressure (IOP) variation and pain following intravitreal (IV) injections using 30-gauge and 32-gauge needles in patients with retinal pathologies in Saudi Arabia.

METHODS

A double-blind randomized clinical trial was conducted in 2018. Participants were randomized to receive IV injections of Ranibizumab using 30-gauge (Gr₁) or 32-gauge (Gr₂) needles. The amount of reflux of injected material, IOP before (IOP₁) and five minutes after injection (IOP₂) were measured. The patient-perceived pain score was assessed using a visual analogue score (VAS). Outcome variables were compared.

RESULTS

The study sample was comprised of 86 eyes (86 patients) in each group. Gender (P=0.76), laterality (P=0.55) and age (P=1.0) were not different between groups. The reflux in Gr₁ [34.9% (95% confidence interval {CI}, 24.8; 45.0)] was significantly higher compared to Gr₂ [22.1% (95% CI, 13.3; 30.9)] (P=0.007). The median pain score was 1 in both Gr₁ [interquartile range (IQR) 1.0: 3.0] and Gr₂ (IQR 0.0; 2.0) (P=0.04). Among 56 eyes without reflux in Gr₁, the IOP₁ and IOP₂ were 13.6±2.7 mmHg and 16.4±5.0 mmHg, respectively. Among 67 eyes without reflux in Gr₂, the IOP₁ and IOP2 were 13.6±2.9 mmHg and 17.0±5.2 mmHg, respectively. The change in percentage in IOP in Gr₁ and Gr₂ was not significantly different (Mann Whiney P=0.3).

CONCLUSIONS

IV injection given by 30-gauge needle compared to 32-gauge needle resulted in greater patient-perceived pain and more reflux of injected material from the injection site. An increase in IOP was not associated with the gauge of the needle used for IV injection.

Novel Needle for Intravitreal Drug Delivery: Comparative Study of Needle Tip Aspirates, Injection Stream and Penetration Forces

Purpose

To study the efficacy of a novel needle for intravitreal injection (IVI) in comparison to the conventional needle under experimental conditions.

Methods

The newly designed 30-gauge (G) needle (NDN) (EP 18158 542.3, patent pending) with occluded outer orifice and a side port for drug delivery was compared to the conventional standard hypodermic 30 G needle for IVI (SHN). An animal study to obtain needle tip aspirates was performed on 10 albino rat eyes. During IVIs, cellular content, which was cut by the needle tip, was aspirated. Cellular material was studied in regard to cell types and their quantity. The injection stream was studied using trypan blue dye in vitro and pig cadaver eyes. The penetration force was tested on polyurethane Testing Foil Strips PU 04 (Melab, Leonberg, Germany) by applying a velocity of 100 mm/min. The results were analyzed using descriptive statistics, correlation matrices and t-test methods with p<0.05 as statistically significant.

Results

Cytological analysis of the needle aspirates showed the presence of cellular content in each case. The amount of conjunctival, ciliary body epithelial cells and granulated basophilic protein sediments (sign of cellular damage) in the case of the NDN tips was significantly lower compared to the SHN. The average penetration force of the NDN was 0.791 N, and in the case of the SHN was 0.566 N. The injection stream study revealed a difference in the initial injection phase between the two needle types, although the diffuse filling of the vitreous area which surrounded the needle tip appeared to be similar.

Discussion

The NDN demonstrated superior performance with regard to a significantly reduced number of cells being captured by the needle tip. Delivery of the injected fluid into the vitreous cavity was comparable. In order to investigate superior properties of the NDN needle design, further studies with improved prototypes would be necessary.

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.

Can Vitreous Reflux Affect The Short-Term Treatment Response After Intravitreal Ranibizumab Injection?

PURPOSE

The aim of this study was to evaluate the effect of vitreous reflux (VR) on the short-term effect of intravitreal ranibizumab injection.

MATERIALS AND METHODS

The study included 181 eyes of 81 age-related macular degeneration (AMD) and 100 diabetic macular edema (DME) patients. Treatment response was evaluated by measuring central macular thickness (CMT) as well as 1 mm and 3 mm central macular thicknesses (MT1 and MT3). Patients were grouped as; Group 1: no VR, Group 2: <3 mm VR, and Group 3: >3 mm VR according to conjunctival bleb diameters. The data were analyzed using variance, correlation and regression analyses.

RESULTS

In AMD patients, reduction of CMT values following the treatment were 88.3 ± 110.6 µm in Group 1, 85.6 ± 158.7 µm in Group 2, and 93.1 ± 92.2 µm in Group 3. Likewise, in DME patients, it was 82.4 ± 88.4 µm, 72.9 ± 109.9 µm, and 73.7 ± 113.7 µm, respectively. Reduction of MT1 values after the treatment were 47.4 ± 72.6 µm, 36.0 ± 131.9 µm, and 36.7 ± 114.4 µm in AMD patients, and 33.3 ± 72.5 µm, 36.6 ± 90.2 µm, and 46.9 ± 83.4 µm in DME patients. In all comparisons among groups of VR, macular thickness (MT) change did not exhibit significant difference following an intravitreal ranibizumab treatment (p > .05).

CONCLUSION

We found that the increase in VR amount did not adversely affect the decrease in MT after intravitreal ranibizumab treatment in AMD and DME patients.

Critical analysis of techniques and materials used in devices, syringes, and needles used for intravitreal injections

Intravitreal injections have become the most commonly performed intraocular treatments worldwide. Because intravitreal injections may induce severe adverse events, such as infectious and noninfectious endophthalmitis, cataract, ocular hypertension, vitreous hemorrhage, or retinal detachment, appropriate awareness of the materials and techniques used are essential to reduce these sight-threatening complications. This review provides insights into the needles, syringes, silicone oil coating, sterilization methods, devices to assist intravitreal injections, scleral piercing techniques using needles, syringe handling, anesthesia, and safety issues related to materials and techniques. It is paramount that physicians be aware of every step involved in intravitreal injections and consider the roles and implications of all materials and techniques used. The ability to understand the theoretical and practical circumstances may definitely lead to state-of-the-art treatments delivered to patients. The most important practical recommendations are: choosing syringes with as little silicone oil as possible, or, preferably, none; avoiding agitation of syringes; awareness that most biologics (e.g., antiangiogenic proteins) are susceptible to changes in molecular properties under some conditions, such as agitation and temperature variation; understanding that improper materials and techniques may lead to complications after intravitreal injections, e.g., inflammation; and recognizing that some devices may contribute to an enhanced, safer, and faster intravitreal injection technique.

Intravitreal injections in clinical practice: results of a survey of eye surgeons in the Ural federal district

Introduction. Intravitreal i njections ( IVI) are widespread in modern ophthalmology as a method of drug delivery in various posterior segment pathologies. Despite the accumulated experience, some aspects of the procedure remain debatable. In addition, in the literature there are no data on the practical aspects of IVI performance in real clinical conditions in Russia. This article presents the results of an anonymous survey of 74 ophthalmologists of the Ural Federal District of the Russian Federation, conducted in 2018 using an original questionnaire, which included 20 questions. It was revealed that respondents generally share the traditional for Russia approach to IVI as to major ophthalmic surgery. The survey revealed a lack of common approaches and incomplete adherence to modern guidelines in certain aspects of the procedure, and therefore correcting measures were proposed.

Major factors affecting intraocular pressure spike after intravitreal ranibizumab injection: Vitreous reflux and its amount

PURPOSE

The aim of this study was to assess the effect of vitreous reflux and its amount on short-term intraocular pressure after intravitreal injection of ranibizumab.

METHODS

The study included 316 eyes of 276 patients. Intraocular pressures were measured before intravitreal injection (preIOP), immediately after intravitreal injection (postIOP0), and 30 min after intravitreal injection (postIOP30). The amount of vitreous reflux was evaluated by measuring conjunctival bleb diameter, and patients were grouped as; group 1: no vitreous reflux, group 2: less vitreous reflux, and group 3: more vitreous reflux. The data were analyzed using variance analysis, chi-square test, and regression analysis.

RESULTS

PostIOP0 values were highest in group 1, followed by group 2 and group 3 (all p values < 0.001). PostIOP30 values were similar in group 1 and group 2 (p = 0.261), but were lower in group 3 than other two groups (p < 0.001, p = 0.001, respectively). Vitreous reflux was identified as the only factor affecting postinjection intraocular pressure changes (p < 0.001), and a negative correlation was found between the total number of intravitreal injection and vitreous reflux (p = 0.032).

CONCLUSION

The major factor affecting short-term postinjection intraocular pressure elevation was vitreous reflux, and intraocular pressure levels increased as the amount of vitreous reflux decreased. Vitreous reflux and its amount decreased as the total number of intravitreal injection increased.

Complications of Intravitreous Injections in Patients with Diabetes

Intravitreous injections are presently the second most frequently performed ophthalmic procedure and the most common vitreoretinal procedure. In diabetic patients, intravitreous injections are frequently performed for the treatment of center-involved diabetic macular edema, proliferative diabetic retinopathy, or other co-existing retinal vascular disease. Diabetic patients may be at higher risk of adverse events compared to non-diabetic individuals, given frequent systemic comorbidities, such as cardiovascular and renal disease and increased susceptibility to infection. This review highlights the potential complications and safety considerations in intravitreous injections in patients with diabetes.

Intravitreal, Subretinal, and Suprachoroidal Injections: Evolution of Microneedles for Drug Delivery

Even though the very thought of an injection into the eye may be frightening, an estimated 6 million intravitreal (IVT) injections were made in the USA during 2016. With the introduction of new therapeutic agents, this number is expected to increase. In addition, drug products that are injectable in ocular compartments other than the vitreous humor are expected to enter the back of the eye market in the not so distant future. Besides the IVT route, some of the most actively investigated routes of invasive administration to the eye include periocular, subretinal, and suprachoroidal (SC) routes. While clinical efficacy is the driving force behind new injectable drug product development for the eye, safety is also being improved with time. In the case of IVT injections, the procedural guidelines have evolved over the years to improve patient comfort and reduce injection-related injury and infection. Similar advances are anticipated for other routes of administration of injectable products to the eye. In addition to procedural improvements, the design of needles, particularly those with smaller diameters, length, and controlled bevel angles are expected to improve overall safety and acceptance of injected ophthalmic drug products. A key development in this area is the introduction of microneedles of a length less than a millimeter that can target the SC space. In the future, needles with smaller diameters and lengths, potentially approaching nanodimensions, are expected to revolutionize ophthalmic disease management.

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.

Comparison of Guided and Unguided Ocriplasmin Injection for the Treatment of Vitreomacular Traction: A Preliminary Study

This retrospective quality control study aimed at comparing resolution in patients treated with intravitreal ocriplasmin (IVO) using two injection techniques, classical injection procedure (unguided) and targeted injection using a surgical microscope with a 30-gauge 1-inch needle (guided) for the treatment of focal VMT without macular hole. The two groups presented a statistically significant difference in terms of resolution of VMT within the first month following treatment: 1/7 for the unguided group versus 6/7 for the guided group (p = 0.0291). The majority of the guided group presented an earlier resolution than the single resolved case in the unguided group. The results of this preliminary study indicate that the injection of ocriplasmin closer to the site of VMT results in the resolution in a higher number of cases and that this resolution occurs in a short time interval.

Endophthalmitis following intravitreal anti-vascular endothelial growth factor (VEGF) injection: a comprehensive review

The purpose of this review is to report and summarize previously reported studies and assess many of the individual steps of the intravitreal injection procedure's possible effect on the prevention of endophthalmitis. The pooled endophthalmitis rate from 20 large retrospective case series of anti-VEGF injections was 144/510,396 (0.028%; 1/3,544). Injections may be performed in an office-based location or in an operating room (OR) and low rates of endophthalmitis can be achieved in either location with careful attention to asepsis. Pre- or post-injection topical antibiotics have not been shown to be effective, and could select for more virulent microorganisms. Povidone-iodine prior to injection is accepted as the gold-standard antiseptic agent, but aqueous chlorhexidine may be an alternative. Antisepsis before and after gel or subconjunctival anesthetic is suggested. The preponderance of Streptococcal infections after intravitreal injection is discussed, including the possible role of aerosolization, which can be minimized by using face masks or maintaining silence. As with other invasive procedures in medicine, the use of sterile gloves, following adequate hand antisepsis, may be considered. Control of the eyelashes and lid margin is required to avoid contamination of the needle, but this can be achieved with or without a speculum. Techniques to minimize vitreous reflux have not been shown to reduce the risk of endophthalmitis. Same day bilateral injections should be performed as two separate procedures, preferably using drug from different lots, especially when using compounded drugs.

Intravitreal injection technique and monitoring: updated guidelines of an expert panel

PURPOSE

To review evidence and provide updated guidelines on intravitreal (IVT) injection technique and monitoring.

METHODS

A review of the published literature on IVT injection from 2004 to 2014 formed the basis for round table deliberations by an expert panel of ophthalmologists.

RESULTS

The dramatic increase in the number of IVT injections has been accompanied by a comparable increase in evidence surrounding IVT practice patterns and techniques. The expert panel identified a number of areas that have evolved since publication of the original IVT injection guidelines in 2004, the most notable of which were a lack of evidence to support the routine use of pre-, peri-, and postinjection antibiotics to reduce the risk of endophthalmitis, and the role of aerosolized droplets containing oral contaminants from the patient and/or providers as a potential source of infection. The panel emphasized the continued importance of applying povidone-iodine to and avoiding eyelid contact with the intended injection site and needle.

CONCLUSION

Updated guidelines on IVT injection technique and monitoring are proposed based on a review of published literature and expert panel deliberations.

Vitreous incarceration after ranibizumab injection: an ultrasound biomicroscopy study

BACKGROUND AND OBJECTIVE

The aim of the study was to evaluate vitreous incarceration at the injection site using ultrasound biomicroscopy (UBM) after intravitreal injection of ranibizumab.

PATIENTS AND METHODS

The study included 39 eyes of 34 patients who underwent intravitreal injection of 0.05 mL of ranibizumab. UBM (HiScan; Optikon, Rome, Italy) with a 50 MHz probe was performed 1 day after surgery to determine the existence of vitreous incarceration at the injection site.

RESULTS

The mean patient age was 59.7 (± 10.1) years, and 58.9% were female. Vitreous incarceration into the pars plana site was detected in six eyes (15.3%) the day after intravitreal injection.

CONCLUSION

Vitreous incarceration at the injection site after intravitreal injection is thought to lead to a higher risk for complications such as infection, retinal breaks, retinal detachment, vitreous hemorrhage, and fibrovascular proliferation at the injection site. To understand the clinical importance of vitreous incarceration, further long-term prospective studies are necessary.

Intraocular Pressure in Eyes Receiving Intravitreal Antivascular Endothelial Growth Factor Injections

Purpose: The aim of the this study was to determine the effect of intravitreal antivascular endothelial growth factor injections on intraocular pressure (IOP) and identify possible risk factors for the development of increased IOP. Materials and Methods: This prospective study included a total of 106 eyes receiving intravitreal injection of bevacizumab as treatment for macular edema or active choroidal neovascularization. IOP was measured by Goldmann applanation tonometry immediately before the intravitreal injection and 5 min, 1 h and 15 days after the procedure. The records of the study patients were reviewed for age, gender, history of glaucoma, diabetes mellitus, phakic status, systemic and topical medication and number of previous injections. Subconjunctival reflux was registered. IOP elevation was defined as IOP ≥21 mm Hg and/or a change from baseline of ≥5 mm Hg recorded at least on two or more measurements on the same visit. Results: Mean preoperative IOP was 15.31 ± 3.90 mm Hg and postoperative IOP values were 27.27 ± 11.87 mm Hg (after 5 min), 17.59 ± 6.24 mm Hg (after 1 h) and 16.86 ± 3.62 mm Hg (after 15 days). The IOP variation was statistically significant between pre- and postoperative measurements (p < 0.05). Subconjunctival reflux was recorded in 11.3%, and in this subgroup the IOP at 5 min and at 1 h was lower than preoperative IOP (p < 0.05). Conclusions: More than one third of the eyes achieved IOPs >30 mm Hg 5 min after injection. Subconjunctival reflux contributed to a lower mean postoperative IOP (p < 0.05). Considerations for the management include prophylactic IOP lowering with medical therapy and/or preinjection ocular decompression for patients with a history of glaucoma or ocular hypertension and switching to an as-needed injection protocol in patients suffering a marked IOP rise in previous injections.