Why carry out this study?
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Intravitreal injections (IVIs) with vascular endothelial growth factor inhibitors represent the most prevalent ophthalmic procedure in developed countries. |
This paper aims to provide a practical approach to IVIs. |
What was learned from the study?
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We describe important aspects relating to the setting, the patient, the procedure, and the information given to the patient. |
We outline a best practice protocol for the procedure. |
Introduction
Setting
Operating Theater Versus Office
Who Should Perform the Injection?
Use of Injection-Assisting Devices
Optimizing Patient Comfort
Patient
Contraindications
Hypersensitivity
Preexisting Ocular Conditions
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IVI therapy is contraindicated in patients with any ocular or periocular infection at the time of the IVI [38]. Infections must be treated and followed by a new assessment prior to IVI.
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IVI is not contraindicated in eyes with prior intraocular or periocular surgery [38]. However, caution is advised for eyes with prior glaucoma surgery such as trabeculectomy or a drainage device to avoid injection at the site of the filtering bleb or shunt. Some evidence suggests that pharmacokinetic properties may be different in previously vitrectomized eyes, with a shorter half-life of the anti-VEGF drug [38], which is no contraindication for IVI but may influence the frequency of IVIs needed.
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In patients with glaucoma, several studies have documented a rise in the intraocular pressure (IOP) after IVIs. Although the rise in IOP may be slightly higher in eyes with glaucoma, the IOP elevation is rarely alarmingly high [39]. Rare cases with an unacceptable IOP elevation after IVI can be managed [40].
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In cases with a history of previously unacceptable IOP elevation after IVI, lowering the IOP prior to the IVI should be considered.
Preexisting Medical Conditions
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Infections elsewhere and any fever in general should prompt caution, as there may be a risk of introducing systemically circulating microorganisms through IVIs. Whether IVI can be performed should be considered on a case-by-case basis and by discussing the risks with the patient. There is no clinical evidence in this regard, so this is more of a theoretical consideration.
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Since anti-VEGF administered through IVIs can be detected systemically [41], there have been debates regarding its use in patients with recent cardiovascular or cerebrovascular events as to whether it could worsen a potentially life-threatening condition [42, 43]. Studies do not prove that IVIs with anti-VEGF increase the risk of cardiovascular or cerebrovascular events [42, 43]. In a systematic review and meta-analysis, Reibaldi et al. did not find any strong evidence suggesting a relationship between IVI with anti-VEGF and increased mortality [44]. In an interesting study of published systematic reviews and meta-analyses on systemic adverse events after IVI with anti-VEGF, Thulliez et al. showed that different meta-analyses found different signals, i.e., some studies found an association with an increased risk of cardiovascular events whereas others did not [45]. One important perspective is that only patients identified as being at high risk of a future cardiovascular event prior to anti-VEGF therapy may have an increased risk of developing a cardiovascular event after the commencement of anti-VEGF therapy [46]. Hence, from a practical perspective, caution is advised in cases with a recent vascular event [47] and, if possible, the IVI should be postponed until ≥ 3 months after the vascular event. In severely vision-threatened cases involving patients with a recent vascular event, the use of an anti-VEGF agent with a shorter half-life should be considered, e.g., ranibizumab instead of aflibercept.
Pregnancy and Postpartum
Bilateral Injections
Proposed Procedure
1. Prepare setting | Operating theater with laminar air flow and a dental chair for the patient. The chair can help the elderly patient move from a sitting to a supine position for the injection, and then from a supine to a sitting position afterwards. All rooms have two members of the medical staff on hand for the injection, music available, and neck pillows. Medical staff use face masks and gloves for all sterile procedures |
2. Ensure patient identification, consent, and eligibility | Talk with the patient to ensure identification and to discuss any contraindications, allergies, and consent, as well as to confirm eye laterality for treatment and the treatment drug |
3. Prepare medication | Prepare the relevant drug under sterile conditions using a large 27-gauge needle and then change the needle used to a smaller 30-gauge needle. For prefilled syringes, simply prepare the 30-gauge needle. Remove dead space and ensure that there is only 0.05 mL of the drug in the syringe |
4. Apply topical anesthesia | Apply topical tetracaine twice, with a 60-s interval between applications |
5. Apply topical disinfection | Apply topical disinfectant once to conjunctiva, lids, and lashes and then wait for 30 s |
6. Lid speculum | Insert a sterile lid speculum |
7. Mark injection location | Mark the location corresponding to the pars plana in the superotemporal quadrant. Mark a distance to the limbus of 3.5 mm for pseudophakic eyes and 4.0 mm for phakic eyes |
8. Coordinate gaze direction | Ask the patient to look in the direction opposite to the injection. For example, when injecting into the superotemporal quadrant of the right eye, ask the patient to look downwards and to the left |
9. Hold the prepared syringe and a Q-tip | Hold the prepared syringe in the dominant hand and a sterile Q-tip in the nondominant hand |
10. Place the Q-tip | Place the Q-tip close to the area of injection and displace the conjunctiva slightly |
11. Insert the syringe | Insert the syringe perpendicularly at the marked area of insertion in one smooth motion. Insert the short 30-gauge needle about 1/2 of its length, ensuring that it extends beyond the subretinal space and into the vitreous. Inject the medicine slowly and remove the syringe |
12. Remove lid speculum and consider irrigation and/or lubricant | Remove the lid speculum. Consider irrigation and/or lubricant drops |
13. Review alarm signs with the patient | The patient should expect slight discomfort during the day of the intravitreal injection, but significant pain, redness, or acute vision loss should prompt contact with emergency eyecare |
Face Masks, Gloves, and Drapes
Topical Anesthesia
Topical Disinfection
Topical Antibiotics
Needle Type
Lid Speculum
Injection
Information
Informed Consent Prior to Therapy
Alarm Signs After Therapy
Common | |
Discomfort and pain | Foreign body sensation and mild ocular discomfort is not unusual, especially as the topical anesthetics wear off |
Subconjunctival hemorrhage | Subconjunctival hemorrhage can look dramatic, but is common and harmless |
Uncommon | |
Traumatic cataract | Needle-induced damage to the lens during an intravitreal injection can lead to a traumatic cataract. This occurs in less than 1 out of 1000 injections |
Retinal tear or detachment | The procedure may facilitate a tear or detach the retina. This occurs in less than 1 out of 1000 injections |
Severe intraocular pressure elevation | The pressure in the eye may increase after an injection. In rare cases, this increase may require medical attention and intervention |
Vitreous hemorrhage | In rare cases, a vitreous hemorrhage may occur after an injection |
Endophthalmitis | Severe pain, red eye, and blurry vision can be a sign of infection in the eye, which should prompt the patient to seek emergency eyecare. This occurs in less than 1 out of 5000 injections |