Improving the accuracy and comfort of intravitreal injections

April 16, 2018

An intravitreal injection device can provide repeatable results and added comfort for the patient, removing the need for a drape and speculum.


With the advent of anti-vascular endothelial growth factor (VEGF) therapies, intravitreal injections have become

routine standard-of-care. Yet, it is often easy to forget that, for many patients, the use of a drape and speculum can be unpleasant.

In addition, inadequate sterility-often caused by the needle tip touching the eyelid or lashes and becoming contaminated with the individual’s own flora-can result in infections such as endophthalmitis.

 

Addressing the discomfort of the procedure

Despite the fact that the use of both a surgical drape and speculum are advised to lower the risk of infection during injections, studies have shown that this sterile procedure can have a negative impact on the patient’s perception of the treatment. In one study, 53% of patients indicated that placement of the drape caused feelings of claustrophobia and anxiety, plus the use of a speculum accounted for a high level of stress, second only to the pain during needle insertion.1,2

To address these issues, I decided to see if I could come up with a better solution. This, in collaboration with the innovation panel at Plymouth Hospitals NHS Trust, led to the development of an intravitreal injection guide (IVT; Malosa Medical/Beaver-Visitec International), a device which eliminates the need for a surgical drape and speculum during the IVT injection procedure, largely due to a built-in lash guard.

In addition, the cylindrical chamber of the injection guide is designed for use with a 30-gauge needle to improve patient tolerance and reduce the pain patients feel during needle insertion.

 

Improving the safety profile of the technique using a guide

The intravitreal device can also help to standardise this procedure, which should lead to a reduction in complications, such as traumatic lens injury. The standard method requires the needle to be inserted perpendicularly through the sclera with the tip of the needle pointing towards the centre of the globe to avoid injury to the posterior lens.4

The injection site is marked using sterile ophthalmic callipers – usually 3.5 mm posterior to the limbus for an aphakic or pseudophakic eye or 4 mm posterior to the limbus for a phakic eye.5

The instrument is specifically designed to overcome these challenges through the addition of an arrow on the apex of the base plate to show the correct positioning at the limbus. A cylindrical chamber eliminates the possibility of over inserting the needle and subsequently causing retinal injury by only allowing 7-mm of a 13-mm/30-gauge needle to enter into the eye.

Meanwhile, with the base plate of the guide firmly in position, the guide allows the injection to be delivered at the correct distance from the limbus, 4mm, and at the correct perpendicular angle to the sclera (Figure 2).

 

IVT and nervous eye movements

The guide also adds confidence and prevents unnecessary risks to the patient. This is particularly true in patients whose eyes move during the procedure, typically due to pre-procedure nerves or the uncomfortable sensation associated with the use of a lid speculum.

This movement can be controlled by the fixation studs located on the footplate of the guide.  Once the patient is looking in the desired direction, the eye can be stabilised through the placement of the device.

The steadying of the eye allows me to deliver the treatment to the correct anatomical position safely and confidently without the risk of the patient moving, which can cause complications such as corneal abrasions and retinal damage.

 

Future direction for the IVT guide

Determining the practicality of the instrument alongside patient satisfaction is an important direction to assess in the future. The increasing demand for intravitreal injections within Europe, and indeed across the world, should make conducting a study evaluating the guide problem-free.

The demand also adds pressure to surgical staff and any device which can help to ease the workload or make a procedure more efficient will always be welcomed.

 

Conclusion

The early use of the device has shown it could be an important addition to the ophthalmology surgery tool kit. The guide not only provides added comfort for the patient during the procedure with its no-drape, no-speculum, no-calliper approach, but also benefits the surgeon or nurse practitioner in terms of efficiency and standardisation of the technique.

Feedback I have received from my own patients and staff members has been positive. The steps required in the original intravitreal injection technique can be time consuming and require precision to ensure the treatment is delivered effectively. The guide however, provides a standard for the procedure with the aim to improve efficiency and accuracy, even in the case of a nervous patient.

 

References

1.     Tailor R, Beasley R and Narendran N. Evaluation of patients’ experiences at different stages of the intravitreal injection procedure – what can be improved? Clin Ophthalmol. 2011;5;1499-1502.

2.     Ghasemi K and Nguyen Q,D. (2013). Adverse events and complications associated with intravitreal injection of anti-VEGF agents: a review of the literature. Eye (Lond).2013;7;787-794.

3.     Rossi E, Meyer CH, Magalhães O and Eid FM. Effect of Needle Type and Injection Technique on Pain Level and Vitreal Reflux in Intravitreal Injection. Journal of Ocular Pharmacology and Therapeutics. 2011.

4.     American Academy of Ophthalmology. (2015). Intravitreal Injections.

5.     Wilson ME and Scott AW. How to give intravitreal injections. Eyenet. 2013;45-46.

 

Mr Salman Waqar

E: salman.waqar@nhs.net

Mr Waqar is a Fellow of the Royal College of Ophthalmologists and, alongside a general ophthalmic practice, specialises in the surgical treatment of complex glaucoma and cataracts.

His academic interests include using virtual reality simulation to investigate surgeon performance, and the development of innovative surgical instruments to improve patient safety. He is the author of ‘Intravitreal Injections: A handbook for ophthalmic nurse practitioners’ and the upcoming ‘Fundamentals of Intravitreal Injections’. Mr Waqar receives royalties from the products mentioned herein.