As many of my patients who tell me ,various doctors often have very different injection protocols, making this topic very confusing for many patients. Currently, most retina surgeons adhere to one of three treatment methods:

Continued interval therapy or ‘monthly’ -injection given every 4 weeks (Avastin and Lucentis) or Eylea which is coming up… every 8 weeks.

‘Treat and extend’ -monthly injections until clinically stable for physician, then increasing intervals between injections.

‘PRN’ or as needed- injections given monthly until deemed clinically stable by physican and then retreat if patient becomes symptomatic or demonstrates new activity of disease.

So why the different methods?

In 2006, the results of ANCHOR and MARINA (2 large trials looking at effectiveness of Lucentis dosed monthly for AMD) left us surprised by providing visual improvements and stability never before seen. Since then, other trials have followed looking at ways to obtain equal outcomes with fewer injections, indeed.

Studies repeatedly show that manufacturer recommended monthly therapy results in the best visual outcomes but at the price of more frequent injections. In fact, patients from the original trials who were switched from monthly injections to as needed after 2 years, lost half of their visual gains in the subsequent year, conferring that the best way to maintain vision is to prevent the disease from progressing.

More recently the National Eye Institute sponsored randomized trial called the Comparison Of Age-related Macular Degeneration Treatments Trial (CATT) compared efficacy of Avastin (bevacizumab) to Lucentis (ranibizumab) dosed monthly or as needed. At two years, this study showed that when compared head to head, PRN treatment was inferior to monthly and resulted in poorer visual outcomes.

While treat and extend seems like a reasonable compromise between the two treatment regimens, unfortunately, no large clinical trials have been performed to compare the outcomes of this technique against monthly therapy. By virtue of the fact that this technique extends the interval outside the 4 week therapeutic window of the drug, patients are left unprotected with an increasing risk of recurrence and irrecoverable vision loss, and in fact, Dr Pratik has seen patients develop bleeding when patient loses follow up and presents at 5 to 8 weeks!. So while we will sometimes extend patients beyond monthly therapy if they have remained stable for several months, it is important that they understand and accept the potential risks.


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For more information on lucentis please visit

Before Intravitreal Injection:

Come after a shower and head and face-wash in the morning of your appointment. Have a light breakfast.

Dr Pratik always advices antibiotic eye drops to be instilled frequently in both eyes, before injection.

Use of Proparacaine 0.5% eye drops and 30 gauge needle makes injection an essentially painless procedure in the hands of

Dr. Pratik.

After Intravitreal injection:

Your eye will patched for an hour or two. Sometimes you are advised to rest in a head-elevated position for one day.

Put antibiotic eye drops and antiglaucoma eye drops as per schedule .

Don’t let water go inside your eye for next 3 days.

You must follow up the next day and after one week.

Dont worry if feel floaters in your visual field.

However if you develop inceasing redness, discharge , pain or blurring of vision please contact 7771089999.