This study demonstrates that the long-term FAc intravitreal implant is effective for the treatment of NIU in a Middle East population. It has shown to control uveitis relapses through reduced inflammation in association with improved visual acuity and structural parameters of uveitis.

Sustained-release corticosteroid implants have emerged to bridge the problems related to intravitreal injections. These implants reduce the number of injections required and therefore minimize the potential adverse effects of multiple injections. They also help to increase patient comfort and adherence to the treatment by being able to deliver a low dose of the drug whilst helping to reduce drug-related adverse events [12].

In comparison to the 0.59 mg fluocinolone acetonide intravitreal implant (Retisert; Bausch + Lomb, Bridgewater, NJ, USA), which requires scleral anchoring whereas the FAc intravitreal implant is administered as an intravitreal injection and by doing so a lower dose of 0.2 µg/day of fluocinolone acetonide is administered to the patient. Compared with the 0.59 mg implant, the 0.19 mg intravitreal implant is associated with a lower risk of raised IOP, and this helps to reduce the need for medication or surgical intervention to control pressure and/or remove cataract formations [9].

Here we demonstrate that the safety profile over a mean follow-up of 29.7 ± 14.6 months shows no concern for use of this treatment in prevention of relapse in NIU. We did not identify an increased risk for IOP developing in the whole group. One eye, however, developed glaucoma which was successfully controlled with topical therapy while uveitis was controlled, and visual acuity improvement maintained. There was progression of cataract in phakic eyes, and two out of three underwent cataract surgery with improvements in both BCVA and CRT by 36 months of follow-up. Two eyes developed visually non-significant mild epiretinal membrane, one of whom had trauma related uveitis. This observation mirrors safety data from the original trials [13, 14]. Procedure related events such as conjunctival hyperemia and temporary ocular surface discomfort were not raised as a concern in the patients studied, which may be because these patients are used to receiving local anti-inflammatory therapies.

The efficacy data are encouraging with significant improvement in signs of inflammation as well as measures of both structure (i.e., CRT) and function (BCVA). These improvements were observed from Month 3 and were maintained in all studied eyes. The disease profile of our patients is similar to those previously reported in other studies from other regions [15, 16]. Concerns have arisen that the lower dose of fluocinolone acetonide in the FAc implant (0.2 µg/day) might lead to a slower onset of action and weaker therapeutic effects in terms of inflammatory control. As shown here, however, this was not the case with the onset of effects documented at Month 3 with clinical improvements observed even earlier after therapy commenced (i.e., within the 1 to 3 months window after therapy commenced). Furthermore, the control of inflammation seems to also be comparable to current publications and even reports where higher intravitreal corticosteroid doses have been administered [17, 18].

Our findings suggest a notable efficacy in the management of NIU in terms of preventing uveitis relapses during the follow-up period. At Month 6, our case series showed that uveitis was inactive in the vitreous with 72.2% of eyes (n = 13 of 18) having a vitritis score less than one and 83.3% of eyes (n = 15 of 18) having an AC cell count less than one. Hence, the FAc implant could control intraocular inflammation and maintaining quiescence during the mean follow-up in the majority of our patients. In diabetic patients, ocassional anti-angiogenic injections were used as a rescue therapy for macular edema.

With regard to diagnoses, it is worth noting that the type of uveitis was not homogenous, and improvements were observed across all uveitis indications, which included chronic uveitis (with known tuberculosis), panuveitis, retinal vasculitis/vitritis, tuberculosis uveitis with controlled and inactive infection on four anti-tuberculous medicines, pseudophakic CME/panuveitis and multifocal choroiditis.

Limitations of this report are a lack of control group with no randomization. However, this is meant to be a clinical audit with the focus being on the long-term safety and initial effectiveness in a Middle East population. While the index cohort is relatively small it is comparable to others recently reporting on use of FAc intravitreal implant in NIU and presents a number of patients with a follow-up of > 36 months [16].

In conclusion, we report initial real-world experience with the long-term FAc intravitreal implant. Our data show it was effective for the treatment of NIU in a Middle East population and worked to control uveitis relapses through reduced inflammation and this was associated with improved visual acuity.