Trabajo presentado por la Dra. Inés Contreras Martín durante el congreso de EURETINA celebrado en Londres.
Ozurdex for macular edema in retinitis pigmentosa
The rationale for the use of intravitreal corticosteroids in macular edema (ME) associated with retinitis pigmentosa (RP) is that an inflammatory response against actively degenerating photoreceptors and retinal pigment epithelium may be involved in its pathogenesis1,2.
Multiple studies have reported positive responses with intravitreal triamcinolone (IVT). However, the effect of IVT is short and adverse effects are relatively high. Recently, several case reports have reported good results with intravitreal dexamethasone (Ozurdex®)3-5.
A 24-year old woman diagnosed with Usher syndrome was seen in 2012. Visual acuity was 0.1 in her right eye (RE) and 0.4 in her left eye (LE). Fundus examination showed the typical signs of RP as well as ME and optic nerve head drusen. Optical coherence tomography (OCT) showed severe ME. The patient did not tolerate oral acetazolamide. Treatment with intravitreal anti-VEGF (bevacizumab and ranibizumab) lead only to a slight reduction in ME. Therefore, treatment was stopped.
In September 2013 the patient reported a decrease in visual acuity: it had dropped to 0.05 in the RE and 0.16 in the LE. ME had increased. The patient was offered treatment with intravitreal Ozurdex. The LE was treated in October 2013. One week later, ME had improved dramatically. Subjectively, the patient reported better contrast sensitivity. These results lead to the decision to treat the RE.
In December 2013, 9 and 6 weeks after the injection in the LE and RE visual acuity had improved to 0.1 in the RE and remained stable at 0.16 in the LE. ME was almost resolved in both eyes and an epiretinal membrane (ERM) could be seen in the RE and a taut posterior hyaloid in the LE. Intraocular pressure (IOP) was 36 mmHg in both eyes. Treatment with a fixed combination of timolol and dorzolamide twice daily was started and one week later IOP was 16 mmHg RE and 17 mmHg LE.
In February 2014, 15 and 18 weeks after treatment, ME had reappeared. A second injection of Ozurdex was performed in both eyes, with an excellent anatomical response. The patient was offered vitrectomy for ERM removal but chose to postpone surgery.
In June 2014, a third injection was performed in both eyes due to recurrent ME. Visual acuity remained stable at 0.1 in the RE and improved to 0.2 in the LE. A subcapsular posterior cataract had developed in the RE. Phacovitrectomy was performed in the RE in July 2014.
One month after surgery, visual acuity remained stable at 0.1 and OCT evidenced partial restoration of the foveal anatomy.
The anatomical resolution of ME in RP after Ozurdex supports the hypothesis that there is an underlying inflammatory response involved in its pathogenesis. Ozurdex may be considered for ME refractory to medical treatment. However, an important drawback is the temporary response and the need for re-injection.
In our case, macular traction may also be an important factor; this will be clarified with further follow-up.
1. Heckenlively et al. Association of antiretinal antibodies and cystoid macular edema in patients with retinitis pigmentosa. Am J Ophthalmol 1999;127:565–573.
2. Yoshida et al. Clinical evidence of sustained chronic inflammatory reaction in retinitis pigmentosa. Ophthalmology 2013;120:100–105.
3. Saatci et al. Bilateral Intravitreal Dexamethasone Implant for Retinitis Pigmentosa- Related Macular Edema. Case Rep Ophthalmol 2013;4:53–58.
4. Alhassan M and Quintyn JC. Unilateral intravitreal dexamethazone implant for bilateral retinitis pigmentosa-related macular edema. Graefes Arch Clin Exp Ophthalmol 2013;251:2827–2828.
5. Srour et al. Intravitreal dexamethasone implant (Ozurdex) for macular edema secondary to retinitis pigmentosa. Graefes Arch Clin Exp Ophthalmol 2013;251:1501–1506.