Abstract
Purpose:
To evaluate the safety and the efficacy of submacular olfactory ecto-mesenchymal stem cell (OEMSC) transplantation in patients with retinitis pigmentosa (RP).
Methods:
This phase 1 clinical study approved by academic and government authorities and performed at Gulhane Military Medical Academy in Turkey includes 10 adult retinitis pigmentosa patients (2 women 8 men) with best-corrected visual acuity (BCVA) of HM to <20/200. In addition to full clinical examinations, ERG (Roland-Consult), macular OCT (Spectralis), microperimetry (MP1), and visual field examinations (Humprey 10-2; 30-2) were used for evaluation of the treatment. Using transconjuctival pars plana approach without vitrectomy in the eye with worse BCVA, OEMSCs, cultured from a single healthy adult donor, provided by GMP-certified laboratory (Acibadem-Labcell) were injected into the submacular area through 41 G needle at a dose of 2x10(6) cells/0.2ml. No topical and systemic anti-inflammatory agents were used. They were followed regularly.
Results:
None showed ocular or systemic inflammatory sign and tumor development in the early period. Intravitreal membrane developed in 1 (10%) patient which was treated with vitrectomy successfully within the first month; silent epimacular membrane in 1(10%), and submacular membrane in 1(10%) were observed. OCT exams confirmed the sensory retinal detachment and placement of SCs in the submacular area within 6 hours and settlement of the cells subfoveally within a month. Five (50%) patients showed minimum 0.1log unit BCVA improvement together with patients’ satisfaction; even 1 patient (10%) with CF at 4 meter gained 20/100 vision after the first month. Central foveal thickness (CFT) increased to normal in 4 of 5 patients (80%) with low CFT. Retinal sensitivity increased 4 dB or more at locations within 10-degree in 6 (60%) patients, and central fixation improved in 5 of 7 (71%) with fixation disability, which was confirmed by patient questionnaire.
Conclusions:
This novel technique with injection of allogeneic adult OEMSC into the submacular area without immunosuppression in RP patients seems to be promising for replacement/restoration of macular functions; manageable side effects, however, might be considered.
Keywords: 696 retinal degenerations: hereditary •
721 stem cells •
741 transplantation