Abstract
Purpose:
To analyze the role of both morphological and functional retinal parameters to evaluate the timing for a re-treatment in retinal vein occlusion with intravitreal steroid implant.
Methods:
This prospective study included 14 eyes of 14 consecutive patients affected by Retinal Vein occlusion who underwent intravitreal implant of dexamethasone (Ozurdex, Allergan. USA). Morphological examination was performed by Spectral OCT (OTI, Toronto, Canada) evaluating macular (MT) and choroidal thickness (CT). Functional assessment included LogMAR visual acuity and retinal sensibility - fixation pattern performed by microperimetry (MP1, Nidek Technologies, Padova, Italy). Follow up visits were scheduled at day 30, 90 and 180 after treatment.
Results:
Baseline morphological quantitative evaluation showed a MT of 393,54±195,36µm (mean±standard deviation) and CT of 254,61±67,28µm; after treatment, at day 30 we found a MT of 240,00±104,50µm (p<0.05) and a CT of 241,82±46,44µm (p<0.05), at day 90 a MT of 321,00±136,25µm (p<0.05) and a CT of 227,90±68,65µm (p>0.05), at day 180 a MT of 316,67±169,56µm (p>0.05) and a CT of 242,50±57,01µm (p<0.05). Baseline functional evaluation showed mean visual acuity of 0,75 ± 0,49 LogMAR and retinal sensitivity of 7,65 ± 4,99 dB; after treatment, at day 30 we found 0,53±0,46 (p<0.05) and 9,31±4,42 dB (p<0.05); at day 90, 0,66±0,48 (p<0.05) and 8,29±4,99 dB (p<0.05), at day 180, 0,71±0,60 (p>0.05) and 8,15±5,31 dB (p<0.05). Fixation pattern improved significantly (p<0.05), showing a stable fixation in 4 of 14 patients at baseline, in 8 of 14 patients at day 30, in 7 of 14 patients at day 90 and in 8 of 14 patients at day 180. At month 3 and more at month 6, compared with month 1, a significative (p<0.05) proportion of patients showed a recurrence of macular edema. 4 of 14 patients need a retreatment before month 6.
Conclusions:
Our study showed a significative control of macular edema till month 3. This effectiveness is showed also by our detailed analysis with the microperimetry. This evaluation represents a useful parameter for a better follow up in particular for the focal variations on visual central scotoma and fixation, a defect that afflict this type of patients on their quality of vision and life. A retreatment need in this way becomes mandatory before month 6 to preserve the function achieved.