Abstract
Purpose: :
Variations in macular optical coherence tomography (OCT) measurements before and after cataract surgery and retinal detachment surgery are known to occur. Possible changes of macular thickness after strabismus surgery were not reported. We examined macular thickness changes before and after uncomplicated extraocular muscle surgery.
Methods: :
We prospectively evaluated 60 eyes of 30 healthy patients undergoing elective unilateral extraocular muscle surgery. The recti muscles were operated in 23 eyes and the oblique muscles in seven. Their fellow eyes served as controls. OCT (Staratus, OCT 3) measurements were performed preoperatively and one day after surgery. The retinal map was divided into minimal foveal thickness, a central 1-mm disk area, and two peripheral ring areas with diameters of 3 mm and 6 mm divided into 4 quadrants and centered on the fovea. We compared the postoperative OCT values to the respective preoperative values.
Results: :
Central foveal thickness (CFT) in the operated eyes was 201.0±18.4 microns (µ) preoperatively compared to 205.32±22.7 µ postoperatively (p=0.0220). Pre- and postoperative perifoveal outer temporal quadrant thicknesses were 219.94±15.98 µ and 225.48±14.63 µ, respectively (p=0008). There were no significant differences in any of the other quadrants of the operated eyes. No differences were found between pre- and postoperative retinal thickness measurements of the fellow eyes (controls). Changes in CFTs of eyes that underwent recti muscle operation were greater than changes in eyes following oblique muscle operation, but not significantly.
Conclusions: :
This is the first demonstration of an asymptomatic increase in foveal and perifoveal thicknesses following extraocular muscle surgery. These findings might be related to a very minimal subclinical macular edema secondary to the traumatic intervention, despite the fact that there is no direct involvement of the retina. Long-term follow-up studies are warranted to establish whether these increased thicknesses eventually return to preoperative levels.
Keywords: strabismus • retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)