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Paper text:
the oct scans from patients whose visual acuity increased gradually after successful closure of macular hole surgery were analyzed retrospectively .
the vertical and horizontal scans with 5 mm lengths were obtained by a skilled technician .
the identical locations of the serial scans for each patient were confirmed based on the oct findings and the video images that were taken simultaneously with the oct scans .
the scanned images were enhanced as described previously.6 in brief , the raw files were exported to adobe photoshop ( version 7.0 ) and the reflectivity level was optimized as follows .
the lowest level below which at least 0.1% of data points were detected was set to be 0 or the darkest in the new scale ; the highest level above which at least 0.1% of raw data points were present was set at 255 or the brightest in the new scale . as a result of using this new scale , we were able to use most of the information present in each image .
the dimensions of the images were changed to reproduce the actual dimensions of the scans . a 67-year - old woman who had complained of decreased vision of the left eye for one month
she underwent pars plana vitrectomy , triamcinolone acetonide - assisted internal limiting membrane ( ilm ) peeling and fluid - gas exchange .
the postoperative oct scans obtained at four weeks demonstrated the photoreceptor layer with 1820 m wide disorganization ( fig .
pars plana vitrectomy , laser photocoagulation and fluid - gas exchange were performed . at six months ,
visual acuity was 20/40 and the oct studies disclosed reorganization of the photoreceptor layer at multiple locations along the macula ( fig .
slight disorganization of the photoreceptor layer was noted under the center of the fovea . by 1 year
, the patient 's visual acuity had improved further to 20/25 and the photoreceptor layer of the fovea had been reorganized on the oct images ( fig .
a 64-year - old woman who had complained of having a four - month period of visual disturbance was diagnosed with a stage 4 macular hole in the right eye ( fig .
the postoperative oct scans obtained at two weeks demonstrated 1870 m wide disorganized features in the outer retina ( fig .
2b and c ) and the patient had visual acuity of 20/125 . by four months
the oct scans revealed partial reorganization of the photoreceptor layer , the signal of which appeared as a broken line ( fig .
, the photoreceptor layer had been reorganized further and had only a small residual defect ( fig .
a 32-year - old woman who had experienced decreased vision of the right eye for six months was diagnosed with a stage 2 macular hole ( fig .
she underwent pars plana vitrectomy , ilm peeling and fluid - gas exchange . at postoperative two weeks , her visual acuity was 20/100 and the oct scans revealed disorganization of the photoreceptor layer under the fovea ( fig .
after six months , visual acuity was 20/80 and the oct studies revealed partly organized photoreceptor layer , which had some signal discontinuity and appeared as a broken line ( fig .
one year after the surgery , visual acuity was 20/40 and the discontinuity of the photoreceptor layer had been resolved on the oct ( fig . 3f and g ) .
a 67-year - old woman who had complained of decreased vision of the left eye for one month was diagnosed with a stage 3 macular hole ( fig .
she underwent pars plana vitrectomy , triamcinolone acetonide - assisted internal limiting membrane ( ilm ) peeling and fluid - gas exchange .
the postoperative oct scans obtained at four weeks demonstrated the photoreceptor layer with 1820 m wide disorganization ( fig .
pars plana vitrectomy , laser photocoagulation and fluid - gas exchange were performed . at six months ,
visual acuity was 20/40 and the oct studies disclosed reorganization of the photoreceptor layer at multiple locations along the macula ( fig .
slight disorganization of the photoreceptor layer was noted under the center of the fovea . by 1 year
, the patient 's visual acuity had improved further to 20/25 and the photoreceptor layer of the fovea had been reorganized on the oct images ( fig .
a 64-year - old woman who had complained of having a four - month period of visual disturbance was diagnosed with a stage 4 macular hole in the right eye ( fig .
the postoperative oct scans obtained at two weeks demonstrated 1870 m wide disorganized features in the outer retina ( fig .
2b and c ) and the patient had visual acuity of 20/125 . by four months
the oct scans revealed partial reorganization of the photoreceptor layer , the signal of which appeared as a broken line ( fig .
, the photoreceptor layer had been reorganized further and had only a small residual defect ( fig .
a 32-year - old woman who had experienced decreased vision of the right eye for six months was diagnosed with a stage 2 macular hole ( fig .
she underwent pars plana vitrectomy , ilm peeling and fluid - gas exchange . at postoperative two weeks , her visual acuity was 20/100 and the oct scans revealed disorganization of the photoreceptor layer under the fovea ( fig .
after six months , visual acuity was 20/80 and the oct studies revealed partly organized photoreceptor layer , which had some signal discontinuity and appeared as a broken line ( fig .
one year after the surgery , visual acuity was 20/40 and the discontinuity of the photoreceptor layer had been resolved on the oct ( fig . 3f and g ) .
ko et al . suggested that the highly backreflecting signal of the photoreceptor layer returns when the photoreceptors return to their anatomical position after macular hole surgery.5 they have noted some discontinuity of the photoreceptor layer and have proposed that this discontinuity represents the residual photoreceptor impairments .
reported two cases in which the macular hole was repaired successfully with a persistent outer retinal defect , which was resolved at five to six months postoperatively.8 they suggested that the partial migration of the photoreceptor into the center of the hole during the healing process would resolve the defect .
these theories , however , are insufficient to explain the reorganization of the photoreceptor layer shown in our cases .
the oct images that were taken in the early postoperative period demonstrated broad disorganization of the photoreceptor layer , which underwent a gradual reorganization over a period of one or more years . unlike the cases of centripetal migration ,
the weak signal of the photoreceptor layer at multiple locations was an early indication of the reorganization of the photoreceptor layer in our cases . due to the discontinuity
these findings suggest that local reorganization of the photoreceptor takes place after anatomical restoration . in the second case ,
this defect would prevent further improvement of visual acuity.4 extent of the defect was reported to be correlated with postoperative visual acuity.7 it is important to perform serial scans at a consistent , predetermined location to verify these results . in spite of repeated scanning by a skilled technician , minimal deviation of the scans could not be avoided due to the following several reasons . as the macula lacks major vessels , shadowing of the vessels can not serve as a reliable reference .
the horizontal temporal vessels are not reliable references for the location of a vertical scan . in an unpublished study ( in peer - review )
, the authors found that there was a long - term change of the foveal thickness after macular hole surgery .
analysis of the foveal contour may be a crude reference , but requires a cautious interpretation , because a minimal anterior - posterior movement of the eye ball during a scan would change of the foveal shape considerably .
we also used the video images that were taken simultaneously with the scans ( fig . 1 to 3 , h to j )
however , the resolution of the video image is low and there is a little delay from scanning oct to taking the image .
nonetheless we think that our hypothesis is still valid , because the reorganization occurred in area of 1 mm or more which is broader than the foveal depression .
it is not clear if the changes in the photoreceptor layer features shown in these cases are usual in the eyes that show the continuing improvement of vision after closure of the macular hole .
however , reorganization of the photoreceptor layer seems to play a role in long - term visual recovery after closure of macular holes . to understand the mechanism , further studies involving more cases using a higher resolution oct are necessary .
to report three cases in which reorganization of the photoreceptor layer on optical coherence tomography ( oct ) was concurrent with long - term visual recovery after macular hole surgery . 
 serial oct scans of three eyes in which visual acuity continued to improve for 1 or more years after successful macular hole surgery were reviewed . 
 case 1 . at postoperative four weeks , visual acuity was 20/100 with disorganized photoreceptor layer on oct . 
 the photoreceptor layer had been reorganized and visual acuity had improved to 20/25 by 1 year . 
 case 2 . 
 two weeks after the operation , visual acuity was 20/125 and disorganization of the photoreceptor layer was noted . 
 visual acuity improved to 20/50 by four months . 
 the photoreceptor layer had been partly reorganized and had appearance of a broken line . 
 visual acuity had improved to 20/40 and the photoreceptor layer had been reorganized further with a residual defect on oct by 15 months . 
 case 3 . 
 visual acuity at two weeks was 20/100 . 
 oct revealed disorganization of the photoreceptor layer . 
 six months after the operation , the partly reorganized photoreceptor layer appeared as a broken line and visual acuity had reached 20/80 . 
 visual acuity had improved further to 20/40 by 1 year , concurrent with improved organization of the photoreceptor layer . 
 the reorganization of the photoreceptor layer plays a part in long - term improvement of visual acuity after macular hole surgery .