Restoration of Photoreceptor Outer Segment after Vitrectomy for Retinal Detachment




Purpose


To report photoreceptor restoration and visual outcomes after vitrectomy for retinal detachment.


Design


Retrospective, observational case series.


Methods


We prospectively studied the tomographic features of reattached retinas in 20 eyes with a macula-off rhegmatogenous retinal detachment using spectral-domain optical coherence tomography 1, 3, and 6 months after 3-port vitrectomy with SF 6 gas tamponade. All eyes were examined more than 3 months after surgery.


Results


The optical coherence tomography foveal findings were classified as a disrupted inner segment and outer segment (IS/OS) line, a residual foveal detachment, and a continuous IS/OS line. A disrupted IS/OS line was seen in 11 eyes (55%) at 1 month and in 8 eyes (40%) at 3 months, a foveal detachment was seen in 8 eyes (40%) at 1 month and in 7 eyes (35%) at 3 months, and a continuous IS/OS line was seen in 1 eye (5%) at 1 month and in 5 eyes (25%) at 3 months. In 18 eyes followed up for 6 months, optical coherence tomography showed a disrupted IS/OS line in 3 eyes (17%), a foveal detachment in 6 eyes (33%), and a continuous IS/OS line in 9 eyes (50%). The mean best-corrected visual acuities at 1 and 6 months were 0.26 and 0.16 with a disrupted IS/OS line, 0.60 and 0.95 with a foveal detachment, and 0.8 and 0.95 with a continuous IS/OS line. The mean best-corrected visual acuity was significantly ( P < .0001) lower with a disrupted IS/OS line compared with the other formations at 6 months.


Conclusions


The IS/OS line at the fovea recovered gradually after surgery. The postoperative visual acuity was correlated with a restored IS/OS line.


The success rates of rhegmatogenous retinal detachment surgery have been reported to be as high as 76% to 94%. Visual recovery varies after successful surgery. Patients occasionally have poor visual outcomes or delayed visual recovery after retinal reattachment. Epiretinal membranes, cystoid macular edema, and persistent subretinal fluid (SRF) affect the postoperative visual acuity (VA). Several studies have reported that time-domain optical coherence tomography (TDOCT) showed persistent SRF and increased foveal thickness at the macula. Although conventional TDOCT with 10-μm resolution can detect foveal detachments, its capability to detect pathologic photoreceptor changes is limited. Using ultra–high-resolution OCT with 3-μm axial resolution, Schocket and associates reported several anatomic abnormalities in the photoreceptor inner segment and outer segment (IS/OS) line after repair of rhegmatogenous retinal detachments. Recently developed spectral-domain (SD) OCT with 5-μm axial resolution allows observation of the IS/OS line and external limiting membrane. Using SD OCT, Smith and associates reported a correlation between microperimetric abnormalities and the presence of photoreceptor disruption or SRF after macula-off retinal detachment surgery. However, these studies did not evaluate the evolutional changes in the photoreceptor outer segment and the correlation with the VA. We evaluated the microstructure of the foveal changes and postoperative VA using SD OCT in macula-off rhegmatogenous retinal detachment after vitrectomy.


Methods


We retrospectively evaluated OCT images and the visual outcomes in 20 eyes of 20 patients (14 men, 6 women) who underwent successful vitreous surgery for rhegmatogenous retinal detachment at Gunma University Hospital from January 2007 through March 2008 ( Table 1 ). The retinal detachments involved 1 to 4 fundus quadrants and extended to the macula in all eyes. OCT was performed after surgery at 1 and 3 months in 20 eyes and at 6 months in 18 eyes. The patients’ ages ranged from 22 to 69 years (median, 55.6 years). The patients were followed up for from 3 to 18 months (mean, 8.3 months). Retinal tears were in the superior periphery in 16 eyes, temporal or nasal periphery in 2 eyes, and the inferior periphery in 2 eyes. The preoperative best-corrected VA (BCVA) levels ranged from 0.01 to 0.7 (mean, 0.13). All patients were examined by biomicroscopy using a noncontact lens (Super Field lens; VOLK, Mentor, Ohio, USA). All patients underwent a 3-port pars plana vitrectomy with gas tamponade (SF 6 ). In conjunction with vitrectomy, phacoemulsification and intraocular lens implantation were performed in 13 eyes. Concomitant scleral buckling was performed in 1 eye. After surgery, all patients were instructed to remain in a prone position at least overnight and to avoid the face-up position for a few days. After the first surgery, retinal detachment was achieved along with closure of the retinal tears in all patients. We obtained cross-sectional macular images with a 6-mm diameter using SD OCT (3D OCT-1000; Topcon, Tokyo, Japan; or Cirrus OCT; Carl Zeiss Meditec, Jena, Germany) at 1, 3, and 6 months after surgery. Using OCT, we assessed the relation between the integrity of the IS/OS line (defined as the border of the photoreceptor inner segment and outer segment) at the fovea, foveal detachments, and the BCVA. When we evaluated the visual improvement, the decimal VA was converted to logarithm of minimum angle of resolution. Statistical analysis was performed using analysis of variance (1-factor analysis of variance) to determine pertinent factors correlated with the postoperative VA and the IS/OS line and foveal detachments. P < .05 was considered significant.



TABLE 1

Demographic Data from 20 Cases after Surgery for Rhegmatogenous Retinal Detachment




































No. patients 20
Mean age (range), yrs 55.6 (22 to 69)
Gender (no.)
Men 14
Women 6
Mean preoperative BCVA (range) 0.12 (0.01 to 0.7)
Lens status
Phakic (no.) 7
Pseudophakic (no.) 13
Symptom duration (range), days 5.3 (1 to 20)
Mean no. quadrants detached (range) 2.0 (1 to 4)

BCVA = best-corrected visual acuity.




Results


Postoperative OCT findings in the fovea had 3 primary patterns ( Figure 1 ), i.e., a disrupted IS/OS line, a foveal detachment, and a continuous IS/OS line. These findings changed with time in all eyes ( Figure 2 ). One month after surgery, a disrupted IS/OS line was seen in 11 (55%) of the 20 eyes, a foveal detachment was seen in 8 eyes (40%), and a continuous IS/OS line was seen in 1 eye (5%). At 3 months, a disrupted IS/OS line was seen in 8 eyes (40%), a foveal detachment was seen in 7 eyes (35%), and a continuous IS/OS line was seen in 5 eyes (25%). At 6 months, a disrupted IS/OS line was seen in 3 (17%) of the 18 eyes, a foveal detachment was seen in 6 eyes (33%), and a continuous IS/OS line was seen in 9 eyes (50%). The IS/OS line was demarcated poorly in eyes with a foveal detachment. We did not categorize these eyes based on the status of the IS/OS until the SRF was absorbed completely. Elongation of the outer segment was observed in 4 of 7 eyes with a foveal detachment at 3 months and in 5 of 6 eyes at 6 months. The SRF was absorbed gradually. Two of the 8 eyes with a foveal detachment achieved reattachment at 6 months. The IS/OS line was continuous in the 2 reattached eyes. We further followed up 4 of the 6 eyes with a foveal detachment at 6 months. Two of the 4 eyes achieved complete absorption of the SRF with a continuous IS/OS line at 8 and 15 months, respectively. The remaining 2 eyes still had a shallow SRD at 12 and 16 months. The mean BCVA of the 4 eyes followed up for more than 6 months was 1.15.




FIGURE 1


Three patterns of optical coherence tomography (OCT) findings after retinal detachment surgery. (Top) A spectral-domain optical coherence tomography (SD OCT) image of a 53-year-old man 1 month after vitrectomy. The border of the photoreceptor inner segment and outer segment (IS/OS) is disrupted in the macula (arrows). (Middle) SD OCT image of a 63-year-old man 3 months after vitrectomy. The residual serous retinal detachment involves the fovea (asterisk). (Bottom) SD OCT image of a 66-year-old woman 6 months after vitrectomy. The IS/OS line is continuous in the macula (arrows).



FIGURE 2


Graph showing the incidences of the 3 patterns at 1, 3, and 6 months after rhegmatogenous retinal detachment surgery. One month after surgery, a disrupted inner segment and outer segment line (IS/OS) line is seen in 11 (55%) of the 20 eyes, a foveal detachment is seen in 8 eyes (40%), and a continuous IS/OS line is seen in 1 eye (5%). At 3 months, a disrupted IS/OS line is seen in 8 eyes (40%), a foveal detachment is seen in 7 eyes (35%), and a continuous IS/OS line is seen in 5 eyes (25%). At 6 months, a disrupted IS/OS line is seen in 3 (17%) of the 18 eyes, a foveal detachment is seen in 6 eyes (33%), and a continuous IS/OS line is seen in 9 eyes (50%).


The mean postoperative BCVA in all eyes was 0.39 at 1 month (n = 20), 0.61 at 3 months (n = 20), and 0.83 at 6 months (n = 18). The BCVA was significantly better at 6 months than at 1 month ( P = .0003). The mean BCVAs at 1 and 3 months in each group were 0.26 and 0.37 in the eyes with a disrupted IS/OS line, 0.60 and 0.87 in the eyes with a foveal detachment, and 0.8 and 0.76 in the eyes with a continuous IS/OS line, respectively. At 6 months (18 eyes), the mean BCVA was 0.16 in 3 eyes with a disrupted IS/OS line, 0.95 in 6 eyes with a foveal detachment, and 0.95 in 9 eyes with a continuous IS/OS line.


The mean BCVA was significantly lower with a disrupted IS/OS line than with a foveal detachment at 1 month ( P = .028), 3 months ( P = .023), and 6 months ( P < .0001) compared with eyes with a continuous IS/OS line at 6 months ( P < .0001). There was no significant difference in the BCVA between eyes with a foveal detachment and those with a continuous IS/OS line at 1, 3, and 6 months ( Table 2 ).



Two of 13 eyes that underwent cataract surgery had mild cystoid macular edema 1 month after surgery that resolved at 3 months. Eyes that did not undergo cataract surgery did not develop cystoid macular edema.


Case 1


A 49-year-old woman had a retinal detachment with a supertemporal peripheral tear in the left eye ( Figure 3 ). The retinal detachment involved the fovea; the preoperative VA was 0.1. One month after surgery, the retina was attached, but the IS/OS line was disrupted at the fovea. At 3 months, the IS/OS line was restored partially and the BCVA improved to 0.8. At 6 months, the IS/OS line was continuous, and the BCVA improved to 1.2.




FIGURE 3


Case 1. Optical coherence tomography (OCT) findings in a 49-year-old woman who underwent successful pars plana vitrectomy for a rhegmatogenous retinal detachment. (Top left) Fundus photograph obtained at 1 month. (Top right) Spectral-domain (SD) OCT image obtained at 1 month. (Middle right) SD OCT image obtained at 3 months. (Bottom right) SD OCT image obtained at 6 months.

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Jan 17, 2017 | Posted by in OPHTHALMOLOGY | Comments Off on Restoration of Photoreceptor Outer Segment after Vitrectomy for Retinal Detachment

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