Ultrahigh-resolution optical coherence tomography in patients with decreased visual acuity after retinal detachment repair

Abstract

Objective: To assess microstructural changes in the retina that may explain incomplete visual recovery after anatomically successful repair of rhegmatogenous retinal detachments (RD) using ultrahigh-resolution optical coherence tomography (UHR OCT).

Design: Retrospective observational case series.

Participants: Seventeen patients with decreased visual acuity after RD repair. Twelve patients had macula-involving and 5 had macula-sparing RDs.

Methods: The UHR OCT prototype capable of approximately 3 mum axial resolution was developed for clinical use. The UHR OCT images through the center of the fovea in 17 patients with visual complaints after RD surgery were obtained. Patients were either postoperative patients from the New England Eye Center or tertiary referrals. Baseline visual acuity, preoperative lens status, location of retinal detachment, macular involvement, and postoperative visual acuity were recorded.

Main outcome measures: The UHR OCT images after RD repair.

Results: The UHR OCT images were obtained 1 to 84 months (median, 5 months) postoperatively. The mean preoperative logarithm of the minimum angle of resolution (logMAR) visual acuity was 1.37 (Snellen equivalent, 20/390). The mean postoperative logMAR visual acuity was 0.48 (Snellen equivalent, 20/60). Anatomical abnormalities that were detected included distortion of the photoreceptor inner/outer segments (IS/OS) junction in 14 of 17 patients (82%), epiretinal membranes in 10 of 17 patients (59%), residual subretinal fluid in 3 of 17 patients (18%), and cystoid macular edema in 2 of 17 patients (12%). Of the 5 patients with preoperative macula-on detachments, 4 had distortion of the outer retina after RD repair.

Conclusions: The higher resolution of UHR OCT facilitates imaging of the IS/OS junction. Therefore, UHR OCT is able to confirm prior histopathologic findings that damage to photoreceptor outer segments may occur as a consequence of retinal detachment. This may explain poor postoperative visual acuity in eyes with anatomically successful repair.

Figure 1

Normal macula after pneumatic retinopexy. The patient is a 28-year-old man with a macula-on retinal detachment (RD) treated with pneumatic retinopexy. Images were taken 6 months after RD repair. Visual acuity was 20/20 in the right eye. A, An ultrahigh-resolution optical coherence tomography (UHR OCT) image shows a normal macular image. The inner retinal layers are labeled: outer plexiform layer (OPL), inner nuclear layer (INL), inner plexiform layer (IPL), ganglion cell layer (GCL), and retinal nerve fiber layer (RNFL). B, The UHR OCT image (×2 magnification). The outer retinal layers are labeled: outer nuclear layer (ONL), external limiting membrane (ELM), photoreceptor inner/outer segments junction (IS/OS), and retinal pigment epithelium (RPE).

Figure 2

Photoreceptor distortion. The patient is a 50-year-old man with a macula-off retinal detachment (RD) treated with a scleral buckle, vitrectomy, and sulfur hexafluoride 20% gas bubble injection. Images were taken 18 months after RD repair. Visual acuity was 20/40 in the right eye. A, Fundus photograph showing the direction of optical coherence tomography (OCT) scans. B, StratusOCT image demonstrates an apparently normal retina. C, The corresponding ultrahigh-resolution optical coherence tomography (UHR OCT) image shows attenuation of the photoreceptor inner/outer segments (IS/OS) signal. Outer retinal layers are labeled. ONL = outer nuclear layer; RPE = retinal pigment epithelium. D, The UHR OCT image (×2 magnification), demonstrating attenuation of the IS/OS signal. ELM = external limiting membrane.

Figure 3

Cystoid macular edema (CME). The patient is a 59-year-old man who had a macula-on retinal detachment treated with a scleral buckle. Images were taken 1 month after surgery, at which time his visual acuity was 20/80. Optical coherence tomography (OCT) images were taken from the right eye at 60°, temporal to nasal. A, StratusOCT image demonstrates CME. B, The corresponding ultrahigh-resolution OCT image demonstrates attenuation of signal of the inner/outer segments (IS/OS) junction below the area of the CME. The outer nuclear layer (ONL) also seems thickened. ELM = external limiting membrane; RPE = retinal pigment epithelium.

Figure 4

Residual subretinal fluid. The patient is a 38-year-old woman who had a macula-off retinal detachment (RD) and underwent a primary scleral buckle with sulfur hexafluoride 20% gas injection. Images were taken 4 months after RD repair. Visual acuity was 20/40. A, Fundus photograph showing the direction of optical coherence tomography (OCT) scans. B, StratusOCT image showing several small pockets of subretinal fluid (horizontal and vertical images show similar findings). C, Corresponding ultrahigh-resolution OCT image shows the photoreceptor inner/outer segments (IS/OS) junction is lifted off the retinal pigment epithelium (RPE). The external limiting membrane (ELM) also seems intact above areas of subretinal fluid.

Figure 5

Resolving subretinal fluid. This is the same patient as in Figure 4. Images were taken 10 months after retinal detachment repair. Visual acuity remained 20/40. A, Fundus photograph showing direction of optical coherence tomography (OCT) images. B, StratusOCT demonstrates one small pocket of residual subretinal fluid. C, The corresponding ultrahigh-resolution OCT (UHR OCT) image demonstrates several disruptions of the photoreceptor inner/outer segments (IS/OS) junction where fluid is less apparent from 6 months prior. ELM = external limiting membrane; RPE = retinal pigment epithelium. D, The UHR OCT image (×2 magnification), demonstrating disruptions of the IS/OS junction.

Figure 6

Epiretinal membrane (ERM). The patient is a 58-year-old man who had a macula-off retinal detachment in the right eye and underwent a scleral buckle and pars plana vitrectomy procedure. Images were taken 7 months later, at which time visual acuity was 20/100. A, Fundus photograph showing direction of optical coherence tomography (OCT) images. B, StratusOCT demonstrates a small amount of cystoid macular edema. C, The corresponding ultrahigh-resolution OCT image additionally demonstrates a thin ERM. D, The ERM (×2 magnification). The retinal nerve fiber layer (RNFL) seems wrinkled underneath the membrane.

Figure 7

Lamellar macular hole. The patient is a 59-year-old man who had a giant retinal tear and subsequent scleral buckle and pars plana vitrectomy. Images were taken 7 years later, at which time visual acuity was 20/25. A, Ultrahigh-resolution optical coherence tomography demonstrating an epiretinal membrane (ERM) and a small lamellar hole. B, The lamellar hole (×2 magnification), showing a sharp break through the inner layers of the retina. There seems to be separation between the outer plexiform layer (OPL) and the outer nuclear layer (ONL). There is also a very small disruption of the photoreceptor inner/outer segments (IS/OS) junction at the foveola. ELM = external limiting membrane; RPE = retinal pigment epithelium.