Postoperative Recovery of Light Sensitivity in Eyes with Rhegmatogenous Retinal Detachment

The Bubble Eye Sign: Understanding the Radiological Imaging of Gas inside the Orbit

Gas, appears as radiolucent on X-ray, is normally absent in the orbit. However, intraocular surgeries occasionally utilize retained intraocular gas for tamponade effect. Intravitreal gas persists after retinal surgery, being confounded by the scleral shell of the operated eye, outlines the shape of the eyeball, and gives the characteristic bubble appearance on skull X-ray. This is different from orbital emphysema caused by orbital fracture when gas is located outside the globe but confined by the orbit, giving a crescent or concave shape over the superior orbit usually. Falls is common after intraocular retinal surgeries due to change of usual stereopsis, prolonged prone posturing, and other systemic comorbidities. By identifying the “Bubble Eye sign” described, attending physician should alert the presence of intravitreal gas, most commonly iatrogenic. Further ophthalmological history taking and examinations are thus indicated, instead of exposing patients to unnecessary radiation under computed tomography scan for orbital fracture investigation.

MULTIFOCAL ELECTRORETINOGRAPHY AND SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY IN MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT: A Prospective Cohort Study

PURPOSE

To analyze the temporal trends in structural changes using spectral-domain optical coherence tomography and functional changes using multifocal electroretinogram after rhegmatogenous retinal detachment surgery.

METHODS

This prospective cohort study enrolled 69 patients with macula-off rhegmatogenous retinal detachment who underwent successful surgery. Early Treatment Diabetic Retinopathy Study visual acuity, multifocal electroretinogram evaluation of the central 5°, and spectral-domain optical coherence tomography were recorded at 1, 3, 6, and 12 months (M) after surgery. The fellow eye served as the control group for multifocal electroretinogram parameters.

RESULTS

Between M1 and M12, visual acuity improved from 64 to 75 letters (P = 0.001) and implicit time of N1 decreased from 27.8 to 25.2 milliseconds (P = 0.001), whereas the other parameters did not vary significantly. Amplitude and implicit time values did not reach normal values at M12. Alterations of the ellipsoid zone and the external limiting membrane decreased over time (P = 0.001). P1 implicit time correlated independently with the alteration of the external limiting membrane (P = 0.007).

CONCLUSION

Foveal wave amplitudes remain lower than normal values after successful surgery of rhegmatogenous retinal detachment, whereas anatomical improvement was found for outer retinal abnormalities and subretinal edema fluid. Retinal recovery improves N1 implicit time over time. Disruption of external limiting membrane seems to be predictive of increased P1 implicit time.

Effect of rhegmatogenous retinal detachment on preoperative and postoperative retinal sensitivities

This retrospective study investigated foveal and perifoveal retinal sensitivities using microperimetry before and after surgery for rhegmatogenous retinal detachment (RRD). Consecutive patients with RRD who underwent vitrectomy or scleral buckling were included. Comprehensive ophthalmological examinations, including microperimetry and swept-source optical coherence tomography, were performed before and 6 months after surgery. Pre- and postoperative retinal sensitivities at the fovea and 4 perifoveal measurement points farthest from the fixation point, both vertically and horizontally (superior, inferior, nasal, and temporal) were examined. A total of 34 foveal and 136 perifoveal measurement points in 34 eyes of 34 patients were evaluated. The postoperative retinal sensitivity was significantly higher than the preoperative value at foveal and perifoveal points with (P < 0.001 for both) and without (fovea: P = 0.005, perifovea: P < 0.001) RRD. The postoperative retinal sensitivity was significantly lower at foveal (P < 0.01) and perifoveal (P < 0.001) points with preoperative RRD than at points without preoperative RRD; furthermore, it was significantly better at points with ellipsoid zone (Ez) continuity than at points with Ez discontinuity (fovea: P < 0.01, perifovea: P < 0.001). RRD deteriorates retinal sensitivity, regardless of its presence or absence at the measurement point before surgery. Postoperative Ez continuity is important for good postoperative retinal sensitivity.