Carlo Torrazza

Swelling of the arcuate nerve fiber layer after internal limiting membrane peeling.

Purpose: The purpose of the study is to report the incidence of changes of the retinal nerve fiber layer in the early postoperative period after internal limiting membrane peeling for idiopathic macular hole and epiretinal membrane surgery. Methods: Interventional, noncomparative retrospective case series. Fifty-six eyes of 55 patients with an epiretinal membrane and 33 eyes of 31 patients with macular hole underwent pars plana vitrectomy and internal limiting membrane peeling. All patients received a complete ophthalmic examination, infrared and autofluorescence photography, and spectral-domain optical coherence tomography preoperatively and also at approximately 1 week, 1 month, and 3 months postoperatively. Vitrectomy and gas tamponade were performed with internal limiting membrane peeling after staining with Brilliant Peel. The main outcome measures were the presence of postoperative swelling of the arcuate retinal nerve fiber layer on spectral-domain optical coherence tomography, infrared and autofluorescence photographs, and its effect on best-corrected visual acuity. Results: On infrared and autofluorescence photographs, 28 (31.46%) of 89 eyes with internal limiting membrane peeling exhibited swelling of the arcuate retinal nerve fiber layer 1 week to 1 month postoperatively. Swelling of the arcuate retinal nerve fiber layer increased during the first month after surgery and resolved after a mean period of 2 months. These features were best visualized by autofluorescence imaging, as three to five dark striae originating from the optic nerve head, radiating in an arcuate pattern toward the macula. Simultaneous spectral-domain optical coherence tomography scanning through the striae indicated that they correspond to areas of focal swelling of the arcuate nerve fiber layer. No significant differences were found in eyes with or without swelling of the arcuate retinal nerve fiber layer for mean age or pre- and postoperative best-corrected visual acuity (P > 0.05). Conclusion: Swelling of the arcuate retinal nerve fiber layer often occurs after internal limiting membrane peeling for macular hole and epiretinal membrane. It is a transient feature after surgery that does not affect visual recovery. It is best visualized using infrared and autofluorescence imaging. Simultaneous infrared and spectral-domain optical coherence tomography imaging after macular surgery can detect transient inner retinal changes, which are not visible on clinical examination.

Retinal nerve fiber layer thickness modification after internal limiting membrane peeling.

Purpose: To identify early and late retinal nerve fiber layer thickness (RNFLT) modification after internal limiting membrane peeling for idiopathic macular hole or epiretinal membrane and to correlate RNFLT to visual field indices. Methods: Single-center, prospective, interventional consecutive case series. Complete ophthalmic examination, fundus images, and spectral domain optical coherence tomography were performed in 30 eyes of 30 patients before and 1, 3, and 6 months after surgery. Six peripapillary sectors (superotemporal, temporal, inferotemporal, inferonasal, nasal, superonasal) and global RNFLT were evaluated. Visual field was performed preoperatively and 6 months postoperatively. Results: Significant RNFLT modification was found after surgery (P < 0.0001). Specifically, RNFLT significantly increased in all, but the temporal sectors, 1 month after surgery, and it returned to preoperative values at the third month. Six months after surgery, RNFLT was lower than basal values in the superotemporal, inferotemporal, and temporal sectors (P < 0.001, P < 0.05, and P < 0.001, respectively) with an average reduction of 18.2 ± 9.8 µm. No correlation was found between RNFLT and the visual field indices. Conclusion: The diffuse RNFLT increase 1 month postoperatively could be because of inflammatory responses. The reduction of RNFLT in the temporal sectors 6 months postoperatively could indicate damage to the macular retinal nerve fiber layer caused by internal limiting membrane peeling.

Thermal deformation of chandelier endoillumination probes exposed to uveal tissue and blood.

Purpose: The purpose of this study was to evaluate the characteristics and thermal properties of a chandelier endoillumination probe under conditions that may induce thermal damage. Methods: Experimental evaluation of a surgical ophthalmic instrument under ex vivo conditions. Results: A 27-gauge dual-tip chandelier endoillumination probe was exposed to air, saline, porcine uveal tissue, and human blood using a Xenon light source at 100% intensity. No alteration of probe tip morphology was observed in air or saline at 10-minute exposure. After exposure to uveal tissue and blood, thermal melting of the probe tip was noted at 10 minutes. Beam focus and intensity were observed to diminish in the probe tips that underwent thermal melting. A thermal imaging device was used to demonstrate increased thermal intensity from the probe tip that had been covered with uveal tissue compared with a control tip in air. Conclusion: Thermal melting of a chandelier fiber probe has been reported only once previously in the literature after exposure to porcine Tenon capsular tissue. We report two separate conditions that may induce thermal damage to a fiber optic probe including encapsulation of uveal tissue at the probe tip and exposure to blood. Vitreoretinal surgeons should be aware of this potential complication.

Two cases of primary vitreoretinal lymphoma: a diagnostic challenge : The supporting role of multimodal imaging in the diagnosis of primary vitreoretinal lymphoma.

PurposeTo report two cases of primary vitreoretinal lymphoma (PVRL), which presented as intermediate and posterior uveitis.MethodsCombined clinical assessment, multimodal imaging with spectral-domain optical coherence tomography, fundus autofluorescence, fluorescein angiography, indocyanine green angiography, brain magnetic resonance imaging and vitreous and retinal biopsy. Case 1 was a 48-year-old woman who complained of visual loss in her right eye secondary to a diffuse vitreous opacification and multiple chorioretinal lesions. Case 2, a 74-year-old man, presented with low vision in his right eye due to a wide chorioretinal lesion at the posterior pole, vitreous opacification and posterior uveitis in both eyes.ResultsDiffuse large B cell lymphoma was histologically diagnosed in the cerebellum in the first case and in chorioretinal tissue in the second patient. Atypical lymphoid cells were detected and allowed to make a diagnosis of primary central nervous system lymphoma in case 1 and PVRL in case 2.ConclusionPVRL often masquerades ad intermediate or posterior uveitis. The management of the patients needed a team of pathologists, haematologists and ophthalmologists to achieve the correct diagnosis and choose the more appropriate therapy. Some peculiar characteristics on multimodal imaging, even in atypical cases of PVRL, should raise suspicious for PVRL and lead to a diagnostic vitrectomy and/or retinal biopsy.