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Abstract-We compare the performance of five indices of retinal vessel tortuosity against sampling rates of vessel centerlines. We consider distance measure, tortuosity density, two curvature-based measures, and a recently introduced slopechain coding for general curves, never before assessed comparatively with retinal vessels. To enable replication of our results, we use the public dataset for retinal tortuosity, RET-TORT. We find that (1) the tortuosity density index offers good performance overall, but is not always the best performer; (2) curvature-based methods are the best if high-frequency resampling is possible, but (3) are the most sensitive to variations of the number of samples; (4) slope-chain coding performs best at low sampling rates, but the length of the linear elements must be chosen carefully. In general, performance may vary considerably with resampling, suggesting that the choice of a tortuosity index for clinical inference requires attention to numerical details, and ideally standardization thereof.

We present a case of a 56-year-old man who suffered an injury to his right eye in June 2012. He presented to an emergency department, however, the presence of a penetrating injury and an intraocular foreign body was not identified. A year later he was referred to the ophthalmology department due to reduced vision and change of iris colour in the same eye. Examination revealed clinical signs consistent with a previous penetrating injury and a retained ferrous intraocular foreign body.

Purpose To investigate the features and outcomes of retinoblastoma (Rb) patients complicated by development of retinal detachment (RD) following systemic chemotherapy with or without local focal consolidation treatment and without external beam radiotherapy (EBRT). Methods A retrospective study of all Rb patients between April 2002 and April 2012 at a tertiary hospital center (Birmingham Children’s Hospital and Birmingham Midlands Eye Centre, United Kingdom). All eyes that had developed RD during or after systemic treatment with or without local focal consolidation treatment were included in the study. The time interval between the type of treatment of Rb, development of RD and relevant surgical intervention were analyzed. Patients with exudative RD were treated conservatively through observation and patients with rhegmatogenous RD were treated with scleral buckling. Final anatomical retinal reattachment rate and visual acuity outcomes were analyzed. Results A total of 258 patients were treated for Rb over the 10-year period. One hundred sixty-nine patients were managed with globe conserving treatment. Ten (5.92%) eyes of 10 patients were complicated with RD. Five eyes were exudative or presumed exudative type of RD while the other five eyes were rhegmatogenous or presumed rhegmatogenous RD. In the exudative group, two patients achieved visual acuity (VA) of 0.2 Single Kays (20/32 Snellen), and the other two patients achieved 0.85 and 0.86 Crowded Kays (20/142 and 20/145 Snellen), respectively, after the RD had resolved. The last patient in the group had to be enucleated due to tumor recurrences. The median time for the exudative RD to resolve is 15 weeks (range, 4–36 weeks). In the rhegmatogenous group, 3 of the 4 operated patients achieved retinal reattachment. The final postoperative VA ranged between 0.05 Crowded Kays to 1.84 Crowded Kays (20/22 to 20/1384 Snellen). The other patient was treated conservatively as no retinal breaks were found with previous cryotherapy and thermotherapy. The final VA in this patient was hand movement, and the RD did not reattach. The median time for the rhegmatogenous RD to reattach is 6 weeks (range, 4–8 weeks). There were no intra- and postoperative complications. Conclusions With long-term conservative management through observation, exudative Rb after systemic treatment of Rb will tend to resolve by itself. However, supplementary local treatment with cryoretinopexy or laser photocoagulation during the systemic treatment of Rb can lead to an increased risk of rhegmatogenous RD. In these cases, most rhegmatogenous RD are successfully repaired with non-drainage scleral buckling and cryoretinopexy.

SUMMARYWe describe a case of a 68-year-old man, referred by his optometrist with suspected low-tension glaucoma, who presented with advanced cupped optic discs and field of vision loss that were subsequently found to be due to a giant prolactinoma. Failing vision in low-tension glaucoma suspects should have a low threshold for neuroimaging. BACKGROUND