In vivo intraocular pressure monitoring during microincision vitrectomy with and without active control of infusion pressure.

PURPOSE: To evaluate intraocular pressure (IOP) fluctuation during vitrectomy, we directly monitored IOP in vivo using 2 vitrectomy machines with or without constant infusion pressure monitoring and control. METHODS: Among 61 eyes of 61 consecutive patients, 32 were assigned to the Accurus system (group 1) and 29 were assigned to the Constellation system (group 2) in this prospective case series. The IOP fluctuations were evaluated during routine vitrectomy procedures. RESULTS: The initial IOP before vitrectomy was 20.3 ± 2.4 mm Hg in group 1 using a conventional vented gas forced infusion system and 20.0 ± 0.0 mm Hg in group 2 using active IOP control at 20 mm Hg (p = 0.532). However, the average IOP change during core vitrectomy was -8.6 ± 4.3 mm Hg in group 1 and -0.8 ± 1.1 in group 2 (p<00.001). Maximum IOP was significantly decreased in group 1 (-17.0 ± 2.6 mm Hg) compared with that in group 2 (-4.1 ± 2.2 mm Hg) (p<00.001). Partial ocular collapse was observed during vitrectomy only in group 1 (78.1%). Peak IOP significantly increased during scleral compression and gas and fluid injection but was not significantly different between the groups (all p≥0.147). The IOP fluctuation range was 50-70 mm Hg in both groups. CONCLUSIONS: The IOP fluctuated significantly during routine vitrectomy using both systems. Hypotony and partial ocular collapse were more frequently observed during vitrectomy with the Accurus system than with the Constellation system. Both systems were vulnerable to IOP surge during indentation and intravitreal injection.

Sorted consecutive local binary pattern for texture classification.

In this paper, we propose a sorted consecutive local binary pattern (scLBP) for texture classification. Conventional methods encode only patterns whose spatial transitions are not more than two, whereas scLBP encodes patterns regardless of their spatial transition. Conventional methods do not encode patterns on account of rotation-invariant encoding; on the other hand, patterns with more than two spatial transitions have discriminative power. The proposed scLBP encodes all patterns with any number of spatial transitions while maintaining their rotation-invariant nature by sorting the consecutive patterns. In addition, we introduce dictionary learning of scLBP based on kd-tree which separates data with a space partitioning strategy. Since the elements of sorted consecutive patterns lie in different space, it can be generated to a discriminative code with kd-tree. Finally, we present a framework in which scLBPs and the kd-tree can be combined and utilized. The results of experimental evaluation on five texture data sets--Outex, CUReT, UIUC, UMD, and KTH-TIPS2-a--indicate that our proposed framework achieves the best classification rate on the CUReT, UMD, and KTH-TIPS2-a data sets compared with conventional methods. The results additionally indicate that only a marginal difference exists between the best classification rate of conventional methods and that of the proposed framework on the UIUC and Outex data sets.

Characteristics of spontaneous idiopathic epiretinal membrane separation in spectral domain optical coherence tomography.

PURPOSE: To investigate the prevalence, characteristics, and visual acuity of spontaneous idiopathic epiretinal membrane (ERM) separations using spectral domain optical coherence tomography. METHODS: In a series of 1,248 consecutive eyes with idiopathic ERM, Group I with preexisting posterior vitreous detachment included 1,091 eyes (87.4%) and Group II without preexisting posterior vitreous detachment included 157 eyes (12.6%). Groups IA and IIA included self-resolution cases of ERM from Groups I and II, respectively. RESULTS: The ERM self-separation occurred in 37 eyes (3.0%) for 32.6 ± 11.7 months, with 16 eyes (1.5%) in Group IA and 21 eyes (13.4%) in Group IIA. The mean best-corrected visual acuity (logMAR) improved in Groups IA and IIA by 0.1 (P = 0.013) and 0.06 (P = 0.078), respectively. From tomographic analyses, dominant undulation and retinal nerve fiber layer defects were more frequent in Group IA than Group IIA (P < 0.001 and P = 0.024, respectively). However, the completeness of ERM separation, inner segment/outer segment junction defects, and ERM recurrence were more frequent in Group IIA than Group IA (P = 0.039, P = 0.023 and P = 0.041, respectively). Multivariate analysis for factors related to visual improvement revealed only inner segment/outer segment junction defects as significantly associated (P = 0.025). CONCLUSION: Different mechanisms underlying the self-resolution of idiopathic ERM lead to distinct tomographic characteristics and may affect the postseparation visual function.