Equivalent tamponade by room air as compared with SF(6) after macular hole surgery.

BACKGROUND: To evaluate the effect of tamponade by room air after vitrectomy for the treatment of idiopathic macular hole (MH). METHODS: There were 156 eyes of 151 patients studied. The patients' ages ranged from 35 to 88 years old (mean: 65.1 years). After conventional pars plana vitrectomy with internal limiting membrane peeling, fluid air exchange was performed using 20% SF(6) (Gas group: 91 eyes) or room air (Air group: 65 eyes). Surgical outcomes were retrospectively analyzed. RESULTS: Mean preoperative hole diameter was 352 microm in the Gas group and 370 microm in the Air group (P = 0.558). The closure rate of all cases was 91.0% after first surgery and 98.7% at last follow-up. The primary closure rate was 90.1% in the Gas group after 7.44 +/- 1.66 (mean +/- SD) days prone positioning period, and 92.3% in the Air group after 3.83 +/- 0.97 days of prone positioning. There was significant difference in prone positioning period (P < 0.0001), but not in the first closure rate (P = 0.132). CONCLUSION: This study suggests that room air may have an equivalent tamponade effect, in spite of the shorter prone positioning period, than SF(6) after MH surgery.

Anatomical findings of vitreoretinal interface in eyes with asteroid hyalosis.

PURPOSE: To investigate the anatomical features of vitreoretinal interface in eyes with asteroid hyalosis (AH) with optical coherence tomography (OCT) and intravitreal triamcinolone acetonide (TA) during vitreous surgery. METHODS: This study was an interventional clinical case series. Records relating to ten eyes from ten patients who underwent a TA-assisted vitrectomy for the treatment of diverse vitreoretinal diseases complicated with AH. The posterior vitreoretinal interface was examined by preoperative OCT and by intraoperative visualization of posterior vitreous cortex utilizing TA. RESULTS: In eight of ten AH eyes, preoperative OCT revealed abnormal vitreoretinal adhesions. In four of these eight eyes, posterior vitreoschisis could be seen on OCT. In the other four of these eight eyes, a clear no posterior vitreous detachment (PVD) pattern could be seen on OCT. Although posterior vitreous cortex could not be clearly identified with preoperative OCT in two of ten AH eyes, a complete PVD was refuted by intraoperative visualization of the posterior vitreous cortex with TA identical to the other eight eyes. CONCLUSION: These results indicate that complete PVD appears to be unlikely to occur in eyes with AH. In addition, spontaneous PVD in eyes with AH might lead to vitreoschisis or residual whole layer or posterior vitreous cortex, possibly due to anomalous vitreoretinal adhesion.

Prostaglandin F2alpha, but not latanoprost, increases the Ca2+ sensitivity of the pig iris sphincter muscle.

PURPOSE: To determine the mechanisms underlying prostaglandin (PG) F(2)alpha-(,) carbachol (CCh)-, or latanoprost (a PGF(2)alpha analogue)-induced contraction of the pig iris sphincter muscle. METHODS: Effects of these agents on myofilament Ca(2+) sensitivity were evaluated and compared with the use of receptor-coupled permeabilized preparations by alpha-toxin. The effects of PGF(2)alpha and CCh on the phosphorylation of myosin light chain (MLC) were also analyzed. RESULTS: In the intact strips, all three of these agents induced contractions. In permeabilized strips, PGF(2)alpha and CCh, but not latanoprost, caused an additional tension development at a fixed intracellular Ca(2+) concentration ([Ca(2+)](i)) and also shifted the [Ca(2+)](i)-tension curve to the left, thus indicating that PGF(2)alpha and CCh, but not latanoprost, induced increases in Ca(2+) sensitivity (Ca(2+) sensitization). This Ca(2+) sensitization could have been inhibited by Y27632, a rho kinase inhibitor, but not by GF109203X, a protein kinase C (PKC) inhibitor or by PD98059, a mitogen-activated protein (MAP) kinase inhibitor. PGF(2)alpha increased the level of MLC phosphorylation at a constant [Ca(2+)](i). CONCLUSIONS: PGF(2)alpha, but not latanoprost, induced Ca(2+) sensitization of the pig iris sphincter muscle in an MLC phosphorylation-dependent manner through the rho-rho kinase pathway. The effect of latanoprost on the Ca(2+) sensitization mechanism was different from that of PGF(2)alpha and was thought to play a beneficial role in glaucoma treatment.