Transscleral tunnel incision related arterial hemorrhage in 23-gauge Vitrectomy: case report.

BACKGROUND: Transscleral tunnel incisions are commonly made to avoid postoperative leakage in small gauge sutureless vitrectomy. We present an unreported intraoperative complication, tunnel incision related arterial hemorrhage from sclerotomy, in 23-gauge (23G) vitrectomy. CASE PRESENTATION: Two cases of intraocular arterial hemorrhage from superonasal sclerotomy were observed at the beginning of vitrectomy. The bleeding filled the vitreous cavity quickly and gushed out from the incision port after the involved supronasal cannula was removed. The active bleeding seemed not to stop spontaneously. We controlled the active bleeding by relocating the involved cannula, elevating the intraocular pressure and compressing the sclera wound. Post-operative intraocular hemorrhage from the sclerotomy was not found in any of the two cases. CONCLUSIONS: We suggest that the bleeding was from injured ciliary artery when the incision crossed 3 or 9 o'clock accidently. Surgeons might avoid this complication by locating the superior incisions away from the horizontal axis, and should be aware the proper management.

Does the disruption of horizontal anterior ciliary vessels affect the blood-aqueous barrier function?

PURPOSE: To investigate the significance of the anterior ciliary vessels (ACVs) preservation during the conventional horizontal strabismus surgery. METHODS: Patients (≥ 8 years) with horizontal strabismus were randomly allocated into group 1 (with ACV preservation) and group 2 (without ACV preservation). The surgical eyes in group 1 were further divided into group A (one rectus muscle operated) and group B (two rectus muscles operated). Similarly, eyes in group 2 were divided into group C (one rectus muscle operated) and group D (two rectus muscles operated). The success rate of ACV preservation was calculated. The anterior chamber flare measurements of each eye by laser flare photometry were recorded on the day prior to and after operation. The flare values between groups and between pre- and post-operation in each group were compared by one-way analysis of variance and a paired t-test respectively. RESULTS: In groups A and B, the success rate of ACV preservation was 82% (27/33) and 70% (28/40)respectively, and the flare values between pre- and post-operation showed no significant differences(4.378 ± 1.527, 4.544 ± 1.452, P = 0.526; 4.625 ± 1.090, 4.989 ± 1.468, P = 0.101 respectively). However, the postoperative values were significantly increased in group C and group D(4.661 ± 1.031, 5.039 ± 1.310, P = 0.025; 4.933 ± 1.691, 5.502 ± 1.430, P = 0.000 respectively). The postoperative flare readings of group D were significantly higher than group B, while group A and group C had no significant variation. CONCLUSION: ACV preservation probably has clinical significance in reducing the undesirable influence on the blood-aqueous barrier.

[The effect of preventing anterior segment ischemia by preservation of anterior ciliary vessels in rabbit].

OBJECTIVE: To investigate the effect of preserving anterior ciliary vessels (ACVs) on the prevention of anterior segment ischemia syndrome (ASI) during the surgery of extraocular muscles. METHODS: Thirty-two adult New Zealand white rabbits were randomly divided into four groups. ACVs of the right eyes were preserved among all of the rabbits, and were cut off in all of the left eyes. Group A: internal and external recti were cut off in two eyes; Group B: superior and inferior recti were cut off in two eyes; Group C: internal, external and superior or inferior recti were cut off in two eyes; Group D: all of the recti were cut off in two eyes. All rabbits were observed under slit microscope. The intraocular pressure (IOP), the total protein and lactic acid in the aqueous humor were recorded preoperatively and postoperatively. Eyes were enucleated at the forth week postoperatively to obtain the iris and the ciliary body for histopathologic study and electron microscopy. RESULTS: No signs of ASI were observed in the right eyes of all four groups under the slit lamp and under the light and election microscopes. The IOP and levels of ingredients of aqueous humor (total protein and lactic acid) showed no difference between preoperative and postoperative interval. No obvious ASI was observed in the left eyes of group A. Mild reactions of ASI were observed in the left eyes of group B. Moderate to severe reactions of ASI were observed in the left eyes in group C and group D. The IOP reduced from (17.21 +/- 3.76) mm Hg (1 mm Hg = 0.133 kPa) preoperatively to (14.48 +/- 3.36) mm Hg postoperatively in group C (P < 0.05); and from (16.68 +/- 2.33) mm Hg reduced to(3.17 +/- 0.92) mm Hg in group D. (P < 0.05). The level of total protein and lactic acid in the aqueous humor increased from (505.3 +/- 5.0) mg/L and (7.54 +/- 0.47) g/L preoperatively to (811.9 +/- 44.4) mg/L and (11.00 +/- 3.59) g/L postoperatively in group C, respectively (P < 0.05). In group D, the level of total protein and lactic acid in the aqueous humor increased from (504.6 +/- 4.1) mg/L and (7.17 +/- 1.44) g/L preoperatively to (1025. 8 +/- 78.3) mg/L, (8.23 +/- 1.68) g/L postoperatively, respectively (P < 0.05). There were various histopathological changes under the light and electron microscope in groups C and D. While no obvious ischemic changes were observed in group A. CONCLUSION: Two vertical muscles cut off at one eye simultaneously would produce mild reactions of ischemia, while three or more muscles cut off simultaneously could obstruct blood flow in eyes and induce ASI. Preservation of the ACVs could avoid the occurrence of ASI.

Experimental study on the prevention of anterior segment ischemia by preservation of anterior ciliary vessels.

PURPOSE: To observe the effect of preserving anterior ciliary vessels (ACVs) on anterior segments of rabbit eyes undergoing tenotomy of extraocular muscles. METHODS: Thirty-two adult New Zealand white rabbits were divided into four groups. Same procedures were done in both eyes in each group except that left eyes underwent preservation of ACVs. In the first group medial and lateral recti, in the second group, superior and inferior recti, in the third group, medial, lateral and superior or inferior recti and in the fourth group, all four recti, underwent tenotomy. Slit-lamp examination, intraocular pressure (IOP) measurement, total protein and lactic acid quantification in aqueous humor were done in all eyes pre- and post-operatively. By four weeks after operation, the eyes were enucleated for histological examination and electron microscopy. All data were analyzed using SPSS version 10. RESULTS: In the left eyes of both group 1 and group 2, no inflammatory response was observed. In the left eyes of group 3 and 4, we observed mild inflammatory response with slit-lamp examination, which disappeared in one wk. However, we did not find significant changes in IOP, total protein and lactic acid of aqueous humor, histology and electron microscopic examination in these groups. In the right eyes in group 2, 3 and 4, we observed moderate to severe inflammatory changes, a few even developed anterior segment ischemia, appeared as decreased IOP, increased total protein and lactic acid in aqueous humor, along with pathological and electron-microscopic changes. CONCLUSION: Simultaneous tenotomy of three or four recti or two vertical recti on one eye may decrease anterior segment blood flow even lead to ischemia. ACVs preservation may protect the blood circulation in anterior segment. Our study suggests that ACVs preservation in strabismus surgeries especially those involving multi-recti tenotomies may prevent potential anterior segment ischemia.