In Vivo Imaging of Intraocular Fluidics in Vitrectomized Swine Eyes Using a Digital Fluoroscopy System

Abstract

Purpose. To describe the characteristics of intraocular fluidics during cataract surgery in swine eyes with prior vitrectomy. Methods. We prepared three groups of enucleated swine eyes (nonvitrectomized, core, and totally vitrectomized). Irrigation and aspiration were performed (2.7 mm conventional sleeved phacosystem) using a balanced saline solution mixed with a water-soluble radiopaque contrast medium at 1 : 1 ratio. We imaged the eyes using a digital fluoroscopy system (DFS) during phacoemulsification and compared the characteristics of the intraocular fluid dynamics between the groups. Results. The anterior chamber depth (ACD) after the commencement of irrigation differed between groups (2.25 ± 0.06 mm; 2.33 ± 0.06 mm; 3.17 ± 0.11 mm), as well as the height of the fluid flowing from the anterior chamber into the posterior cavity that was identified by lifting up the iris to correct the infusion deviation syndrome (0.00 ± 0.00 mm; 0.41 ± 0.04 mm; 2.19 ± 0.35 mm). Conclusions. DFS demonstrated differences in fluid dynamics during phacoemulsification in swine eyes with or without prior vitrectomy. In completely vitrectomized eyes, the large ACD, which developed during phacoemulsification, could be reduced by lifting the iris and allowing the fluid to shift to the posterior cavity. Recognizing the differences in fluidics of vitrectomized eyes as compared to those of the nonvitrectomized eyes may reduce the frequency of intraoperative complications.

Figure 1

(a) Nonvitrectomized, (b) core vitrectomized, and (c) totally vitrectomized swine eyes.

Figure 2

Fluoroscopic image of a swine eye: (a) anterior chamber depth, (b) angle-to-angle length, and (c) height of the contrast medium in the posterior cavity.

Figure 3

Fluoroscopic images of a swine eye (a, c, e) before lifting the iris and (b, d, f) after lifting the iris; (a, b) nonvitrectomized, (c, d) core vitrectomized, and (e, f) totally vitrectomized swine eyes.

Figure 4

Mean anterior chamber depth after commencement of irrigation.

Figure 5

Change of mean anterior chamber depth before and after lifting the iris. In the nonvitrectomized eyes, the mean change of the ACD was not significant (P = 0.094). However, in the core vitrectomized and totally vitrectomized swine eyes, the mean changes of the ACD were significant (P = 0.023, P = 0.009, resp.).

Figure 6

Mean height of the contrast medium in the posterior cavity of the eyes according to group. The mean height of the contrast medium in the posterior cavity in the totally vitrectomized eyes was significantly greater than that of the core vitrectomized eyes (P = 0.001). However, there was no flow of contrast medium into the posterior cavity in the nonvitrectomized eyes.