New side-view imaging technique for observing posterior chamber structures during cataract surgery in porcine eyes

Abstract

BackgroundTo develop a side-view imaging technique for observing the dynamic behavior of posterior chamber structures (PCSs) in porcine eyes which mimics closed-eye cataract surgery in humans.MethodsEnucleated porcine eyes were placed into liquid nitrogen for 5 seconds and immediately bisected at about a 45-degree angle to the equatorial plane. The anterior portion was attached firmly to a glass slide with superglue and sprinkled with wheat flour. Phacoemulsification and aspiration (PEA) was performed as in humans on 10 consecutive porcine eyes. The movements of the PCSs were monitored through the glass slide with a high-resolution video camera set below the cut surface of the eye. The intraocular pressure (IOP) was monitored during the surgery. The highest IOP, operation time, and volume of irrigation fluid of 10 whole eyes were compared to that obtained from the bisected eyes glued to a glass slide. In a second set of experiments, the strength of the seal between the bisected eye and the glass slide was tested in three sets of eyes: 1) frozen eye fixed with superglue with wheat flour for 3 min; 2) frozen eye fixed with superglue for 3 min; and 3) non-frozen eye fixed with superglue for 30 min. The highest IOP that led to a disruption of the seal was compared among the three groups.ResultsPEA was successfully performed on 9 of 10 (90%) eyes with the movements of the PCSs clearly observed. The average maximum intraocular pressure of the 9 bisected eyes was 55.8 ± 4.7 mmHg and that for the 10 unbisected eyes was 55.3 ± 5.0 mmHg (P = 0.650). The frozen eye fixed with superglue in combination with wheat flour (Group 1) had the strongest sealing strength with an average IOP at the breaking point of 117.3 ± 36.2 mmHg.ConclusionsOur side-view imaging technique can be used to evaluate the changes of the PCSs during intraocular surgery and for surgical training of new residents.

Gross anatomy, histological, and histochemical analysis of the eyelids and orbital glands of the neonate pygmy hippopotamus (Suina: Choeropsis liberiensis or Hexaprotodon liberiensis, Morton 1849) with reference to its habitat

“…Studies were also carried out to investigate the dynamics of the developmental changes of the eye accessory organs in the domestic pig in the fetal period (from the 20th to the 112th day of gestation) (Klećkowska‐Nawrot, 2005; Klećkowska‐Nawrot & Dzięgiel, 2007, 2008a, 2008b). Due to its morphological similarities to the human eye, the pig eye is often used as an ex vivo animal model in ophthalmologic scientific research and as a model of various ocular diseases, such as in aberrometry studies (Acosta, Vazquez, & Castillo, 2009; Wong, Koopmans, Terwee, & Kooijman, 2007), in corneal transplant research (Faber et al, 2009; Kim et al, 2009; Tavandzi et al, 2007; Zhigiang, Cun, Ying, Ningli, & Li, 2007), in a novel animal model of glaucoma (Ruiz‐Ederra et al, 2005), in cataract surgery studies (Nishi, Nishi, Nishi, & Chang, 2008; Speri et al, 2017; Tasaka et al, 2013) as well as in neuroretinal studies (Fernandez‐Bueno, Pastor, Gayoso, Alcalde, & Garcia, 2008) and a pig model of retinitis pigmentosa (Ross et al, 2012; Scott, Fernandez de Castro, Kaplan, & McCall, 2014; Scott, Kaplan, & McCall, 2015).…”

Evaluation of a new method of irrigation and aspiration for removal of ophthalmic viscoelastic device during cataract surgery in a porcine model

“…To check safe and effective I/A techniques, it is important to know dynamics of irrigation flow behind IOL during surgery. The porcine eyes were usually used for checking techniques because of similar anatomy of human and easy availability [ 20 – 24 ]. We recently observed the dynamic movements of posterior chamber-associated structures, e.g., the lens capsule, zonular fibers, and anterior hyaloid membrane during cataract surgery using view technique in bisected porcine eyes [ 24 ].…”

“…The porcine eyes were usually used for checking techniques because of similar anatomy of human and easy availability [ 20 – 24 ]. We recently observed the dynamic movements of posterior chamber-associated structures, e.g., the lens capsule, zonular fibers, and anterior hyaloid membrane during cataract surgery using view technique in bisected porcine eyes [ 24 ]. Furthermore we confirmed influence of eye bisection to anatomy were minimized [ 22 – 24 ].…”

“…We recently observed the dynamic movements of posterior chamber-associated structures, e.g., the lens capsule, zonular fibers, and anterior hyaloid membrane during cataract surgery using view technique in bisected porcine eyes [ 24 ]. Furthermore we confirmed influence of eye bisection to anatomy were minimized [ 22 – 24 ]. Thus porcine model could be useful for checking I/A techniques.…”

Anatomic Studies of the Miniature Swine Cornea

“…Swine are increasingly being used in ophthalmology and vision science research to model various ocular diseases (Stricker-Krongrad et al, 2016), develop surgical techniques (Tasaka et al, 2013; Ibarz et al, 2016; McQuaid et al, 2016; Nanavaty and Kubrak-Kisza, 2017; Speri et al, 2017; Tandogan et al, 2016), novel therapies and intervention strategies (Umazume et al ., 2013; Scott et al, 2015; Wang et al, 2016; Lin et al, 2017; Drozhz- hyna et al, 2017; Cong et al, 2018) to prevent vision loss in humans due to similar ocular anatomy and physiology (Beauchemin, 1974; De Schaepdrijver et al, 1992; Gerke et al, 1995; Bartholomew et al, 1997; Ninomiya and Inomata, 2006; Acosta et al ., 2009; Sanchez et al ., 2011). Although studies (Bartholomew et al, 1997; Faber et al, 2008; Jay et al, 2008) have examined anatomical features of the domestic swine cornea, none have compiled a characterization of miniature corneal morphology at both the light and electron microscopic level.…”