Phacoemulsification And Aspiration Research Articles

Transient Intraocular Pressure Elevation after Trabeculotomy and its Occurrence with Phacoemulsification and Intraocular Lens Implantation

Purpose: To elucidate the characterization of intraocular pressure (IOP) spike after trabeculotomy, and after the combined procedure of phacoemulsification and aspiration (PEA) and intraocular lens (IOL) implantation. Methods: Included in this study were 39 patients (53 eyes) with primary open-angle glaucoma with IOPs uncontrolled even with anti-glaucoma medication. We conducted a retrospective study for the following two groups: Patients who underwent trabeculotomy alone (25 eyes) and patients undergoing trabeculotomy combined with PEA and implantation of an IOL (28 eyes). Results: In 7 (28%) of the 25 eyes after trabeculotomy alone and 7 (25%) of the 28 eyes after the combined procedure, transient IOP elevation was found postoperatively. The incidence of hyphema-related IOP spike was significantly higher in eyes after trabeculotomy alone (16%) than after the combined procedure (0%). After removal of the blood present in the anterior chamber in eyes with hyphema-related IOP spikes, the IOP levels were well controlled. Conclusions: Hyphema-related IOP spike is one of the common complications in eyes after trabeculotomy alone, and the combined procedure decreases the incidence of this complication. It is thought that removal of prolonged massive hyphema is effective as treatment for hyphema-related IOP spike.

Combined surgery with deep lamellar keratoplasty

The opportunity to perform two or more ophthalmic operations simultaneously has increased in recent years. In keratoplasty too, the simultaneous operation consisting of cataract extraction and IOL insertion (triple procedure) has become common. Penetrating keratoplasty (PKP) and planned extracapsular cataract extraction (PECCE) or vitrectomy is today often done simultaneously. However, phacoemulsification and aspiration (PEA) or 3 ports vitrectomy has to be performed on patients with corneal opacity due to some corneal diseases. In such cases, we performed the PEA or vitrectomy coupled with deep lamellar keratoplasty (DLK), successfully applied to closed eye surgery with corneal opacity. Simultaneous surgery using DLK, free of postoperative endothelial type of rejection, and PEA, enabling cataract extraction by a small incision, is a surgical technique making use of the advantage of the two types of operation. We performed the DLK + PEA + IOL on 17 cases. In the other hand, simultaneous surgery consisting of DLK and vitrectomy may be taken into consideration. The use of DLK will make it possible to perform surgery on urgent vitreoretinal diseases with corneal opacity and cataract. We performed the DLK + 3 ports vitrectomy on 3 cases. The current study describes the advantages and disadvantages of these types of operation.

Risk Factors for Unsatisfactory Intraocular Pressure Control in Combined Trabeculectomy and Cataract Surgery

Trabeculectomy combined with posterior chamber intraocular lens (PC IOL) insertion is often chosen for the treatment of glaucoma combined with cataract. In this study, the clinical prognostic indicators for late intraocular pressure (IOP) control in combined procedures were investigated. The clinical records of 60 eyes that underwent trabeculectomy combined with PC IOL implantation were retrospectively analyzed using the Cox proportional hazards model. All of the patients received postoperative 5-fluorouracil injections. Extracapsular cataract extraction (ECCE) was found to be a statistically significant risk factor for unsatisfactory late IOP control (hazard ratio 2.54; P < .01) and for unsatisfactory filtering bleb appearance (hazard ratio 5; P < .001). The frequency of fibrin formation and the incidence of a transient IOP spike (> or = 25 mm Hg) were significantly lower in the phacoemulsification and aspiration (PEA) group than in the ECCE group. In the PEA group, the probability of IOP control (< or = 15 mm Hg) without medication was 54%, and the probability of persistent filtering bleb appearance was 80% at 18 months. The PEA technique, not ECCE, should be employed in combined trabeculectomy and PC IOL implantation.

Relationship between postoperative intraocular pressure elevation and residual sodium hyaluronate following phacoemulsification and aspiration

Purpose: To investigate the relationship between postoperative intraocular pressure (IOP) elevation and the amount and viscosity of sodium hyaluronate remaining in the anterior chamber after phacoemulsification and aspiration (PEA).Setting: Hachioji Medical Center and Tokyo Medical College Hospital, Tokyo, Japan.Methods: In 107 eyes, washout (irrigation and aspiration [I/A]) of sodium hyaluronate was performed for randomly assigned durations of 5, 10, or 20 seconds following PEA and intraocular lens (IOL) implantation. At the conclusion of washout, the flow from the I/A tip was reversed and a sample of the irrigating solution obtained from the anterior chamber. The residual sodium hyaluronate concentration was measured by sandwich assay. The kinematic viscosity of the sample was calculated from a regression equation derived from measured viscosities of standard hyaluronate solutions of various concentrations.Results: The preoperative mean IOP in the groups that received 5-, 10-, and 20-second washout was 11.9, 10.9, and 11.6 mm Hg, respectively. The mean IOP on the first postoperative day in the 5-second group was significantly higher (P = .001, Kruskal-Wallis test) than those in the 10- and 20-second groups (10.8 and 11.6 mm Hg, respectively). A significant correlation was observed between residual hyaluronate concentration and IOP on the first postoperative day (Spearman's rank correlation coefficient 0.319, n = 80, P = .045) and also between kinematic viscosity and IOP on the first postoperative day (one-factor analysis of variance, P < .001).Conclusion: The sod ium-hyaluronate-induced IOP elevation is related to its viscosity as well as to its high molecular weight. Washout times of at least 10 seconds are desirable to prevent IOP elevation.

The Effects of Phacoemulsification Cataract Surgery via Local Anesthesia on Preoperative and Postoperative Blood Pressure Levels

Purpose: The authors prospectively evaluated the preoperative and postoperative blood pressure (BP) levels of 2270 patients with cataracts.Methods: All surgeries were performed by the same surgeon using the same method of phacoemulsification and aspiration (PEA) with posterior chamber intraocular lens implantation with the patients under local anesthesia.Results: The daily systolic BP was 140.7 ± 22.9 mmHg; the preoperative and postoperative systolic BPs were 149.5 ± 23.9 and 145.6 ± 23.8, respectively. The tendency for the preoperative BPs to increase and the postoperative BPs to decrease also was evident in the diastolic and the mean BPs. However, when the authors categorized the cases into normal, intermediate, and hypertension groups, the preoperative BP increased less and the postoperative BP decreased more when the daily BP was higher.Conclusion: Overall, the daily, preoperative, and postoperative BPs were relatively stable with the patients under local anesthesia. However, the BP change was characteristic of each group when the patients were categorized as normal, intermediate, and hypertensive. Surgeons should be aware of the greater-than-anticipated BP change during cataract surgery.

Ten-year follow-up of intraocular pressure after phacoemulsification and aspiration with intraocular lens implantation performed by the same surgeon.

We evaluated the pre- and postoperative intraocular pressure (IOP) levels of 498 patients, to determine whether IOPs are affected over a 10-year period. All surgeries were performed by the same surgeon using phacoemulsification and aspiration (PEA) with posterior chamber intraocular lens (PCIOL) implantation. The mean preoperative IOP was 12.2 +/- 4.0 mm Hg, and the mean postoperative IOPs were not affected for 10 years. However, when the preoperative IOP was over 20 mm Hg, a significant decrease was achieved without glaucoma surgery. When the preoperative IOP was under 10 mm Hg, the IOP significantly increased. PEA with implantation of a PCIOL provides an excellent chance for improved intraocular tension control, providing that the surgery is properly performed.

Collagen synthesis in lens epithelial cells on capsules containing intraocular lens implants in rabbits: immunolocalization of prolyl 4-hydroxylase.

We evaluated ultrastructurally the presence and distribution of lens epithelial cells and extracellular matrix on the posterior capsule after implantation of a silicone or a polymethyl-methacrylate (PMMA) intraocular lens (IOL) in rabbits. The immunolocalization of prolyl 4-hydroxylase, an enzyme involved in procollagen synthesis, was also examined in such cells. Anesthetized adult albino rabbits (n = 12) underwent phacoemulsification and aspiration (PEA) of the crystalline lens and implantation of a silicone or a PMMA IOL into the capsular bag of one eye. They were killed by an intravenous overdose of pentobarbital sodium. The lens capsules were processed for transmission electron microscopy and for immunohistochemical detection of the beta-subunit of prolyl 4-hydroxylase. Ultrastructurally, lens epithelial cells on the posterior capsule evidenced an accumulation of collagenous extracellular matrix. Prolyl 4-hydroxylase immunoreactivity was detected in the cytoplasm of cells distributed on the capsules. Lens epithelial cells are involved in the production of collagenous matrix on lens capsules after PEA and implantation of IOL, resulting in a fibrotic process of the lens capsule.

Protective efficacy of sodium hyaluronate on the corneal endothelium against the damage induced by sonication.

The protective efficacy of sodium hyaluronate (Na-HA) on the corneal endothelium against the damage induced by sonication was investigated using enucleated rabbit eyes and Na-HA fluorescence labeled with 5-aminofluorescein (FA-HA). The anterior chamber was reformed by injecting a 1% solution of FA-HA, and then sonication, irrigation and aspiration were performed in the anterior chamber using a phaco-needle attached to phacoemulsification and aspiration (PEA) equipment. The protective efficacy was evaluated by the area of damaged corneal endothelium. When the anterior chamber was reformed by the solution of FA-HA with a molecular weight of 2010 x 10(3) (FA-HA (2010 x 10(3) group), most of the FA-HA was eliminated within 20 seconds after starting the irrigation and aspiration, and the area of damaged endothelium was the same with the case when the FA-HA was not pre-injected (Control group). On the other hand, when the anterior chamber was reformed by the solution of FA-HA with a molecular weight of 1130 x 10(3) (FA-HA (1130 x 10(3) group), the FA-HA was gradually eliminated after mixing with an irrigating solution, and the area of damaged endothelium was significantly smaller than those of the Control and FA-HA (2010 x 10(3)) groups. These results suggest that the corneal endothelial damage induced by PEA can be avoided by pre-injecting a viscoelastic material which can remain in the anterior chamber during PEA.

Outcome of preoperative against-the-rule astigmatism after phacoemulsification: characteristic changes over time. Part II.

To determine the outcome of preoperative against-the rule (AR) astigmatism among 1,648 phacoemulsification and aspiration (PEA) procedures, we analyzed the post-cataract time course of astigmatism over 6 months in 618 eyes divided into three groups. In preoperative AR astigmatism less than 0.75 dptr (n = 208), the astigmatism increase 1 week postoperatively was rapid. In preoperative AR astigmatism greater than or equal to 1.5 dptr (n = 185), no difference in the power of astigmatism was apparent between 1 and 3 months postoperatively. The third group (0.75 less than or equal to preoperative AR astigmatism less than 1.5 dptr, n = 143) showed intermediate characteristics. The eyes with preoperative low AR astigmatism showed exacerbation of astigmatism after the PEA procedure, whereas the degree of astigmatism, corneal curvatures and the rate of AR astigmatism became lower in the eyes with higher preoperative AR astigmatism.