A Novel "Slit Side View" Method to Evaluate Fluid Dynamics during Phacoemulsification.

Due to recent technical advances in cataract surgeries, there has been a significant improvement in the safety and surgical outcomes of phacoemulsification. However, the corneal endothelium can be damaged during phacoemulsification by multiple factors. Therefore, we used a slit lamp to analyze the fluid dynamics of ophthalmic viscosurgical devices (OVDs) in the anterior chamber during phacoemulsification. In this experimental study, extracted porcine eyes were injected with OVDs stained with fluorescein through a side port of the eye and then fixed on a slit lamp microscope. After inserting a phaco tip, phacoemulsification simulation was then performed on the iris plane. Subsequent movements of OVDs in the anterior chamber were observed during the procedure by using a slit lamp microscope. Aspiration and removal of cohesive OVDs from the inside of the anterior chamber occurred within a few seconds after the ultrasonic vibration. Aspiration of dispersive OVDs occurred gradually, with some of the OVDs remaining on the side of the anterior chamber side in an irregular shape. This shape enabled the OVD to trap the air, thereby preventing the air from directly touching the corneal endothelium. Viscoadaptive OVDs remained inside the anterior chamber as a lump, with the infusion solution flowing between the corneal endothelium and the OVD, thus leading to the eventual aspiration of the OVD. Viscous dispersive OVDs remained as a lump between the corneal endothelium and the phaco tip. However, once the infusion solution flowed between the cornea and the OVD, the OVD detached from the corneal endothelium, indicating that this type would likely be aspirated and removed. This method, termed the "slit side view," enables viewing of the movement of OVDs during surgery, as well as observation of the fluid dynamics in the anterior chamber.

Efficacy of Ophthalmic Viscosurgical Devices in Preventing Temperature Rise at the Corneal Endothelium during Phacoemulsification.

PURPOSE: To investigate temperature alterations in the aqueous humor and the corneal endothelium during phacoemulsification, and to evaluate the effect of ophthalmic viscosurgical devices in preventing a temperature rise at the corneal endothelium during phacoemulsification. METHODS: Temperatures of the aqueous humor and corneal endothelium were measured using two temperature probes set in the anterior chamber during ultrasound oscillation in porcine eyes, with or without ophthalmic viscosurgical devices. RESULTS: Without an ophthalmic viscosurgical device, temperatures in both the aqueous humor and the corneal endothelium rapidly rose during the ultrasound oscillation, while with an ophthalmic viscosurgical device, the temperature elevation of the corneal endothelium site was suppressed compared with the aqueous humor. CONCLUSION: Surgeons need to be especially aware of ophthalmic viscosurgical device retention during phacoemulsification, because it can protect the corneal endothelium from heat generated during this procedure.

Temperature in the anterior chamber during phacoemulsification.

PURPOSE: To evaluate changes in the aqueous humor temperature using 2 phacoemulsification units (Stellaris 28.5 kHz device and Whitestar Signature 40 kHz device). SETTING: Nippon Medical School, Musashikosugi Hospital, Kawasaki City, Kanagawa, Japan. DESIGN: Experimental study. METHODS: Aqueous humor temperatures were measured with a temperature probe set in the anterior chamber during ultrasound (US) oscillation in porcine eyes under 5 conditions. RESULTS: Continuous longitudinal oscillation caused a rapid rise in aqueous humor temperature, while the pulse and elliptical modes suppressed temperature elevation. Reducing the number of US tip vibrations did not reduce the temperature in the anterior chamber. However, raising the vacuum setting allowed the aspirations to rise to the set value, thereby lowering the temperature in the anterior chamber. CONCLUSION: Because differences in the phacoemulsification settings can lead to temperature elevations in the anterior chamber, surgeons must carefully monitor these settings to prevent corneal tissue damage.

Simultaneous treatment of pterygium and temporal conjunctivochalasis.

Pterygium and conjunctivochalasis are common diseases in elderly people and are not uncommonly observed together. However, there have been few reports of the simultaneous treatment of pterygium and conjunctivochalasis. We report such a surgical method and describe the results of two cases. Two patients presented with pterygium accompanied by temporal conjunctivochalasis. We decided to perform simultaneous pterygium excision and free conjunctival autograft transfer using the excess conjunctiva from the conjunctivochalasis surgery. The free graft was obtained from the bulbar conjunctiva from the 6 to 8 o'clock position in the conjunctivochalasis. To reduce the temporal conjunctivochalasis, the conjunctiva was extended and sutured to the perilimbal conjunctiva and episclera at the 6 o'clock position using 8-0 polyglactin suture. Tear meniscus break-up induced by pterygium and by conjunctival laxity was reduced, and the patients' symptoms had been significantly reduced by several days postoperatively.

Usefulness of a semicircular capsulotomy marker.

PURPOSE: To evaluate usefulness of a new semicircular capsulotomy marker in continuous curvilinear capsulorrhexis (CCC). METHODS: In 20 eyes of 20 patients who underwent cataract surgery, a newly designed semicircular marker with an internal diameter of 5.5 mm was used to place a circular mark directly on the lens capsule. The mark was then used as a guide to complete CCC of the set diameter. The resultant size of CCC in each case was confirmed by analysis of the video image. RESULTS: The average CCC diameter size was 5.2 ± 0.3 mm. In all cases, the edge of the intraocular lens was completely covered by the anterior capsule. CONCLUSION: The semicircular capsulotomy diameter marker was useful in making a complete CCC of a set diameter.

Effect of bottle height on the corneal endothelium during phacoemulsification.

PURPOSE: To directly measure intraocular pressure (IOP) in simulated phacoemulsification and to assess the usefulness of lowering the bottle height in protecting the corneal endothelium in clinical phacoemulsification. SETTING: Nippon Medical School Hospital, Tokyo, Japan. METHODS: Simulated phacoemulsification was performed in porcine eyes with 2 bottle heights, 65.0 cm (BH 65 group) and 19.0 cm (BH 19 group). The IOP was continuously measured with a microprobe. In a clinical study, phacoemulsification was performed with a bottle height of 60.0 cm (BH 60 group) and of 30.0 cm (BH 30 group). One day, 1 week, and 1 and 3 months after surgery, cell density and corneal volumes were measured using specular microscopy and rotating Scheimpflug photography, respectively. RESULTS: In the simulation study, IOP fluctuated between 50 mm Hg and 60 mm Hg in the BH 65 group and between 20 mm Hg and 30 mm Hg in the BH 19 group. In the clinical study of 31 eyes, the rate of cell density decrease was significantly lower in the BH 30 group than in the BH 60 group at all time points. The rate of increase in corneal volume was significantly lower in the BH 30 group than in the BH 60 group at 1 month. CONCLUSIONS: Intraoperative IOP in phacoemulsification with a usual bottle height appeared to exceed the normal range. Phacoemulsification with a low bottle height was less harmful to the corneal endothelium.

Functional evaluation of corneal endothelium by combined measurement of corneal volume alteration and cell density after phacoemulsification.

PURPOSE: To assess a new method of functional evaluation of corneal endothelium using combined measurement of corneal volume alteration and cell density (CD) after phacoemulsification. SETTING: Nippon Medical School Hospital, Tokyo, Japan. METHODS: Phacoemulsification was performed in 28 cases. The corneal volume within 3.0 mm and 10.0 mm circles of the cornea was measured using Scheimpflug imaging (Pentacam, Oculus, Inc.) and the cell density, using specular microscopy (Noncon Robo, Konan Medical). The volume stress index (VSI), a parameter for measuring functional evaluation, was calculated by dividing the volume increase within the 3.0 mm circle (preoperative corneal volume - corneal volume at time of measurement) by the central cell density value. The resulting value is indicative of the amount of postoperative increase in corneal volume with which each corneal endothelial cell should be able to cope. RESULTS: Three months after surgery, the 3.0 mm corneal volume returned to preoperative values, while the 10.0 mm corneal volume remained significantly higher than preoperatively. The cell density values did not significantly change throughout the study. The VSI showed a significant decrease by 7 days after surgery followed by a gradual decrease until the end of the study. At 3 months, the VSI value was significantly smaller than at 1 day. CONCLUSION: The corneal volume increase after surgery may be indicative of the degree of the endothelial damage in the area; thus, the VSI may be useful in the functional assessment of the corneal endothelium.

Increases in central retinal artery blood flow in humans following carotid artery and stellate ganglion irradiation with 0.6 to 1.6 microm irradiation.

The authors applied near-infrared low-level laser irradiation (LLLI) directed to the stellate ganglion (SG) and to the common carotid artery (CCA), and compared the effects on central retinal artery blood flow using color pulse Doppler sonography. In 10 healthy volunteers, LLLI (0.92 W, 1 : 1 duty cycle, 10 min) to both the SG and CCA significantly increased peak systolic blood velocity in the ophthalmic artery (p<0.001, each) and central retinal artery (p<0.001, each) without changes in vessel resistance. Irradiation to the CCA produced a stronger effect than that to the SG in the ophthalmic artery (p=0.007) and central retinal artery (p=0.031). These data suggest that LLLI to the SG or to the CCA is a useful therapy for increasing the retrobulbar blood flow, with irradiation directed to the CCA being more effective than that directed to the SG in clinical settings.

Quantitative analysis of posterior capsule opacification of hydrophobic acrylic intraocular lenses.

Posterior capsule opacification (PCO) remains a common complication of modern cataract surgery, although both modification of materials used and changes in the intraocular lens (IOL) optic edge design have helped to decrease its incidence slightly. Recently, various kinds of quantitative methods have been developed for measuring PCO. The purpose of this study was to compare the quantitative analysis of PCO between different types of IOL designs. Patients enrolled in the study had age-related cataract and underwent uneventful cataract surgery and implantation of either the AcrySof MA30BA (Alcon) or the Sensor AR40e (AMO), which are differently designed hydrophobic acrylic IOLs with a sharp-edged optic design. Postoperative examination was performed at 6 months. Retroillumination photographs of each eye were obtained, and the degree of PCO was assessed using the Evaluation of Posterior Capsule Opacification (EPCO) system. Grade 1 PCO was noted in both the MA30BA and the AR40e groups. There was no significant difference in the mean PCO score between the MA30BA and AR40e groups. Although the sharp-edged optic designs of both IOLs might similarly inhibit PCO at 6 months, a long-term follow-up period is needed to determine if any PCO differences occur between these 2 hydrophobic acrylic IOLs.

Two cases of true exfoliation of the lens capsule after cataract surgery.

True exfoliation of the lens capsule is known to be associated with glassblower's cataract, which is caused by extended exposure to excessive heat. Furthermore, inflammation and trauma are also considered to be predisposing factors. We report two cases of true exfoliation that were confirmed after cataract surgery. Neither patient exhibited true exfoliation before cataract surgery. In addition, neither patient had a history of occupation with exposure to excessive heat, inflammation or trauma. We observed the anterior lens capsules of these two patients with slit-lamp microscopy before and after cataract surgery. True exfoliation disappeared by adhering to the anterior capsule in both cases, and there were no complications during the observation period.

Alteration of free radical development by ophthalmic viscosurgical devices in phacoemulsification.

PURPOSE: To determine the effect of ophthalmic viscosurgical devices (OVDs) and irrigation/aspiration (I/A) settings on free radical development during phacoemulsification. SETTING: Department of Ophthalmology, Nippon Medical School, Tokyo, Japan. METHODS: Free radicals were detected by the electron spin resonance (ESR) spin-trap method. After a spin-trapping agent, 5,5-dimethyl-1-pyrroline N-oxide 1%, was mixed with the irrigating solution, phacoemulsification simulation was performed in an eye model at 100% ultrasound power levels for 10, 20, and 30 seconds. A high I/A setting (35 mL/min with 250 mm Hg vacuum) and a low I/A setting (15 mL/min with 60 mm Hg vacuum) were used in combination with no OVD, sodium hyaluronate 1% (Healon), sodium hyaluronate 2.3% (Healon5), sodium hyaluronate 3%-chondroitin sulfate 4% (Viscoat), or sodium hyaluronate 1% (Opegan). Immediately after phacoemulsification, the solution in the anterior chamber was collected and signals from the spin adduct were measured using an ESR spectrometer. RESULTS: With the low setting, all OVDs significantly suppressed the signals for up to 20 seconds. At 30 seconds, the signals were still significantly smaller in all OVD groups, except Healon, than those in the no-OVD. With the high setting, the effect was not significant in the Healon and Opegan groups at 10 seconds; by 20 seconds and after, only Viscoat showed significant suppression. CONCLUSIONS: Free radical development in phacoemulsification can be altered by OVD properties and I/A settings. To reduce oxidative stress to the corneal endothelium, attention should be paid to the retention of OVDs in the anterior chamber during phacoemulsification.

Phacoemulsification associated corneal damage evaluated by corneal volume.

PURPOSE: To determine the usefulness of the Pentacam corneal volume assay in the assessment of corneal endothelial damage caused by phacoemulsification and aspiration (PEA). DESIGN: Prospective, comparative, observational case series. METHODS: PEA was performed in 85 eyes by three surgeons under different conditions. Central cell density (CD) was determined using a specular microscope before and one month after surgery. Pentacam was used before and one day, one week, and one month after surgery to determine 3- and 10-mm corneal volumes. RESULTS: For all surgeons, no significant differences in the 3-mm corneal volumes were noted between the before and one-month after surgery values. However, 10-mm corneal volumes at one month were significantly higher than preoperative levels. No correlation was noted between the increasing rate of the 10-mm corneal volume and decreasing rate of CD. CONCLUSIONS: Pentacam-determined corneal volumes may be useful in assessing PEA-caused corneal damage.

Post-cataract surgery endophthalmitis treated with core vitrectomy: a case report.

Postoperative endophthalmitis is one of the most serious complications after cataract surgery though its frequency may be low. We report a case with post-cataract extraction bacterial endophthalmitis treated favorably by core vitrectomy through pars plana with anterior vitrectomy cutter (A-vit). The patient, a 72-year-old woman, presented with blurred vision 7 days after phacoemulsification and aspiration (PEA) and intraocular lens (IOL) implantation. Her initial visual acuity was counting fingers. As hypopyon and corneal edema progressed in a few hours, we decided to perform vitectomy. Firstly, we performed IOL explantation and anterior vitrectomy through the corneal stab incision with A-vit attached to the phaco machine. The inflammation, however, appeared to be severe. Secondly we performed core vitrectomy with the same cutter as we used in the first operation through pars plana as well as intravitreal injection of vancomycin on the following day. The inflammation was gradually subsided and her corrected visual acuity was recovered to 30/20 at 7 months after the vitrectomy. The results is suggest that for cataract surgeons in the facilities that are not equipped with 3-port vitrectomy machine, post-cataract extraction bacterial endophthalmitis of the emergency stage can be successfully treated by core vitrectomy through pars plana as well as intravitreal injection of antibiotics with neither vitreous shaving at the vitreous base nor artificial posterior vitreous detachment.

Idiopathic opacification of Berger's space.

We report a case of idiopathic opacification of Berger's space in a 68-year-old man. The opacification was in the retrolental space between the crystalline lens and the anterior vitreous in the right eye. Opaque fluid was surgically removed, and chemical analysis detected a high concentration of protein and a low concentration of mucopolysaccharides. No underlying pathology was observed.

Anterior chamber irrigation with an ozonated solution as prophylaxis against infectious endophthalmitis.

PURPOSE: To assess the validity of anterior chamber irrigation with an ozonated solution as prophylaxis against endophthalmitis. SETTING: Department of Ophthalmology, Nippon Medical School, Tokyo, Japan. METHODS: Viability of human corneal endothelium in culture was assessed by the WST-8 assay, lactate dehydrogenase (LDH) release assay, and trypan blue exclusion assay after exposure to a 4 to 40 parts per million (ppm) solution for 10 to 60 seconds. The in vivo effect was observed 1 week after irrigation of a 4 ppm solution in the rabbit anterior chamber by trypan blue exclusion assay. Bactericidal efficacy of the anterior chamber irrigation with the 4 ppm solution was examined by bacterial colony count of the aqueous humor following methicillin-resistant Staphylococcus aureus (MRSA) contaminated intraocular lens implantation in the porcine eye. RESULTS: The WST-8 assay revealed no significant reduction of viability with 10-second exposure to a 4 ppm solution. Lactate dehydrogenase release and trypan blue exclusion assays similarly demonstrated little damage after 60-second exposure to a 4 ppm solution. In the rabbit cornea 1 week after treatment, damage caused by 30-second exposure to a 4 ppm solution was not significant. The MRSA colony count documented almost complete bactericidal action with 5-second exposure to the 4 ppm solution when no ophthalmic viscosurgical device existed in the anterior chamber. CONCLUSION: Limited damage to the corneal endothelium after 10-second exposure and potent bactericidal action with 5-second exposure suggests the validity of anterior chamber irrigation with a 4 ppm ozonated solution as prophylaxis against endophthalmitis.