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Purpose To investigate the relationship between the generation of free radicals and femtosecond laser lens irradiation. Setting AMO Laboratory, Tokyo, Japan. Design Ex vivo studies. Methods Hydroxyphenyl fluorescein (HPF) was injected into the anterior chamber of fresh 6-month-old porcine cadaver eyes (N = 31). After laser irradiation, a plate reader was used to measure the fluorescence of the aqueous humor samples. Relative fluorescence units (RFU) were calculated by subtracting the average control value from the measured values of all the samples. Experiment 1: After determining the RFU in the 7 laser-irradiated eyes, the relationship with the amount of laser energy was then assessed. Experiment 2: To clarify the issue regarding the degree of attenuation of the fluorescence intensity, HPF was simultaneously injected into 2 eyes, with 1 eye irradiated and the other eye used as a control. After dividing the RFU of the laser-irradiated eye by the control RFU, the laser irradiation–control RFU ratio was calculated, and the relationship with the laser irradiation energy amount then assessed. Results There was a significant correlation between the femtosecond laser lens irradiation energy and the RFU in the aqueous humor (P Conclusions Femtosecond laser lens irradiation increases the quantity of free radicals in the aqueous humor, with the extent of the increase dependent on the amount of laser energy. These results suggest that excessive laser irradiation during femtosecond laser–assisted cataract surgery might cause corneal endothelial damage because of the free radicals created during the procedure.

Yoichiro Masuda,1 Hisaharu Iwaki,2 Akira Watanabe,3 Akiko Takada,3 Toshinori Okamoto,4 Kotaro Oki,5 Tadashi Nakano,3 Hiroshi Tsuneoka3 1Department of Ophthalmology, The Jikei University, Katsushika Medical Center, Tokyo, Japan; 2Iwaki Eye Clinic, Tokyo, Japan; 3Department of Ophthalmology, The Jikei University, School of Medicine, Tokyo, Japan; 4Nakamurabashi Eye Clinic, Tokyo, Japan; 5Oki Eye Surgery Center, Tokyo, Japan Abstract: Femtosecond laser-assisted cataract surgery (FLACS) changes the intraoperative environment due to the generation of intracapsular gas that induces a high intracapsular volume. Manual hydrodissection (mH) may induce high intracapsular pressure (ICP) and additional intracapsular volume, thereby leading to capsular block syndrome (CBS). Since the phaco-sleeve irrigation-assisted hydrodissection (iH) technique is used to initially groove and split the lens and remove the intracapsular gas, this can reduce the intracapsular volume while bypassing the intracapsular lens prior to the hydrodissection. As iH uses the phaco tip to intentionally vacuum the intraocular fluid for use in inducing the irrigation jet from the sleeve side holes, the ICP cannot surpass the set irrigation pressure, thereby avoiding CBS. Using this technique, we performed FLACS without CBS in 310 cataract eyes. Our findings suggest that the iH technique may be beneficial for patients by preventing CBS during FLACS. Keywords: FLACS, irrigation dynamic pressure, hydrodissection-related complication, capsular block syndrome, CBS, low invasive cataract surgery

Yoichiro Masuda,1 Kotaro Oki,2 Hisaharu Iwaki,3 Toshinori Okamoto,1 Hiroshi Tsuneoka4 1Department of Ophthalmology, Jikei University Katsushika Medical Center, 2Oki Eye Surgery Center, 3Iwaki Eye Clinic, 4Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan Abstract: Use of the phaco tip technique for lens cleavage and removal does not require manual hydrodissection using a syringe and cannula, or cortical removal using an irrigation/aspiration tip. The phaco tip is the only surgical instrument required for this technique. Its advantages include maintaining a stable intraocular pressure during cortical cleaving hydrodissection and lens removal, which includes the cortex. Keywords: cataract surgery, hydrodissection, capsular block syndrome, FLACS, Dewey tip

An integrated questionnaire was administered to a total of 4142 (2137 women, 2005 men; answer rate: 94.4%) university students and medical training schools students aged 18–40 years. The survey was carried out between May and October, 2004–2013. This questionnaire consisted of assessment of diurnal type, questions on sleep habits, mental health (upset emotionally, irritated, angered by small triggers, and suppressed), frequency of watching TV at night, use of mobile phone and playing TV games between 21:00 and 03:00 h, and questions on lighting conditions during the daytime and night. Sleep length in evening-type students (E-type; diurnal-type scores = 7–12) was shorter than in intermediate-types (I-type; diurnal-type scale (DTS) = 13–16) and morning-types (M-type; DTS = 17–28) on weekdays (p

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. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

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.

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.

To estimate the incidence rate of endophthalmitis after cataract surgery performed by Japanese surgeons.A sample of 20% of members of the Japanese Society of Ophthalmic Surgeons was randomly selected. Each member was sent a postal survey asking for information on the number of cataract surgeries performed in 2003 and the number of postsurgery cases of endophthalmitis.Replies were received from 78.7% (513/652) of survey recipients. The total number of cataract surgeries was 100 539, among which 52 cases of endophthalmitis occurred, resulting in an overall incidence rate of 0.052%. Incidence rates were 0.049% (38/78 170) for scleral incision phacoemulsification and 0.043% (9/20 894) for clear corneal incision phacoemulsification, with no significant difference between groups. The average annual volumes of surgery were 210 and 280 cases for surgeons who preferred scleral incision and clear corneal incision, respectively. There was a significant difference between volumes (Student's t-test, p0.01). The incidence of endophthalmitis was significantly lower with high-volume (300 cases/year) surgeons than with low-volume (or = 300 cases/year) surgeons (0.040% versus 0.066%, chi-square test, p0.05).The incidence of endophthalmitis after cataract surgery in Japan as estimated by a postal survey was low (0.052%) and consistent with rates reported previously. Surgeons who preferred clear corneal incision performed significantly more surgeries annually, but the incidence of endophthalmitis was similar between scleral and clear corneal incision phacoemulsification surgery.