Reverse pupillary block after implantation of a scleral-sutured posterior chamber intraocular lens: a retrospective, open study

Abstract Background To report the clinical features of patients with reverse pupillary block (RPB) after scleral-sutured posterior chamber intraocular lens (PC IOL) implantation and biometric changes after laser peripheral iridotomy (LPI). Methods Eight patients attending our hospital’s ophthalmology outpatient clinic, who developed RPB after implantation of a scleral-sutured PC IOL due to subluxation of the crystalline lens or IOL, were investigated in this retrospective, observational study. Results Preoperative evaluations showed angle pigmentation in all cases and iridodonesis in 2 cases. Two subjects had used an α1A-adrenoceptor antagonist for benign prostatic hyperplasia. Pars plana or anterior partial vitrectomy was performed in all cases. All eyes showed an extremely deep anterior chamber, a concave iris configuration, and contact between the IOL optic and the iris at the pupillary margin. Pupil capture was detected in 2 cases. The mean (± SD) anterior chamber angle (ACA) was 89.91 ± 10.06°, and the anterior chamber depth (ACD) was 4.42 ± 0.16 mm before LPI. After LPI, the iris immediately became flat with a decreased ACA (51.70 ± 2.59°; P = 0.018) and ACD (4.14 ± 0.15 mm; P = 0.012). After LPI, the intraocular pressure decreased from 19.75 ± 3.77 mmHg to 15.63 ± 4.30 mmHg (P = 0.011), and the spherical equivalent decreased from -0.643 ± 0.385 D to − 0.875 ± 0.505 D (P = 0.016). Conclusion Concomitant vitrectomy, angle pigmentation, and iridodonesis may be risk factors for RPB after scleral-sutured PC IOL implantation. LPI is effective for relieving the RPB

Assessment of Optical Quality at Different Contrast Levels in Pseudophakic Eyes

Purpose. To assess visual function using Optical Quality Analysis System (OQAS) at varying levels of contrast in pseudophakic eyes. Methods. The study included patients admitted to Seoul St. Mary’s Hospital between January and February 2012: 143 pseudophakic eyes with one of five intraocular lens types, examined 2–6 months after cataract surgery, and 93 normal eyes (enhanced visual acuity (VA) < 0.1 logMAR) in age-matched controls. Subjects were examined at three contrast levels using the OQAS. Results. At 100%, 20%, and 9% contrast, simulated mean VA was 0.16±0.18 logMAR, 0.30±0.18 logMAR, and 0.52±0.17 logMAR, in normal eyes, and 0.16±0.12 logMAR, 0.33±0.20 logMAR, and 0.56±0.21 logMAR, respectively, in pseudophakic eyes. Simulated VA decreased significantly when contrast was reduced, regardless of ocular status, age group, and lens type (p<0.05). There were no significant differences between normal and pseudophakic eyes among subjects aged 50–69 (p>0.05). Among subjects aged 70–79, pseudophakic eyes showed improved simulated VA (p=0.000) and objective scattering index values (p=0.008). Conclusions. Patients with intraocular lenses have similar or superior visual function when compared to those with normal eyes at 2–6 months after cataract surgery, even under low-contrast conditions

Polar Value Analysis of Corneal Astigmatism in Intrastromal Corneal Ring Segment Implantation

Purpose. To evaluate surgically induced astigmatism (SIA) and the average corneal power change in symmetric intrastromal corneal ring segment (ICRS) implantation. Methods. The study included 34 eyes of 34 keratoconus patients who underwent symmetric Intacs SK ICRS implantation. The corneal pocket incision meridian was the preoperative steep meridian. Corneal power data were obtained before and 3 months after Intacs SK ICRS implantation using scanning-slit topography. Polar value analysis was used to evaluate the SIA. Hotelling’s trace test was used to compare intraindividual changes. Results. Three months postoperatively, the combined mean polar value for SIA changed significantly (Hotelling’s T2=0.375; P=0.006). The SIA was 1.54 D at 99° and the average corneal power decreased significantly by 3.8 D. Conclusion. Intacs SK ICRS placement decreased the average corneal power and corneal astigmatism compared to the preoperative corneal power and astigmatism when the corneal pocket incision was made at the preoperative steep meridian

Activation of MAPK and CREB by GM1 Induces Survival of RGCs in the Retina with Axotomized Nerve

PURPOSE. Neuronal cells undergo apoptosis when the supply of neurotrophic factor is limited by injury, trauma, or neurodegenerative disease. Ganglioside has both neuritogenic and neurotropic functions. Exogenously administered monosialoganglioside (GM1) has been shown to have a stimulatory effect on neurite outgrowth and to prevent degeneration of neuronal cells in the central nervous system. Even though GM1 has been shown to mimic, or have synergy with, neurotrophic factors, the neuroprotective mechanism of GM1 has not been well understood. In this study, optic nerve transection, or axotomy, was used as an in vivo model system for injury, to examine the protective mechanism of GM1 in injured retinal ganglion cells. METHODS. GM1 was injected into the vitreous body before axotomy, and the protective effect of GM1 observed with regard to activation of mitogen-activated protein kinase (MAPK) and phosphorylation of cAMP-responsive elementbinding (CREB) protein. Activation of MAPK and CREB were examined by Western blot analysis and immunohistochemistry, and the surviving retinal ganglion cells were counted after retrograde fluorescence labeling. RESULTS. GM1 inhibited the degeneration of axotomized retinal ganglion cells. In addition, GM1 enhanced the activation of MAPK and CREB with the treatment of GM1 in the retina with axotomized nerve. Treatment of MAPK inhibitor PD98059 with GM1 reduced the protective action of GM1 and prevented GM1-induced phosphorylation of CREB. CONCLUSIONS. GM1 protected the axotomized retinal ganglion cells (RGCs) from cell death after axotomy through the activation of MAPK and CREB. (Invest Ophthalmol Vis Sci

Development of a Conjunctivitis Outpatient Rate Prediction Model Incorporating Ambient Ozone and Meteorological Factors in South Korea

Ozone (O3) is a commonly known air pollutant that causes adverse health effects. This study developed a multi-level prediction model for conjunctivitis in outpatients due to exposure to O3 by using 3 years of ambient O3 data, meteorological data, and hospital data in Seoul, South Korea. We confirmed that the rate of conjunctivitis in outpatients (conjunctivitis outpatient rate) was highly correlated with O3 (R2 = 0.49), temperature (R2 = 0.72), and relative humidity (R2 = 0.29). A multi-level regression model for the conjunctivitis outpatient rate was well-developed, on the basis of sex and age, by adding statistical factors. This model will contribute to the prediction of conjunctivitis outpatient rate for each sex and age, using O3 and meteorological data

Lamellar keratoplasty using position-guided surgical needle and M-mode optical coherence tomography

Deep anterior lamellar keratoplasty (DALK) is an emerging surgical technique for the restoration of corneal clarity and vision acuity. The big-bubble technique in DALK surgery is the most essential procedure that includes the air injection through a thin syringe needle to separate the dysfunctional region of the cornea. Even though DALK is a well-known transplant method, it is still challenged to manipulate the needle inside the cornea under the surgical microscope, which varies its surgical yield. Here, we introduce the DALK protocol based on the position-guided needle and M-mode optical coherence tomography (OCT). Depth-resolved 26-gage needle was specially designed, fabricated by the stepwise transitional core fiber, and integrated with the swept source OCT system. Since our device is feasible to provide both the position information inside the cornea as well as air injection, it enables the accurate management of bubble formation during DALK. Our results show that real-time feedback of needle end position was intuitionally visualized and fast enough to adjust the location of the needle. Through our research, we realized that position-guided needle combined with M-mode OCT is a very efficient and promising surgical tool, which also to enhance the accuracy and stability of DALK