A case of intractable infectious keratitis and subsequent flap necrosis after laser in situ keratomileusis

We report on a patient in whom intractable infectious keratitis and subsequent lamellar flap necrosis necessitating flap amputation after laser in situ keratomileusis (LASIK). A 34-year-old woman undergoing LASIK complained of blurred vision and pain in the left eye. The best spectacle-corrected visual acuity was 0.01, and slit-lamp examination showed a marked presence of stromal infiltrates involving the flap and the underlying stroma in that eye. The patient was treated topically with hourly instillation of micronomicin, levofloxacin, and cefmenoxime, together with systemic administration of imipenem, but the left eye developed corneal flap necrosis. We performed surgical debridement of the diseased stroma and excised the lamellar flap. Since nontuberculous mycobacterium was detected on the surgical instruments, we then added oral clarithromycin, and substituted systemic administration of amikacin with that of imipenem. At one month after the flap removal, the visual acuity gradually improved to 0.7, but the stromal opacity of the central cornea and hyperopic shift of +3.0 diopters remained. LASIK can cause intractable keratitis, resulting in significant visual disturbance that presumably results from insufficient antisepsis of the medical instruments used for this surgery, supporting the importance of strict sterilization of these instruments

Crystalline lens changes in porcine eyes with implanted phakic IOL (ICL) with a central hole

BACKGROUND: We calculated the smallest diameter of a hole in the center of the optic at which the optical character of a phakic IOL (ICL) may be maintained. The changes induced in the aqueous humor dynamics and the pathology of cataract development with such a hole were investigated. METHODS: A simulation was performed using ZEMAX software to calculate the hole diameter that makes possible the maintenance of a stable optical character of a phakic IOL. After a hole of calculated diameter was trepanned in the center of the optic of the ICL, the latter was implanted into one eye of a 5-month-old minipig, and an unperforated ICL into the other. The postoperative course was observed for 3 months. Then, Evans blue was injected into the vitreous body under general anesthesia to stain the anterior capsule of the crystalline lens. Within 30 min, the eye was enucleated and the tissues removed were fixed. RESULTS: The MTF of the perforated ICL (hole diameter, 1.0 mm) in the center of the optic resembled that of the unperforated ICL. In all cases with non-perforated ICLs, subcapsular turbidity developed, but no staining caused by EB was observed in the anterior capsule. On the other hand, the anterior capsules of the eyes fitted with ICLs with a 1.0-mm hole were stained, but exhibited no turbidity. CONCLUSION: An ICL with a central hole of diameter 1.0 mm in the optic is similar to an unperforated ICL. The size of the hole influenced the aqueous humor dynamics and increased the aqueous humor perfusion volume over the entire anterior surface of the crystalline lens. The possibility of preventing cataracts was therefore suggested

Pengaruh Pemberian Momentum Pada Artificial Neural Network Backpropagation

Salah satu algoritma Artificial Neural Network (ANN) yang biasa digunakan adalah algoritmabackpropagation dengan pola model gradient descent pada proses pembelajarannya. Akan tetapi,gradient descent memiliki kelemahan yaitu tidak mudah digunakan dan terkadang lambat dalampengkonvergenan solusinya. Untuk mengatasi kelemahan tersebut dilakukan suatu modifikasi yaitudengan memberikan momentum pada Perubahan bobotnya. Pada proses prediksi surface roughnesspada CNC Milling menggunakan ANN Backpropagation dengan momentum pada Perubahan bobotini, nilai rata-rata persentase error yang dihasilkan pada masing-masing nilai momentum yangdiberikan adalah tidak banyak mengalami Perubahan. Namun jika nilai momentum yang diberikanmendekati nilai maksimal momentum yaitu mendekati nilai satu maka akan menyebabkanterjadinya overshoot. Pemberian momentum pada Perubahan bobot menyebabkan Perubahan yangcukup besar yaitu pada waktu prosesnya, semakin besar nilai momentum yang diberikan makasemakin cepat pula waktu proses yang dibutuhkan. Hal ini berarti jika ingin waktu prosesprediksinya menjadi cepat maka gunakan nilai momentum yang besar, namun sebaiknya kurangdari 0.9

Repeatability, Reproducibility, and Comparability of Subjective and Objective Measurements of Intraocular Forward Scattering in Healthy Subjects

. Purpose. To assess the repeatability, reproducibility, and comparability of measurements of subjective and objective forward scattering in healthy subjects. Methods. We prospectively examined twenty eyes of 20 healthy volunteers (7 men and 13 women; ages, 28.4 ± 4.1 years). The logarithmic straylight value (log(s)) and the objective scattering index (OSI) were measured with a straylight meter (C-Quant) and a point-spread function meter (OQAS), respectively. Results. The 95% limits of agreement (LoA) between first and second measurements ranged from −0.211 to 0.207 for the C-Quant and from −0.302 to 0.477 for the OQAS. The intraclass correlation coefficients for the repeatability of the log(s) and OSI measurements were 0.815 and 0.926, respectively. The mean difference between examiners was −0.051 ± 0.133 (95% LoA; −0.311 to 0.209) for the C-Quant and 0.080 ± 0.307 (−0.522 to 0.682) for the OQAS. There was a modest, but significant, correlation between the log(s) and the OSI (Spearman correlation coefficient = 0.498, = 0.026). Conclusions. The C-Quant and the OQAS provide good repeatability and reproducibility, although the OQAS measurement provides a slightly higher ICC than the C-Quant measurement. The subjective forward scattering may be to some extent expressed in the objective forward scattering in healthy subjects

Anterior and Posterior Corneal Astigmatism after Refractive Lenticule Extraction for Myopic Astigmatism

Purpose. To assess the amount and the axis orientation of anterior and posterior corneal astigmatism after refractive lenticule extraction (ReLEx) for myopic astigmatism. Methods. We retrospectively examined 53 eyes of 53 consecutive patients (mean age ± standard deviation, 33.2 ± 6.5 years) undergoing ReLEx to correct myopic astigmatism (manifest cylinder = 0.5 diopters (D)). Power vector analysis was performed with anterior and posterior corneal astigmatism measured with a rotating Scheimpflug system (Pentacam HR, Oculus) and refractive astigmatism preoperatively and 3 months postoperatively. Results. Anterior corneal astigmatism was significantly decreased, measuring 1.42 ± 0.73 diopters (D) preoperatively and 1.11 ± 0.53 D postoperatively (p<0.001, Wilcoxon signed-rank test). Posterior corneal astigmatism showed no significant change, falling from 0.44 ± 0.12 D preoperatively to 0.42 ± 0.13 D postoperatively (p=0.18). Refractive astigmatism decreased significantly, from 0.92 ± 0.51 D preoperatively to 0.27 ± 0.44 D postoperatively (p<0.001). The anterior surface showed with-the-rule astigmatism in 51 eyes (96%) preoperatively and 48 eyes (91%) postoperatively. By contrast, the posterior surface showed against-the-rule astigmatism in all eyes preoperatively and postoperatively. Conclusions. The surgical effects were largely attributed to the astigmatic correction of the anterior corneal surface. Posterior corneal astigmatism remained unchanged even after ReLEx for myopic astigmatism

The Taman Siswa in Postwar Indonesia

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Successful toric intraocular lens implantation in a patient with induced cataract and astigmatism after posterior chamber toric phakic intraocular lens implantation: a case report

<p>Abstract</p> <p>Introduction</p> <p>We report the case of a patient in whom simultaneous toric phakic intraocular lens removal and phacoemulsification with toric intraocular lens implantation were beneficial for reducing pre-existing astigmatism and acquiring good visual outcomes in eyes with implantable collamer lens-induced cataract and astigmatism.</p> <p>Case presentation</p> <p>A 53-year-old woman had undergone toric implantable collamer lens implantation three years earlier. After informed consent was obtained, we performed simultaneous toric implantable collamer lens removal and phacoemulsification with toric intraocular lens implantation. Preoperatively, the manifest refraction was 0, -0.5 × 15, with an uncorrected visual acuity of 0.7 and a best spectacle-corrected visual acuity of 0.8. Postoperatively, the manifest refraction was improved to 0, -0.5 × 180, with an uncorrected visual acuity of 1.2 and a best spectacle-corrected visual acuity of 1.5. No vision-threatening complications were observed.</p> <p>Conclusion</p> <p>Toric intraocular lens implantation may be a good surgical option for the correction of spherical and cylindrical errors in eyes with implantable collamer lens-induced cataract and astigmatism.</p

Antiglaucoma drugs for achieving monovision after laser in situ keratomileusis

Kazutaka Kamiya, Kimiya ShimizuDepartment of Ophthalmology, University of Kitasato School of Medicine, JapanAbstract: We report on a patient in whom the use of antiglaucoma drugs has been beneficial for the attainment of monovision after laser in situ keratomileusis (LASIK). A 57-year-old woman undergoing LASIK complained of blurred vision in the right eye. After a successful trial of monovision with contact lenses, antiglaucoma drugs (2.5% nipradilol) were administered topically to the right eye twice a day to establish monovision. In the right eye, the manifest refraction was changed from &amp;minus;4.0, &amp;minus;1.0 &amp;times; 80, with an uncorrected visual acuity (UCVA) of 0.3 for near vision before treatment, to &amp;minus;2.5, &amp;minus;1.0 &amp;times; 80, with an UCVA of 0.9 for near vision after treatment, while, in the left eye, it was 0, &amp;minus;1.0 &amp;times; 100, with an UCVA of 0.9 for far vision. Binocular UCVA was improved from 0.3 for near and 0.9 for distance vision before treatment, to 0.9 for near and 1.0 for distance vision after treatment. No complications were observed and the manifest refraction remained stable during the 6-month follow-up period. The use of antiglaucoma drugs may be helpful for the achievement of monovision by reduction of myopic regression after LASIK.Keywords: antiglaucoma drugs, regression, monovision, LASI