Shiow-Wen Liou

Validity of the keratometric index: Evaluation by the Pentacam rotating Scheimpflug camera

PURPOSE: To determine the keratometric index based on actual measurements of the anterior and posterior corneal surfaces using a rotating Scheimpflug camera (Pentacam, Oculus) and evaluate the accuracy of this keratometric index in estimating total and posterior corneal powers. SETTING: Departments of Ophthalmology, Taipei Medical University Hospital and Taipei City Hospital, Taipei, Taiwan. METHODS: The right eye of 221 subjects was measured with the Pentacam system. The radius of the best‐fit sphere for the anterior corneal surface (rant) and posterior corneal surface (rpost), mean radius of simulated keratometry (rsimK), and central corneal thickness were obtained. The ratio of rant to rpost (AP ratio) and keratometric index were calculated in each eye. RESULTS: The means for rant, rpost, rsimK, and AP ratio were 7.75 mm ± 0.28 (SD), 6.34 ± 0.28 mm, 7.75 ± 0.27 mm, and 1.223 ± 0.034 mm, respectively. These parameters were normally distributed. The mean calculated keratometric index (Ncal) was 1.3281 ± 0.0018. Using the keratometric indices of 1.3281 (Ncal), 1.3315 (Gullstrand schematic eye), and 1.3375 (conventional), the mean arithmetic and absolute estimation errors for the total corneal power were, 0.00 ± 0.24 diopter (D) and 0.17 ± 0.17 D, 0.43 ± 0.23 D and 0.45 ± 0.21 D, and 1.21 ± 0.24 D and 1.21 ± 0.24 D, respectively. The total corneal power was predicted to within ±0.50 D of the actual value in 95.0%, 60.2%, and 0.9% of eyes, respectively. The mean arithmetic and absolute estimation errors for the posterior corneal power using an AP ratio of 1.223 (this study) or 1.132 (Gullstrand schematic eye) were 0.00 ± 0.17 D and 0.13 ± 0.12 D and 0.47 ± 0.18 D and 0.47 ± 0.17 D, respectively. The posterior corneal power was estimated to within ±0.50 D of the actual value in 97.7% and 60.2% of eyes, respectively. CONCLUSION: Using the Pentacam‐derived keratometric index improved the prediction accuracies of total and posterior corneal powers.

Iritis and pupillary distortion after periorbital cosmetic alexandrite laser.

BackgroundTo describe a case of ocular complications associated with laser-assisted periorbital cosmetic treatment and to recommend consideration of the ocular damage caused by dermatological laser therapy, including pupillary distortion and anterior uveitis.MethodsCase report.ResultsA 29-year-old Caucasian woman underwent cosmetic alexandrite laser therapy in the left upper eyelid area without protective eye shields. She complained of an irregular oval pupil, photophobia, and blurred vision in her left eye. Initially, her best-corrected visual acuity (BCVA) was 30/25 (OD) and 30/25 (OS). Slit-lamp biomicroscopy revealed a distorted left pupil with 3+ cell activity in the anterior chamber, but normal intraocular pressure. She was treated with topical corticosteroids. However, marked anterior chamber activity, pigment dispersion over the iris surface, and deteriorating BCVA of 10/25 (OS) had developed at the two-week follow-up. The ocular inflammation subsided gradually and her BCVA returned to normal after intensive steroid treatment. At the six-month follow-up, an ocular examination showed poor pupillary motility and persistent pigment over the iris surface. The patient still suffered from glare in dim light and experienced problems with dark adaptation.ConclusionsAlexandrite laser treatment of the upper eyelid region may penetrate the eyelid, causing anterior uveitis and irreversible damage to the iris. We recommended appropriate eye protection during this therapeutic procedure.

Candida parapsilosis keratitis treated successfully with topical and oral fluconazole

A 73-year-old male patient presented with ocular pain, redness, and blurred vision in the left eye, which had been ongoing for more than 2 months. An oval-shaped paracentral corneal ulcer with stromal infiltration and a mild anterior chamber reaction were found. Despite treatment with empiric antibiotics, the lesion progressed and corneal thinning in the middle area was noted. The culture yielded Candida parapsilosis. We therefore prescribed topical 0.2% fluconazole (FCZ) in combination with oral FCZ as an antifungal treatment, following which the stromal infiltration gradually subsided. Complete epithelial-ization was noted on the 8th day after initiating FCZ therapy. There was no recurrent disease in the subsequent 2 years. Our case demonstrates that topical FCZ 0.2% in combination with oral FCZ can successfully treat C. parapsilosis keratitis and result in a good visual outcome.

Regulatory SNPs Alter the Gene Expression of Diabetic Retinopathy Associated Secretary Factors

Objectives: Diabetic retinopathy (DR) is a common microvascular complication in both type I and type II diabetes. Several previous reports indicated the serum centration of some secretary factors were highly associated with DR. Therefore, we hypothesis regulatory SNPs (rSNPs) genotype in secretary factors may alter these gene expression and lead to DR. Methods: At first, pyrosequencing were applying to screen the SNPs which present allele frequency different in DR and DNR. Then individual genotyping was processed by Taqman assays in Taiwanese DR and DNR patients. To evaluate the effect of SNP allele on transcriptional activity, we measured promoter activity using luciferase reporter constructs. Results: We found the frequencies of the CC, CG, and GG genotype of the rs2010963 polymorphism were 15.09%, 47.14%, and 37.74% in DR and 12.90%, 19.35%, and 67.74% in DNR, respectively (p = 0.0205). The prevalence of DR was higher (p = 0.00793) in patients with the CC or CG genotype (62.26% and 32.26% for DR and DNR, respectively) compared with the patients with the GG genotype. To evaluate the effect of rs2010963-C allele on transcriptional activity, we measured promoter activity using luciferase reporter constructs. The rs2010963-C reporter showed 1.6 to 2-fold higher luciferase activity than rs2010963-G in 3 cell lines. Conclusion: Our data proposed rs2010963-C altered the expression level of VEGFA in different tissues. We suggested small increase but long term exposure to VEGFA may lead to DR finally.

Herpetic keratouveitis mixed with bilateral Pseudomonas corneal ulcers in vitamin A deficiency

A 56-year-old woman complained of blurred vision and pain in her right eye for several days. Slit lamp examination revealed a large epithelial defect and disciform stromal edema with ring infiltration in her right cornea. Unfortunately, hypopyon and purulent discharge subsequently developed in both eyes. Herpetic keratouveitis and a superimposed pseudomonas infection were diagnosed. A systemic review on the patient showed malnutrition due to her dietary preference and vegetarianism. After the infection was controlled, bilateral epithelial defects persisted for a long time. We performed amniotic membrane transplantation on both eyes and the clinical status improved with administration of vitamin and protein supplements. Although rare in Taiwan, vitamin A deficiency should be kept in mind when conjunctival and corneal xerosis occurred. Vitamin A supplements are suggested because of the increased susceptibility to infection in patients with this clinical status.

Atypical Rosai-Dorfman Disease with Lacrimal Gland Involvement

Abstract Purpose: Rosai-Dorfman disease is a rare, benign, idiopathic histocytic proliferative disorder that typically presents in young adults with painless cervical lymphadenopathy. Here we report an atypical case of Rosai-Dorfman disease involving orbit tissue and lacrimal gland, unilaterally. Case: A 69-year-old Asian women developed a painless palpable mass with local edema over the left upper eyelid over several months. Computed tomography (CT) showed an orbital mass with homogenous soft tissue density over the left lacrimal gland and superior orbital area. The patient underwent complete excision of the orbital tumor. Observations: The histopathology revealed diffuse and nodular infiltrations of S-100 positive histiocytes, plasma cells and lymphocytes. Emperipolesis (lymphocytophagocytosis) was also noted. These findings were consistent with Rosai-Dorfman disease. Chest CT revealed hilar lymphadenopathy. Three months after excision of the orbital mass, the patient developed lymphadenopathy in the extremities that resolved spontaneously over a few weeks. There were no complications or recurrence without systemic treatment after the complete excision. Conclusions: Orbital Rosai-Dorfman disease is a rare disorder, especially in Asia. Though there is no consensus on therapeutic choices, including corticosteroids, chemotherapy, radiation therapy, and surgical excision, the complete surgical excision performed in this case was without complication and had a favorable outcome.

The electrostatic coupling of longitudinal optical phonon and plasmon in wurtzite InN thin films

We utilize coherent longitudinal optical phonon as an optical nanoprobe to investigate the plasmonic behavior of wurtzite c-plane InN thin films. The transition from the three-dimensional electron gas in InN bulk toward the two-dimensional electron gas in InN thin film is revealed via measuring the coupling strength of coherent A1(LO) phonon and plasmon coupling mode. The coupling strength diminishes as the film thickness reduces and finally vanishes at 3±1 nm. This phenomenon is ascribed to the detuning of the intersubband plasmon frequency above the A1(LO) frequency, which is originated from the electronic quantum confinement in InN thin films.

27-GAUGE NEEDLE-ASSISTED TECHNIQUE FOR REPOSITIONING A DISLOCATED INTRAOCULAR LENS.

Background: Several techniques for the reposition of a posterior chamber intraocular lens (IOL) posterior dislocating into the vitreous cavity have been developed. However, most of these methods are complicated or include externalizing part of the IOL from a corneal or scleral wound. We here describe a 27-gauge needle-assisted technique for management of a dislocated posterior chamber IOL. Methods: This is a retrospective, noncomparative, interventional case series that discusses the results of 27-gauge needle-assisted reposition of the posterior chamber IOL with transscleral sulcus fixation in 5 consecutive cases with an IOL dislocated into vitreous cavity. These patients underwent IOL reposition with the above-mentioned technique between April 2013 and October 2014 and were followed up for at least two months thereafter. Results: The IOLs of the five cases were stable with proper centrations. The postoperative best-corrected visual acuity ranged from 20/30 to 20/20. Conclusion: The technique of 27-gauge needle-assisted reposition of the posterior chamber IOL with transscleral fixation is effective for reposition of a dislocated IOL. This technique provides good IOL fixation without creating a large corneal wound or scleral flap.

Intraocular lens opacification after Descemet's stripping automated endothelial keratoplasty

Compared with conventional penetrating keratoplasty, Descemets stripping automated endothelial keratoplasty (DSAEK) more effectively maintain global integrity and rapid vision rehabilitation with less ocular surface disorders in patients with endothelial dysfunction. Here, we report a case of a 76-year-old woman who experienced opacification of a hydrophilic intraocular lens (IOL) approximately 10 months after DSAEK. The patient with no history of systemic disease developed pseudophakic bullous keratopathy in the right eye 2 years after undergoing cataract surgery. The best-corrected visual acuity (BCVA) of the right eye was Snellen 0.01 when presented to our hospital. DSAEK was arranged and performed smoothly. However, the graft detached over the upper part of the cornea on postoperative day 1. Thus, rebubbling was performed immediately. After the procedure, the graft was well attached, and the cornea became clear gradually. The BCVA returned to Snellen 0.6. However, progressive opacification over the anterior surface of the IOL was observed 10 months postoperatively. Vision deteriorated to 0.5 with various refractive errors during 2-year follow-up. IOL exchange may be considered if the vision is getting worse. IOL opacification may result from a direct contact between the IOL surface and exogenous air, particularly in a hydrophilic IOL, and can be a rare but significant complication after DSAEK. Clinicians planning to perform DSAEK should consider the composition of the IOL, the amount of intracameral air, duration of air filling, and high intraocular pressure.

Surgical treatment of neovascular glaucoma with Ex-PRESS glaucoma shunt: Case report

Rationale: Neovascular glaucoma (NVG) is one of the most aggressive types of glaucoma, and its abnormal fibrovascular tissue growth on the iris and trabecular meshwork may create difficulties to control the intraocular pressure (IOP) and perform the operation such as trabeculectomy. Patient concerns: Ex-PRESS glaucoma shunt has been introduced to serve as one alternative operation for glaucoma, and is thought to have the potential advantage of being less traumatic than traditional trabeculectomy. The purpose of our study is to evaluate the efficacy and safety of primary Ex-PRESS implantation in eyes with NVG. Diagnoses and interventions: This was a retrospective study of four patients with NVG in whom primary Ex-PRESS implantation was performed between January 2012 and October 2016. Outcomes: After a mean follow-up of 20.8 ± 8.9 months (range, 15–34 months), three of four NVG patients (75.0%) receiving primary Ex-PRESS implantation had postoperative IOP under 21 mmHg without any antiglaucoma medication control at the last follow-up, but shunt reposition had been performed due to failed blebs or recurrent NVG. Besides, the best corrected visual acuity at the last follow-up was stabilized or improved in three of four NVG patients (75.0%), accompanied with the regression of iris neovascularization. Only one patient had self-resolved postoperative hyphema; otherwise, there were no other perioperative complications. Lessons: Primary Ex-PRESS implantation might constitute a safe and alternative treatment for patients with NVG. In spite of the possible reoperations, the final outcomes were still shown effective after shunt reposition.