Expression Profiling of Exosomal miRNAs Derived from the Aqueous Humor of Myopia Patients.

Myopia is the most common refractive disorder in Eastern Asia. The development of myopia is associated with the cooperation of various ocular tissues. Exosomes in the aqueous humor (AH) have been implicated to modulate intracellular communications by transferring exosomal miRNAs and proteins between cells. These exosomal miRNAs and proteins are likely involved in the pathogenesis of various eye diseases. In this study, we aimed to explore human exosomal miRNA profiles and their roles in myopia development. AH samples were collected from 16 patients (8 myopia and 8 control) undergoing routine cataract surgeries. Exosomes were isolated from AH of each individual using the ExoQuick solution. The numbers and sizes of exosomes were not significantly different between the myopia and control groups. The individual exosomes of the same group were pooled to purify RNA. Unexpectedly, the myopia group contained 2.78-fold total RNA amount than that in the control group. Thereafter, miRNA profiles were analyzed using the OpenArray system. We thus found 15 myopia-specific miRNAs and four myopia-absent miRNAs. By using bioinformatics analysis, we identified six well-known myopia-associated genes that are potential targets of five myopia-specific miRNAs (has-miR-582-3p, has-miR-17-5p, has-miR-885-3p, has-miR-19b-3p, and has-miR-450b-5p). These genes are cholinergic receptor muscarinic 2 (CHRM2), cyclic nucleotide-gated channel beta 3 (CNGB3), vascular endothelial growth factor A (VEGFA), adenosine A2a receptor (ADORA2A), insulin-like growth factor 1 (IGF1), and lumican (LUM). Moreover, CHRM2 may be a target of myopia-absent miRNA (has-miR-378a-5p). In conclusion, we show the expression profiles of AH-derived exosomal miRNAs and their potential roles in myopia development.

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.

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.

Subconjunctival Herniated Orbital Fat Mimicking Adipocytic Neoplasm.

PURPOSE: To describe and discuss rare and benign conditions of subconjunctival orbital fat herniation that may mimic adipocytic neoplasm. METHODS: Sixteen eyes of 13 patients with subconjunctival orbital fat herniation were included. They all underwent transconjunctival excision owing to cosmesis, discomfort, or suspicion of malignancy. Histopathologic examination, postoperative complications, and recurrent conditions were analyzed. RESULTS: Eleven male and two female patients were included. The lesion was unilateral in 10 and bilateral in 3 cases. Excision was performed via conjunctival wound and removing the prolapsed orbital fat. The conjunctiva was then closed with two to three interrupted sutures. All the histopathologic specimens revealed Lochkern cells, floret cells, and mature adipocytes separated by fibrovascular septae without hyperchromatic cells, consistent with subconjunctival herniated orbital fat. All the patients were treated successfully with transconjunctival excision without recurrence at an average follow-up of 10.6 months (range, 6 to 16 months). CONCLUSIONS: Prolapse of subconjunctival orbital fat is an uncommon entity of intraorbital masses and may mimic adipocytic neoplasm. It is usually associated with a dehiscence in the Tenon capsule. Surgical excision is indicated and pathologic evaluation is necessary if any malignancy is suspected.

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.

Coenzyme Q10 rescues ethanol-induced corneal fibroblast apoptosis through the inhibition of caspase-2 activation.

Recent studies indicate that caspase-2 is involved in the early stages of apoptosis, particularly before the occurrence of mitochondrial damage. Here we report the important role of the coenzyme Q10 (CoQ10) on the activity of caspase-2 upstream of mitochondria in ethanol (EtOH)-treated corneal fibroblasts. After EtOH exposure, cells produce excessive reactive oxygen species formation, p53 expression, and most importantly, caspase-2 activation. After the activation of the caspase-2, the cells exhibited hallmarks of apoptotic pathway, such as mitochondrial damage and translocation of Bax and cytochrome c, which were then followed by caspase-3 activation. By pretreating the cells with a cell-permeable, biotinylated pan-caspase inhibitor, we identified caspase-2 as an initiator caspase in EtOH-treated corneal fibroblasts. Loss of caspase-2 inhibited EtOH-induced apoptosis. We further found that caspase-2 acts upstream of mitochondria to mediate EtOH-induced apoptosis. The loss of caspase-2 significantly inhibited EtOH-induced mitochondrial dysfunction, Bax translocation, and cytochrome c release from mitochondria. The pretreatment of CoQ10 prevented EtOH-induced caspase-2 activation and mitochondria-mediated apoptosis. Our data demonstrated that by blocking caspase-2 activity, CoQ10 can protect the cells from mitochondrial membrane change, apoptotic protein translocation, and apoptosis. Taken together, EtOH-induced mitochondria-mediated apoptosis is initiated by caspase-2 activation, which is regulated by CoQ10.

Efficacy and safety of transscleral cyclophotocoagulation versus cyclocryotherapy in the treatment of intractable glaucoma: A systematic review and meta-analysis.

To perform a meta-analysis to compare the efficacy and safety of diode laser transscleral cyclophotocoagulation (TSCPC) and cyclocryotherapy (CCT) in the treatment of intractable glaucoma. Systemic searches of the Ovid MEDLINE, EMBASE, and Cochrane Library databases yielded experimental and observational comparative studies. TSCPC and CCT efficacy and safety outcomes were compared. Subgroup analyses of participant ethnicity, preoperative intraocular pressure (IOP) level, and underlying causes of glaucoma were conducted. The pooled effects were computed using the random-effects model. The meta-analysis included nine studies totalling 668 eyes. There was no statistically significant difference between the TSCPC and CCT groups in the IOP reduction (IOPR%), decrease in antiglaucoma medications, the operative success rate with or without medications, or retreatment rate in the efficacy analysis. In the subgroup analysis, CCT had a better IOP-lowering effect among non-Asian participants and a non-inferior IOPR% to TSCPC among Asian participants. TSCPC and CCT were associated with similar rates of deterioration in visual acuity, postoperative visual analog scale, and other analysed postoperative complications in the safety analysis. In both groups, severe complications were uncommon. Diode laser TSCPC and CCT had nearly equivalent clinical efficacy in treating intractable glaucoma, while CCT demonstrated a better IOP-lowering effect in non-Asian. Both cyclodestructive procedures have a comparable safety profile.

Iritis and pupillary distortion after periorbital cosmetic alexandrite laser.

BACKGROUND: To 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. METHODS: Case report. RESULTS: A 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. CONCLUSIONS: Alexandrite 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.

Recurrent cytomegalovirus corneal endotheliitis after penetrating keratoplasty.

PURPOSE: To report a case of recurrent cytomegalovirus (CMV) corneal endotheliitis after penetrating keratoplasty. METHODS: Penetrating keratoplasty (PK) was performed in a 49-year-old man with bullous keratopathy. Pigmented keratic precipitates (KPs) were found in the corneal endothelium of the graft 13 days after surgery, with the subsequent appearance of coin-shaped lesions. Confocal microscopy was performed on the corneal endothelium. Aqueous humor was analyzed for viral DNA by polymerase chain reaction (PCR). RESULTS: CMV DNA was detected from the excised corneal button, and aqueous humor revealed positive results for CMV and HSV1 by PCR. Confocal microscopy showed large corneal endothelial cells, consistent with the typical owl's eye morphology of CMV endotheliitis. After systemic ganciclovir was administered, the pigmented KPs and coin-shaped lesions gradually decreased. CONCLUSIONS: Stress from surgery and corticosteroid usage can revitalize CMV activity. PCR and confocal microscopy are valuable for the diagnosis of CMV corneal endotheliitis.

A STROBE-compliant case-control study: Effects of cumulative doses of topical atropine on intraocular pressure and myopia progression.

Topical atropine has become a mainstream treatment of myopia throughout East and Southeast Asia, but it is uncertain whether long-term topical atropine therapy induces intraocular pressure (IOP) elevation and subsequent development of glaucoma. We then prospectively examined the effects of long-term atropine treatment on IOP.Our case series collected 186 myopic children who were younger than 16 years of age. Complete ocular examination data, IOP and refractive status measurements beginning in 2008 were collected for all participants. Participants were divided into two groups: 121 children who received atropine therapy at various concentrations were classified as the treated group, whereas 65 children who did not receive atropine therapy were classified as the untreated (reference) group. In the treated group, clinicians prescribed different concentrations of atropine eye drops according to their discretion with regard to the severity of myopia on each visit of the patient. We then calculated the cumulative dose of atropine therapy from 2008 to the patients' last follow-up in 2009. Furthermore, the treated group was then further divided into low- and high-refractive-error groups of nearly equal size for further analysis.There were no significant differences for the baseline refractive errors and IOPs between the treated and untreated groups. Both the low- and high-cumulative atropine dosage subgroups showed significantly lower myopic progression than the untreated group, but there was no significant difference between the two subgroups in terms of different cumulative dosages. All groups, including the untreated group, showed an increase of mean IOP at the last follow-up, but both low- and high-cumulative atropine dosage subgroups experienced a smaller increase of IOP. The mean IOP of all atropine-treated groups showed no significant increase in either low- or high-refractive-error eyes.This study revealed that topical atropine eye drops do not induce ocular hypertension and are effective for slowing the progression of myopia. The treatment effects are not correlated with the cumulative atropine dosages.

Detection of hepatitis B virus in the aqueous humor of a hepatitis B virus carrier.

The prevalence of hepatitis B virus (HBV) is particularly high in Asian countries, including Taiwan. Previous studies have reported detection of HBV surface antigens in tears and aqueous humor of HBV-seropositive individuals, suggesting that ophthalmologists may be at risk of contracting HBV infection by treatment of such patients. Herein we report the case of an asymptomatic Taiwanese HBV patient in whom HBV was detected in aqueous humor using PCR. To our knowledge this is the first report of HBV detection in aqueous humor by PCR. Eye care providers should take all necessary precautions when treating individuals who have or are at high risk of being infected with HBV.

Seasonal variations in the occurrence of retinal vein occlusion: a five-year nationwide population-based study from Taiwan.

PURPOSE: To determine whether seasonal variation exists in the incidence of retinal vein occlusion. DESIGN: Retrospective, nationwide population-based administrative database study. METHODS: We collected data on outpatient and emergency visits for the period from January 1999 through December 2003 from the Taiwan National Health Insurance Research Database, a source that covers more than 96% of Taiwan's 23 million citizens. In total, 20,792 patients with a first-time diagnosis of either central retinal vein occlusion or branch retinal vein occlusion (The International Classification of Disease, Ninth Revision, Clinical Modification [ICD-9-CM] code 362.35 or 362.36, respectively) were identified. Monthly incidence of retinal vein occlusion was obtained for each age group, each gender group, and for the entire sample. The autoregressive integrated moving average method of analysis was adopted to examine seasonality in the monthly incidence of retinal vein occlusion. RESULTS: The monthly incidence rates of retinal vein occlusion revealed significant seasonality, with a clear peak in January for each age group and each gender group, as well as for the total sample. CONCLUSIONS: Our study demonstrates significant seasonal variations in the retinal vein occlusion incidence, with the peak occurrence in the winter month of January.

Estimation of the effective lens position using a rotating Scheimpflug camera.

PURPOSE: To describe a no-history method of estimating the effective lens position (ELP) for double-K intraocular lens (IOL) power calculation in eyes that had previous refractive surgery. SETTING: Departments of Ophthalmology, Taipei Medical University Hospital and Taipei City Hospital, Taipei, Taiwan. METHODS: The corneal height (H(m)) and anterior chamber diameter (AG(m)) in 106 unoperated eyes were measured using a rotating Scheimpflug camera. The theoretical anterior corneal radius (R(rt)) was then derived from H(m) and AG(m) by regression and rearrangement of the Fyodorov equation. The ELP estimate was then calculated from R(rt). The performance of this ELP estimation method in double-K IOL power calculation and the performance of other methods were compared retrospectively in 11 eyes having cataract surgery that had previous refractive surgery. The refractive results 9 to 12 weeks after cataract surgery were selected for data analysis. RESULTS: The new ELP estimation method, combined with the BESSt formula or the Savini et al. method for estimating post refractive-surgery corneal power (K(post)) in the double-K SRK/T formula, provided the best IOL power prediction results. The mean arithmetic and absolute IOL prediction errors were -0.05+/-0.62 diopters (D) and 0.49+/-0.34 D, respectively, when combined with the BESSt formula and 0.03+/-0.73 D and 0.60+/-0.36 D, respectively, when combined with the Savini et al. method. With either combination, all 11 eyes were within+/-1.00 D of the refractive prediction error. CONCLUSION: This ELP estimation method may be helpful for IOL power calculation in post refractive-surgery eyes when historical data are unavailable.

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.

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 ±â€Š8.9 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.

Intraocular lens opacification after Descemet's stripping automated endothelial keratoplasty.

Compared with conventional penetrating keratoplasty, Descemet's 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.

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.

Ocular decompression retinopathy after laser iridotomy in a patient with acute angle closure.

A 65-year-old female developed elevated intraocular pressure (IOP) with angle closure in the right eye. The fundus examination revealed vitreo-retinal hemorrhage that had occurred after neodymium-doped yttrium aluminum garnet (Nd:YAG) laser iridotomy. The retinal hemorrhage resolved spontaneously. This is a rare complication that occurs when the IOP is lowered rapidly. Ocular decompression retinopathy (ODR) was identified. We reviewed several cases of ODR that were treated by various interventions. We also discuss the possible pathogenesis, prognosis, and treatment strategy.

Comparison of subjective visual acuity with visual acuity predicted from C-scan topography.

PURPOSE: To compare the capability of objective measures of visual acuity (potential visual acuity from C-scan) to predict subjective visual acuity (best spectacle-corrected visual acuity [BSCVA]). METHODS: Patients with BSCVA > or = 20/20 were enrolled in four groups (Group 1: normal [33 eyes]; Group 2: < -7.00 D myopia [43 eyes]; Group 3: > or = -7.00 D myopia [28 eyes]; Group 4: At least 1 month after LASIK [93 eyes]). Videokeratography was performed with the ray tracing Technomed C-scan. The potential visual acuity from C-scan was obtained with pupils undilated and intact precorneal tear films. All visual acuity was recorded in logMAR, and the significance of differences between acuities was assessed with a one-way ANOVA test. RESULTS: The potential visual acuity from C-scan ray tracing of normal and myopic eyes in response to both photopic and mesopic stimuli did not differ. In a given eye, the potential visual acuity from C-scan ray tracing was better than BSCVA, and the difference was statistically significant. Although the potential visual acuity from C-scan of postoperative LASIK eyes in response to photopic stimuli was the same, it decreased under mesopic conditions. CONCLUSIONS: Potential visual acuity from C-scan overestimates subjective visual acuity due to the inadequate assumptions in ray tracing or individual retinal resolution ability. In addition, the potential visual acuity from C-scan ray tracing varies with pupil diameter in different illumination.

Effect of intracameral injection of lidocaine and carbachol on the rabbit corneal endothelium.

PURPOSE: To determine the effect of intracameral injection of preservative-free lidocaine 1% and carbachol 0.01% on corneal endothelial cells of rabbits. SETTING: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan. METHODS: Forty eyes of 20 New Zealand White rabbits were divided into 2 equal groups. In the first group, 1 eye was injected with 0.02 mL of preservative-free lidocaine 1% and the fellow eye was injected with 0.02 mL of normal saline as a control. In the second group, 1 eye was injected with 0.02 mL of carbachol 0.01% and the fellow eye was injected with 0.02 mL of normal saline. Specular microscopy was used to evaluate corneal endothelial cell loss and corneal thickness 1 week and 1 month postinjection. For morphologic studies, corneal buttons were excised and stained with alizarin red with trypan blue. Scanning electron microscopy (SEM) examination was performed. RESULTS: Specular microscopy revealed no significant endothelial cell loss and normal endothelial thickness with the intracameral injection of preservative-free lidocaine 1% and carbachol 0.01% compared with the control eye. Alizarin red with trypan blue stain and SEM examinations revealed smooth, distinct, and intact intercellular borders and normal viability of corneal endothelial cells in both groups. CONCLUSIONS: Intracameral injections of preservative-free lidocaine 1% and carbachol 0.01% do not produce morphologic and functional changes in the corneal endothelial cells of rabbits.