A comparison of Scansys and Sirius tomography in healthy eyes.

PURPOSE: To assess the level of agreement and evaluate the reliability of measurements between two Scheimpflug imaging modalities, Scansys (MediWorks, China) and Sirius (CSO, Italy), in quantifying the anterior segment parameters in healthy eyes. METHODS: In a cross-sectional study, the right eyes of 38 healthy participants without any ocular or systemic diseases were examined. A range of anterior segment parameters including anterior and posterior flat and steep keratometry, central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior chamber depth (ACD), anterior chamber angle (ACA), corneal volume, anterior chamber volume, and horizontal white to white diameter, derived from the sagittal curvature maps were measured. To evaluate the reliability of the measurements, intraclass correlation coefficient (ICC) and correlation coefficient were measured. Additionally, Bland-Altman plots were employed to examine the agreement in mean (bias line) and 95% limits of agreement between the two devices. RESULTS: The mean age was 31.5 ± 6.9 (range: 19-47) years. The ICC indicated that the majority of anterior segment parameters had an excellent or good level of reliability, surpassing the threshold of 0.9. Nevertheless, CCT and ACA exhibited a moderate level of reliability, with ICC values of 0.794 and 0.728, respectively. The correlation analysis showed a strong correlation for all the variables tested. The Bland-Altman plots revealed that the bias line was near zero and the 95% limits of agreement were narrow for most variables, except for the anterior flat and steep keratometry, which were found to range from - 0.57 to 0.84 D and - 0.68 to 0.87 D, respectively. CONCLUSION: Scansys and Sirius devices can be effectively used interchangeably for the evaluation of most anterior segment parameters; however, for anterior corneal curvatures, CCT and ACA, their alternative use is not recommended.

Evaluation of the effect of artificial tears on corneal epithelial thickness changes after photorefractive keratectomy.

PURPOSE: This study aimed to evaluate the corneal epithelial thickness changes after photorefractive keratectomy (PRK) and the impact of long-term artificial tear usage on epithelial thickness changes in these patients. METHODS: This study was performed on 71 patients (142 eyes) without dry eye disease who received PRK for myopic refractive correction. The corneal epithelial thickness profile was obtained before, one, three, and six months after surgery using anterior segment optical coherence tomography. Patients were randomly divided into two groups: group A, who received preservative-free artificial tears post-surgery, and group B, who did not receive artificial tears. RESULTS: The epithelial thickness decreased universally in the first month and then increased in the 3- and 6-month follow-ups. Group A had a significantly thicker epithelium in central, paracentral, and midperipheral zones compared with group B in the 3-month follow-up. In the 6-month follow-up, no significant differences were detected between groups. At the last follow-up, the central, paracentral, and midperipheral zone epithelial thicknesses in all patients were significantly higher than preoperative values, but peripheral zone thickness only increased to preoperative values. CONCLUSIONS: Patients using artificial tears showed a faster thickening, especially in the central and paracentral zones, but there were no significant differences between the two groups in the final follow-up. Artificial tear usage may increase the rate of the epithelial remodeling process in post-PRK patients without significantly altering the final epithelial thickness profile. Further studies are warranted to evaluate the influence of different factors on epithelial remodeling.

Role of Different Types of Contact Lenses in Epithelial Thickness.

OBJECTIVE: To evaluate the potential role of different types of contact lenses, such as soft (SCL), hard (HCL), and mini scleral (SCCL), in corneal epithelial thickness with anterior segment optical coherence tomography (AS-OCT). METHODS: In this cross-sectional study, patients who used contact lens at recent 6 months were recruited consecutively from September 2019 to October 2019, and the epithelial thicknesses of the cornea were obtained by AS-OCT and compared with control subjects who did not use contact lens. RESULTS: In total, 184 eyes (115 subjects) were included; of them, 75 eyes were keratoconic (KCN) and 109 eyes were nonkeratoconic (non-KCN). Twenty eyes in KCN and 79 eyes of non-KCN group had no history of contact lens use and were included for comparison with KCN and non-KCN contact lens users, respectively. Mean duration of contact lens wearing was 75.63±50.42 months. The epithelial thickness of non-KCN SCL group was thinner than that of non-KCN control subjects all over the cornea, whereas the epithelium of non-KCN HCL was thinner at central site as well as nasal and temporal paracentral and midperipheral areas. Epithelial thickness of the KCN HCL group was not different from the KCN control subjects in all sectors. The KCN SCCL group had thinner epithelium at nearly all peripheral sectors as well as inferior, inferotemporal, inferonasal, and nasal midperipheral sectors compared with KCN control subjects. CONCLUSION: The corneal epithelium was thinner at the peripheral zones in KCN SCCL users; at both peripheral and central zones in non-KCN SCL users and in central zones in non-KCN HCL users.

Outcomes of the infantile cataract surgery: case series with a 5-year follow-up.

PURPOSE: To present the 5-year outcomes obtained from the infantile cataract surgery in pediatric population. METHODS: Medical records of all patients with unilateral or bilateral infantile cataract who had undergone lensectomy and anterior vitrectomy with or without intraocular lens implantation before 10 years of age were evaluated. Patients with any history of ocular trauma, retinal or corneal dystrophy, ocular or orbital surgery, retinopathy of prematurity, raised intraocular pressure at the time of diagnosis, or incomplete follow-up sessions were excluded from the research. RESULTS: A total of 85 eyes belonged to 52 patients were analyzed. Bilateral and unilateral diseases were present in 33 (63.5%) and 19 (36.5%) patients, respectively. After performing the first operation, 43 (50.6%) eyes still remained aphakic. The mean corrected distance visual acuity (CDVA) of the aphakic and pseudophakic eyes was estimated as 0.77 ± 0.52 and 0.43 ± 0.39 logMAR with no statistical difference. The age at the time of performing the cataract surgery was not associated with the final CDVA in either group. Complications in the anterior segment structures were noted in 39 (45%) eyes. Strabismus and amblyopia were noted in 52 (61%) and 75 (88.2%) eyes, respectively. Glaucoma was found in 17 (20%) eyes with no correlation with the final CDVA, age at the time of cataract surgery, or the status of the lens. CONCLUSION: Due to high prevalence rates of amblyopia, strabismus, and glaucoma after the infantile cataract surgery, specific attention should be paid to these complications in each follow-up examination.

Safety of grafting acellular human corneal lenticule seeded with Wharton's Jelly-Derived Mesenchymal Stem Cells in an experimental animal model.

The present study was conducted to evaluate safety of grafting acellular human corneal lenticule seeded with Wharton's Jelly-derived Mesenchymal Stem Cells (WJSC) in an experimental animal model. Human corneal lenticules were decellularized with a rate of about 97% with an acceptable lack of cytotoxicity and relatively intact ultrastructure of the lenticules. 12 rabbits underwent unilateral stromal pocketing with implantation of decellularized lenticules. Implantation was performed for 6 rabbits along with graft recellularization with WJSCs. Rabbits were euthanized after 1 month (n = 6) and 3 months (n = 6) to evaluate progression of graft bio-integration. No clinical rejection sign was detected during the study. Histopathological analysis showed that, grafts were integrated well with the least distortion of surrounding collagen bundles. After 3 months, labeled WJCS was detected representing viability of stem cells in the host. Increased expression of keratocyte-specific markers showed the potential of recruiting WJSCs as keratocyte progenitor cells to reinforce corneal ultrastructure.

Reliability and Validity of the Persian Version of Quality of Life Impact of Refractive Correction Questionnaire.

PURPOSE: To evaluate the psychometric properties of the Persian version of quality of life impact of refractive correction (QIRC) questionnaire and its utility in assessment of refractive error-related quality of life (QoL) following photorefractive keratectomy (PRK). METHODS: Patients with low-to-moderate myopia (-0.75 to - 6.0) were enrolled in this study. Standard alcohol-assisted PRK was performed in all patients. The QIRC questionnaire was translated into a Persian version using the standard method. Patients completed QIRC questionnaire preoperatively and 3-month postoperatively. A group of patients completed the questionnaire twice preoperatively. Psychometric properties were evaluated by internal consistency (Cronbach's α), item-total correlation, and known group construct validity. Intraclass correlation coefficient (ICC) were used to examine the repeatability. RESULTS: One hundred forty-seven patients (60 males and 87 females) with a mean age of 26.3 ± 5.5 (range, 18-39) years were enrolled. Cronbach's α for total score was 0.923. Item-total correlation was above 0.3 for all items. ICC was 0.978 for total score. Preoperatively, predominantly contact lens wearers showed significantly better total QIRC score than predominantly spectacle wearers (P = 0.017), which showed good known group validity. Total QIRC score significantly increased from 41.31 ± 6.69 preoperatively to 50.47 ± 7.26 postoperatively (P < 0.0001). Improvement in total QIRC score was observed both in contact lens wearers and spectacle wearers. CONCLUSION: The Persian version of QIRC questionnaire is a valid and reliable tool. Refractive error-related QoL assess by QIRC was significantly improved after PRK in an Iranian population.

Novel Bi-allelic PDE6C Variant Leads to Congenital Achromatopsia.

Background: The clinical phenotyping of patients with achromatopsia harboring variants in phosphordiesterase 6C (PDE6C) has poorly been described in the literature. PDE6C encodes the catalytic subunit of the cone phosphodiesterase, which hydrolyzes the cyclic guanosine monophosphate that proceeds with the hyperpolarization of photoreceptor cell membranes, as the final step of the phototransduction cascade. Methods: In the current study, two patients from a consanguineous family underwent full ophthalmologic examination and molecular investigations including WES. The impact of the variant on the functionality of the protein has been analyzed using in silico molecular modeling. Results: The patients identified with achromatopsia segregated a homozygous missense variant (c.C1775A:p.A592D) in PDE6C gene located on chromosome 10q23. Molecular modeling demonstrated that the variant would cause a protein conformational change and result in reduced phosphodiesterase activity. Conclusion: Our data extended the phenotypic spectrum of retinal disorders caused by PDE6C variants and provided new clinical and genetic information on achromatopsia.

Retraction notice to "Endophthalmitis Occurring after Cataract Surgery: Outcomes of More Than 480 000 Cataract Surgeries, Epidemiologic Features, and Risk Factors" (Ophthalmology. 2016;123:295-301).

This article has been retracted: please see Elsevier policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). The editors wish to note that concerns were raised regarding coding errors in the data set that formed the basis of this study. Patient record numbers were found to be duplicated, so that the number of endophthalmitis cases was unclear as was the associated treatment, and the number of unique patients estimated to be far less than the 480,000 reported. Upon review of the information provided, Ophthalmology has determined the dataset to be flawed with unverifiable elements from which reliable conclusions cannot be drawn, and therefore has made the decision to issue a retraction of the manuscript.

Changes in Corneal Asphericity after MyoRing Implantation in Moderate and Severe Keratoconus.

PURPOSE: To evaluate the effect of MyoRing implantation on corneal asphericity in moderate and severe keratoconus (KCN). METHODS: This cross-sectional observational study comprised 32 eyes of 28 patients with KCN, who had femtosecond-assisted MyoRing corneal implantation. The primary outcome measures were preoperative and six-month postoperative corneal asphericity in 6-, 7-, 8-, 9-, and 10-mm optical zones in the superior, inferior, nasal, temporal, and central areas. The secondary outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, thinnest location value, and keratometry readings. RESULTS: A significant improvement in the UDVA and CDVA was observed six months after the surgery (P < 0.001) with a significant reduction in the spherical (4.67 diopters (D)) and cylindrical (2.19 D) refractive errors. A significant reduction in the corneal asphericity in all the optical zones and in the superior, inferior, nasal, temporal, and central areas was noted (P < 0.001). The mean thickness at the thinnest location of the cornea decreased from 437.15 ± 30.69 to 422.81 ± 36.91 µm. A significant corneal flattening was seen. The K1, K2, and Km changes were 5.32 D, 7 D, and 6.17 D, respectively (P < 0.001). CONCLUSION: MyoRing implantation is effective for improving corneal asphericity in patients with KCN. It allows successful corneal remodeling and provides a significant improvement in UDVA, CDVA, and refractive errors.

Characteristics of Posterior Corneal Astigmatism in Different Stages of Keratoconus.

PURPOSE: To evaluate the magnitudes and axis orientation of anterior corneal astigmatism (ACA) and posterior corneal astigmatism (PCA), the ratio of ACA to PCA, and the correlation between ACA and PCA in the different stages of keratoconus (KCN). METHODS: This retrospective case series comprised 161 eyes of 161 patients with KCN (104 men, 57 women; mean age, 22.35 ± 6.10 years). The participants were divided into four subgroups according to the Amsler-Krumeich classification. A Scheimpflug imaging system was used to measure the magnitude and axis orientation of ACA and PCA. The posterior-anterior corneal astigmatism ratio was also calculated. The results were compared among different subgroups. RESULTS: The average amounts of anterior, posterior, and total corneal astigmatism were 4.08 ± 2.21 diopters (D), 0.86 ± 0.46 D, and 3.50 ± 1.94 D, respectively. With-the-rule, against-the-rule, and oblique astigmatisms of the posterior surface of the cornea were found in 61 eyes (37.9%), 67 eyes (41.6%), and 33 eyes (20.5%), respectively; corresponding figures in the anterior corneal surface were 55 eyes (32.4%), 56 eyes (34.8%), and 50 eyes (31.1%), respectively. A strong correlation (P ≤ 0.001, r = 0.839) was found between ACA and PCA in the different stages of KCN; the correlation was weaker in eyes with grade 3 (P ≤ 0.001, r = 0.711) and grade 4 (P ≤ 0.001, r = 0.717) KCN. The maximum posterior-anterior corneal astigmatism ratio (PCA/ACA, 0.246) was found in patients with stage 1 KCN. CONCLUSION: Corneal astigmatism in anterior surface was more affected than posterior surface by increasing in the KCN severity, although PCA was more affected than ACA in an early stage of KCN.

Characteristics of Astigmatism after MyoRing Implantation.

Considering the rising number of MyoRing implantation procedures in keratoconic corneas and the refractive outcomes associated with this treatment modality, this study aimed to evaluate and compare the magnitude and axis orientation of total and corneal astigmatism between before and after MyoRing implantation in 34 eyes of 28 patients with keratoconus (KCN) (mean age: 29.41 ± 7.0 years). The inclusion criterion was a reliable diagnosis of clinical KCN based on corneal biomicroscopic and tomographic findings. The mean total astigmatism of ocular refraction decreased significantly from -4.27 ± 3.15 D (before MyoRing implantation) to -2.18 ± 1.63 D (after MyoRing implantation) (P < 0.001). The mean astigmatism in the anterior and posterior surface of the cornea decreased significantly by 1.16 D (P = 0.001) and 0.24 D (P = 0.009), respectively, after MyoRing implantation. Before MyoRing implantation, the axis orientation of total ocular astigmatism for with-the-rule, oblique, and against-the-rule astigmatism was 21%, 42%, and 37%, respectively; at 6 months after MyoRing implantation, it was 18%, 24%, and 58%, respectively. Before MyoRing implantation, the axis orientation for with-the-rule, against-the-rule, and oblique astigmatism of the anterior surface of the cornea was 59%, 24%, and 17%, respectively; at 6 months after MyoRing implantation, it was 52%, 24%, and 24%, respectively. Before MyoRing implantation, the axis orientation of with-the-rule, oblique, and against-the-rule astigmatism of the posterior surface of the cornea was 68%, 29%, and 3%, respectively; at 6 months after MyoRing implantation, it was 67%, 12%, and 12%, respectively. MyoRing implantation significantly decreased the amount of total, anterior, and posterior corneal astigmatism.

Histopathology of Conjunctivochalasis Compared to Normal Conjunctiva.

PURPOSE: To evaluate the histopathologic changes in the conjunctiva of patients with conjunctivochalasis (CCh) compared to age-matched controls. METHODS: This cross-sectional, controlled study included 27 eyes of 27 patients with CCh and 16 eyes of 16 age-matched controls. A biopsy of the bulbar conjunctiva was performed along the temporal lower lid margin before cataract surgery in both groups. Histopathologic evaluation of the specimens was done with light microscopy using staining with hematoxylin/eosin, periodic acid Schiff, and van Gieson elastic stain. Various histopathologic features of the conjunctival epithelium and stroma were compared between the two groups. RESULTS: The mean age of patients was 62.4 ± 6.9 years in the CCh group and 65.1 ± 6.3 years in the control group (P = 0.54). No significant differences were noted between the two groups in terms of conjunctival epithelial changes including papillomatosis, epithelial clefts, epithelial goblet cells, or infiltration of inflammatory cells. Mean thickness of the conjunctival stroma was 0.21 ± 0.08 mm in the CCh group and 0.26 ± 0.21 mm in the control group (P = 0.10). For the conjunctival stroma, there were no significant differences between the two groups in terms of elastosis, fibrosis, lymphangiectasia, or infiltration of inflammatory cells. CONCLUSION: No noticeable differences were found in the histopathologic features by light microscopy between eyes with CCh and those of age-matched controls. Therefore, the primary pathology of CCh may not be within the conjunctiva itself. Instead, loose attachment of the conjunctiva to the underlying tissue may be the reason for the redundant folds in the bulbar conjunctiva.

Post-cataract surgery endophthalmitis: Brief literature review.

PURPOSE: To investigate recent evidence in prophylaxis and management of post-cataract surgery endophthalmitis. METHODS: We conducted a literature search using Pubmed database for post cataract surgery endophthalmitis, and relevant articles were selected from original English papers published since 2015. RESULTS: Forty-nine articles were published regarding post-cataract surgery endophthalmitis from January 2015 to February 2016. A low incidence of post-cataract surgery endophthalmitis has been reported. A growing number of articles are focusing on preventing endophthalmitis using intracameral antibiotics. CONCLUSION: Based on the current evidence, intracameral antibiotics seems to be effective in preventing endophthalmitis after cataract surgery.

Changes in stereopsis after photorefractive keratectomy.

PURPOSE: To evaluate the effects of photorefractive keratectomy (PRK) on the stereopsis of myopic and hyperopic patients. SETTING: Farabi Eye Hospital, Tehran, Iran. DESIGN: Prospective case series. METHODS: This study included patients having PRK to achieve emmetropia. The patients were divided into the following 3 groups: low myopia (<-6.0 diopters [D]), high myopia (>-6.0 D), and hyperopia (<+4.0 D). Near stereoacuity was measured using the Randot test under photopic conditions (with corrective glasses) at 40 cm preoperatively (with corrective glasses) and 1, 3, and 12 months postoperatively. Repeated-measure analysis of variance was used to assess changes in stereopsis over time in the 3 groups. RESULTS: Each group comprised 60 patients. The mean preoperative stereoacuity was 121.16 seconds of arc (arcsec) ± 149.92 (SD), improving to 83.66 ± 75.84 arcsec 1 month postoperatively and 80.66 ± 64.31 arcsec at 3 months (both P < .001). It remained unchanged (83.33 ± 75.01 arcsec) at 12 months (P = .610). Patients with high myopia had the greatest improvement in stereopsis after PRK compared with low myopic and hyperopic patients (P < .001). The improvement in stereoacuity was significantly higher in the severe anisometropic group; the lowest improvement was in the group without anisometropia. CONCLUSION: Photorefractive keratectomy could result in an improvement in stereopsis. Patients with high myopia benefitted most from PRK in terms of improvement in stereopsis. FINANCIAL DISCLOSURE: None of the authors has a financial or proprietary interest in any material or method mentioned.

Endophthalmitis Occurring after Cataract Surgery: Outcomes of More Than 480 000 Cataract Surgeries, Epidemiologic Features, and Risk Factors.

PURPOSE: To report the incidence of endophthalmitis after senile cataract surgery and to describe the epidemiology and main risk factors. DESIGN: Retrospective, single-center, cross-sectional descriptive study. PARTICIPANTS: Patients who underwent cataract surgery in Farabi Eye Hospital from 2006 through 2014. METHODS: All patients were evaluated retrospectively to compare risk factors, epidemiologic factors, and prophylaxis methods related to endophthalmitis. Patient records were used to gather the data. MAIN OUTCOME MEASURES: Epidemiologic factors, systemic diseases, other ocular pathologic characteristics, complications during the surgery, technique of cataract surgery, intraocular lens type, method of antibiotic prophylaxis, surgeon experience, vitreous culture, and vision outcome were evaluated in these patients. RESULTS: One hundred twelve endophthalmitis cases among 480 104 operations reported, equaling an incidence of 0.023%. Patients with diabetes mellitus (14.3%) and of older age (mean age, 81 years), perioperative communication with the vitreous (17.9%), extracapsular cataract surgery procedure (11%), and surgery on the left eye (58.9% vs. 41.1% for right eye; P = 0.03) showed a statistically significant association with endophthalmitis. Short-term treatment with topical or systemic preoperative antibiotics or postoperative subconjunctival injection was associated with a 40% to 50% reduced odds of endophthalmitis compared with no prophylaxis (P = 0.2). No cases of endophthalmitis were observed among the 25 920 patients who received intracameral cefuroxime, suggesting that this approach to antibiotic prophylaxis may be far more effective than traditional topical or subconjunctival approaches. CONCLUSIONS: The incidence of endophthalmitis after cataract surgery in our center was 0.023%, comparable with that of other previously published international studies. Older rural patients with immune suppressive diseases, such as diabetes mellitus, are particularly more prone to endophthalmitis. Vitreous loss at the time of surgery was associated with a significantly increased risk. Whereas antibiotic prophylaxis overall showed a 40% to 50% reduction in risk, intracameral cefuroxime was 100% effective in preventing endophthalmitis in this series.