Changes in Stress-Strain Index and Corneal Biomechanics in Granular Corneal Dystrophy.

Background: The aim of this study was to assess stress-strain index (SSI) and corneal biomechanical parameters in eyes with granular corneal dystrophy (GCD). Methods: This case-control study included 12 eyes of 12 patients with GCD (mean age 45.2 ± 18.7 years) and 20 eyes of 20 healthy individuals (mean age 54.4 ± 3.8 years). In addition to SSI, dynamic corneal response (DCR) parameters were assessed at the first and second applanation, including length (AL1, AL2), velocity (AV1, AV2), time (AT1, AT2), and deformation amplitude (DA A1, DA A2), and at the highest concavity (HC) phase, including DA, peak distance (PD), radius (HCR), and DA ratio (DAR 1 and 2 mm), by Corvis ST. Central corneal thickness (CCT) and biomechanically corrected intraocular pressure (bIOP) were considered covariates in comparing DCR parameters between the two groups. Results: SSI was statistically significantly lower in eyes with GCD than in normal eyes (p = 0.04). The corneal velocity towards the first applanation was 0.02 m/s faster in the GCD eyes AV1 (0.15 ± 0.02 vs. 0.13 ± 0.02 m/s, p < 0.001) and IR (7.48 ± 1.01 vs. 6.80 ± 1.22 mm, p = 0.003) parameters were significantly higher in the GDC group, while AT1 (7.33 ± 0.66 vs. 7.47 ± 0.36 ms, p = 0.002) and HCR (7.42 ± 0.76 vs. 8.20 ± 1.08 mm, p = 0.014) were significantly lower in the normal group. Conclusions: GCD led to a change in biomechanical properties of the cornea. SSI refers to fewer stiff corneas in GDC than normal.

Innovative intra-corneal ring-supported graft surgery for treatment of keratoconus and cornea regeneration: Surgical technique and case report.

Therapeutic options for corneal ectasia are evolving, with emphasis on the intra-stromal corneal ring for delaying or eliminating the need for penetrating keratoplasty. A 33-year-old man with grade 4 keratoconus and rising intolerance of the hard contact lens underwent a combination of a new innovative ring and graft with suture in the left eye. Excellent structural support and stability of the cornea were observed immediately post-operatively and 12 months after surgery. It appears as a feasible and safe therapy option for keratoconus eyes with reference to the instability and asymmetry of the cornea. Hence, as a safe and effective technique, it can be performed easily.

Unusual presentation of corneal laceration in a post-LASIK eye following blunt trauma.

PURPOSE: To report a case with full thickness corneal laceration behind the intact LASIK flap after blunt trauma. OBSERVATIONS: A 48-year-old man with a history of LASIK surgery was hit by a shovel. Slit-lamp examination showed 4+ corneal edema. The anterior chamber (AC) was deep and the Seidel test was negative. Uncorrected distance visual acuity (UDVA) was hand motion. A more accurate evaluation was performed with an anterior segment optical coherence tomography (OCT) and it was found that the paracentral corneal tissue was ruptured while the flap remained completely intact. Under the surgical procedure, the rupture site was sutured, and then the flap was replaced, and two U-shaped sutures were performed to ensure the flap stability. Three months after surgery, corrected distance visual acuity (CDVA) was 9/10 decimal with a manifest refraction of +1-3 x 60°. CONCLUSIONS AND IMPORTANCE: In a traumatic post-LASIK eye, the posterior part of the flap should be carefully evaluated. The role of the OCT device in the diagnosis and management of complication is also very valuable.

Biomarker Discovery by Imperialist Competitive Algorithm in Mass Spectrometry Data for Ovarian Cancer Prediction.

BACKGROUND: Mass spectrometry is a method for identifying proteins and could be used for distinguishing between proteins in healthy and nonhealthy samples. This study was conducted using mass spectrometry data of ovarian cancer with high resolution. Usually, diagnostic and monitoring tests are done according to sensitivity and specificity rates; thus, the aim of this study is to compare mass spectrometry of healthy and cancerous samples in order to find a set of biomarkers or indicators with a reasonable sensitivity and specificity rates. METHODS: Therefore, combination methods were used for choosing the optimum feature set as t-test, entropy, Bhattacharya, and an imperialist competitive algorithm with K-nearest neighbors classifier. The resulting feature from each method was feed to the C5 decision tree with 10-fold cross-validation to classify data. RESULTS: The most important variables using this method were identified and a set of rules were extracted. Similar to most frequent features, repetitive patterns were not obtained; the generalized rule induction method was used to identify the repetitive patterns. CONCLUSION: Finally, the resulting features were introduced as biomarkers and compared with other studies. It was found that the resulting features were very similar to other studies. In the case of the classifier, higher sensitivity and specificity rates with a lower number of features were achieved when compared with other studies.

Effects of intracorneal ring segments implementation technique and design on corneal biomechanics and keratometry in a personalized computational analysis.

The implementation of intracorneal ring segments (ICRS) is one of the successfully applied refractive operations for the treatment of keratoconus (kc) progression. The different selection of ICRS types along with the surgical implementation techniques can significantly affect surgical outcomes. Thus, this study aimed to investigate the influence of ICRS implementation techniques and design on the postoperative biomechanical state and keratometry results. The clinical data of three patients with different stages and patterns of keratoconus were assessed to develop a three-dimensional (3D) patient-specific finite-element model (FEM) of the keratoconic cornea. For each patient, the exact surgery procedure definitions were interpreted in the step-by-step FEM. Then, seven surgical scenarios, including different ICRS designs (complete and incomplete segment), with two surgical implementation methods (tunnel incision and lamellar pocket cut), were simulated. The pre- and postoperative predicted results of FEM were validated with the corresponding clinical data. For the pre- and postoperative results, the average error of 0.4% and 3.7% for the mean keratometry value ([Formula: see text]) were predicted. Furthermore, the difference in induced flattening effects was negligible for three ICRS types (KeraRing segment with arc-length of 355, 320, and two separate 160) of equal thickness. In contrast, the single and double progressive thickness of KeraRing 160 caused a significantly lower flattening effect compared to the same type with constant thickness. The observations indicated that the greater the segment thickness and arc-length, the lower the induced mean keratometry values. While the application of the tunnel incision method resulted in a lower [Formula: see text] value for moderate and advanced KC, the induced maximum Von Mises stress on the postoperative cornea exceeded the induced maximum stress on the cornea more than two to five times compared to the pocket incision and the preoperative state of the cornea. In particular, an asymmetric regional Von Mises stress on the corneal surface was generated with a progressive ICRS thickness. These findings could be an early biomechanical sign for a later corneal instability and ICRS migration. The developed methodology provided a platform to personalize ICRS refractive surgery with regard to the patient's keratoconus stage in order to facilitate the efficiency and biomechanical stability of the surgery.

Safety and Efficacy of Oral Supplementation of Lentil (Lens culinaris Medic) in Dry Eye Patients.

OBJECTIVE: To evaluate the safety and efficacy of dietary lentil capsules in patients suffering from dry eye symptoms. METHODS: A randomized, triple-blind, interventional, placebo-controlled study was done. Sixty patients were randomized in two groups to receive either one capsule containing 500 mg of lentil powder or placebo daily for 3 months. UCVA, tear film breakup time (TBUT), Schirmer's test, tear film osmolarity, and OSDI score were recorded at baseline and 3 months after intervention. Data analysis was performed using IBM SPSS for Windows version 20 (SPSS, Chicago, IL, USA). RESULTS: In the lentil group, at baseline, the mean UCVA (LogMAR), OSDI, TBUT (S), tear film osmolarity (mOsm/L), and Schirmer (mm) scores were 0.104 (0.026), 22.66 (19.40), 10.31 (5.32), 301.07 (15.57), and 8.22 (6.87), respectively. These values were 0.101 (0.026), 20.85 (19.44), 13.04 (7.11), 299.81 (11.60), and 9.87 (10.11). In the placebo group, these values were 0.084 (0.027), 25.35 (20.08), 10.56 (4.95), 299.77 (15.09), and 9.35 (8.06) at baseline and 3 months later were 0.077 (0.027), 23.32 (22.90), 13.62 (6.30), 297.54 (12.08), and 8.64 (9.60), respectively. Three patients (one in the lentil group and two in the placebo group) experienced severe gastrointestinal symptoms. CONCLUSION: Although consumption of 500 mg of lentil is safe, this amount is not sufficient for reduction of dry eye syndrome in 3 months. For more validation, a clinical study with increased dosage of lentil is proposed.

An innovative approach for determining the customized refractive index of ectatic corneas in cataractous patients.

The aim of this study is to determine the customized refractive index of ectatic corneas and also propose a method for determining the corneal and IOL power in these eyes. Seven eyes with moderate and severe corneal ectatic disorders, which had been under cataract surgery, were included. At least three months after cataract surgery, axial length, cornea, IOL thickness and the distance between IOL from cornea, and aberrometry were measured. All the measured points of the posterior and anterior parts of the cornea converted to points cloud and surface by using the MATLAB and Solidworks software. The implanted IOLs were designed by Zemax software. The ray tracing analysis was performed on the customized eye models, and the corneal refractive index was determined by minimizing the difference between the measured aberrations from the device and resulted aberrations from the simulation. Then, by the use of preoperative corneal images, corneal power was calculated by considering the anterior and posterior parts of the cornea and refractive index of 1.376 and the customized corneal refractive index in different regions and finally it was entered into the IOL power calculation formulas. The corneal power in the 4 mm region and the Barrett formula resulted the prediction error of six eyes within ± 1 diopter. It seems that using the total corneal power along with the Barrett formula can prevent postoperative hyperopic shift, especially in eyes with advanced ectatic disorders.

A Novel Approach to Treatment of Conjunctival Cyst Ablation Using Atmospheric Low-Temperature Plasma.

PURPOSE: Introducing a new technique to remove the conjunctival cyst using atmospheric low-temperature plasma (ALTP) and assessing its effectiveness. PATIENTS AND METHODS: Five eyes with conjunctival cysts were included in this study. The procedure was started by applying a plasma spot on the highest point of the cyst, and then other spots were spirally applied to the base of the cyst to debulk it. The conjunctival cysts were removed using the white handpiece of the plasma generator device (Plexr, GMV s.r.l Grottaferrata, Italy). Refraction, visual acuity, intraocular pressure (IOP), contrast sensitivity (CS), aberrometry, dry eye tests, and ocular surface disease index (OSDI) questionnaire were measured before, one and six months after treatment. RESULTS: The mean size of the cysts was 3.6 mm (range 2.1 to 4.8 mm). No intraoperative and postoperative complications were observed. Postoperative examinations showed that the patients' cysts were completely healed and recurrence did not occur. Significant changes in visual parameters, IOP, CS, aberrometry and dry eye tests were not observed in the follow-up periods after treatment compared to before. OSDI score decreased after cyst removal. CONCLUSION: Our recommended technique using ALTP can be used as a new approach to treating conjunctival cysts. This technique is a simple, office-based, minimally invasive, effective and inexpensive way to remove a cyst.

Visual and subjective outcomes following trifocal intraocular lens implantation in Iranian cataractous patients.

BACKGROUND: The aim of this study was to evaluate visual and refractive outcomes and quality of vision after implantation of the AT LISA tri 839MP intraocular lens (IOL). PATIENTS AND METHODS: This interventional clinical trial comprised 46 cataractous eyes of patients who underwent phacoemulsification with IOL implantation (mean age of 58.08 ± 11.01 years; range: 36-76 years old). Spherical equivalent (SE), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), corrected intermediate visual acuity (CIVA), uncorrected near visual acuity (UNVA), and corrected near visual acuity (CNVA) were measured 1, 3, and 6 months after surgery. Contrast sensitivity (CS) was measured at 6 months. Subjective quality of vision and presence of dysphotopsia by a short questionnaire were evaluated postoperatively. RESULTS: At 6 months, the mean visual acuity was 0.08 ± 0.11, 0.03 ± 0.08, 0.07 ± 0.09, 0.02 ± 0.08, 0.05 ± 0.09, and 0.02 ± 0.08 LogMAR for UDVA, CDVA, UIVA, CIVA, UNVA, and CNVA, respectively. The mean values of SE were - 0.4728 ± 0.32D. These variables improved over time, yet significant changes were detected in UDVA (P = 0.009) and SE (P = 0.0001). The mean CS value was 1.74 ± 0.08. The mean scores (0% = no symptoms; 100% = strong symptoms/unable to perform activities) for glare and halos were 7.07 ± 0.22% and 8.70 ± 0.23%, respectively. These items were reduced over time. Patients' level of satisfaction mean score for performing activities was 96.66%. CONCLUSIONS: The AT LISA tri 839MP IOL provides excellent uncorrected distance, intermediate and near vision, and CS. This IOL showed a minimal level of photic phenomena and a high level of patient satisfaction.

A Study of Corneal Biomechanics in Delayed-Onset Mustard Gas Keratopathy Compared to Cases With Corneal Scarring and Normal Corneas.

PURPOSE: This study compares the corneal biomechanical properties, as measured with Corvis ST, in three groups of cases with delayed-onset mustard gas keratopathy (DMGK), chronic corneal scarring (CCS), and those with normal corneas. METHODS: Forty-five eyes were enrolled in the DMGK, CCS, and normal groups (15 eyes each). All patients were examined with the slitlamp and Corvis ST. Extracted corneal biomechanical parameters included first and second applanation time (AT1, AT2), first and second applanation length (AL1, AL2), first and second applanation velocity (AV1, AV2), deformation amplitude (DA), highest concavity time, peak distance, highest concavity radius (HCR), central corneal thickness, corrected intraocular pressure (IOP), and noncorrected IOP. RESULTS: The mean age of the participants in the DMGK, CCS, and normal groups was 49.20±5.16, 60.40±22.92, and 44.60±8.32 years, respectively. Comparison between DMGK and CCS groups showed significant differences in AT1, AT2, corrected IOP, and noncorrected IOP. There were also significant differences in AT1, AT2, HCR, DA, and noncorrected IOP between the DMGK and normal groups. None of the parameters were significantly different between the CCS and normal groups. CONCLUSION: There seems to be reduced corneal rigidity and stiffness in cases exposed to mustard gas, which causes the cornea in the DMGK group to become applanated more easily and take longer to rebound compared with the other two groups. Also, IOP was lower than normal in the DMGK group, and thus, misdiagnosis of glaucoma is likely for these patients.

Comparison of the MyoRing implantation depth by mechanical dissection using PocketMaker microkeratome versus Melles hook via AS-OCT.

BACKGROUND: This paper seeks to evaluate the depth and outcomes of MyoRing implantation using two mechanical dissection procedures including: PocketMaker microkeratome in opposition to the Melles hook method. METHODS: This retrospective study was carried out on 39 eyes of 38 keratoconus patients (28 male and 10 female) with the mean age of [Formula: see text] years and had undergone MyoRing implantation by the two mentioned methods. The MyoRing was inserted into the corneal pocket which was made manually in 18 eyes (Melles hook group) or with PocketMaker microkeratome in 21 eyes (PocketMaker group). The mean follow up time was [Formula: see text] months with pre-operative and post-operative ophthalmic examination including uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), keratometry readings and central corneal thickness measurement. AS-OCT (Casia, SS-1000, Tomey, Nagoya, Japan) imaging was used to measure MyoRing insertion depth, exactly. RESULTS: Pre-operative and post-operative UCVA (LogMAR) mean change for the PocketMaker and Melles hook groups were recorded at 0.75 ± 0.32 and 0.78 ± 0.33, respectively. Similarly, BCVA (LogMAR) mean change were 0.27 ± 0.22 and 0.23 ± 0.22. Mean keratometry (Kmean) change were 6.06 ± 4.18 and 6.56 ± 3.55 respectively. UCVA change (P = 0.767), BCVA change (P = 0.77) and Kmean change (P = 0.693) showed that there was no statistically significant difference between both groups for any parameter. Depth measurements achieved from AS-OCT images showed that there was no statistically significant difference in pocket depth between two methods of MyoRing implantation (P = 0.413). CONCLUSIONS: The results of Myoring implantation outcomes using mechanical dissection via PocketMaker microkeratome as against Melles hook are comparable.

Simultaneous Presence of Macular Corneal Dystrophy and Retinitis Pigmentosa in Three Members of a Family.

Macular corneal dystrophy (MCD) is an autosomal recessive hereditary disease. In most cases, various mutations in carbohydrate sulfotransferase 6 (CHST6) gene are the main cause of MCD. These mutations lead to a defect in keratan sulfate synthesis. Retinitis pigmentosa (RP) is another eye disorder with nyctalopia as its common symptom. It has been shown that more than 65 genes have been implicated in different forms of RP. Herein, we report on a 9-member family with 2 girls and 5 boys. Both parents, one of the girls and one of the boys had normal eye vision and another boy had keratoconus. Other children (1 girl and 2 boys) suffered from both MCD and RP. Corneal transplantation and medical supplements were used for MCD and RP during the follow-up period, respectively. Based on the family tree, it seems that the inheritance of both diseases is autosomal recessive. Based on our search of databases, there is no report on the simultaneous presence of MCD and RP. To the best of our knowledge, the present article is the first case report on this topic. Molecular genetic investigation is needed to clarify the mechanism of concurrent MCD and RP.

Comparison of preoperative and postoperative intraocular lens power values in eyes with Keraring implantation / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate intraocular lens power (IOL) calculation and biometry before and 3mo after implantation of Keraring 355° intrastromal corneal ring segment (ICRS;Mediphacos, Belo Horizonte, Brazil) in keratoconic eyes.METHODS: In this cohort study, data of 19 keratoconus eyes of 18 patients which undergone ICRS implantations were gathered before and 3mo after surgery.Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, IOL power calculation formulas, axial lenght (AL) and keratometry were analayzed.RESULTS: Mean age of participants was 29.58±0.6.UCVA improved from 0.84 (0.35) logMAR to 0.43 (0.31) logMAR significantly (P<0.001).BCVA and AL didn`t change significantly after 3mo.All Sphere, cylinder and spherical equivalent (SE) were improved significantly (P<0.001).On the other hand, keratometry 1 (K1) and keratometry 2 (K2) decreased significantly.It was a considerable change in SRK/Ⅱ (P<0.001), Hoffer Q (P<0.001) and Holladay Ⅰ(P<0.001) after 3-month`s follow-up.Among this formula SRK/II had the lowest change.CONCLUSION: In addition to improvement in visual, refractive, and keratometry outcomes after Keraring implantation, there was a significantly changes in IOL calculation formulas values.However, ICRS procedure doesn`t interfere considerably AL in eyes, but it seems reduced keratometric values lead to IOL power calculations more accurately and all formulas suggested same IOL power.

Biomarker Discovery Based on Hybrid Optimization Algorithm and Artificial Neural Networks on Microarray Data for Cancer Classification.

The improvement of high-through-put gene profiling based microarrays technology has provided monitoring the expression value of thousands of genes simultaneously. Detailed examination of changes in expression levels of genes can help physicians to have efficient diagnosing, classification of tumors and cancer's types as well as effective treatments. Finding genes that can classify the group of cancers correctly based on hybrid optimization algorithms is the main purpose of this paper. In this paper, a hybrid particle swarm optimization and genetic algorithm method are used for gene selection and also artificial neural network (ANN) is adopted as the classifier. In this work, we have improved the ability of the algorithm for the classification problem by finding small group of biomarkers and also best parameters of the classifier. The proposed approach is tested on three benchmark gene expression data sets: Blood (acute myeloid leukemia, acute lymphoblastic leukemia), colon and breast datasets. We used 10-fold cross-validation to achieve accuracy and also decision tree algorithm to find the relation between the biomarkers for biological point of view. To test the ability of the trained ANN models to categorize the cancers, we analyzed additional blinded samples that were not previously used for the training procedure. Experimental results show that the proposed method can reduce the dimension of the data set and confirm the most informative gene subset and improve classification accuracy with best parameters based on datasets.