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PurposeTo report two cases of patients with late extrusion following uneventful implantation of intrastromal corneal ring segments (ICRS) for myopia.ObservationsTwo patients with previously implanted ICRS for low myopia presented with spontaneous onset of extrusion of their ICRS, one at 7 years post-operatively and the other at 17 and 20 years. Both cases underwent explantation and maintained excellent best-corrected visual acuity. These cases represent the longest reported intervals between implantation of the ICRS and subsequent extrusion.Conclusions and importanceLate extrusion can occur many years following implantation of ICRS, even in eyes without pre-existing thinning or ectasia. The technique for explantation described herein can result in favorable clinical outcomes in such cases. These cases demonstrate the importance of long-term follow up of eyes that have undergone ICRS implantation.

Purpose: To compare the efficacy of implanting a single Keraring segment according to a novel Q‐value‐based nomogram (QN) to that of segment implantation according to the manufacturer's standard nomogram (SN), for keratoconus treatment. Methods: This was a prospective, randomized controlled trial of 104 patients (104 eyes) with Amsler‐Krumeich grade 1 or 2 keratoconus, and type 1 or 2 cone asymmetry determined according to manufacturer's classification. They were randomly distributed into two groups: group A patients (n = 52) underwent Keraring implantation according to the SN, and group B patients (n = 52) underwent implantation of a single (210° arc‐length) Keraring segment according to the QN. Both treatments were combined with accelerated transepithelial cross‐linking, and follow‐up was 6 months. Main outcome measures were preoperative and postoperative visual acuity, subjective refraction and corneal topography. Results: At postoperative month 6, group B exhibited statistically significantly higher values of mean uncorrected distance visual acuity (UDVA), sphere, K2, K‐average, K‐max and Q‐anterior (p = 0.02, 0.01, 0.002, 0.001, 0.0001 and 0.03, respectively) compared to that of group A. However, group A exhibited better refractive cylindrical improvements (p = 0.04). In group A, we documented spontaneous extrusion of one Keraring segment. Conclusion: Single 210° arc‐length segment implantation using our objective QN was more efficacious for keratoconus treatment than using the subjective SN. The nomograms were comparable when the Q‐anterior value was >−1.00; however, the QN was superior to the SN when the Q‐anterior value was ≤−1.00. The QN yielded greater postoperative UDVA and smoother corneal remodelling than did the SN for treatment of grade 1 and 2 keratoconic eyes. [ABSTRACT FROM AUTHOR]

Abstract 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 28.97+.10.37 $$ 28.97\frac{+}{.}10.37 $$ 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 9.81+.3.7 $$ 9.81\frac{+}{.}3.7 $$ 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.

Amr Mounir, Gamal Radwan, Mahmoud Mohamed Farouk, Engy Mohamed Mostafa Department of Ophthalmology, Faculty of Medicine, Sohag University, Sohag, Egypt Objectives: To document the difference between complication rate in the early curve of practicing intracorneal stromal rings and after gaining experience. Patients and methods: A retrospective study of 623 eyes of 417 patients with keratoconus who underwent Keraring implantation using femtosecond laser for channel creation. Results: The main outcome measures were reported intraoperative and postoperative complications. The overall complication rate was 12.7% (79 eyes) over the 4 years with 34 eyes in the first year (5.5%) and six eyes in the fourth year (0.96%). Over the 4 years of our practice, intraoperative complications were 7.1% and postoperative complications were 5.6%. Yet, there was a significant difference in intraoperative complications between the first and the fourth year where it was 3.5% and 0.48%, respectively. This also applies to the postoperative complication rate, which decreased from 1.9% to 0.5% in the fourth year. Conclusion: Complications with femtosecond-assisted intracorneal stromal ring procedure can be reduced by experience, making this procedure a safe and effective means of treating keratoconus. Yet, there are some complications that cannot be avoided such as sterile keratitis. Keywords: femtosecond laser, intracorneal rings, Kerarings, keratoconus

Purpose: To report two cases of patients with late extrusion following uneventful implantation of intrastromal corneal ring segments (ICRS) for myopia. Observations: Two patients with previously implanted ICRS for low myopia presented with spontaneous onset of extrusion of their ICRS, one at 7 years post-operatively and the other at 17 and 20 years. Both cases underwent explantation and maintained excellent best-corrected visual acuity. These cases represent the longest reported intervals between implantation of the ICRS and subsequent extrusion. Conclusions and importance: Late extrusion can occur many years following implantation of ICRS, even in eyes without pre-existing thinning or ectasia. The technique for explantation described herein can result in favorable clinical outcomes in such cases. These cases demonstrate the importance of long-term follow up of eyes that have undergone ICRS implantation.

Background: keratoconus (KC) is an ectatic condition of the cornea which is usually progressive and non-inflammatory, affecting both eyes asymmetrically. It is characterized by stromal thinning that leads to corneal surface irregularity. Vision affection is due to irregular astigmatism and corneal scarring. Aim of the Work: assessment of the effectiveness of Myoring intreating patients with keratoconus. Patients and Methods: prospective non-randomized non-comparative clinically controlled study, Myoring was implanted for (20) eyes of 20 patients with progressive keratoconus. Results: visual acuity and corneal parameters improved significantly in all patients after one year postoperatively. Conclusion: Myoring when used in suitable patients has the potential to produce excellent long-term vision results in mild, moderate and advanced keratoconus cases, regardless of cone position and disease progression. [ABSTRACT FROM AUTHOR]

Aims The aim of the study was to evaluate the refractive, topometric and aberrometric changes in corneas with keratoconus treated with femtosecond laser intracorneal ring segment (ICRS) implantation following a proposed modified nomogram. Settings and design This is a retrospective, consecutive case series. Materials and methods ICRS implantation using the new proposed nomogram was performed in 10 eyes of seven patients with type 1 and type 2 keratoconus. Corneal tunnels were created using femtosecond laser, and KeraRings were inserted in all eyes. All cases were followed up every 3 months for 6 months using the Pentacam Phoenix system. Statistical analysis All analyses were performed with SPSS for windows 2007. Results None of our patients developed complications related to ring placement, such as migration, extrusion or infection. In this limited case series an improvement was seen in uncorrected visual acuity (P 0≤ 0.05), best spectacle corrected visual acuity (P ≤ 0.001) and refraction at 6 months (P < 0.001). Keratometric readings improved (P < 0.001), with flattening of the cornea. Corneal aberrations showed significant reduction when analysed by Zernike (P < 0.001) and Fourier analysis ( P ≤ 0.001). Corneal asphericity (Q value) also showed improvement (P < 0.05). Conclusion Femtolaser ICRS implantation using the proposed modified nomogram showed promising results in improving refraction, visual acuity, corneal topography and aberrations in patients with keratoconus.

Objective: To study the influence of soft contact lens (SCL) central thickness and material in keratoconus on visual function after intracorneal ring segment (ICRS) surgery.Methods: A pilot, experimental, prospective, cross-sectional and double-blind study was performed. Fourteen keratoconus patients with age range of 34.75±9.22years (7 males and 7 females) with ICRS implanted were involved in the study. Two different SCL materials [Hioxifilcon A (G-5X/p-GMA/HEMA) and Lucifilcon A (silicone-hydrogel)] with four different central thicknesses (0.1, 0.2, 0.3 and 0.4mm) were fitted in one eye per patient, selected randomly. High and low corrected distance visual acuity (CDVA) and contrast sensitivity (CS), corneal topography and corneal and total aberrometry were measured.Results: Corneal spherical like, coma like and root mean square (RMS) decreased significantly for 0.3 and 0.4mm in both SCL materials (p<0.05). Total RMS decreased significantly for 0.4mm with both SCL materials (p<0.05). High and low CDVA improved for 0.4mm of thickness for both materials (p<0.05). Statistically increasing were found in all thicknesses studied for CS in both materials (p<0.05).Conclusion: A central thickness of the SCL equal or superior to 0.4mm seems to decrease the ocular high order aberration (HOA) and to improve the visual function in keratoconus patients implanted with ICRS. However, the modulus of rigidity of the SCL would not influence the HOA correction. [ABSTRACT FROM AUTHOR]

Purpose To analyze the feasibility of a custom-made hydrogel silicone contact lens (CL) in keratoconus with intracorneal ring segments (ICRS) and to compare outcomes taking in consideration the geometry of the fitted lens—full periphery (FP) vs. sector management control (SMC). Method A retrospective review of cases with previous KeraRings ICRS implantation and subsequently fitted with Kerasoft-IC CL was performed. The main outcome measurements were corrected spectacle distance visual acuity (CDVA), differences between flat and steep simulated keratometries (K-diff) and between steep and flat P values (CPV-diff), CL visual acuity (CLVA), wearing time (WT) and complications associated with wear. Results Thirty eyes of 22 patients and a follow-up time of 10.3 ± 2.3 months were reviewed. Statistically significant improvement was observed between LogMAR CDVA and CLVA (0.25 ± 0.19 vs. 0.04 ± 0.05; P < 0.0001). WT was 11.2 h ± 1.2. Two eyes with mild corneal staining and another two with mild injection were noted. Twenty SMC designs were recorded and associated with lower levels of CDVA (0.36 ± 0.22 vs. 0.18 ± 0.10; P = 0.006), CLVA (0.06 ± 0.05 vs. 0.01 ± 0.03; P = 0.03), and larger amounts of CPV-diff (2.31 ± 1.86 vs. 1.03 ± 1.11; P = 0.02) than those eyes fitted with FP designs. No statistical differences were found in the amount of K-diff and WT between both sub-groups. Conclusions Fitting custom-made hydrogel silicone CL in keratoconus with ICRS is a feasible treatment with low rate of complications and adequate visual acuity and WT. [ABSTRACT FROM AUTHOR]

Keratoconus is a bilateral, asymmetrical, non-inflammatory, and progressive thinning disease of the cornea. The etiology and pathogenesis of the disease are not known exactly. However, significant advances have been achieved in the treatment of keratoconus in the recent years. In the past, penetrating keratoplasty was the only treatment option in advanced keratoconus. Nowadays, therapeutic advances for keratoconus have been provided various treatment options in different stages of the disease and opportunity to stop the progression of the disease, to rehabilitate vision, or to achieve both. This review analyzes the current methods in the treatment of keratoconus, such as new contact lens designs, corneal collagen cross-linking, intracorneal rings, deep anterior lamellar keratoplasty, conductive keratoplasty, intraocular refractive lenses, photorefractive keratectomy, and combinations of these. [ABSTRACT FROM AUTHOR]

Aims: The aim of the study was to evaluate the refractive, topometric and aberrometric changes in corneas with keratoconus treated with femtosecond laser intracorneal ring segment (ICRS) implantation following a proposed modified nomogram. Settings and design: This is a retrospective, consecutive case series. Materials and methods: ICRS implantation using the new proposed nomogram was performed in 10 eyes of seven patients with type 1 and type 2 keratoconus. Corneal tunnels were created using femtosecond laser, and KeraRings were inserted in all eyes. All cases were followed up every 3 months for 6 months using the Pentacam Phoenix system. Statistical analysis: All analyses were performed with SPSS for windows 2007. Results: None of our patients developed complications related to ring placement, such as migration, extrusion or infection. In this limited case series an improvement was seen in uncorrected visual acuity (P ≤ 0.05), best spectacle corrected visual acuity (P ≤ 0.001) and refraction at 6 months (P < 0.001). Keratometric readings improved (P < 0.001), with flattening of the cornea. Corneal aberrations showed significant reduction when analysed by Zernike (P < 0.001) and Fourier analysis (P ≤ 0.001). Corneal asphericity (Q value) also showed improvement (P < 0.05). Conclusion: Femtolaser ICRS implantation using the proposed modified nomogram showed promising results in improving refraction, visual acuity, corneal topography and aberrations in patients with keratoconus. [ABSTRACT FROM AUTHOR]

Highlights: [•] Optimization of corneal ring implantation using Machine Learning techniques. [•] Prediction of astigmatism and corneal curvature improvement in patients with keratoconus after ring implantation by means Machine Learning techniques. [•] Finding out the most relevant features for a successful ring implantation. [Copyright &y& Elsevier]

Background: Keratoconus, the most common primary corneal ectasia, is a bilateral asymmetric corneal degeneration accompanied with local corneal thinning and occurs mostly in the inferior and central part of the cornea, it usually causes high myopia and irregular astigmatism which results in poor quality of vision. Based on disease severity, many treatment modalities exist including glasses and contact lenses for mild to moderate disease, while corneal graft preserved for more advanced disease. In advent of alternative treatments, intrastromal ring implantation have been introduced which improves visual acuity and optical aberrations and also corrects refractive errors and mean keratometric data, anterior segment Optical cohehernce Tomography epithelial mapping is anew modality to assess epithelial thickness. Objective: To investigate epithelial thickness changes in keratoconic patients before and after intracorneal ring segment implantation using AS OCT. Methods: Thirty eyes with early to moderate keratoconus were included in this prospective interventional case series study which has been conducted at patients from Ain shams university hospitals, after the approval of the research ethical committee in the Faculty of Medicine, Ain Shams University between March to October. All cases underwent a Complete ophthalmological examination before surgery. the examination included Visual acuity assessment and Best corrected visual acuity. Slit Lamp Biomicroscopy examination with fundus examination through dilated pupil using D lens & Corneal Topography, Anterior segment Optical cohehernce Tomography Epithelial mapping(- zeiss). Results: we found that epithelial thickness showing statistically significant change comparing pre and post operative epithelial mapping especially in certain areas in the map, area (_),(_) mm. Conclusion: There is increase in epithelium thickness in keratoconic corneas after intracorneal ring segment implantation to compensate for stromal irregularities in patients with keratoconus. [ABSTRACT FROM AUTHOR]

Keratoconus is a corneal degeneration that usually appears during puberty and may seriously deteriorate the quality of life of the patients. This corneal disease is today the first indication of corneal transplantation in young patients. Until the last decade of the XX century, keratoplasty procedures were the only alternative to treat this pathological condition. In the beginning of the XXI century, intracorneal ring segments implantation was proposed as a therapeutic choice for treating keratoconus patients. Since then, several published articles have reported the benefits of this surgical procedure in treating this type of corneal ectatic disorder. The purpose of the present investigative work is to summarize the characteristic of the intracorneal ring segments and also to review the different features published in the literature in relation to this surgical technique for the treatment of keratoconus patients.