Myoring (Full 360 Ring)
All content on Eyewiki is protected by copyright law and the Terms of Service. This content may not be reproduced, copied, or put into any artificial intelligence program, including large language and generative AI models, without permission from the Academy.
Introduction
Intracorneal ring segments (ICRSs) play an important role in the management of keratoconus by flattening the central cornea via an "arc-shortening" effect on the corneal lamellae, reducing the refractive power of the cornea and shifting the cone apex.[1] They are synthetic, biocompatible implants (or, more recently, allogenic corneal tissue) designed to reduce corneal curvature and optimize the refractive profile. First used in 1978 for the treatment of myopia, their role in keratoconus was established in 2000.[2]
Suggested by Albert Daxer in 2007, the MyoRing (Dioptex GmbH, Linz, Austria) is a flexible, polymethylmethacrylate (PMMA) intracorneal implant that is a continuous (360°) ring, in contrast to the arc-length segments of Intacs, Ferrara, and Keraring designs. It is available in diameters ranging from 5 to 6 mm and thicknesses of 200 to 400 μm in 20 μm increments. The anterior surface is convex and the posterior surface concave, with a radius of curvature of 8.00 mm.[3]
The MyoRing is implanted into a closed intrastromal pocket rather than a peripheral tunnel, a distinction that has important implications for both technique and complication profile. MyoRing implantation is considered a reversible and adjustable surgical procedure: the ring may be exchanged for a different thickness or diameter, repositioned, or explanted with return of the cornea toward its preoperative state.[4][5]
Mechanism of Action
Ring implants act by an arc-shortening effect on the corneal lamellae anterior to the implant, producing central flattening proportional to implant thickness and inversely proportional to implant diameter. Because the MyoRing is a complete 360° ring positioned at the mid-peripheral cornea, it produces a more symmetric and generally larger arc-shortening effect than paired arc-length segments.[6][7]
Analysis using the ABCD keratoconus grading system has clarified where the anatomic effect occurs. In 17 eyes implanted with femtosecond laser–assisted MyoRing, significant flattening was observed in both the anterior (6.02 ± 0.40 to 7.18 ± 0.54 mm; P < .001) and posterior (4.49 ± 0.41 to 4.66 ± 0.40 mm; P = .001) radius of curvature, with no significant change in thinnest corneal thickness (P = .981). Despite placement of the ring in the posterior one-third of the stroma, the greatest curvature change occurred on the anterior corneal surface. Mean ABCD staging changed from A4B4C2D2 to A1B4C2D1 at 6 months.[8]
Ring implantation is a shape-modifying, not disease-modifying, intervention. It does not arrest ectatic progression, which is the role of corneal collagen crosslinking (CXL).[9]
Indications and Patient Selection
Keratoconus
All grades of non-central and central keratoconus and pellucid marginal degeneration, provided minimal corneal thickness exceeds 350 μm, based on long-term results of up to 8 years.[10]
Evidence-based selection criteria derived from a multicentric cohort of 118 eyes support the following profile as optimal:[11]
Corrected distance visual acuity (CDVA) worse than 20/25 with documented contact lens intolerance
No central corneal scarring
Minimum corneal thickness > 350 μm
Central mean keratometry < 55 D
In that series, ICCR implantation improved CDVA from a mean of 0.38 to 0.15 logMAR (P < .0001). Lower preoperative CDVA was the single best predictor of improvement: eyes with CDVA of 20/80 or worse gained a mean of 4.3 ± 2.0 lines. Eyes with mean K > 55 D gained substantially (9.04 ± 4.83 lines UDVA, 2.86 ± 3.09 lines CDVA) but ended with a significantly inferior final CDVA of 0.32 ± 0.21 logMAR compared with the standard treatment group (P = .001). The main limitation is low predictability of the magnitude of improvement in eyes with preoperative CDVA better than 20/30.[11]
Post-LASIK Keratectasia
MyoRing and other ring implants have been used for post-LASIK ectasia.[7][12] Note that in the United States ICRSs are FDA-approved under a Humanitarian Device Exemption for keratoconus, and use in post-LASIK ectasia is off-label; long-term efficacy for this indication remains to be fully determined per the American Academy of Ophthalmology Refractive Surgery Preferred Practice Pattern.[13]
Supporting data include a 5-year series of 45 post-LASIK ectasia eyes implanted with a 150° arc-length Ferrara-type segment in which UDVA improved from 0.53 ± 0.33 to 0.26 ± 0.24 logMAR (P < .0001), CDVA from 0.12 ± 0.13 to 0.04 ± 0.06 (P < .0001), no eyes lost CDVA lines, and 93.3% showed no progression or regression across follow-up.[14] A 2-year multicenter series of 34 post-LASIK ectasia eyes found that UCVA did not improve (P = .17), but BSCVA increased significantly, with 60% gaining ≥2 lines at 24 months and a significant reduction in coma-like RMS (P = .03); a higher apical curvature gradient predicted explantation.[15]
Moderate and High Myopia
In eyes not eligible for excimer laser refractive surgery, including:[3]
thin corneas
irregular corneal surface
forme fruste keratoconus
high myopia
patients who decline LASIK but desire a minimally invasive and reversible myopia treatment
This indication is now uncommon; per the AAO, intrastromal corneal ring segments are rarely used to correct myopia in contemporary practice.[13]
Contraindications and Relative Contraindications
Central corneal scarring or opacity involving the visual axis
Minimum corneal thickness < 350 μm at the intended implant plane
Hydrops or history of hydrops
Active ocular surface disease, severe atopy with vigorous eye rubbing, or active blepharitis
Uncontrolled autoimmune or connective tissue disease
Very advanced ectasia (mean K > 55 D) — not absolute, but associated with inferior final CDVA and higher spontaneous extrusion risk[11][16]
Documented ectatic progression without planned adjunctive CXL
Preoperative Evaluation
Manifest and cycloplegic refraction, UDVA and CDVA
Scheimpflug or OCT-based corneal tomography — anterior and posterior elevation, pachymetry map, thinnest point location, cone location and decentration, ABCD staging
Corneal aberrometry, particularly coma-like RMS, the dominant aberration in ectasia and the parameter most improved by ring implantation[17]
Documentation of progression (serial tomography) to determine need for concurrent or sequential CXL
Endothelial cell count and slit-lamp assessment for scarring
Assessment of contact lens tolerance — ring implantation is generally reserved for contact lens–intolerant eyes[11]
Effect of MyoRing Implantation on IOP Measurement
Biomechanical changes after MyoRing implantation may affect measurement of intraocular pressure (IOP). Studies show a slight reduction in measured IOP when taken at the corneal center; when measured near the implanted ring, IOP reads falsely higher because of localized stiffness produced by the implant.[18] Broader ICRS literature indicates slight corneal stiffening after implantation without significant overall change in IOP.[2] In the femtosecond MyoRing pilot series, no statistically significant change was detected in corneal hysteresis or corneal resistance factor by Ocular Response Analyzer (P ≥ .176), although keratometric flattening correlated inversely with corneal resistance factor (r = −0.782, P = .008).[17]
Clinically, applanation IOP in these eyes should be interpreted with caution and measured consistently at the corneal center; glaucoma surveillance should rely on optic nerve and visual field assessment rather than IOP alone.
Technique
A corneal pocket is created in the corneal stroma at a depth of 250 or 300 μm.[19] This can be achieved by one of two methods:
Corneal intrastromal implantation system (CISIS) using the Pocket Maker microkeratome (Dioptex GmbH, Linz, Austria) Femtosecond laser–created pocket[6][20] In both methods, the corneal pocket is made 9 mm in diameter followed by a tunnel less than 5.5 mm in width. The ring is implanted with special forceps and centered using the postoperative optical axis as reference. The wound is self-sealing with no need for sutures.[10][12]
Best results are achieved using a surgical microscope with a concentric light source on which the patient can fixate. At the end of the procedure, after ring implantation, the patient fixates on the light and the ring is shifted to its central position inside the pocket, between the center of the pupil and a point between the first and second Purkinje images of the concentric light source.[10]
Femtosecond Laser Versus Mechanical Dissection
A meta-analysis of 115 pre-post studies evaluating ICRS and MyoRing found considerable improvement in visual, refractive, and keratometric outcomes across all implant models, with both tunnel/pocket creation methods yielding similar efficacy — but complication rates were, without exception, higher with mechanical dissection.[21]
A comparative study of 376 eyes reported complications in 48 of 265 eyes (18.1%) in the manual group versus 4 of 111 eyes (3.6%) in the femtosecond group. The most frequent manual-group complications were ring exchange/adjustment for refractive enhancement (9.4%) and late spontaneous extrusion (5.7%). Notably, 81.25% of complications occurred within the surgeon's first 3 years of experience, underscoring a substantial learning curve.[22]
Femtosecond laser tunnel creation offers improved control over stromal depth and uniformity and is now the preferred approach where available.[2][23]
Outcomes
Visual and Refractive Outcomes
In the largest single-center prospective series (95 eyes with moderate and advanced keratoconus, ≥12 months follow-up), MyoRing implantation produced significant improvement in UDVA and CDVA at 1 month, with reduction in sphere of 5.74 D and cylinder of 3.02 D; these parameters remained stable thereafter. Mean corneal flattening was 9.78 D. Higher-order and coma-like aberrations decreased significantly, but spherical aberration increased. No significant change in central corneal thickness was observed. Importantly, there was no significant difference in visual gain between eyes with K higher or lower than 53 D. Explantation was performed in 4 eyes (4%), with refraction, visual acuity, and topography returning to preoperative status within 1 month.[5]
The femtosecond pilot series (12 ectatic eyes, including 1 post-LASIK ectasia) showed significant UDVA improvement at 1 week (P = .001) with reduction in sphere (P = .002) and cylinder (P = .004), mean corneal flattening of 8.03 D (P = .005), significant increase in primary spherical aberration at 1 month (P = .001), and significant reduction in total corneal higher-order aberrations at 3–6 months (P = .027). The authors advised use of larger implant diameters.[17]
Long-term follow-up reports mean improvement in UCVA of approximately 6 Snellen lines with stability of visual acuity in keratoconus.[24]
Comparison With Arc-Length ICRS
Comparison Design Findings References MyoRing (360°) vs Keratacx 320° vs Keratacx 160° 2-segment Prospective, 73 eyes, central KC, 6 months All devices improved UDVA, CDVA, SE, astigmatism, K readings, and Q value (P < .01). The 320° near-total ring and the continuous MyoRing reduced SE more effectively than the 2-segment device (P < .01); no difference in cylinder, K, or asphericity between groups [1] MyoRing (pocket) vs Keraring 340° (tunnel) Prospective randomized, 74 eyes, central KC, 12 months Comparable visual, refractive, and tomographic improvement. Complication rates higher but not statistically significantly so with pocket MyoRing. Interface central haze in 13.5% and infectious keratitis in 5.4% of MyoRing eyes vs 2.7% keratitis in Keraring eyes [2] ICRS and MyoRing, all models Meta-analysis, 115 studies Considerable improvement in visual, refractive, and keratometric outcomes across all models [3] The MyoRing has a greater potential for myopic and astigmatic correction in keratoconus than arc-length ICRSs, likely because of the greater arc-shortening effect achieved by the completely circular mid-peripheral design.[6][7] By comparison, conventional arc-length ICRS carry an expectation of more modest corneal flattening of 2 to 3 D with 2 to 3 lines of visual improvement.[25]
Trade-off between pocket and tunnel approaches: the randomized comparison found that avoiding surgical manipulation of the central cornea and visual axis enhances the safety of the tunnel approach, while the pocket approach carries risks of incomplete pocket formation (8.1%), limbal bleeding (10.8%), and interface central haze (13.5%).[26]
Topographic Signature
Topographically, the tangential map shows a central island with a homogeneous ring-shaped topography corresponding to the MyoRing.[10]
Overcorrection presents as a hyperopic shift, with increased intensity of the ring pattern over the central island on the tangential map.
Undercorrection presents as residual myopia with under-representation of the concentric ring on the tangential map.[10]
Both are managed by ring exchange for a different thickness/diameter — a distinct advantage of the reversible, adjustable design. In the multicentric cohort, 15 of 118 eyes (12.7%) underwent ring exchange for refractive undercorrection (9 eyes) or overcorrection (6 eyes).[11]
Complications
Ring implantation is generally a safe procedure with a low rate of serious adverse events, and long-term follow-up reveals low rates of vision-threatening complications.[2]
Intraoperative complications (pocket technique):[26]
Incomplete pocket formation (8.1%)
Limbal bleeding (10.8%)
Anterior or posterior corneal perforation
Ring decentration
Postoperative complications:[13][27][26]
Interface/central haze — the most common complication after pocket MyoRing implantation (13.5%)
Infectious keratitis — reported in 5.4% of pocket MyoRing eyes in the randomized comparison; a sight-threatening complication requiring prompt culture, intensive topical therapy, and usually explantation
Segment migration, extrusion, or decentration
Corneal thinning, melting, and perforation
Channel/interface deposits
Epithelial plug at the incision site and persistent incisional gaping
Glare, halos, and fluctuating vision
Under- or overcorrection; induced regular or irregular astigmatism
Chronic pain, foreign body sensation, focal edema
Explantation
Explantation rates in high-volume series range from 0% to 1.4%; in a multicenter series of 121 explanted ICRSs the overall explantation rate was 5.60%.[27][16] The distribution of causes is clinically informative:[16]
Functional failure — 61.2% (refractive failure 39.7%; removal at the time of keratoplasty 21.5%)
Anatomic failure — 38.8% (spontaneous extrusion 29.8%, overall extrusion rate 1.58%; suspected infectious keratitis 5.8%; corneal melting 2.5%; corneal perforation 0.8%)
A key clinical pattern: mild keratoconus cases were more prone to explantation for loss of initial visual improvement, whereas spontaneous extrusion occurred more often in advanced keratoconus.[16] Electron microscopy correlates extrusion with inflammatory cells and cell debris on the implant surface, whereas implants removed for refractive failure show a clean surface, supporting distinct mechanisms.[28]
MyoRing explantation is reliably reversible: in one series, refraction, visual acuity, and corneal topography returned to preoperative status within 1 month in all 4 explanted eyes.[5]
Combination With Corneal Collagen Crosslinking
CXL has been used widely to control progression of keratoconus by modifying the biomechanical properties of the cornea, using riboflavin and UV-A light to induce covalent bonds between collagen fibrils and between collagen and proteoglycans, resulting in a more stretch-resistant corneal architecture.[29] The American Academy of Ophthalmology Ophthalmic Technology Assessment concluded that epithelium-off CXL should be considered a first-line treatment for progressive keratoconus and post–laser refractive surgery ectasia, with rare adverse events.[9]
Because ring implantation regularizes corneal shape but does not halt progression, combining the two addresses complementary goals: ICRS for surface regularization, CXL for progression arrest.[30]
Evidence for the combination
A 5-year cohort of 35 progressive keratoconus eyes randomized to 360° intracorneal ring alone versus ring plus CXL found greater improvement in both UCVA and CDVA in the combined group (P = .002 and P = .001). Mean CDVA improvement was 0.56 ± 0.67 with CXL versus 0.33 ± 0.61 without. The postoperative Tomographic and Biomechanical Index was significantly better in the combined group (P = .012). The authors concluded that although ring implantation alone might halt progression with acceptable outcomes, the combination has an adjuvant and synergistic effect, especially in long-term follow-up.[31]
A prospective randomized trial of 198 eyes comparing concurrent versus sequential ICRS and CXL found overall reduction in maximum K of 2.5 D, improvement in inferior-superior difference of 3.9 D, UDVA improvement of 2.0 logMAR lines, and CDVA improvement of 1.1 lines, with no significant difference between concurrent and sequential groups in any outcome and only 6 clinically significant adverse events. Thicker segments and single-segment placement produced greater topographic improvement.[32]
A systematic review and meta-analysis of 17 studies categorized by surgical sequence (same day, ICRS first, CXL first) found no significant differences in UDVA, CDVA, or cylinder among the three, but simultaneous surgery was superior to CXL-first for spherical error and flat-K (P = .011, P = .0001) and superior to both staged approaches for steep-K (P = .002, P = .007), suggesting simultaneous surgery may provide better corneal shape outcomes.[33]
Kazakbaeva reported that MyoRing implantation alone and MyoRing combined with CXL both showed efficacy and safety in stabilizing progressive keratoconus and correcting concomitant ametropia at 3 years.[34]
Practical advantage of the pocket
The main advantages of a full ring are ease of implantation, excellent centration, and the postoperative ability to adjust ring position. The corneal pocket can additionally be used for direct intrastromal application of riboflavin, bypassing the epithelium. This appears to be a safe and effective method that preserves the epithelium and avoids the pain and discomfort associated with epithelium-off protocols.[35][5][24]
Staged Multimodal Approaches
Ring implantation is increasingly used as the first stage of a multimodal sequence in eyes requiring further refractive rehabilitation after shape normalization.
ICRS + CXL + topography-guided PRK: In a prospective study of 101 eyes, two-stage treatment combining ICRS with CXL followed by transepithelial topography-guided PRK at 8 months was clinically more effective at preventing ectatic progression and increasing visual acuity than non-combined two-stage techniques. Customized ablation permitted full spherical and cylindrical correction in 49.5% of patients; 10% had delayed epithelial healing and no stromal opacities developed.[36]
ICRS + CXL + toric phakic IOL: In 31 eyes with stage II–III keratoconus and post-LASIK ectasia, a three-step protocol improved decimal UDVA from 0.13 ± 0.17 to 0.69 ± 0.18 and CDVA from 0.56 ± 0.24 to 0.80 ± 0.18 at 1 year, with significant improvement in topometric indices and higher-order aberrations.[37]
A network meta-analysis of refractive surgical approaches to keratoconus concluded that for corneas with relatively good preoperative BCVA (regular corneas), phakic IOL combined with ICRS and CXL may offer the best approach provided disease does not exceed stage 3; for irregular corneas at higher stages, surface ablation combined with ICRS and CXL was favored at longer follow-up.[38]
The distinct and complementary contributions of each surgical stage are illustrated in the following figure, which tracks refractive, keratometric, and aberrometric parameters across a two-stage ring-then-PRK/CXL protocol. Ring implantation produced the keratometric flattening while the subsequent PRK-CXL stage was primarily responsible for reduction in coma and total higher-order aberrations.
Postoperative Care and Follow-Up
Topical antibiotic for approximately 1 week and topical corticosteroid tapered over 2 to 4 weeks, with preservative-free lubrication as needed.
Refractive stabilization typically occurs by 1 month, with the majority of the visual and keratometric effect present at the first postoperative week and stable thereafter.[5][17]
Serial tomography at 3, 6, and 12 months and annually thereafter, to detect ongoing ectatic progression, ring migration, or channel deposits. Ring implantation alone does not reliably halt progression, so documented progression should prompt CXL.[9][31]
Counsel on eye rubbing cessation and atopy control at every visit.
Late-onset symptoms — new pain, redness, or infiltrate at any point after surgery should be treated as possible infectious keratitis or impending extrusion and evaluated urgently, as these are the principal anatomic causes of explantation.[16]
Residual ametropia after stabilization may be managed with spectacles, rigid gas-permeable or scleral lenses (often better tolerated after shape regularization), ring exchange, topography-guided PRK with CXL, or toric phakic IOL implantation.[38][37]
Prognosis
Most eyes achieve durable improvement in UDVA and CDVA with reduction in coma-like aberration and mean keratometry, and long-term series report stability of effect out to 5 to 8 years.[10][31] The greatest gains occur in eyes with the poorest preoperative CDVA; predictability is limited in eyes with preoperative CDVA better than 20/30, where the risk of losing an initial visual benefit and requiring explantation is disproportionately high.[11][16]
Ring implantation does not preclude subsequent keratoplasty. Explantation restores the cornea toward baseline within weeks and, where progression continues or scarring develops, deep anterior lamellar or penetrating keratoplasty remains available.[5][16]
Summary of Key Points
The MyoRing is a continuous 360° PMMA implant placed in a closed intrastromal pocket, distinguishing it from arc-length ICRS placed in peripheral tunnels.[3]
Its mechanism is arc shortening, producing central flattening; the greatest curvature change occurs at the anterior corneal surface despite posterior stromal placement.[8]
Best candidates are contact lens–intolerant eyes with CDVA worse than 20/25, no central scarring, thinnest pachymetry > 350 μm, and mean K < 55 D.[11]
The continuous ring achieves greater spherical equivalent reduction than 2-segment devices, with reported sphere reduction near 5–6 D and corneal flattening of 8–10 D in published series.[5][17]
Spherical aberration increases after implantation even as coma-like aberration falls — a relevant counseling point for quality-of-vision expectations.[17][5]
Femtosecond pocket creation has a lower complication rate than mechanical dissection, and most complications cluster in the surgeon's early experience.[21][22]
The pocket approach carries a higher burden of interface haze and infectious keratitis than the tunnel approach; the tunnel approach avoids manipulation of the visual axis.[26]
Ring implantation regularizes shape but does not arrest progression; CXL is the disease-modifying step and epithelium-off CXL is first-line for progressive ectasia.[9]
Combined ring + CXL shows synergistic long-term benefit; concurrent and sequential protocols yield comparable visual outcomes, though simultaneous surgery may give better keratometric results.[31][32][33]
The procedure is reversible — explantation returns refraction, acuity, and topography to baseline within about 1 month.[5]
Additional Resources
American Academy of Ophthalmology. Refractive Surgery Preferred Practice Pattern.
American Academy of Ophthalmology. Keratoconus. EyeSmart/Eye Health.
Global Consensus on Keratoconus and Ectatic Diseases.
References
- ↑ Frost NA, Wu J, Lai TF, Coster DJ. A review of randomized controlled trials of penetrating keratoplasty techniques. Ophthalmology. 2006;113:942–949.
- ↑ 2.0 2.1 2.2 2.3 Hayat UK, Shiwani HA, Memon D, Walkden A. Intracorneal ring segments in keratoconus: a narrative literature review. Clin Ophthalmol. 2025;19:437-450.
- ↑ 3.0 3.1 3.2 Mahmood H, Venkateswaran RS, Daxer A. Implantation of a complete corneal ring in an intrastromal pocket for keratoconus. J Refract Surg. 2011;27:63–68.
- ↑ Jadidi K, Janani L, Mosavi S, Nejat F, Naderi M, Nourijelyani K. MyoRing implantation in keratoconic patients: 3 years follow-up data. J Ophthalmic Vis Res. 2016;11(1):26-31.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Jabbarvand M, Salamatrad A, Hashemian H, Khodaparast M. Continuous corneal intrastromal ring implantation for treatment of keratoconus in an Iranian population. Am J Ophthalmol. 2013;155(5):837-842.
- ↑ 6.0 6.1 6.2 Daxer A. Adjustable intracorneal ring in a lamellar pocket for keratoconus. J Refract Surg. 2010;26:217-221.
- ↑ 7.0 7.1 7.2 Daxer A, Mahmoud H, Venkateswaran RS. Intracorneal continuous ring implantation for keratoconus: one-year follow-up. J Cataract Refract Surg. 2010;36:1296-1302.
- ↑ 8.0 8.1 Sedaghat MR, Momeni-Moghaddam H, Belin MW, et al. Anatomical and visual effects of the MyoRing implantation measured by the ABCD keratoconus grading system. Eye Contact Lens. 2020;46(1):e1-e7.
- ↑ 9.0 9.1 9.2 9.3 Cortina MS, Greiner MA, Kuo AN, et al. Safety and efficacy of epithelium-off corneal collagen cross-linking for the treatment of corneal ectasia: a report by the American Academy of Ophthalmology. Ophthalmology. 2024.
- ↑ 10.0 10.1 10.2 10.3 10.4 10.5 Daxer A, Ettl A, Hörantner R. Long-term results of MyoRing treatment of keratoconus. J Optom. 2017;10(2):123-129.
- ↑ 11.0 11.1 11.2 11.3 11.4 11.5 11.6 Thiwa D, Linke SJ, Daxer A, Steinberg J. Continuous intracorneal ring implantation in keratoconus: efficacy, predictive factors, and complications. Clin Ophthalmol. 2022;16:1571-1580.
- ↑ 12.0 12.1 Jabbarvand M, Hashemian M, Hashemian H, Bazvand F, Khodaparast M. Femtosecond laser-assisted MyoRing implantation in postoperative LASIK ectasia. J Refract Surg. 2014;30(7):462-466.
- ↑ 13.0 13.1 13.2 Jacobs DS, Lee JK, Shen TT, et al. Refractive Surgery Preferred Practice Pattern. American Academy of Ophthalmology. 2023.
- ↑ Ibares-Frías L, Fernández-Vega-Cueto L, Alfonso-Bartolozzi B, et al. Long-term follow-up of a 150° arc-length intrastromal corneal ring segment implantation in post-LASIK ectasia. Curr Eye Res. 2023;48(4):373-380.
- ↑ Piñero DP, Alio JL, Uceda-Montanes A, El Kady B, Pascual I. Intracorneal ring segment implantation in corneas with post-LASIK keratectasia. Ophthalmology. 2009;116(9):1665-1674.
- ↑ 16.0 16.1 16.2 16.3 16.4 16.5 16.6 D'Oria F, Abdelghany AA, Ledo N, Barraquer RI, Alio JL. Incidence and reasons for intrastromal corneal ring segment explantation. Am J Ophthalmol. 2021;222:351-358.
- ↑ 17.0 17.1 17.2 17.3 17.4 17.5 Alio JL, Piñero DP, Daxer A. Clinical outcomes after complete ring implantation in corneal ectasia using the femtosecond technology: a pilot study. Ophthalmology. 2011;118(7):1282-1290.
- ↑ El-Radi M, Saleh M. Effect of continuous intrastromal corneal ring (MyoRing) implantation on intraocular pressure measurements in patients with keratoconus. Delta J Ophthalmol. 2019;20(4):144.
- ↑ Jabbarvand M, Hashemi H, Mohammadpour M, Khojasteh H, Khodaparast M, Hashemian H. Implantation of a complete intrastromal corneal ring at 2 different stromal depths in keratoconus. Cornea. 2014;33(2):141-144.
- ↑ Daxer A. Corneal intrastromal implantation surgery for the treatment of moderate and high myopia. J Cataract Refract Surg. 2008;34:194-198.
- ↑ 21.0 21.1 Struckmeier AK, Hamon L, Flockerzi E, et al. Femtosecond laser and mechanical dissection for ICRS and MyoRing implantation: a meta-analysis. Cornea. 2022;41(4):518-529.
- ↑ 22.0 22.1 Monteiro T, Alfonso JF, Freitas R, et al. Comparison of complication rates between manual and femtosecond laser-assisted techniques for intrastromal corneal ring segments implantation in keratoconus. Curr Eye Res. 2019;44(12):1291-1298.
- ↑ Morales P, Durán JA. Advances in intracorneal ring segment (ICRS) implantation for keratoconus: a comprehensive literature review, clinical insights, and future prospects. J Clin Med. 2025;14(13):4453.
- ↑ 24.0 24.1 Daxer A, Mahmoud HA, Venkateswaran RS. Corneal crosslinking and visual rehabilitation in keratoconus in one session without epithelial debridement: new technique. Cornea. 2010;29(10):1176-1179.
- ↑ Zadnik K, Money S, Lindsley K. Intrastromal corneal ring segments for treating keratoconus. Cochrane Database Syst Rev. 2019;5:CD011150.
- ↑ 26.0 26.1 26.2 26.3 Abdel-Radi M, Anwar M, Mostafa MM. Complications and outcomes of femtosecond laser-assisted corneal pocket implantation of 360-degree MyoRing versus corneal tunnel implantation of 340-degree Keraring for the management of central keratoconus. Curr Eye Res. 2026;51(3).
- ↑ 27.0 27.1 Bautista-Llamas MJ, Sánchez-González MC, López-Izquierdo I, et al. Complications and explantation reasons in intracorneal ring segments (ICRS) implantation: a systematic review. J Refract Surg. 2019;35(11):740-747.
- ↑ Ferrer C, Alió JL, Montañés AU, et al. Causes of intrastromal corneal ring segment explantation: clinicopathologic correlation analysis. J Cataract Refract Surg. 2010;36(6):970-977.
- ↑ Wollensak G, Spörl E, Mazzotta C, Kalinski T, Sel S. Interlamellar cohesion after corneal crosslinking using riboflavin and ultraviolet A light. Br J Ophthalmol. 2011;95(6):876-880.
- ↑ Zaky AG, KhalafAllah MT, Sarhan AE. Combined corneal cross-linking and 320° intrastromal corneal ring segments in progressive keratoconus: one-year results. Graefes Arch Clin Exp Ophthalmol. 2020;258(11):2477-2485.
- ↑ 31.0 31.1 31.2 31.3 Mohammadpour M, Khoshtinat N, Khorrami-Nejad M. Comparison of visual, tomographic, and biomechanical outcomes of 360 degrees intracorneal ring implantation with and without corneal crosslinking for progressive keratoconus: a 5-year follow-up. Cornea. 2021;40(3):303-310.
- ↑ 32.0 32.1 Hersh PS, Issa R, Greenstein SA. Corneal crosslinking and intracorneal ring segments for keratoconus: a randomized study of concurrent versus sequential surgery. J Cataract Refract Surg. 2019;45(6):830-839.
- ↑ 33.0 33.1 Hashemi H, Alvani A, Seyedian MA, et al. Appropriate sequence of combined intracorneal ring implantation and corneal collagen cross-linking in keratoconus: a systematic review and meta-analysis. Cornea. 2018;37(12):1601-1607.
- ↑ Kazakbaeva G. MyoRing implantation in comparison with MyoRing implantation combined with corneal collagen crosslinking for keratoconus. Ophthalmology in Russia. 2019;16(1S):85-90.
- ↑ Studeny P, Krizova D, Stranak Z. Clinical outcomes after complete intracorneal ring implantation and corneal collagen cross-linking in an intrastromal pocket in one session for keratoconus. J Ophthalmol. 2014;2014:568128.
- ↑ Maharramov PM, Aghayeva FA. Evaluation of the effectiveness of combined staged surgical treatment in patients with keratoconus. PLoS One. 2022;17(3):e0264428.
- ↑ 37.0 37.1 He C, Joergensen JS, Knorz MC, McKay KN, Zhang F. Three-step treatment of keratoconus and post-LASIK ectasia: implantation of ICRS, corneal cross-linking, and implantation of toric posterior chamber phakic IOLs. J Refract Surg. 2020;36(2):104-109.
- ↑ 38.0 38.1 Niazi S, Doroodgar F, Hashemi Nazari S, et al. Refractive surgical approaches to keratoconus: a systematic review and network meta-analysis. Surv Ophthalmol. 2024;69(2):219-230.
