MyoRing植入术治疗圆锥角膜的疗效观察

目的：比较MyoRing植入前后圆锥角膜(KCN)患者角膜前后表面散光和全屈光散光。

方法：历史队列研究。比较植入360度全环植入物(MyoRing)的KCN患者的术前和术后全屈光、角膜前后表面散光,术后3、6、9、12 mo连续随访四次。

结果：共纳入KCN患者79例85眼,其中男43例,女36例,平均年龄29±7.41(17-48)岁。随访期间,全屈光散光、角膜前后表面散光呈减少趋势。MyoRing植入后12 mo,总屈光散光测量值显著下降2.09 D(4.27±3.15 vs 2.18±1.63 D,P<0.001)。此外,术后测量显示,角膜前表面和后表面散光分别改善约3.20 D和0.59 D\〖6.40±1.90 vs 3.20±1.75 D(P<0.001)和1.30±0.55 vs 0.71±0.35(P<0.001)\〗

结论：MyoRing植入可显著改善散光参数,包括全屈光散光以及角膜前后表面散光。     

Clinical outcomes after intrastromal corneal ring segments reoperation in keratoconus patients

AIM:To evaluate the clinical outcomes after Ferrara intrastromal corneal ring segments (ICRS) reoperation in patients with keratoconus.RESULTS: The mean follow-up time after the reoperation was 30.5±9.7 months. The mean UCVA improved from 20/300 to 20/80 (P=0.005); the mean BCVA improved from 20/160 to 20/50 (P=0.0002), the mean keratometry reduced from 49.33±4.19D to 46.16±3.90D (P=0.0001), the mean pachymetry at the thinnest point increased from 450±42.9mm to 469±40.8mm (P=0.0001). The asphericity increased from -0.84±0.74 to -0.35±0.81 (P=0.15) and the spherical equivalent reduced from -4.64±4.87D to -3.04±3.45D (P=0.137). The changes in the asphericity and spherical equivalent were not statistically significant.CONCLUSION: Ferrara ICRS implantation showed to be a reversible and readjustable surgical procedure for keratoconus treatment. Good outcomes can be obtained even after removal, addition, reposition or exchange of ICRS.     

Clinical outcomes after implantation of a new intrastromal corneal ring with 140-degree of arc in patients with corneal ectasia

AIM: To evaluate the clinical and tomographic outcomes after implantation of a new intrastromal corneal ring segment (ICRS) with 140-degrees of arc in eyes with corneal ectasia. METHODS: We evaluated patients with corneal ectasia implanted with Ferrara 140° ICRS from April 2010 to February 2015. Outcome measures included preoperative and postoperative corrected distance visual acuity (CDVA), keratometry simulated (K) reading, tomographic astigmatism and asphericity. All patients were evaluated using the Pentacam Scheimpflug system. RESULTS: The study evaluated 58 eyes. The mean follow-up was 16.81±10.8mo. The CDVA (logMAR) improved from 0.5±0.20 (20/60) to 0.3±0.21 (20/40) (P<0.01). The average K reduced from 49.87±7.01 to 47.34±4.90 D (P<0.01). The asphericity changed from -0.60±0.86 to -0.23±0.67 D (P<0.01). The mean preoperative tomographic astigmatism decreased from -8.0±3.45 to -4.53±2.52 D (P<0.01). CONCLUSION: The new ICRS model with 140-degrees of arc effectively improve the visual acuity and reduce the high astigmatism usually found in patients with corneal ectasia.     

圆锥角膜治疗进展

圆锥角膜是一种以角膜扩张为特征,病因不明的双侧进行性角膜病变。角膜接触镜是轻中度圆锥角膜最常用的矫正方法。角膜表层镜片术、深板层角膜移植术、角膜基质环植入术、角膜交联疗法及穿透性角膜移植术是临床上常用的手术治疗方法。     

Safety and efficacy of Intacs in Indian eyes with keratoconus: An initial report

Context

In contact lens-intolerant keratoconus patients, intrastromal placement of Intacs is becoming a promising new modality of treatment.

Aims

To study the safety and efficacy of implantation of microthin corneal inserts (Intacs) in Asian-Indian keratoconus patients.

Settings and Design

Retrospective interventional case series, in the cornea and refractive surgery service, at a tertiary care eye hospital in South India, between May 2006 and July 2007.

Materials and Methods

Intacs (Addition Technology, USA) were successfully implanted by mechanically creating tunnels, in 12 eyes of 12 keratoconus patients, who were contact lens-intolerant. The patients (mean age 25.58 years, nine male and three female) had a minimum follow-up of six months. Five patients had severe keratoconus (mean K > 53 D) and nine had central cones.

Results

All patients improved or retained visual acuity. The uncorrected visual acuity (UCVA) improved from a mean value of 0.06, (SD ± 0.08) to 0.19 postoperatively (SD± 0.15) (P= 0.01). The change in mean best corrected visual acuity (BCVA) was from 0.51, (SD ± 0.24), to 0.69, (SD ±0.00) (P = 0.01) postoperatively. The average central keratometry reading was 52.55 D. The change in mean K from 52.84 to 49.16 and 49.15 at one and six months respectively, was statistically significant. We did not have any major intra- or early postoperative complications. Eight of 12 eyes became contact lens-tolerant post-surgery.

Conclusion

The procedure of Intacs implantation appears to be safe and effective in a small group of Indian population at an intermediate follow-up.     

Complications of intrastromal corneal ring segment implantation using a femtosecond laser for channel creation: a survey of 850 eyes with keratoconus

Acta Ophthalmol. 2011: 89: 54–57

Abstract.

Purpose: To report complications after the implantation of intrastromal corneal ring segments (Keraring; Mediphacos, Belo Horizonte, Brazil) in keratoconic eyes using a femtosecond laser (IntraLase; Advanced Medical Optics, Santa Ana, California, USA) for channel creation. Methods: Retrospective chart review of 531 patients (850 eyes) who underwent Keraring insertion using a femtosecond laser for channel creation. Intraoperative and postoperative complications were recorded. Results: Intraoperatively, there were 22 (2.7%) cases of incomplete channel formation. The rest of the intraoperative complications were galvo lag error (system malfunction) [five eyes (0.6%)], endothelial perforation [five eyes (0.6%)] and incorrect entry of the channel [two eyes (0.2%)]. Postoperatively, there were 11 (1.3%) cases of segment migration, two (0.2%) cases of corneal melting and one (0.1%) case of mild infection. The overall complication rate was 5.7% (49 cases out of 850 eyes). Conclusion: In this study, intracorneal ring segment implantation using a femtosecond laser for channel creation was related to a number of complications. The most common complications were incomplete channel creation (intraoperatively) and segment migration (postoperatively).     

Contralateral eye study of refractive, topographic and aberrometric outcomes after femtosecond assisted MyoRing implantation and DALK for management of keratoconus

AIM: To evaluate the efficacy of femtosecond laser assisted MyoRing intrastromal corneal implant and deep anterior lamellar keratoplasty (DALK) for management of moderate to advanced keratoconus regarding the degree of changes in visual acuity, refraction, corneal asphericity and aberrations. METHODS: A prospective non comparative interventional case study was conducted in Ophthalmology Department, Ain Shams University Hospital in the period from January 2015 to February 2017. The study included 30 eyes of moderate to advanced keratoconus. MyoRing was implanted in one eye (Group I) and DALK operation was performed in the contralateral eye of the same patient (Group II). Preoperative and 6mo post-operative uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), spherical equivalent (SE), corneal and refractive astigmatisms, keratometry and Q-value using topography images were acquired. Quality of vision was assessed in all eyes including total corneal, anterior corneal high order aberrations analysis at 5 mm pupil size and the Strehl ratio of point spread function (PSF) as an objective measure of glare. RESULTS: Mean postoperative UCVA, CDVA, SE, refractive astigmatism, keratometry readings and asphericity were statistically improved compared to preoperative parameters in both groups (P<0.05). Significant reduction of all corneal aberrations following both techniques (P<0.05) was achieved except mean trefoil and mean PSF in Group I (P>0.05). Postoperative corneal aberrations were significantly lower in Group II compared to Group I. A statistically significant negative correlation was found in Group I between the mean change in CDVA (logMAR) and the mean preoperative and mean postoperative total corneal aberrations root mean square (RMS; r=-0.78, P=0.04). Also a statistically significant negative correlation was found between mean preoperative coma RMS and mean post PSF (r=-0.86, P=0.01). In Group II, there was a statistically significant positive correlation between mean change in CDVA (logMAR) and mean change in Kmax (r=0.87, P=0.01) and between mean change in refractive cylinder and mean postoperative PSF (r=0.76, P=0.05). CONCLUSION: Femtosecond laser assisted MyoRing and DALK are effective in improving visual acuities, refraction, corneal asphericity and aberrations. MyoRing reduced spherical error more than the corneal cylinder. Post operative homogenous corneal surface and good image quality were achieved following both techniques compared to the preoperative state. However, DALK results in better image quality and lower corneal aberrations.     

Investigation of the efficiency of intrastromal ring segments with cross-linking using different sequence and timing for keratoconus

AIM:To evaluate and compare the efficacy and stability of intrastromal corneal ring segment (ICRs) implantation with cross-linking (CXL) using different sequence and timing.METHODS:In this single retrospective study, 86 keratoconic eyes subjected the ICRs implantation. We analyzed only 41 eyes that had complete follow-ups. They were divided into three groups:ICRs implantation was applied only (group normal), ICRs first followed by CXL immediately (group CXL-S), CXL first followed by ICRs long after (group CXL-B). The visual acuity, refractive results, keratometry were compared preoperatively and 1y postoperatively. Their differences among the three groups were also analyzed.RESULTS:Group normal comprised 25 eyes, group CXL-S 8 eyes, and group CXL-B 8 eyes. There were improvements in the mean uncorrected distance visual acuity (UDVA) and the mean corrected distance visual acuity (CDVA) compared preoperatively and 1y postoperatively {UDVA:0.31 (P=0.030) logarithmic minimum angle of resolution [logMAR] group normal, 0.4 (P=0.020) group CXL-S, 0.45 (P=0.001) group CXL-B; CDVA:0.21 logMAR (P=0.013) group normal, 0.30 (P=0.036) group CXL-S; 0.26 (P=0.000) group CXL-B}. The refractive and topographic outcomes also showed improvements. In terms of comparisons among the three groups, all the P values were above 0.05, showing no significant difference. But only group CXL-B had improvement in UDVA and CDVA for all the patients.CONCLUSION:With safety and good visual outcomes, ICRs implantation is a viable alternative for keratoconus. No significant difference was found among these three groups.     

圆锥角膜的治疗进展

本文通过对圆锥角膜治疗方法的综述,为临床医生选择合适的治疗方法做出参考。通过数据库对“圆锥角膜”“隐形眼镜”“角膜胶原交联”“Intacs(角膜环)”“角膜成形术”“基因治疗”“不规则散光”等关键词进行搜索,并根据相关文献对圆锥角膜的治疗方法进行综述。眼镜和隐形眼镜可用于圆锥角膜早期,而疾病晚期时可采用前弹力层移植术、穿透性角膜成形术(PK)和深层前板层角膜成形术(DALK)、传导性角膜成形术和基因治疗。此外,角膜胶原交联可以阻止圆锥角膜进展,角膜基质环植入术(ICRS)通过使变形角膜变平,减少屈光不正以达到治疗目的。总得来说,眼科诊断技术和治疗方法的发展可以减缓圆锥角膜进展,从而减少晚期角膜圆锥患者对角膜移植的需要。选择恰当的圆锥角膜治疗方案可以帮助患者改善视力和预防失明。     

Evaluation of anterior and posterior surfaces of the cornea using a dual Scheimpflug analyzer in keratoconus patients implanted with intrastromal corneal ring segments

AIM: To evaluate corneal parameters measured with a dual Scheimpflug analyzer in keratoconus patients implanted with intrastromal corneal ring segments (ICRS). METHODS: Fifty eyes of 40 keratoconus patients had Ferrara ICRS implantation from November 2010 to April 2014. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, keratometry, asphericity, elevation, pachymetry, root mean square (RMS), spherical aberration and coma were studied. All patients were evaluated using a dual Scheimpflug system. RESULTS: The mean follow-up time after the procedure was 12.7mo. The mean UCVA improved from 0.82 to 0.31 (P<0.001); the mean BCVA improved from 0.42 to 0.05 (P<0.0001), the mean spherical refraction changed from -3.06±3.80 D to -0.80±2.5 D (P<0.0001) and the mean refraction astigmatism reduced from -4.51±2.08 D to -2.26±1.18 D (P<0.0001). The changes from preoperative to postoperative, in parameters of the anterior and posterior surface of the cornea, were statistically significant except the elevation posterior at the apex of the cornea and posterior asphericity. CONCLUSION: The implantation of Ferrara ICRS induces changes in both anterior and posterior surfaces of the cornea.     

Clinical effectiveness of intrastromal corneal ring segments among keratoconus patients

AIM: To evaluate the clinical effectiveness of intrastromal corneal ring segments (ICRS) among the patients suffering from keratoconus. METHODS: A retrospective and non-comparative interventional design had been utilized on the basis of postoperative follow-up among 56 keratoconus patients. Visual acuity was significantly assessed during complete ophthalmic examination of the patients. The femtosecond laser had been used to create the corneal tunnels in 15 eyes; whereas, the corneal tunnels were created in 72 eyes mechanically. RESULTS: The ranges and standard deviations had been used to obtain results. It had been revealed through ophthalmic assessment that the mean preoperative uncorrected visual acuity observed was 1.38±0.37 logarithm of Minimal Angle of Resolution. Moreover, a significant improvement was observed postoperatively in visual acuity by 0.58±0.32 during the 4th month. The improvement was also witnessed in the 16th month by 0.48±0.30. CONCLUSION: The implantation of ICRS is an efficient and effective surgical intervention for the treatment of keratoconus. Thus, identified intervention seems to be associated with appropriate visual outcomes and safety after the development of femtosecond as well as mechanical tunnels.     

Visual rehabilitation in low-moderate keratoconus:intracorneal ring segment implantation followed by same-day topography-guided photorefractive keratectomy and collagen cross linking

AIM:To present the results of same-day topography-guided photorefractive keratectomy (TG-PRK) and corneal collagen crosslinking (CXL) after previous intrastromal corneal ring segment (ISCR) implantation for keratoconus.METHODS:An experimental clinical study on twenty-one eyes of 19 patients aged 27.1±6.6y (range 19-43y), with low to moderate keratoconus who were selected to undergo customized TG-PRK immediately followed by same-day CXL, 9mo after ISCR implantation in a university ophthalmology clinic. Refraction, uncorrected distance visual acuities (UDVA) and corrected distance visual acuities (CDVA), keratometry (K) values, central corneal thickness (CCT) and coma were assessed 3mo after TG-PRK and CXL.RESULTS:After TG-PRK/CXL:the mean UDVA (logMAR) improved significantly from 0.66±0.41 to 0.20±0.25 (P<0.05); Kflat value decreased from:48.44±3.66 D to 43.71±1.95 D; Ksteep value decreased from 45.61±2.40 D to 41.56±2.05 D; Kaverage also decreased from 47.00±2.66 D to 42.42±2.07 D (P<0.05 for all). The mean sphere and cylinder decreased significantly post-surgery from, -3.10±2.99 D to -0.11±0.93 D and from -3.68±1.53 to -1.11±0.75 D respectively, while the CDVA, CCT and coma showed no significant changes. Compared to post-ISCR, significant reductions (P<0.05 or all) in all K values, sphere and cylinder were observed after TG-PRK/CXL.CONCLUSION:Same-day combined topography-guided PRK and corneal crosslinking following placement of ISCR is a safe and potentially effective option in treating low-moderate keratoconus. It significantly improves all visual acuity, reduced keratometry, sphere and astigmatism, but causes no change in central corneal thickness and coma.     

角膜基质环植入术治疗圆锥角膜的临床疗效

目的：评估角膜基质环植入术治疗圆锥角膜的临床疗效。

方法：这一回顾性对照干预性研究对56例87眼圆锥角膜患者进行手术后随访。所有患者完善眼科检查,评估视力。15眼使用飞秒激光制备角膜隧道。72眼使用机械的方法制备角膜隧道。

结果：所有患者术前裸眼视力1.38±0.37。术后4mo裸眼视力达到0.58±0.32。术后16mo达到0.48±0.30。

结论：角膜基质环植入术是治疗圆锥角膜的有效方法。有效的干预与理想的术后视力相关。飞秒激光角膜隧道制备和机械方法一样安全。     

Evaluation of intrastromal corneal ring segments for treatment of keratoconus with a mechanical implantation technique

Purpose:

To evaluate the clinical outcomes of intrastromal corneal ring segment (ICRS) implantation in patients with keratoconus using a mechanical implantation technique.

Materials and Methods:

Thirty eyes of 17 patients with keratoconus were enrolled. ICRSs (Keraring) were implanted after dissection of the tunnel using Tunc''s specially designed dissector under suction. A complete ophthalmic examination was performed, including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent, keratometric readings, inferosuperior asymmetry index (ISAI), and ultrasound pachymetry. All 3-, 6-, and 12-month follow-ups were completed, and statistical analysis was performed.

Results:

The mean preoperative UDVA for all eyes was 1.36 ± 0.64 logMAR. At 12 months, the mean UDVA was 0.51 ± 0.28 logMAR (P = 0.001), and the mean preoperative CDVA was 0.57 ± 0.29 logMAR, which improved to 0.23 ± 0.18 (P = 0.001) at 1 year. There was a significant reduction in spherical equivalent refractive error from –6.42 ± 4.69 diopters (D) preoperatively to –1.26 ± 1.45 D (P = 0.001) at 1 year. In the same period, the mean K-readings improved from 49.38 ± 3.72 D to 44.43 ± 3.13 D (P = 0.001), and the mean ISAI improved from 7.92 ± 3.12 to 4.21 ± 1.96 (P = 0.003). No significant changes in mean central corneal thickness were observed postoperatively. There were no major complications during and or after surgery.

Conclusion:

ICRS implantation using a unique mechanical dissection technique is a safe and effective treatment for keratoconus. All parameters improved by the 1-year follow-up.     

Intrastromal corneal ring segments: visual outcomes from a large case series

Background: To evaluate the clinical safety and efficacy of implanted Ferrara intrastromal corneal ring segments in a large sample of patients with ectatic corneal disease. Design: Retrospective, consecutive case series. Samples: A total of 1073 eyes of 810 patients consecutively operated from January 2006 to July 2008 were evaluated. Methods: Two groups were created according to the type of ring implanted: Group 1 – patients implanted with the 160° of arc ring – and Group 2 – patients implanted with the 210° of arc ring. Main Outcome Measures: Uncorrected visual acuity, best‐corrected visual acuity, keratometry, asphericity and pachymetry at the thinnest point of the cornea. All patients were evaluated using a corneal tomography (Pentacam, Oculus, Inc., Lynnwood, WA, USA). Results: For Group 1 patients, uncorrected visual acuity increased to 20/80, best‐corrected visual acuity increased to 20/40, asphericity decreased to ?0.35, spherical equivalent decreased to ?2.26 D and keratometry decreased to 45.72 D (P < 0.001 for each compared with preoperative values). For Group 2 patients, uncorrected visual acuity increased to 20/130, best‐corrected visual acuity increased to 20/60, asphericity decreased to ?0.56, spherical equivalent decreased to ?4.14 D and keratometry decreased to 48.10 D (P < 0.001 for each compared with preoperative values). The 210° intrastromal corneal ring segments reduced keratometry and asphericity more than the 160° intrastromal corneal ring segments did. The complication rate was 3.82%. Conclusions: Ferrara intrastromal corneal ring segments implantation is safe and effective and has a low complication rate. It can effectively reduce the corneal steepening and improve uncorrected visual acuity and best‐corrected visual acuity in patients with keratoconus.