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.     

【In Press】 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 (Q). All patients were evaluated using the Pentacam Scheimpflug system. RESULTS: The study evaluated 67 eyes. The mean follow-up was 16.81±13.96mo. The CDVA (logMAR) improved from 0.5±0.20 logMAR (20/60) to 0.3±0.21 logMAR (20/40) (P<0.01). The average K reduced from 49.8±7.01 D to 47.34±4.90 D (P<0.01). The asphericity changed from -0.60±0.86 to -0.23±0.67 (P<0.01). The mean preoperative tomographic astigmatism decreased from -8.0±3.45 D to -4.53±2.52 D (P<0.01). CONCLUSION: The new ICRS model with 140-degrees of arc effectively improved the visual acuity and reduced the high astigmatism usually found in patients with corneal ectasia.     

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.     

Clinical outcomes of management of posterior capsule rupture with air bubble techniques

AIM: To evaluate the clinical outcomes after implantation of a new intrastromal corneal ring segment associated with photorefractive keratectomy (PRK) to correct high myopia (ICRS HM) in patients with thin corneas. METHODS: We evaluated 42 eyes of 23 patients that had ICRS HM implantation followed by PRK. The mean age of patients was 29.1±7.12y (range 18 to 40 years old). Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), keratometry, spherical equivalent, pachymetry, and aberrometry were compared using ANOVA with repeated measurements assessed preoperatively and at last follow-up visit after the procedures. The refractive predictability and simulated/real corneal ablation were also assessed. RESULTS: The mean follow-up time after PRK was 6.8±1.6mo. The mean preoperative UCVA improved from 20/800 preoperative to 20/100 after ICRS and 20/35 after PRK. The mean preoperative BCVA was 20/25 (range from 20/40 to 20/20) and remained unchanged after ICRS HM implantation. Following the PRK the mean BCVA was 20/25 (range from 20/40 to 20/20). The mean spherical equivalent decreased from -7.25±1.12 (range -5.00 to -9.00) preoperatively to -3.32±1.0 (range -2.00 to -5.00) postoperatively (P<0.001) after ICRS HM, ICRS implantation and decreased from -2.44±1.51 preoperatively to 0.32±0.45 (range -0.625 to 0.875) postoperatively (P<0.001) after PRK. The change in BCVA and topographic astigmatism was statistically significant (P<0.0001). CONCLUSION: ICRS HM associated with PRK can be a tissue saving procedure and an alternative surgical option for correction of moderate to high myopia.     

Intacs implantation using a femtosecond laser for management of keratoconus: Comparison of 306 cases in different stages

PURPOSE: To evaluate the efficacy of intrastromal ring segment (Intacs, Addition Technology, Inc.) implantation and analyze outcomes according to different keratoconus stages. SETTING: Kudret Eye Hospital, Ankara, Turkey. METHOD: In this retrospective noncomparative case series, 306 keratoconic eyes of 255 patients who had Intacs segment implantation were reviewed. Patients were grouped according to the Amsler-Krumeich keratoconus classification (stage II, 155 eyes; stage III, 83 eyes; stage IV, 68 eyes). The uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), central corneal curvature, spherical and cylindrical manifest refractions, and central corneal thickness were analyzed and compared according to keratoconus stage. RESULTS: At a mean follow-up of 10.39 months +/- 5.04 (SD), the BCVA improved in 71.6% of eyes and the UCVA improved in 75.7% of eyes. The mean keratometry (K) decreased from 50.7 diopters (D) to 47.9 D (P<.05); the mean manifest spherical refraction, from -6.04 D to -3.09 D (P<.05); and the mean manifest cylindrical refraction, from -4.11 D to -3.82 D (P>.05). The changes in BCVA and manifest spherical and cylindrical refractions were not statistically different between the different keratoconus stages (P >.05). There was less change in UCVA and more improvement in the mean K value after Intacs treatment in stage IV than in the other stages (P<.05, analysis of variance). CONCLUSIONS: Intacs treatment with a femtosecond laser was effective for management of keratoconus of all stages. Improvement in UCVA may be less in severe keratoconus than in moderate keratoconus.     

Photorefractive keratectomy after cataract surgery in uncommon cases: long-term results

AIM: To evaluate the efficacy and safety of the excimer laser correction of the residual refractive errors after cataract extraction with intraocular lens (IOL) implantation in uncommon cases. METHODS: Totally 24 patients with high residual refractive error after cataract surgery with IOL implantation were examined. Twenty-two patients had a history of phacoemulsification and IOL implantation, and two had extra-capsular cataract extraction with IOL implantation. Detailed examination of preoperative medical records was done to explain the origin of the post-cataract refractive errors. All patients underwent photorefractire keratectomy (PRK) enhancement. The mean outcome measures were refraction, uncorretted visual acuity (UCVA), best corrected visual acuity (BCVA) and corneal transparency and follow up ranged from 1 to 8y. RESULTS: The principal causes of residual ametropia was inexact IOL calculation in abnormal eyes with high myopia and congenital lens abnormalities, followed by corneal astigmatism both suture induced and preexisting. After cataract surgery and before the laser enhancement the mean spherical equivalent (SE) was -0.56±3 D ranging from -4.62 to +2.25 D in high myopic patients, instead it was -1±1.73 D ranging from -3.25 to +3.75 D in the astigmatic eyes, with a mean cylinder of -3.75±0 ranging from -3 to +5.50 D. After laser refractive surgery the mean SE was 0.1±0.73, ranging from -0.50 to +1.50 in the myopic group, and it was -0.50±0.57 ranging from -1.25 to +0.50 in astigmatic patients, with a mean cylinder of -0.25±0.75. In myopic patients the mean UCVA and BCVA were 0.038±0.072 logMAR and 0.018±0.04 respectively, both ranging from 0.10 to 0.0. In astigmatic patients, the mean UCVA and BCVA were 0.213±0.132 and 0.00±0.0 respectively, UCVA ranging from 0.50 to 0.22 and BCVA was 0.00. All patients presented normal corneal transparency. No ocular hypertension was detected and no corneal haze was observed. All registered values remained stable also at the end line evaluation. CONCLUSION: The excimer laser treatment of residual refractive errors after cataract surgery with IOL implantation in abnormal eyes resulted in satisfactory and stable visual outcome with good safety and efficacy.     

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.     

单切口植入有晶状体眼后房型人工晶状体治疗高度近视

目的：评价单切口有晶状体眼后房型人工晶状体植入术治疗高度近视的有效性和安全性。

方法：对9例18眼高度近视患者行有晶状体眼后房型人工晶状体植入术。术后随访3～9mo,观察手术前后裸眼视力、最佳矫正视力、屈光度、散光变化、眼压、内皮细胞计数等。

结果：所有患者成功植入眼内接触镜(implantable contact lens,ICL),18眼手术前后平均屈光度分别为-13.38±-5.32,

-0.25±0.38D; 手术前后裸眼视力分别为0.06±0.04,0.6±0.2; 最佳矫正视力分别为0.5±0.3,0.7±0.3; 术后裸眼视力和最佳矫正视力均明显好于术前(P<0.05)。术前平均眼压为13.23±3.18mmHg,术后平均眼压为15.03±1.25mmHg; 内皮细胞计数术前为3 008±298个/mm²,术后为2 896±246个/mm²; 前房深度术前平均为3.56±0.29mm,术后为3.68±0.37mm,角膜散光术前0.52±0.30D,术后角膜散光0.67±0.45D,差异均无统计学意义(P>0.05)。

结论：单切口植入有晶状体眼后房型人工晶状体矫正高度近视近期临床效果有效、可靠,具有手术操作风险低、眼表损伤小、成本低、术源性散光小的优点,为一种适用的手术方式。     

ICL植入术矫正超高度近视的临床效果观察

目的:评估有晶状体眼后房型人工晶状体(ICL)矫正超高度近视的疗效及安全性。方法:对超高度近视患者20例40眼接受普通型ICL或散光型后房型人工晶状体(TICL)治疗,术前屈光度球镜-10.0～-18.0D,柱镜-0.25～-3.00D,等效球镜-15.32D,术后随访12mo,观察指标包括UCVA,BCVA、角膜地形图、主观和客观验光、角膜内皮细胞计数、眼压测量、裂隙灯检查。结果:术后12mo,裸眼视力≥0.8者占80.0%(32眼)。30.0%(12眼)的术眼BCVA较术前提高1行,15.0%(6眼)的术眼BCVA较术前提高2行。术后12mo术眼屈光度在±0.50D者达70.0%(28眼)。术前患者平均眼压为16±2.8mmHg,术后6mo平均眼压为17±3.4mmHg,术前术后相比较差异无显著性(t=0.518,P=0.776),术前患者角膜内皮细胞计数平均为2823±243.6个/mm2,术后6mo平均为2709±273.2个/mm2,术前术后比较无显著性差异(t=0.794,P=0.422)。未发生继发性青光眼、视网膜脱离及并发性白内障。结论:ICL植入术矫正超高度近视具有良好的疗效和安全性,远期效果有待进一步观察。     

Videokeratography in conductive keratoplasty

PURPOSE: We used EyeSys videokeratography to evaluate corneal shape changes induced by conductive keratoplasty, a procedure that utilizes radio frequency energy to alter corneal shape to correct hyperopia. METHODS: Follow-up data were available for 19 eyes (out of 24 eyes of 13 patients). Preoperative spherical hyperopia ranged from +0.75 to +3.25 D with astigmatism <0.75 D. Manifest refractive spherical equivalent refraction (MRSE), uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), topographical parameter predicted corneal acuity (PCA), corneal uniformity index (CU Index), regular astigmatism, total astigmatism, average simulated keratometry (Avg Sim K), effective refractive power, and asphericity were measured preoperatively and at 6 and 12 months postoperatively. RESULTS: Twelve months postoperatively, mean PCA, CU Index, and BSCVA were maintained at preoperative levels. Mean UCVA (LogMAR) improved from 0.53+/-0.21 to 0.10+/-0.19 (P<.05) with a mean MRSE change from +1.62+/-0.76 D to -0.06+/-0.84 D (P<.05) from preoperative to 12 months postoperative. Mean asphericity increased +0.044+/-0.24 D (P>.05), mean Avg Sim K increased 1.88+/-0.72 D (P<.05), mean effective refractive power increased 1.71+/-0.79 D (P<.05), mean cylinder (cycloplegic refraction) increased 0.19+/-0.36 D (P<.05), mean regular astigmatism increased 0.25+/-0.49 D (P>.05), and mean irregular astigmatism decreased 0.01+/-0.13 D (P>.05) from preoperative to 12 months after conductive keratoplasty. CONCLUSIONS: Avg Sim K and effective refractive power changes support the refractive results; 12-month postoperative maintenance of BSCVA, PCA, and CU Index suggest the procedure is safe. Conductive keratoplasty induced a slight regular astigmatism in some eyes, which decreased with time. The increase in mean corneal asphericity indicated possible induction of central and peripheral cornea changes.     

Ferrara intracorneal ring segments for keratoconus

PURPOSE: To assess the outcome of Ferrara intracorneal ring segments for keratoconus. SETTING: Private practice and university hospital, Porto Alegre, Brazil. METHODS: In this retrospective noncomparative interventional case series, 51 keratoconus eyes of 47 patients that had Ferrara intracorneal ring segment implantation were reviewed. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), central corneal curvature, corneal astigmatism, surface regularity index, surface asymmetry index, and complications were analyzed. RESULTS: At a mean follow-up of 13.0 months +/- 8.7 (SD), the BSCVA improved in 86.4% of eyes, was unchanged in 1.9%, and worsened in 11.7%. The UCVA improved in 86.4% of eyes, was unchanged in 7.8%, and worsened in 5.8%. The mean spherical equivalent (SE) was reduced from -6.08 +/- 5.01 diopters (D) to -4.55 +/- 5.71 D and the mean refractive astigmatism, from -3.82 +/- 2.13 D to -2.16 +/- 2.07 D. The mean central corneal curvature was reduced from 48.76 +/- 3.97 D to 43.17 +/- 4.79 D. Eyes with central keratoconus had statistically significantly better results than eyes with inferior keratoconus in topographic astigmatism, SE, and refraction cylinder. Penetrating keratoplasty was avoided in 38 eyes (74.5%) during the follow-up. Intracorneal ring segment decentration occurred in 2 eyes (3.9%), segment extrusion in 10 eyes (19.6%), bacterial keratitis in 1 eye (1.9%) with segment extrusion, and a disciform keratitis in 1 eye (1.9%). CONCLUSION: Implantation of Ferrara intracorneal ring segments in patients with keratoconus was a safe and reversible procedure that led to stable results and avoided or delayed PKP in many cases.     

Efecto de los segmentos anulares intracorneales en la topografía corneal posterior en ojos con queratocono

PurposeTo analyze the changes in the anterior and posterior corneal surfaces measured with a Scheimpflug imaging device in keratoconus patients implanted with intracorneal ring segments and to correlate those changes with the visual outcomes.MethodsThis prospective interventional case series study included 92 eyes of 60 patients with keratoconus who underwent Kerarings (Mediphacos, Belo Horizonte, Brazil) intracorneal ring segments implantation. Keratometric (K) readings, corneal asphericity (Q value) and elevations of both anterior and posterior corneal surfaces were evaluated using a Scheimpflug imaging device preoperatively and at one, 3, 6 and 12 months after surgery.ResultsThe mean best corrected visual acuity (BCVA) improved from 0.61 to 0.19 logMAR at 12 months after surgery. Both anterior and posterior corneal surfaces showed significant flattening with statistically significant reduction of the mean anterior K reading by 3.39 D and the mean posterior K reading by 0.39 D (P < .001) at 12 months. Statistically significant change of the anterior Q to a less negative value (from ?1.05 to ?0.36) was observed (P < .001) with no significant change of the posterior Q value. Improvement of the anterior Q was significantly correlated to better postoperative BCVA (P = .03). Better postoperative BCVA significantly correlated to better preoperative BCVA, flatter preoperative anterior and posterior K, less prolate anterior Q value and lower anterior elevations.ConclusionsImplanted with intracorneal ring segments implantation has a significant flattening effect on both anterior and posterior corneal surfaces. Improvement of corneal asphericity is correlated to better visual outcome. Certain preoperative parameters were predictive factors of the postoperative visual improvement.     

Intacs insertion with the femtosecond laser for the management of keratoconus: one-year results

PURPOSE: To assess the outcomes of intrastromal ring segment (Intacs, Addition Technology) implantation for keratoconus using the femtosecond laser. SETTING: Kudret Eye Hospital, Ankara, Turkey. METHODS: In a retrospective noncomparative case series, 118 eyes of 69 patients with keratoconus who had Intacs segments implanted with the femtosecond laser were evaluated. Preoperative and postoperative evaluations included slitlamp examination, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and mean keratometry values measured with the Pentacam Scheimpflug camera (Oculus Opticgerate GmbH). All parameters were assessed preoperatively and 1 year after Intacs implantation. RESULTS: Intacs were successfully implanted in all eyes. At the end of the first postoperative year, 81.3% of eyes had improved UCVA and 73.7% had improved BCVA. The mean keratometry decreased from 51.56 diopters (D) to 47.66 D, and the mean refractive spherical equivalent decreased from -7.57 D to -3.72 D. CONCLUSIONS: Intacs implantation with the femtosecond laser was safe and effective for the treatment of keratoconus. All parameters had improved by the 1-year follow-up.     

Intrastromal ring segment insertion using a femtosecond laser to correct pellucid marginal corneal degeneration

PURPOSE: To assess the outcomes of intrastromal ring segment (Intacs, Addition Technology) implantation using a femtosecond laser in patients with pellucid marginal corneal degeneration. SETTING: Kudret Eye Hospital, Ankara, Turkey. METHODS: In this retrospective noncomparative case series, 9 eyes of 6 patients with pellucid marginal corneal degeneration had implantation of Intacs segments by a femtosecond laser technique. Preoperative and postoperative evaluations included slitlamp examination, uncorrected (UCVA) and best corrected (BCVA) visual acuities, and keratometry by a Pentacam Scheimpflug camera (Oculus Opticgerate GmbH). All parameters were reviewed within 6 months. RESULTS: Intacs were successfully implanted in all eyes. The UCVA significantly improved from preoperatively to 6 months after Intacs implantation (mean 0.18 +/- 0.24 [SD] and 0.53 +/- 0.23, respectively). The mean difference between the preoperative and postoperative UCVA was 3.5 +/- 1.6 lines (P = .008). The BCVA also significantly improved from preoperatively to 6 months after implantation (mean 0.63 +/- 0.26 and 0.85 +/- 0.18 at 6 months, respectively). The Snellen BCVA was 1.0 in 5 eyes postoperatively. The mean difference between preoperative and postoperative BCVA was 2.3 +/- 51 lines (P = .011). The mean preoperative spherical refraction decreased from -3.86 +/- 2.91 diopters (D) to -2.77 +/- 1.43D (P = .091) and the mean cylindrical refraction, from -2.41 +/- 2.27 D to -0.94 +/- 1.07 D (P = .046). The mean central corneal curvature decreased from 48.20 +/- 4.19 D preoperatively to 46.90 +/- 5.00 D (P = .008) at 6 months and the mean posterior elevation, from 53.88 +/- 21.72 microm to 32.55 +/- 11.23 microm (P = .008). CONCLUSION: Intacs insertion using a femtosecond laser was safe and efficient in the correction of pellucid marginal corneal degeneration.     

Toric intraocular lens for correction of high corneal astigmatism in cataract patients

AIM: To evaluate the efficacy of Bi-Flex toric intraocular lens (T-IOL; Medicontur, Medical Engineering, Ltd., Inc.) implantation to correct preexisting astigmatism in patients having cataract surgery. METHODS: This retrospective consecutive study included 22 eyes of 16 patients with more than 2.50 diopters (D) of corneal preexisting astigmatism having cataract. Preoperative and postoperative uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), objective and subjective refraction and keratometric and topographic cylinder were measured. Postoperative the toric IOL axis was evaluated using vector analysis. RESULTS: Postoperatively, subjective refractive cylinder was reduced significant (P<0.05) from 4.05±1.53 D to 1.35±0.86 D. The component J0 reduced in magnitude from -0.81±2.02 D to -0.12±0.62 D (P<0.05). Both, UCVA and BCVA improved significantly at 1mo after surgery (P<0.05 in both cases). After the surgery, the UCVA and BCVA were 0.24±0.19 and 0.06±0.08, respectively. The mean toric IOL axis rotation was 2.95±5.25 degree, with rotation less than 10 degrees in 86.36% of eyes. No differences in mean keratometric values obtained before and after surgery were found (P>0.05 for J0 and J45). CONCLUSION: Implantation of the Bi-Flex toric IOL is a safe and effective method to correct the preexisting regular astigmatism (greater than 2.50D).     

A retrospective analysis of vision correction and safety in keratoconus patients wearing Toris K soft contact lenses

The purpose of this study was to investigate the efficacy and safety of the Toris K silicone hydrogel contact lens (SwissLens; Prilly, Switzerland) in keratoconus patients. A database with information on 50 keratoconus patients (64 eyes) fitted with Toris K soft contact lenses over a 2-year period was retrospectively reviewed. Demographic data, prefitting refraction, the reason for choosing the Toris K soft contact lens, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), best-corrected visual acuity with a rigid gas permeable lens (BCVA RGP), best-corrected visual acuity with the Toris K lens (BCVA Toris K), and complications were evaluated. The mean age ± standard deviation at the time of fitting was 27.92 ± 9.86 years. The mean spherical refractive power was ?4.62 ± 6.53 dioptres, and the mean cylinder was ?3.78 ± 2.43 dioptres. The most common reason for using Toris K soft contact lenses was an inability to fit the patient with a RGP contact lens. There was a statistically significant difference between UCVA and BCVA Toris K (p = 0.0001), as well as between BSCVA and BCVA Toris K (p = 0.0001). However, there was no statistically significant difference between BCVA Toris K and BCVA RGP (p = 0.20). Superficial punctate keratitis and giant papillary conjunctivitis were the most common complications. The Toris K contact lens is a viable alternative for the optical management of all grades of keratoconus. The Toris K soft contact lens is a promising alternative for the visual rehabilitation of keratoconus patients who cannot tolerate RGP lenses or achieve a good fit.     

Long-term follow up of intracorneal ring segment implantation in 932 keratoconus eyes

PurposeTo evaluate the progression of keratoconus in 932 eyes of 659 patients through visual, refractive and topographic data after intracorneal ring segment (ICRS) implantation.MethodsRetrospective review of 659 patients who underwent ICRS (Intacs®) implantation for keratoconus between September 1997 and November 2017. Demographics, preoperative and postoperative uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) in LogMAR, corneal topography parameters (thinnest pachymetry, Kmax), central corneal pachymetry and total follow-up time were evaluated. Statistical analysis was performed using IBM SPSS Statistics 24.0 for windows.ResultsNine hundred and thirty-two eyes of 659 patients, with a mean age of 30.41 years (range 11–76 years), were evaluated. Mean total follow up time was 3.02 years. Forty-one eyes had a total follow up of over 10 years. Both UCVA and BCVA improved significantly after ICRS implantation (P < 0.01). Only 18 eyes (2.66% of eyes of patients under 35 years of age) were found to have progression of keratoconus based on postoperative topographic data (Mean age 23.00 years, 55.6% female, total follow-up 2 to 10 years)ConclusionICRS implantation showed long-term improvement and stability in visual and topographic results in a large case series of patients with keratoconus. Only a minimal rate of progression was detected in young patients. However, further prospective studies need to be conducted to better define predictability of postoperative visual outcomes and progression.     

Intracorneal ring segment implantation for the management of keratoconus: safety and efficacy

PURPOSE: To assess the safety and efficacy of intracorneal ring segment (Intacs, Addition Technology, Inc.) implantation in the management of keratoconus. SETTING: Department of Ophthalmology and Ophthalmic Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran. METHODS: This prospective case series comprised 30 keratoconic eyes (22 patients) with a clear central cornea that had Intacs implantation. All patients were contact-lens intolerant. The main outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, keratometry, and pachymetry. Patients were examined before Intacs implantation as well as 1 week and 1, 3, and 6 months postoperatively. RESULTS: The mean age of the 5 women and 17 men was 25.9 years +/- 5.29 (SD). The mean UCVA improved from 0.60 +/- 0.311 logMAR preoperatively to 0.29 +/- 0.20 logMAR 6 months postoperatively (P<.001) and the mean BSCVA, from 0.25 +/- 0.16 logMAR to 0.13 +/- 0.14 logMAR, respectively (P<.001).The mean spherical equivalent improved from -6.93 +/- 3.52 diopters (D) preoperatively to -3.23 +/- 2.81 D at 6 months and the mean refractive cylinder, from -4.65 +/- 1.85 D to -3.90 +/- 1.70 D, respectively. The mean keratometry decreased from 49.84 +/- 3.58 D preoperatively to 47.90 +/- 3.58 D postoperatively (P<.001). Three eyes had ring exposure, and 1 eye had bacterial keratitis and ring exposure. CONCLUSION: Intacs implantation appeared to be effective in improving UCVA and BSCVA in patients with mild to moderate keratoconus and contact-lens intolerance.     

Toric人工晶状体在合并高度角膜散光白内障中的应用

目的：评估Bi-Flex toric人工晶状体在合并散光的白内障中的应用。

方法：回顾性研究包括16例22眼合并2.50D以上散光的白内障患者。测量了术前与术后的裸眼视力、最佳矫正视力、客观及主观验光、角膜散光仪和角膜地形图测量的散光值。术后人工晶状体屈光轴位置使用向量进行分析。

结果：术后,主观验光散光值从4.05D±1.53D显著降低至1.35D±0.86D,(P<0.05)。屈光轴位置指标J₀,从术前的-0.81±2.02D降至 -0.12±0.62D(P<0.05)。裸眼视力和最佳矫正视力术后1mo时均显著改善(P<0.05),分别为0.24±0.19和0.06±0.08。人工晶状体屈光轴旋转程度平均为2.95±5.25度,86.36%的患眼旋转程度小于10度。术前、术后角膜散光计测量值未见显著差异(J₀ 和J₄₅均有P>0.05)。

结论：对于合并大于2.50D散光的白内障患者,Bi-Flex toric人工晶状体植入是安全有效的治疗方法。     

Intrastomal corneal ring segments: reversibility of refractive effect

PURPOSE: To evaluate the reversibility of refractive effect following removal of the ICRS (intrastromal corneal ring segments; Intacs). METHODS: Data from 34 eyes from which ICRS were removed during United States FDA Phase II and III clinical trials were evaluated with regard to segment size, loss or change of best spectacle-corrected visual acuity (BSCVA), any change of uncorrected visual acuity (UCVA), manifest spherical equivalent refraction, manifest cylinder refraction, stability of manifest cylinder refraction, and subjective visual symptoms. RESULTS: Out of 725 initial or contralateral eyes placed with the ICRS during Phase II and III clinical trials, segments were removed from 34 eyes (4.7%). Other than one (1/725, 0.1%) safety related ICRS removal, 30/725 (4.1%) were due to visual symptoms. ICRS removal was accomplished under topical anesthesia without complications in all eyes. The mean length of time the segments remained in the cornea after initial surgery was 10.3 +/- 5.4 months. At 3 months after ICRS removal, 21 eyes had monitored data available and were within +/-1 line or 10 letters of their preoperative BSCVA. Twenty eyes (20/21, 95%) returned to within +/-1.00 D of their preoperative manifest spherical equivalent refraction. All eyes had a stable refraction at the 3-month examination after removal, and a manifest spherical equivalent refraction within +/-1.00 D of their 1-month examination after removal. Nineteen eyes (19/21, 90%) returned to within +/-2 lines and 16 eyes (16/21, 76%) returned to within +/-1 line of preoperative UCVA. CONCLUSION: The ICRS (Intacs) was easily and safely removed, and eyes returned to preoperative refractive status within 3 months.