Visual outcomes of a new implantable phakic contact lens in patients with stable keratoconus

AIM: To assess the efficacy, safety, stability and predictability of an implantable Phakic contact lens in patients with stable keratoconus. METHODS: The uncorrected and the best corrected visual acuity, defocus curve, contrast sensitivity, refraction and possible side effects were measured in 14 patients after utilizing implantable phakic contact lens (IPCL) to correct refractive errors. The result was assessed for more than 6mo. RESULTS: The mean preoperative spherical equivalent (SE) and astigmatism got changed from -6.94±2.79 DS and -4.24±1.42 DC to -0.23±0.43 DS and -1.05±0.49 DC, respectively at the last examination after 6mo. Before the preoperative the mean Snellen visual acuity was 0.18±0.10 logMAR. The mean uncorrected and the best corrected visual acuity got changed to 0.13±0.10 logMAR and 0.05±0.15 logMAR, respectively in 6mo. The mean safety indices were 1.11. There was no loss of visual acuity in any of the eyes and 22 eyes (78.5%) gained one or more lines. Twenty eyes (71.4%) were within 0.50 ?D and 27 (96.42%) were within ±1.00?D of the desired SE refraction. There was a change in manifest refraction of -0.23±0.43 (range from -1.00 to +0.75) from the first week of surgery to 6mo. Contrast sensitivity got improvement value at 3 per degree (P<0.005) after Toric IPCL implantation. The total 6mo corneal endothelial cell loss (ECL) was <5%. Intraocular pressure (IOP) was 11.32±2.28 mm Hg after 6mo. CONCLUSION: The clinical consequences of the present study exhibit the efficacy, safety, and predictability of Toric implantable Phakic contact lens in the correction of myopia and myopic astigmatism related with stable keratoconus.     

稳定型圆锥角膜患者植入新型Phakic角膜接触镜的视觉效果分析

目的：评估可植入式Phakic角膜接触镜治疗稳定型圆锥角膜患者的疗效、安全性、稳定性和可预测性。

方法：共14例患者采用植入式Phakic角膜接触镜(IPCL)矫正屈光不正,测量了未矫正视力、最佳矫正视力、离焦曲线、对比敏感度、屈光度及可能的副作用。评估结果超过6mo。

结果：平均等效球镜度(SE)和散光在术后6mo末次检查时由术前-6.94±2.79 DS和-4.24±1.42 DC分别变为术后-0.23±0.43 DS和-1.05±0.49 DC。术前平均Snellen视力为0.18±0.10。6mo内未矫正视力和最佳矫正视力平均值分别为0.13±0.10和0.05±0.15。平均安全指数为1.11。所有眼视力均无降低,其中22眼视力提高超过1行。20眼(71.4%)屈光度在0.50 D以内,27眼(96.42%)在±1.00 D以内。术后1wk至6mo,屈光度变化为-0.23±0.43(范围： -1.00至+0.75)。6mo内角膜内皮细胞(ECL)丢失率小于5%。术后6mo眼压(IOP)为11.32±2.28 mmHg。

结论：Toric植入式Phakic角膜接触镜在矫正与稳定圆锥角膜相关的近视和近视散光方面具有有效性、安全性和可预测性。     

Clinical performance of a custom-designed soft contact lens in patients with keratoconus and intolerance to rigid contact lenses

Japanese Journal of Ophthalmology - This study evaluated the efficacy and safety of YOUSOFT® soft contact lens (CL) (TOMEY-CL) in patients with keratoconus and intolerance to rigid CLs....     

Clinical and self-reported outcomes after multifocal intraocular lens implantation of patients with stable keratoconus

International Ophthalmology - Multifocal intraocular lens (IOL) implantation is generally not considered in patients with keratoconus; however, it may provide good optical results in selected...     

Kalt, keratoconus, and the contact lens

A complete English translation is presented of the communication given in 1888 by Professor Photinos Panas in which he reported the innovative use by his junior colleague, Dr. Eugène Kalt, of a contact shell in a case of keratoconus. The patient showed a dramatic visual improvement but tolerance of the shell was limited to a few hours. A biography of Kalt is included, together with a number of explanatory notes.     

Limitations of eyeglasses and contact lens care of keratoconus

The principal criteria for the correction of keratoconus with spectacles are the upper radii values, meridian differences and the position of the apex in relation to the fixation line. Possibilities of correction with contact lenses may be limited by optical (opacities, bad peripheral image influence etc.) and fitting factors (among others increasing ectasis, major differences in the arrow height between the apex of the cone and the surrounding cornea). Some of the problems encountered hitherto can be solved with a new "smooth flat fitting" lens.     

Effects of contact lens wearing on keratoconus: a confocal microscopy observation

AIM: To evaluate the corneal cell morphology of new keratoconus patients wearing two different types of rigid gas-permeable (RGP) contact lenses for 1y. METHODS: Thirty nine eyes of 39 new keratoconus patients were selected and randomly fitted with two types of RGP contact lenses. Group 1 had 21 eyes with regular rigid gas-permeable (RRGP) contact lens and rest 18 eyes were in group 2 with specially designed rigid gas-permeable (SRGP) contact lens. Corneal cell morphology was evaluated using a slit scanning confocal microscope at no-lens wear and after 1y of contact lens wearing. RESULTS: After 1y of contact lens wearing in group 1, the mean anterior and posterior stromal keratocyte density were significantly less (P=0.006 and P=0.001, respectively) compared to no-lens wear. The mean cell area of anterior and posterior stromal keratocyte were also significantly different (P=0.005 and P=0.001) from no-lens wear. The anterior and posterior stromal haze increased by 18.74% and 23.81%, respectively after 1y of contact lens wearing. Whereas in group 2, statistically significant changes were observed only in cell density & area of anterior stroma (P=0.001 and P=0.001, respectively) after 1y. While, level of anterior and posterior stromal haze increased by 16.67% and 11.11% after 1y of contact lens wearing. Polymegathism and pleomorphism also increased after 1y of contact lens wearing in both the contact lens groups. CONCLUSION: Confocal microscopy observation shows the significant alterations in corneal cell morphology of keratoconic corneas wearing contact lenses especially in group 1. The type of contact lens must be carefully selected to minimize changes in corneal cell morphology.     

Alterations in contact lens fitting parameters following cross-linking in keratoconus patients of Indian ethnicity

Background

Most studies have either excluded patients using contact lens or not taken their effect while analyzing post-collagen cross-linkage (CXL) changes. This study aims to study impact of CXL on lens fit in both quantitative and qualitative manner.

Objective

To evaluate changes in CL fit post-CXL and to correlate these changes with alterations in corneal topographic parameters.

Study design

Prospective intervention study on 20 keratoconic eyes of 14 patients (age > 18 years), with mean follow-up of 6 months.

Methods

Preoperative evaluation included UCVA, BCVA, corneal topography, AS-OCT and contact lens fit. Patients were evaluated at 2 weeks, 1, 3, 4 and 6 months post-CXL; contact lens trial with standard rigid gas permeable (RGP) lens performed at 3 and 6 months.

Main outcome measure

Changes in objective and subjective parameters of lens fit.

Results

Over 6-month follow-up post-CXL, improvement in visual acuity by one Snellen line, both UCVA and BCVA, and decrease in flat/mean/apical K by 0.8 D, 0.8 D and 1.3 D, respectively, resulted in significant improvement in RGPCL fit. Almost 20% increase in near-ideal fit, 100% acceptable fit, 65% improved subjective comfort with 8 h/day increase in duration of comfortable CL wear were observed.

Conclusion

Despite no statistically significant change in objective parameters of lens fit, a tendency for flatter lens fit along with contact lens induced further flattening of the ectatic cornea which resulted in marked improvement in both objective and subjective contact lens fit.

     

硬性透气性角膜接触镜矫正圆锥角膜疗效分析

目的 探讨硬性透气性角膜接触镜(RGP)矫正圆锥角膜的临床疗效及安全性.方法 对2004～2010年视光门诊应用RGP矫正的63例圆锥角膜患者,男41例,女22例.年龄16-35岁,平均年龄(24.6±7.81)岁.双眼57例,单眼6例.对散光度明显增大,框架眼镜矫正视力下降的患者应用电脑验光仪、角膜地形图仪、角膜内皮镜检测,筛查圆锥角膜病.对确诊及疑似圆锥角膜患者根据角膜圆锥程度采用普通RGP镜或特殊设计圆锥角膜镜进行矫正.测量RGP矫正视力及戴镜验光.应用SPSS13.0统计软件对框架眼镜矫正视力、RGP矫正视力、及配戴RGP前后球镜度、散光度进行统计学分析,P＜0.05为有统计学意义.结果 (1)本组病例框架眼镜矫正视力均值:0.56±0.29,RGP矫正视力均值:0.93±0.20,(t=-14.627,P=0.000),RGP矫正视力明显优于框架矫正视力.(2)配戴RGP前散光均值:(-4.16±2.19)DC,配戴RGP后散光均值:(-0.77±1.2)DC,(t=-14.585,P=0.000),配戴RGP散光度明显降低与配镜前比较差异显著有统计学意义.(3)其中22只眼平均观察3.5年,其中1只眼角膜混浊加重,施板层角膜移植术.其余21只眼角膜散光度降低,有统计学意义.角膜厚度、角膜曲率变化差异无统计学意义.结论 RGP矫正圆锥角膜不规则散光明显提高矫正视力,改善视觉质量,在一定程度上延缓圆锥角膜病的进展.     

MeniconE-1硬性透气性接触镜矫治圆锥角膜的临床观察

目的观察MeniconE-1硬性透气性角膜接触镜（MeniconE1 RGP）矫治圆锥角膜的临床应用效果。方法在角膜地形图指导下,为12例22眼圆锥角膜验配MeniconE-1RGP,评估镜片配适状态,比较最佳框架眼镜和Menicon E-1 RGP矫正视力,随访4个月～7个月,观察并发症的发生情况。结果所有病例均能通过Menicon E-1 RGP获得满意的矫正视力,Menicon E-1 RGP与框架眼镜矫正视力比较差别有统计学意义（t=25.49,P〈0.05）。18眼（81.82%）为三点接触配适状态,2眼（9.09%）为顶点离开的配适状态,2眼（9.09%）为可接受的顶点接触配适状态。结论在角膜地形图指导下,圆锥角膜患者验配MeniconE-1RGP成功率高,容易达到比较好的配适状态,获得满意的矫正视力,且无严重并发症发生。