Contact Lenses In Keratoconus Research Articles

Corneal Surface Elevation and Thickness in Relation to the Fit of Rigid Contact Lenses in Keratoconus and After Corneal Cross-Linking

Corneal Surface Elevation and Thickness in Relation to the Fit of Rigid Contact Lenses in Keratoconus and After Corneal Cross-Linking

Era of "Dr. YouTube": Evaluation of YouTube Videos as a Valid Source for Patient Education on Keratoconus.

To evaluate the content, quality, and reliability of keratoconus-related YouTube videos as sources for patient education. YouTube was queried using the keywords "keratoconus," "contact lenses for keratoconus," "corneal cross-linking," and "corneal transplant surgery for keratoconus." Two ophthalmologists independently classified videos as useful, misleading, or patient testimonials and rated them using the DISCERN score (range, 16-75), Journal of the American Medical Association score (JAMAS; range, 0-4), Global Quality Score (GQS; range, 1-5), and Keratoconus-Specific Score (KSS; range, 0-32). Interrater agreement was analyzed using intraclass correlation coefficients. Multivariate linear regression models were fitted to identify factors associated with quality and popularity indices. Of the 300 videos screened, 201 were included in the study, 58% were classified as useful, 13% as misleading, and 29% as patient views. Overall video quality was poor, with an average DISCERN score of 22, JAMAS of 1.2, GQS of 1.8, and KSS of 4.5. Misleading videos scored significantly lower than average but had higher popularity compared with useful videos. Video length inversely correlated with popularity index. Television shows were more likely to share misleading information than other uploaders, whereas all videos uploaded by university channels provided useful information but constituted only 12% of all videos. Videos rated the best source of information were not the ones most popular. YouTube has great potential to change the attitude of individuals both for and against the right choice. Therefore, health professionals should act to use this potential in favor of effective and reliable health communication.

Clinical Outcome of Hybrid Contact Lenses in Keratoconus.

To report the clinical outcome of hybrid contact lens fitting in keratoconus. A retrospective chart review was performed of keratoconus patients who had been fitted with hybrid contact lenses in one or both eyes. Patients with a history of previous intraocular surgery (except for corneal crosslinking) and relevant concurrent ocular disease limiting visual outcome were excluded. The outcome data at 6-month follow-up included hybrid lens-corrected visual acuity, wearing time, and lens discontinuation. Fifty-four keratoconus patients (102 eyes) were included. Mean visual acuity with habitual correction before hybrid lens fitting was 0.63±0.29 (decimal Snellen). Eyes were fitted with Eyebrid lenses (LCS Laboratories, Caen, France) and SynergEyes lenses (SynergEyes Inc., Carlsbad, CA). Refits were necessary in 13 eyes, because of poor fitting (76.9%) or suboptimal refraction (23.1%). Visual acuity had significantly improved with hybrid lenses (0.93±0.14; P<0.0001). In 37 eyes (37.8%), hybrid lens wear was discontinued within 6 months after lens fitting. Reported issues were discomfort in 27 eyes (73%), handling difficulties in 14 eyes (37.8%) and poor vision in 1 eye (2.7%). Success rate of lens fitting was significantly correlated to cone morphology (P=0.01). New generation hybrid lenses are an appropriate, safe therapeutic option for keratoconus patients. Excellent visual outcomes are achieved in successful fittings, yet a dropout rate of 37.8%-mainly occurring in sagging, more peripheral, cones - still limit their clinical success.

Challenges Face during Fitting of RGP Contact Lenses in Keratoconus

Challenges Face during Fitting of RGP Contact Lenses in Keratoconus

Results in keratoconus correction with Kerasoft 3 Contact lenses

Introduction: The purpose of the paper was to evaluate the indications, fitting, advantages and functional results of Kerasoft 3 contact lenses in keratoconus. Material and method: A retrospective single center study was performed at Oculens Private Clinic in Cluj-Napoca, Romania. Our study included 61 eyes of 35 patients diagnosed with keratoconus in different stages of evolution fitted with Kerasoft 3 lens. The study was undergone between August 2015 and January 2019. Results: In our study, the mean age of the patients was 26.36±8.69 years. The group of study included 80.32% males and 19.62% females. Regarding previous surgeries, CXL was performed in 25 eyes, ICR in 1 eye, CXL and ICR in 15 eyes. The mean BCVA habitual was 0.38±0.19 logMar and with the lens 0.22±0.23 logMar (p<0.01). Spherical equivalent (SE) at baseline was -5.78 and after fitting the lens it decreased to -0.46. Comfort and tolerance level were maximum in all cases. No significant complications were noted with the use of contact lens. Conclusions: Kerasoft 3 contact lenses provide many of the benefits of RGP lenses (avoiding RGP's discomfort and allergic reactions), along with excellent comfort, visual acuity, high oxygen permeability and longer wearing times. Abbreviations: CXL = cross-linking; ICR = intrastromal corneal ring; BCVA = best corrected visual acuity; SE = spherical equivalent; RGP = rigid gas permeable contact lenses.

Binocular cross-correlation analyses of the effects of high-order aberrations on the stereoacuity of eyes with keratoconus.

Stereoacuity losses are induced by increased magnitudes and interocular differences in high-order aberrations (HOAs). This study used keratoconus as a model to investigate the impact of HOAs on disparity processing and stereoacuity. HOAs and stereoacuity were quantified in subjects with keratoconus (n = 21) with HOAs uncorrected (wearing spectacles) or minimized (wearing rigid gas-permeable contact lenses) and in control subjects without keratoconus (n = 5) for 6-mm pupil diameters. Disparity signal quality was estimated using metrics derived from binocular cross-correlation functions of stereo pairs convolved with point-spread functions from these HOAs. Metrics computed for all subjects were compared with stereoacuities. The effects of contrast losses and phase shifts on disparity signal quality were studied independently by manipulating the amplitude and phase components of optical transfer functions. The magnitudes, orientations, interocular relationships in magnitude, and shape of the point-spread function affected the cross-correlation metrics that determine disparity signal quality. Stereoacuity covaries strongly with cross-correlation metrics and moderately with image-quality metrics. Both phase distortions and contrast losses due to HOAs significantly influence computations of binocular disparity. HOA-induced stereoacuity reductions are attributable to disparity blur and noise from image properties that reduce the height and kurtosis of the peak stimulus disparity match of the cross-correlation. Phase distortions and contrast losses due to HOAs are both partly responsible for the greater stereoacuity losses seen with spectacles compared to rigid gas-permeable contact lenses in keratoconus.

Contact Lenses for Keratoconus- Current Practice.

Background:Keratoconus is a chronic, bilateral, usuallly asymmetrical, non-inflammatory, ectatic disorder, being characterized by progressive steepening, thinning and apical scarring of the cornea. Initially, the patient is asymptomatic, but the visual acuity gradually decreases, resulting in significant vision loss due to the development of irregular astigmatism, myopia, corneal thinning and scarring. The classic treatment of visual rehabilitation in keratoconus is based on spectacles and contact lenses (CLs).Objective:To summarize the types of CLs used in the treatment of keratoconus. This is literature review of several important published articles focusing on the visual rehabilitation in keratoconus with CLs.Method:Gas permeable (GP) CLs have been found to achieve better best corrected visual acuity than spectacles, eliminating 3rd-order coma root-mean-square (RMS) error, 3rd-order RMS, and higher-order RMS. However, they have implicated in reduction of corneal basal epithelial cell and anterior stromal keratocyte densities. Soft CLs seem to provide greater comfort and lower cost, but the low oxygen permeability (if the lens is not a silicone hydrogel), and the inability to mask moderate to severe irregular astigmatism are the main disadvantages of them. On the other hand, scleral CLs ensure stable platforms, which eliminate high-order aberrations and provide good centration and visual acuity. Their main disadvantages include the difficulties in application and removal of these lenses along with corneal flattening and swelling.Result:The modern hybrid CLs are indicated in cases of poor centration, poor stability or intolerance with GP lenses. Finally, piggyback CL systems effectively ameliorate visual acuity, but they have been related to corneal neovascularization and giant papillary conjunctivitis.Conclusion:CLs seem to rehabilitate visual performance, diminishing the power of the cylinder and the high-order aberrations. The final choice of CLs is based on their special features, the subsequent corneal changes and the patient’s needs.

Implantable Contact Lenses in Keratoconus

ABSTRACT Keratoconus is a progressive inherited disorder with varying economic and social consequences. Varying modalities of visual rehabilitation such as spectacles, contact lenses, surgical treatment in the form of corneal collagen cross-linking to arrest progression, and surface refractive procedures such as photorefractive keratectomy, implantation of phakic intraocular lenses (IOLs), or Intacs have been undertaken with varying results. This review article focuses on the introduction of phakic IOLs/implantable contact lenses in keratoconus. Thorough research was made on PubMed, Google, HINARI, and related sites for all related material, and it was thoroughly studied to draft this article. How to cite this article Gupta S. Implantable Contact Lenses in Keratoconus. Int J Kerat Ect Cor Dis 2016;5(1):17-20.

Feasibility of custom-made hydrogel contact lenses in keratoconus with previous implantation of intracorneal ring segments

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). 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. 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 11.2h±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. 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.

Feasibility of custom-made hydrogel contact lenses in keratoconus with previous implantation of intracorneal ring segments

Purpose: To analyze the feasibility of a custom-made hydrogel silicone contact lens (CL) (material Efrofilcon-A) in keratoconus with intracorneal ring segments (ICRS) and to compare outcomes taking in consideration the geometry of the CL-full periphery (FP) vs. sector management control (SMC)-fitted.

Long-Term Effect and Safety of Contact Lenses for Keratoconus

Purpose: To evaluate the long-term clinical effect and safety of YK-KC lens (LucidKorea Ltd., Seoul, Korea) for keratoconus. Methods: In this study we investigated 152 keratoconic eyes fitted with YK-KC lens and followed up for at least 5 years. We assessed retrospectively self-reported patient comfort, best corrected visual acuity, corneal topographic indices before and after contact lens fitting and complications during contact lens wearing. Results: The study included 57 male and 40 female patients with a mean age of 28.6 ± 8.5 years. The mean follow-up was 8.0 ± 2.9 years. Regarding lens comfort, 126 eyes (82.9%) showed self-reported comfort for YK-KC lenses. The mean best corrected visual acuity (log MAR) improved from 0.49 ± 0.42 before lens fitting to 0.19 ± 0.27 after lens wearing, which was statistically significant (p < 0.001). Based on the keratometric values, after contact lens fitting both Simulated keratometry (Sim K) max and Sim K min tended to be steeper, but these differences were not statistically significant (p = 0.66 and 0.11, respectively). There were no statistically significant differences between the values before and after fitting with respect to the astigmatic powers (p = 0.22). Complications observed included punctate or coalesced epithelial corneal staining in 24 eyes (16%), however, persistent full-thickness epithelial defect was not observed. Conclusions: The YK-KC lens in patients with keratoconus can provide excellent visual improvement and comfort without any significant influence on the progression of keratoconus or corneal complications during a long-term follow-up period. J Korean Ophthalmol Soc 2015;56(7):1006-1011

Applications of Different Types of Gas-Permeable Contact Lenses in Keratoconus and Their Visual Results

To show applications of different types of gas-permeable contact lenses in patients with keratoconus and to compare visual acuity (VA) results. A total of 229 eyes of 133 patients who used different types of rigid gas-permeable contact lenses between April 2003 and April 2010 at the Cornea and Contact Lens Unit of Eye Clinic 2 of the Ministry of Health, Ulucanlar Eye Training and Research Hospital, were included. Visual acuity of patients was classified as uncorrected and corrected with eyeglasses and corrected with contact lenses. The patients were compared in terms of VA, daily contact lens wear time, and complications. A total of 70 out of 133 (52.6%) patients in our study were male, and 63 (47.4%) were female. The mean age was 25.9 ± 7.03 years (12-45). As for the classification of the 229 eyes included in the study, 136 of 229 (59.4%) eyes had moderate keratoconus, 88 (38.4%) had advanced keratoconus, and 5 (2.2%) had severe keratoconus. Following the contact lens application, the VA in all patients increased when compared to uncorrected and corrected with eyeglasses groups and the difference was statistically significant (p<0.005). When a comparison of different types of contact lenses was made, a statistically significant difference was not found (p>0.5) in terms of increase in VA. When patients were evaluated in terms of contact lens wear times, it was observed that Boston Equalens II was preferred by patients wearing lenses 4-8 hours/day. For patients wearing lenses more than 8 hours a day, Rose K lens was used the most. No serious complication was observed in any of the patients that would lead them to stop wearing contact lenses during the follow-up period. There was also no need for keratoplasty in any patient during the follow-up period. We detected an increase in VA in patients with rigid contact lenses. In addition, some contact lenses were better tolerated by patients and were used for a longer time during the day.

Rose-K versus soper contact lens in keratoconus: A randomized comparative trial

Purpose:To perform a comparative evaluation of the efficacy and acceptability of Rose-K and Soper contact lenses in Keratoconus.Setting:Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi.Materials and Methods:A randomized comparative clinical trial was performed in keratoconic eyes fitted with Rose-K (Rose-K group) and Soper (Soper group) contact lenses. Patients data were evaluated for best spectacle corrected visual acuity, best contact lens corrected visual acuity (BCLCVA), corneal topography, glare acuity, contrast sensitivity, tear function tests and specular microscopy. Patients were also asked to complete a self-reported comfort questionnaire at each visit.Results:Sixty eyes were randomized to the Rose-K and Soper groups. The two groups were comparable in all the baseline parameters. There was a statistically significant improvement in BCLCVA in both groups at 3 months (P < 0.01, both groups). The difference between in BCLCVA in both groups was not statistically significant. In both groups, there was a significant improvement in the comfort score at 3 months compared to baseline (P < 0.05, both group). The Rose-K group had statistically significantly better scores at 1 and 3 months compared with the Soper group (P = 0.006 and P < 0.001 respectively). Both groups were associated with a significant (P < 0.01), but comparable improvement in glare acuity at 3 months. There was a significant improvement in contrast sensitivity at 3 months in both groups (P < 0.01); the Rose-K group was significantly better than the Soper group at 1 and 3 months (P = 0.001 and 0.002 respectively). The mean number of trial lenses required for fitting Rose-K lens (2.00 ± 0.59) was significantly lower than the Soper lens (3.43 ± 0.82; P < 0.001).Conclusion:Both the contact lens designs provide an equal improvement in visual acuity in patients with Keratoconus. However, Rose-K contact lens provides greater comfort, better quality of vision and requires less chair time compared with the Soper lens and hence may possibly have a greater acceptability.

Use of Acular LS in the Pain Management of Keratoconus: A Pilot Study

The purpose of this pilot study was to determine the efficacy of ketorolac tromethamine 0.4% for pain management in conjunction with rigid gas permeable contact lenses in keratoconus. Any potential side effects and complications of this application were examined. A total of 12 current keratoconus patients who were presently experiencing discomfort or pain associated with their rigid gas permeables for keratoconus and/or who were contact lens-intolerant were identified from the existing patient population at the SUNY University Optometric Center. Symptomatic subjects were identified through positive feedback to a study Inclusion Questionnaire mailed to their homes. Subjects were treated on the basis of each eye separately in a modified monocular trial that spanned 5 weeks. After establishing that all inclusion and exclusion criteria were met, subjects were instructed to first use an unlabeled bottle of artificial tear solution (placebo) for 2 weeks, and then an unmarked bottle of ketorolac tromethamine 0.4% for 2 weeks in the designated eye. One drop was instilled twice a day, and the eye not assigned to take the drops served as the control. Subjects were monitored through weekly follow-up visits and repeated Keratoconus Symptom and Severity Questionnaires. Responses from the Keratoconus Symptom and Severity Questionnaire were analyzed using a 2-factor Repeated Measures Analysis of Variance. Among the small subject subset, there was no statistically significant predilection for the ketorolac tromethamine 0.4% in managing the discomfort and pain associated with keratoconus. The artificial tear solution appeared to be equally effective in improving comfort. There was no conclusive result as to the efficacy of the ketorolac tromethamine 0.4% vs. the artificial tear solution in the pain management of keratoconus. This could be attributed to a number of physiological and situational factors, as well as small sample size.

Comparison of Flat and Steep Rigid Contact Lens Fitting Methods in Keratoconus

The purpose of this article is to compare the safety and efficacy of flat- and steep-fitting rigid contact lenses in keratoconus. The Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study is a 16-center observational study. Cross-sectional results at baseline were generated for 1091 subjects with longitudinal results from the 871 subjects who completed 8 years of follow up. Of the 761 rigid contact lens-wearing patients at baseline, 41% had a scar at baseline compared with 24% of the nonrigid contact lens wearers (odds ratio [OR], 2.15; 95% confidence interval [CI], 1.35-3.43; p = 0.001). Eighty-seven percent were fitted with flat-fitting lenses, whereas 13% were fitted with steep-fitting lenses. Rigid lens fitting method was also associated with incident corneal scarring. A greater proportion of the corneas wearing flat-fitting contact lenses were scarred (43% compared with 26% for the steep-fitted eyes; OR,= 2.19; 95% CI, 1.37-3.51; p = 0.001). After controlling for corneal curvature, the association of rigid contact lens fit and corneal scarring at baseline did not persist (adjusted OR, 1.20; 95% CI, 0.70-2.06; p = 0.52). Thirty-two percent of unscarred eyes at baseline fitted flat had developed an incident corneal scar by the eighth year follow-up visit compared with 14% of eyes fitted steep (OR, 2.93; 95% CI, 1.34-6.42; p = 0.007). The data reported here indicate that, after controlling for disease severity in the form of corneal curvature, keratoconic eyes fitted with a rigid contact lens resulting in an apical touch fluorescein pattern did not have an increased risk of being scarred centrally at baseline. This "natural history" sample cannot determine causal proof that one method of fitting lenses is safer than another. To achieve this, a randomized clinical trial is needed.

Piggyback Lenses in Keratoconus

Intolerance to rigid contact lenses in keratoconus may occur as a result of epithelial pathology or a suboptimal fitting. The application of a soft lens as a bandage makes it possible to tolerate a rigid lens over it. This study gives the results of 40 eyes in 26 patients who were consecutively fitted with a new aspheric combination lens. Thirty-five eyes (87.5%) showed no discomfort, acceptable wearing time, and visual acuity. Four of these eyes showed an improvement of the corneal condition, eliminating the need for a further piggyback wearing system. Failures were found in five eyes (12.5%), which were caused by giant papillary conjunctivitis (two eyes), severe keratoconus (one eye), difficulty in lens handling and lack of motivation (two eyes). The successful use of an aspheric piggyback combination lens in rigid lens-intolerant keratoconus may preclude early surgical therapy.

Success of hydrocone (TORIS-K) soft contact lens for keratoconus and traumatic keratopathy.

Objective:To present success of Toris-K contact lenses in keratoconus and traumatic keratopathy with irregular corneal surface.Methods:Toris-K contact lenses were used to treat 7 eyes of 4 patients with traumatic keratopathy (Case 1) or keratoconus (Case 2, Case 3, and Case 4). All cases had a complete eye examination before the contact lens application. The case with traumatic keratopathy was a 32-year-old male who had corneal penetrating injury due to hobnail strike 23 months ago. The other 3 keratoconus cases were females at the age of 14, 16 and 22 years old. They had high myopia and irregular astigmatism due to keratoconus. All patients refused using rigid gas permeable contact lens because of intolerance. Toris-K contact lenses were fitted on all eyes. All patients were followed-up for 28 months with a complete ophthalmic examination and corneal topography every two months.Results:Improvement of BCVA of the cases was remarkable. All cases were comfortable with their Toris-K contact lenses for 28 months. There was no significant distortion on the lenses during follow-up period.Conclusion:Toris-K lenses may be an effective alternative treatment option for the patients with keratoconus and traumatic keratopathy, especially who cannot tolerate rigid gas permeable contact lenses.