A Comparison of Synergeyes Versus Traditional Rigid Gas Permeable Lens Designs for Patients With Irregular Corneas

Smart decision support system for keratoconus severity staging using corneal curvature and thinnest pachymetry indices

BACKGROUND

This study proposes a decision support system created in collaboration with machine learning experts and ophthalmologists for detecting keratoconus (KC) severity. The system employs an ensemble machine model and minimal corneal measurements.

METHODS

A clinical dataset is initially obtained from Pentacam corneal tomography imaging devices, which undergoes pre-processing and addresses imbalanced sampling through the application of an oversampling technique for minority classes. Subsequently, a combination of statistical methods, visual analysis, and expert input is employed to identify Pentacam indices most correlated with severity class labels. These selected features are then utilized to develop and validate three distinct machine learning models. The model exhibiting the most effective classification performance is integrated into a real-world web-based application and deployed on a web application server. This deployment facilitates evaluation of the proposed system, incorporating new data and considering relevant human factors related to the user experience.

RESULTS

The performance of the developed system is experimentally evaluated, and the results revealed an overall accuracy of 98.62%, precision of 98.70%, recall of 98.62%, F1-score of 98.66%, and F2-score of 98.64%. The application's deployment also demonstrated precise and smooth end-to-end functionality.

CONCLUSION

The developed decision support system establishes a robust basis for subsequent assessment by ophthalmologists before potential deployment as a screening tool for keratoconus severity detection in a clinical setting.

Aberration change after scleral lens wear in eyes with pellucid marginal degenerations

PURPOSE

To investigate the impact of scleral lenses (SLs) on higher-order aberrations (HOAs), corrected distance visual acuity (CDVA), and contrast sensitivity (CS) in pellucid marginal degeneration (PMD) eyes.

METHODS

SLs were fitted in 24 eyes diagnosed with PMD. CDVA, CS, and HOAs were measured at baseline and with the lens on the eye. The HOAs were measured using an i-Trace aberrometer.

RESULTS

A statistically significant improvement was noted in CDVA ( P < 0.001) with BSS lenses (0.05 ± 0.04) compared to baseline (0.42 ± 0.06). Front surface eccentricity 1 (FSE1) lens provided the best CDVA in most of the eyes. The baseline CS of 1.24 ± 0.74 improved to 1.58 ± 0.48 with SL and reported a statistically significant improvement ( P < 0.001) and a gain of 6 letters. The baseline higher order-root mean square (HO-RMS) was 0.89 ± 0.53 µm, which reduced to 0.38 ± 0.24 µm ( P < 0.001), and RMS coma of 0.45 ± 0.29 µm improved to 0.20 ± 0.12 µm ( P < 0.001). Though there was a marginal reduction from 0.04 ± 0.14 to 0.03 ± 0.07, RMS spherical aberration did not show any statistically significant difference ( P = 0.37). RMS secondary astigmatism reduced from 0.17 ± 0.15 µm to 0.08 ± 0.12 µm ( P = 0.007), and RMS trefoil reduced to 0.13 ± 0.09 µm from 0.64 ± 0.36 µm ( P < 0.001) with SLs and showed statistically significant improvement.

CONCLUSION

SLs can be considered an effective option that corrects a significant amount of HOAs and enhances visual performances in PMD eyes.

Scleral lens induced short term corneal changes in eyes with Pellucid Marginal Degeneration

PURPOSE

To investigate the short-term effect of scleral lens (SL) on corneal curvature and corneal oedema in Pellucid Marginal Degeneration (PMD) eyes.

METHODS

Corneal anterior, posterior curvature and corneal thickness were measured in 14 eyes of 14 PMD participants with Schiempflug imaging at different corneal diameters and meridians at baseline and after 6 h of SL wear.

RESULTS

There was a significant flattening (up to 0.26 mm) of the anterior corneal curvature noted in the inferotemporal quadrant (from 210 to 255 degree at 2 mm, 8 mm and 10 mm corneal diameter), inferonasal quadrant (from 285 to 345 degree at 6 mm and 8 mm corneal diameter), and inferiorly at 2 mm and 10 mm corneal diameter (p < 0.05). Similarly, posterior corneal curvature showed statistically significant steepening mostly in inferotemporal quadrants (from 195 to 255 degree from 4 mm to 8 mm corneal diameter) and inferonasally at 2 mm and 4 mm corneal diameter (p < 0.05). A statistically significant increase in the corneal thickness noted in different corneal diameters with corneal oedema ranging from 2.10 % to 4.00 % after 6 h of SL wear. A gradual increase in corneal oedema was noted form centre to periphery. The baseline central fluid reservoir thickness (FRT) was 341.07 ± 139.8 which reduced to 276.71 ± 114.32 µm after 6 h of lens wear. No significant correlation was noted between corneal oedema with different parameters like initial and final FRT, change in anterior and posterior corneal curvature, and lens thickness (p > 0.05).

CONCLUSIONS

Short-term SL wear induced a clinically acceptable range of corneal oedema. A clinically significant flattening in anterior curvature and minimal steepening in posterior curvature were noted. Practitioners should be careful while measuring corneal parameters in PMD eyes wearing SL, as these alterations can provide false impression of disease progression.

Effects of Custom-Designed Soft Contact Lenses on Irregular Astigmatism Correction in Patients with Keratoconus

Purpose

To evaluate the efficacy of YOUSOFT soft contact lenses in correcting irregular astigmatism and prescription results of patients with keratoconus.

Patients and Methods

The retrospective observational study included 55 eyes (mean age, 32.2 ± 10.6 years; 36 men and 6 women) of 42 patients with keratoconus who tried YOUSOFT for rigid gas permeable (RGP) lens intolerance. Average keratometry, corneal astigmatism, and maximum keratometry were 49.4 ± 5.2 diopters (D), 3.7 ± 2.1 D, and 57.3 ± 8.2 D, respectively. Patients were divided into YOUSOFT prescription and non-prescription cases, wherein the prescription rates were calculated. YOUSOFT visual acuity was compared with spectacle-corrected distance visual acuity (CDVA) and RGP lens-CDVA.

Results

YOUSOFT was prescribed to 28 out of 42 patients (prescription rate 67%). In the YOUSOFT prescription cases, YOUSOFT-CDVA (logMAR -0.04; 95% confidence interval [CI]: -0.08 to 0.00) was significantly better than spectacle-CDVA (logMAR 0.23; 95% CI: 0.08 to 0.38; P < 0.0001), whereas YOUSOFT-CDVA (logMAR -0.03; 95% CI: -0.08 to 0.03) did not significantly differ from the RGP lens-CDVA (logMAR -0.02; 95% CI: -0.08 to 0.04; P = 0.856).

Conclusion

YOUSOFT was effective in correcting irregular corneal astigmatism, suggesting that it is highly effective in patients with RGP lens intolerance.

Clinical Outcome of Hybrid Contact Lenses in Keratoconus

OBJECTIVES

To report the clinical outcome of hybrid contact lens fitting in keratoconus.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

CLEAR - Medical use of contact lenses

The medical use of contact lenses is a solution for many complex ocular conditions, including high refractive error, irregular astigmatism, primary and secondary corneal ectasia, disfiguring disease, and ocular surface disease. The development of highly oxygen permeable soft and rigid materials has extended the suitability of contact lenses for such applications. There is consistent evidence that bandage soft contact lenses, particularly silicone hydrogel lenses, improve epithelial healing and reduce pain in persistent epithelial defects, after trauma or surgery, and in corneal dystrophies. Drug delivery applications of contact lens hold promise for improving topical therapy. Modern scleral lens practice has achieved great success for both visual rehabilitation and therapeutic applications, including those requiring retention of a tear reservoir or protection from an adverse environment. This report offers a practical and relevant summary of the current evidence for the medical use of contact lenses for all eye care professionals including optometrists, ophthalmologists, opticians, and orthoptists. Topics covered include indications for use in both acute and chronic conditions, lens selection, patient selection, wear and care regimens, and recommended aftercare schedules. Prevention, presentation, and management of complications of medical use are reviewed.

Update on Contact Lens Treatment of Keratoconus

Keratoconus (KC) is a progressive disease that leads to a decrease in visual acuity and quality and impairs vision-related quality of life. Contact lens (CL) application has a primary place and importance in the correction of the optic problems due to the disease. The corneal changes and increased irregular astigmatism that occur with KC progression necessitate special CL designs and fitting methods. In addition to disease stage, the patient's lens tolerance also plays a role in the application of CLs in KC patients. With recent advances in materials and design technology, the CLs used in the treatment of KC have developed considerably and there are various types available. In this review, we discuss the wide range of CLs, including rigid and soft lenses, hybrid and scleral lenses, and even custom lens designs, in light of recent scientific advances.

Evaluation of Visual Acuity Outcomes and Corneal Alterations of New Generation Hybrid Contact Lenses in Patients With Advanced Keratoconus

PURPOSE

To evaluate the visual and corneal outcomes of new generation hybrid contact lenses (HCL) in patients with advanced keratoconus.

METHODS

This was a retrospective study undertaken at a single academic center. The study cohort consisted of subjects with advanced keratoconus who had elected not to undergo keratoplasty and were fitted with HCLs. Patients were fitted either with EyeBrid (LCS, Cane, France) or Airflex (SwissLens, Prilly, Switzerland) HCLs. Primary outcome measures included contact lens (CL) drop-out rate, best corrected visual acuity, and corneal endothelial cell density (ECD) measurements at the end of a 6-month HCL wear. ECD was measured using in vivo confocal microscopy (ConfoScan4; Nidek, Tokyo, Japan). One eye per patient was included for statistical purposes. Paired t tests and Wilcoxon signed-rank tests were used for comparative analyses.

RESULTS

Thirty-two keratoconic eyes of 32 patients (14M/18F) with a mean age of 25.9 ± 11.5 years were included in the study. All patients were able to continue CL wear for a duration of 6 months. There was a significant improvement in the mean best corrected visual acuity from 0.5 ± 0.2 logarithm of minimal angle of resolution to 0.1 ± 0.1 logarithm of minimal angle of resolution after daily CL wear with HCL at the 6-month follow-up visit (P < 0.001). No vision-threatening CL-related corneal adverse effects were observed. There was no significant reduction in the ECD noted at the 6-month visit [2625.8 ± 300.3 cells/mm (baseline) vs. 2566.4 ± 309.8 cells/mm (6-month); P = 0.623].

CONCLUSIONS

Hybrid contact lenses can provide improved visual function without inducing any short-term clinical or microscopic adverse effects on corneal endothelial cells in patients with advanced keratoconus.

Use of new-generation hybrid contact lenses for managing challenging corneas

INTRODUCTION

To evaluate the safety and efficacy of new-generation hybrid contact lenses (HCL) among patients with irregular astigmatism.

METHODS

Medical records of 25 patients fit with new-generation HCL (Eyebrid^® and AirFlex^®) were retrospectively reviewed. The data collected included etiology of irregular astigmatism, uncorrected visual acuity, manifest refraction, spectacle-corrected visual acuity (S-CDVA), steep / flat keratometric values, corneal astigmatism, records of rigid / soft CL fitted before HCL, all parameters of the trial lenses, and the final prescribed HCL parameters and HCL-CDVA.

RESULTS

The study included 34 eyes from 25 patients (nine females and 16 males) with an average age of 29 ± 13 (ranging from 8-56) years. In total, 25 eyes with keratoconus, four with post - keratoplasty astigmatism, three with irregular astigmatism due to corneal trauma and two with residual astigmatism after radial keratotomy were fit with HCL. The mean S-CDVA (logMAR) improved significantly from 0.76 ± 0.41 to 0.14 ± 0.15 with HCL (p < 0.01). The most common indication for HCL was inability to fit with rigid gas permeable (RGP) lenses (22 eyes). The average number of lenses to successful fit was 1.4 (mode, 1; median, 1) and ideal fit was achieved with the first trial lens in 25 eyes (73%). Seven patients (nine eyes, 36%) discontinued lens use within the first 6 months because of discomfort (six eyes, 24%), ocular allergy (two eyes, 8%) and tearing of contact lens (one eye, 4%).

DISCUSSION

New-generation HCL may be a suitable option for fitting challenging corneas with irregular astigmatism that cannot be rehabilitated efficiently with rigid lenses.

Mushroom keratoplasty and contact lens application: Strategy for management of a pediatric eye injury

We show the challenging visual rehabilitation of a penetrating eye injury in a child with wide central corneal scar and aphakia. A 9-year-old male patient underwent combined surgery, including membranectomy with pupilloplasty and mushroom penetrating keratoplasty. Corneal transparency was restored; aphakia and irregular astigmatism were corrected first with a rigid gas-permeable contact lens (CL) and then, successfully, with hybrid CL. We discuss the surgical treatment used to restore corneal transparency and the choice of the best CL to overcome irregular astigmatism and aphakia.

Fitting Tips and Visual Rehabilitation of Irregular Cornea with a New Design of Corneoscleral Contact Lens: Objective and Subjective Evaluation

OBJECTIVES

To study the fitting and the visual rehabilitation obtained with a corneoscleral contact lens, namely, Rose K2 XL in patients with irregular cornea.

METHODS

This prospective study included 36 eyes of 36 patients with irregular cornea fitted with Rose K2 XL. Refractive and visual outcomes and mesopic and aberrometric parameters of fitted eyes were assessed at 2 weeks, 3 months, and 6 months after the initial lens use. Objective and subjective parameters of patient satisfaction and lens comfort were noted. Causes of lens discontinuation and complications were also recorded.

RESULTS

Average logMAR VA improved significantly from 0.95 ± 0.09 without correction to 0.04 ± 0.05 six months after lens wear. Similarly, mesopic and aberrometric measures were significantly improved. Statistical analysis of the subjective patients' responses showed a significant acceptance of the lens by most of them. At the end of follow-up, the mean wearing time was 9.9 ± 2.9 hours per day. The most common cause of wearing discontinuation was persistent discomfort (16.7%) and high lens expenses(16.7%). Self-assessed questionnaire showed statistically significant improvement in nearly all measured subjective parameters.

CONCLUSION

Rose K2 XL lenses provide patients with irregular cornea with both quantitative and qualitative optimal visual function with high degree of patient comfort and satisfaction.

A comparison of the visual acuity outcome between Clearkone and RGP lenses

Purpose

To compare the visual acuity outcome of the ClearKone SynergEyes™ hybrid contact lens and Boston XO rigid gas permeable (RGP) contact lens in patients with keratoconus.

Methods

Twenty-eight eyes with keratoconus participated in this study. The visual acuity was examined once with the RGP lens and once with the ClearKone SynergEyes™ hybrid contact lens.

Results

The mean corneal keratometry, the mean lens back optic zone radius, and the mean vault was 7.23 ± 0.62 mm, 7.67 ± 0.44 mm, and 277.94 ± 104.5 μm, respectively. Visual acuity was significantly better with the ClearKone SynergEyes™ hybrid lens (P = 0.004). The mean best corrected visual acuity (logMAR) was 0.022 ± 0.03 and 0.057 ± 0.09 for the ClearKone and RGP lens, respectively. The Clearkone lens yields an average improvement of one line of the Snellen chart in comparison with the RGP lens.

Conclusion

The ClearKone hybrid contact lens and the RGP lens may improve visual acuity in corneal irregularities. But patients who are able to afford hybrid lens wearing may show better visual acuity.

Nonsurgical Procedures for Keratoconus Management

Objectives

To describe the past 20 years' correction modalities for keratoconus and their visual outcomes and possible complications.

Methods

A review of the published literature related to the visual outcomes and possible complications in the context of keratoconus management using nonsurgical procedures for the last 20 years (glasses and contact lenses) was performed. Original articles that reported the outcome of any correction modalities of keratoconus management were reviewed.

Results

The most nonsurgical procedure used on keratoconus management is the contact lens fitting. Soft contact lenses and soft toric contact lenses, rigid gas-permeable contact lenses, piggyback contact lens system, hybrid contact lenses, and scleral and corneoscleral contact lenses form the contemporary range of available lens types for keratoconus management with contact lenses. All of them try to restore the vision, improve the quality of life, and delay surgical procedures in patients with this disease. Complications are derived from the intolerance of using contact lens, and the use of each depends on keratoconus severity.

Conclusions

In the context of nonsurgical procedures, the use of contact lenses for the management of keratoconic patients represents a good alternative to restore vision and improve the quality of live in this population.

Clinical Performance of a Spherical Hybrid Lens Design in High Regular Astigmatism

OBJECTIVES

To evaluate safety, efficacy, and comfort of a spherical hybrid contact lens design in management of the regular astigmatic cornea.

METHODS

This prospective study included 18 eyes from 18 subjects with regular corneal astigmatism greater than -3.00 diopters. All patients were fitted with optimal hybrid contact lenses. Demographic data and fitting parameters were recorded. Patient refraction, visual outcomes, contrast sensitivity, and glare levels were measured 2 weeks, 3 months, and 6 months after the start of lens use. Duration of lens use, comfort grades, causes of lens discontinuation, and any noticed complications were recorded.

RESULTS

An average of 1.8 lenses (range 1-3) was required to achieve the optimal fit. Average logMAR visual acuity had improved significantly from 0.92±0.03 to 0.03±0.04 (P<0.001) at the last follow-up. Contrast sensitivity and glare tests were also significantly improved. Statistical analysis of the subjective responses indicated a strong acceptance of the lens by most of the patients. Mean wearing time of lenses was 10.1±3.2 hr/d. Causes of discontinuation were discomfort (2 patients), high lens price (2 patients), and handling problems (1 patient). Minimal complications were demonstrated in wearers of the lenses during follow-up visits.

CONCLUSION

Spherical hybrid contact lenses provide a good option for patients with regular astigmatic corneas. They provide optimal visual function with high comfort and patient satisfaction, especially when surgery is undesirable or contraindicated.

Estimation of the hybrid lens parameters through rigid gas permeable lens fitting

PURPOSE

To estimate the fitting parameters of the hybrid contact lens in patients with corneal ectasia using the rigid gas permeable (RGP) lens.

METHODS

Thirty-four eyes with corneal ectasia were evaluated in this study. The patients were examined once with the RGP lens and once with the hybrid contact lens. The relationship between the base curvature of the RGP and the vault of the hybrid lens and the correlation between their powers were analyzed.

RESULTS

We found a linear relationship between the base curvature of the RGP lens and the vault of the hybrid lens (P < 0.001) (R(2) = 0.45). Moreover, we found a correlation between the power of the RGP and hybrid lens (P < 0.001) (R(2) = 0.4). However, a 0.5 mm decrease in the base curvature radius of the RGP lens increased the vault of the hybrid lens by 72 μ.

CONCLUSION

The results of this study could be used for better and faster selection of the first hybrid contact lens.

Objective and subjective evaluation of the performance of medical contact lenses fitted using a contact lens selection algorithm

PURPOSE

To evaluate the performance of medical contact lenses (CLs) for a wide range of clinical indications.

DESIGN

Prospective cross-sectional study.

METHODS

A total of 281 eyes were evaluated in 281 consecutive patients (≥18 years of age; CL use ≥3 months) who visited the contact lens service in a tertiary academic clinic for a scheduled follow-up visit. The main outcome measured were clinical indications for CL wear; CL type; change in corrected distance visual acuity (CDVA) with CL use; CL wearing duration; CL wearing time; subjective performance measured using a visual analog scale (VAS) questionnaire (score range: 0-100); and effectiveness of the lens-selection algorithm.

RESULTS

Wearing CLs significantly improved CDVA compared to wearing spectacles (median change: -0.15 logMAR, range: 1.00 to -2.10; P<.001). Daily-wear CLs were worn by 77% of patients for a median of 15h/day (range: 5-18h/day), median 7 days/week (range: 1-7 days/week). High subjective scores were measured, with similar results obtained between the scleral lens and soft lens groups. The medical CL fitting was found to be generally effective (the overall satisfaction rating was ≥70 for 81% of patients).

CONCLUSIONS

Fitting CLs based on the lens-selection algorithm yielded positive clinical results, including improved visual acuity, satisfactory wearing time, and high overall subjective performance. Moreover, subjective performance was similar between users of scleral lenses and users of soft lenses. These results underscore the importance of prescribing scleral lenses and the need for tertiary eye clinics to offer patients a variety of CL types.

Full-Ring Intracorneal Implantation in Corneas With Pellucid Marginal Degeneration

BACKGROUND

Keratoconus (KCN) is a progressive, non-inflammatory ectacic disorder characterized by bilateral and asymmetrical conical protrusion of the cornea. MyoRing implantation and Collagen Crosslink (CXL) are two separate effective treatments for all stages of keratoconous. This study wants to show the effect of these treatments combination in patients with moderate and severe keratoconus.

OBJECTIVES

The aim of this study was to report on the visual and refractive outcomes of corneas with pellucid marginal degeneration following MyoRing implantation (DIOPTEX GmbH).

PATIENTS AND METHODS

This study included 15 eyes of 15 patients, with an age range from 22 to 49 years old, and pellucid marginal degeneration. An intrastromal corneal ring (MyoRing) was inserted by the means of mechanical dissection using a PocketMaker microkeratome. The main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, and keratometry readings. The mean postoperative follow-up was ten months (range 6 - 12 months).

RESULTS

The mean UDVA (LogMAR) improved significantly from 1.13 ± 0.21 preoperatively to 0.24 ± 0.13 postoperatively (P < 0.001), and the mean CDVA (LogMAR) improved significantly from 0.39 ± 0.12 to 0.19 ± 0.09 (P < 0.001). The mean cylinder of manifest refraction decreased significantly by 4.00 diopter (D) (P < 0.001). The mean spherical equivalent error (SE) decreased significantly from -6.00 ± 3.60 D to -0.70 ± 1.90 D, at the end of the follow-up period. Furthermore, with regards to corneal topography, a significant reduction was observed in keratometric values. The Kmax, Kmin and Kaverage decreased significantly by 5.00, 1.10 and 4.00 D, respectively (P < 0.001).

CONCLUSIONS

MyoRing implantation using the PocketMaker microkeratome appears to provide an effective method for treating pellucid marginal degeneration. Both UDVA and CDVA improved significantly. The corneal steepening and astigmatism were reduced in all subjects after MyoRing implantation.

Severe epithelial edema in Clearkone SynergEyes contact lens wear for keratoconus

OBJECTIVE

The aim was to report three cases of severe bilateral epithelial edema (central corneal clouding [CCC]) in association with ClearKone SynergEyes hybrid contact lenses for the vision rehabilitation of keratoconus.

METHODS

Retrospective case series of six eyes of three patients that developed CCC with ClearKone SynergEyes hybrid contact lens wear shortly after beginning to wear those lenses.

RESULTS

Severe CCC was diagnosed on removal of the lenses. Despite attempts to modify the parameters of the lenses to reduce edema, two patients discontinued lens wear entirely, and one patient was able to wear lenses only on a limited basis.

CONCLUSIONS

Different degrees of CCC have been reported with the use of polymethyl methacrylate lenses; however, the condition may also occur with the use of ClearKone SynergEyes lenses. Although the lenses may provide good subjective responses, careful observation of the corneal response after 5 hrs of wear is advised.