Update on Contact Lens Treatment of Keratoconus

A novel large diameter rigid gas-permeable corneal contact lens design for keratoconus

PURPOSE

To assess the fitting process and clinical feasibility of a novel large diameter rigid gas-permeable (RGP) corneal contact lens (CL) presenting regular or reverse geometry for managing keratoconus (KC). The lens was designed to rest on the peripheral cornea and vault over the cone, aiming to enhance visual quality, comfort, and corneal physiology.

METHODS

32 KC patients across all severity stages, including central, paracentral and peripheral cones enrolled. Lens parameters were customized from corneal measurements obtained via Oculus Pentacam HR tomography, mainly based on sagittal height and accounting for adequate tear film clearance. Visual acuity (VA), contrast sensitivity (CS), ocular complications, and user satisfaction were evaluated at baseline, and at one week and three months of lens wear.

RESULTS

Twenty-four patients (41 eyes) were fitted and completed the 3-month follow-up (median age of 28.5 years, 9 females). A median of 2 trial lenses per eye (interquartile range of 4.5) were needed during the fitting process. Significant improvements in median VA (baseline: 0.32 logMAR; three months: 0.01 logMAR; p = 0.002) and CS (p < 0.001 at all frequencies) were observed compared to baseline values. Ocular complications remained below clinical significance, with superior limbic keratoconjunctivitis showing significant reduction over time (p < 0.001). Patient satisfaction was high, with a median daily lens wear of 9.5 h. Most users (79.2%) reported consistent comfort with their CLs.

CONCLUSION

The novel large diameter RGP corneal CL demonstrated comparable efficacy to existing RGP CL designs, offering high levels of comfort and improved vision with minimal ocular complications.

Evaluating the Accuracy and Readability of ChatGPT-4o's Responses to Patient-Based Questions about Keratoconus

PURPOSE

This study aimed to evaluate the accuracy and readability of responses generated by ChatGPT-4o, an advanced large language model, to frequently asked patient-centered questions about keratoconus.

METHODS

A cross-sectional, observational study was conducted using ChatGPT-4o to answer 30 potential questions that could be asked by patients with keratoconus. The accuracy of the responses was evaluated by two board-certified ophthalmologists and scored on a scale of 1 to 5. Readability was assessed using the Simple Measure of Gobbledygook (SMOG), Flesch-Kincaid Grade Level (FKGL), and Flesch Reading Ease (FRE) scores. Descriptive, treatment-related, and follow-up-related questions were analyzed, and statistical comparisons between these categories were performed.

RESULTS

The mean accuracy score for the responses was 4.48 ± 0.57 on a 5-point Likert scale. The interrater reliability, with an intraclass correlation coefficient of 0.769, indicated a strong level of agreement. Readability scores revealed a SMOG score of 15.49 ± 1.74, an FKGL score of 14.95 ± 1.95, and an FRE score of 27.41 ± 9.71, indicating that a high level of education is required to comprehend the responses. There was no significant difference in accuracy among the different question categories (p = 0.161), but readability varied significantly, with treatment-related questions being the easiest to understand.

CONCLUSION

ChatGPT-4o provides highly accurate responses to patient-centered questions about keratoconus, though the complexity of its language may limit accessibility for the general population. Further development is needed to enhance the readability of AI-generated medical content.

Relationship between objective and subjective refraction measurements in patients with mild keratoconus

AIM

To compare objective dry retinoscopy and subjective refraction measurements in patients with mild keratoconus (KCN) and quantify any differences.

METHODS

This cross-sectional study was done on 68 eyes of 68 patients diagnosed with mild KCN. Objective dry retinoscopy using autorefractometer and subjective refraction measurements were performed. Sphere, cylinder, J0, J45, and spherical equivalent values were compared between the two techniques.

RESULTS

The mean age of 68 patients with mild KCN was 21.32±5.03y (12-35y). There were 37 (54.4%) males. Objective refraction yielded significantly more myopic sphere (-1.44 D vs -0.57 D), higher cylinder magnitude (-2.24 D vs -1.48 D), and more myopic spherical equivalent (-2.56 D vs -1.31 D) compared to subjective refraction (all P<0.05). The mean differences were -0.87 D for sphere, -0.76 D for cylinder, and -1.25 D for spherical equivalent. No significant differences were found for J0 and J45 values, indicating agreement in astigmatism axis (P>0.05).

CONCLUSION

In patients with mild KCN, objective dry retinoscopy overestimates the degree of myopia and astigmatism compared to subjective refraction. The irregular cornea in KCN likely impacts objective measurements. Subjective refraction allows compensation for irregularity, providing a more accurate correction. When determining refractive targets, the tendency of objective methods to overcorrect should be considered.

Effect of corneal cross-linking on biomechanical properties of swollen rabbit corneas

Corneal cross-linking (CXL) is an effective method to prevent the progression of keratoconus. CXL combined with hypotonic riboflavin solution is a modified treatment for thin corneas, which are deemed to be below the safe thickness threshold. In this study, rabbit corneas were subjected to different hydration levels using different osmolarity of riboflavin dextran solutions before CXL. Inflation testing was performed to evaluate the corneal biomechanical stiffening effect of hypotonic riboflavin solutions crosslinking. One-month post-CXL, the stromal demarcation line depth (DLD) and the biomechanical property parameter - tangent modulus (Et) - were measured. All CXL groups showed higher Et than the corresponding Ctrl groups (all P < 0.001), however, the Et values showed no statistical differences between the CXL-ed groups with different hydration levels (all P > 0.05). The relative depth ratio of DLD to total corneal thickness (TCT) did not show significant differences (P > 0.05), while the DLD was statistically different in three CXL groups (P < 0.001). The research suggested that riboflavin solutions with different osmolarities are suitable for preoperative swelling of corneas with different thickness ranges. Furthermore, crosslinking with hypotonic riboflavin solutions has no significant effect on corneal biomechanical improvement under a certain degree of hydration.

Keratoconus in children in Tunisia: Epidemiological, clinical and therapeutic features

AIM

To report the clinical and therapeutic particularities of pediatric keratoconus (KC).

METHODS

Retrospective study focusing on patients aged less than 18 years, presenting with KC and followed in a tertiary reference center in Sfax, Tunisia.

RESULTS

Our study involved 38 eyes of 20 children. We found a mean age of 12.8 years, a family history of keratoconus for 25% of cases and an atopic background in 30% of children. The mean best-corrected visual acuity was 5.3/10, the mean myopia was -6.3D and the mean total astigmatism was -4.9D. The average maximum simulated keratometry (Kmax) was 54.6 D. The visual acuity decrease was correlated with the presence of corneal opacities, with all keratometric indices except Skewed Radial Axes (SRAX) at 3 and 5 mm, with all elevation parameters and those of pachymetry except the delocalization of the thinnest point. 71.1% of eyes were classified as clinical KC and 47% of eyes were classified as Amlser-Krumeich stage 4. 42.1% of eyes were fitted with glasses and 57.9% with contact lenses. Six patients (10 eyes) underwent cross-linking (CXL). We noted an evolution of the KC for 64.29% of eyes not treated with CXL and a stabilization of 80% of eyes treated with CXL. The difference in follow-up parameters between the two groups was significant.

CONCLUSION

Pediatric KC is a severe disease, often diagnosed at a late stage. CXL is a safe and effective way to stop the disease.

Successful Management of a Keratoconus Patient With Rarely Used Large-Diameter Corneal RGP Contact Lenses: A Case Report

Keratoconus is a degenerative corneal disease that is usually bilateral and asymmetric. In keratoconus, the cornea progressively thins and steepens, leading to vision impairment. This unique case report highlights the management of a keratoconus patient with infrequently used large-diameter corneal RGP contact lenses. This method of fitting provides remarkable stability and patient comfort. Here, I describe a case of a 39-year-old man with a known history of keratoconus. He was referred to our contact lens clinic for management with RGP lenses. Throughout the eye exam, the patient was deemed eligible to wear RGP contact lenses. Uncorrected visual acuity was 20/400 in the right eye and 20/400 in the left eye. Visual acuity improved to 20/40 in the right eye with a correction of -6.00/-3.00 x 90 and to 20/30 in the left eye with a correction of -6.00/-2.00 x 95. I fitted this patient with large-diameter (10.30 mm) corneal RGP lenses in both eyes, and the fitting was optimal, resulting in a significant improvement in visual acuity to 20/20 in each eye. This case study aims to document the success of large-diameter corneal RGP contact lenses in the management of keratoconus.

One-Year Results of a Posterior Chamber Toric Phakic Intraocular Lens Implantation in Patients with Keratoconus

Purpose

To determine clinical and refractive results after the implantation of EyeCryl Phakic Toric intraocular lens in patients with stable keratoconus.

Methods

The study included all patients diagnosed with keratoconus who underwent implantation of an EyeCryl Phakic Toric intraocular lens (Biotech Healthcare Holding; Ahmedabad, India) in at least one eye and had a follow-up of at least 12 months. Visual and refractive data were collected for all patients, along with corneal tomography measurements using Pentacam, and vault measurement using optical coherence tomography. This retrospective study was conducted at a high-volume private refractive surgery center in Medellín, Colombia.

Results

A total of 83 eyes from 47 patients were included in the study. The majority (71.1%) were female, with a mean age of 31.2 ± 5.1 years. After 12 months of follow-up post-surgery, the spherical equivalent improved significantly from -8.19 ± 4.04 D to -0.06 ± 0.48 D (p < 0.001). Furthermore, 77% of eyes had a post-surgical spherical equivalent within ±0.50 D, while 92% had residual astigmatism ≤0.50 D. Twelve months after surgery, mean manifest astigmatism was -0.28 ± 0.27 D. Uncorrected visual acuity also showed improvement, from 1.11 ± 0.35 LogMAR to 0.14 ± 0.11 LogMAR. Moreover, 52.4% of eyes demonstrated an improvement of at least one line in best-corrected visual acuity. Notably, no intraoperative or postoperative complications were observed in the study population.

Conclusion

The implantation of EyeCryl Phakic Toric intraocular lenses represents a highly effective and safe option for correcting refractive errors in patients with a history of keratoconus. Refractive accuracy is excellent, and a significant proportion of patients experienced an improvement in their best-corrected vision by at least one line.

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

Purpose

To determine if factors pertaining to corneal thickness and elevation were linked to the prescribed back optic zone radius and overall diameter in keratoconus (group I), and cross-linked keratoconus (group II), cases successfully fitted with rigid contact lenses.

Patients and Methods

A review of cases adapted to contact lens wear (Rose K™) and assessed using Pentacam™ (for corneal anterior surface topography, astigmatism, elevation, and topographic thickness variation) was undertaken to determine the significance of any correlation with comfort, lens usage, grading of keratoconus, corrected distance visual acuity (with glasses and contacts), refractive error, prescribed lens powers, back optic zone radius and overall diameter values were assessed.

Results

Chief findings were, comfort was rated highly, lenses were worn for more than 10 hours/day in 75% of cases. RCL corrected distance logMAR acuities (median, mode, inter-quartile ranges) were 0.11, 0.12 (0.08-0.13) and 0.08, 0.08 (0.06-0.11) in groups I and II, respectively. Multiple linear regression revealed significant correlations (p<0.01) between the [A] back optic zone radius, the thinnest value of corneal thickness (x1) and anterior corneal surface elevation (x2). The respective r2 values were 0.471 in group I and 0.512 in group II. [B] overall diameter, x1 and x2. The respective r2 values were 0.282 in group I and 0.505 in group II.

Conclusion

RCLs were well-tolerated in both groups. The r2 values imply there is a 50% chance of correctly predicting the suitable back optic zone radius in both groups, a 50% chance of correctly predicting the overall diameter in group II and 28% in group I cases using just x1 and x2. The thinnest value of corneal thickness and anterior corneal surface elevation could be used to quickly select the BOZR and OD during RCL fitting. This has the potential to reduce chair-time, waste and improve efficiency.

Effect of Keratoconus Stage and Classification Parameters on Deep Anterior Lamellar Keratoplasty Outcomes

PURPOSE

The aim of this study was to investigate the effect of the keratoconus (KC) stage according to the Amsler-Krumeich classification system and the parameters used in this classification on deep anterior lamellar keratoplasty outcomes.

METHODS

The preoperative KC stage was determined, and the presence of corneal scarring was noted. The preoperative and postoperative best-corrected visual acuity (BCVA), refractive error, mean central keratometry (K mean ) readings, topographic astigmatism, and minimum corneal thickness (CT) values were recorded. Intraoperative and postoperative complications were also noted.

RESULTS

One hundred thirty-seven eyes (54 eyes in stage 3-83 eyes in stage 4) were included in the study. The mean follow-up period was 42.20 ± 24.36 months. There was no statistically significant difference between stage 3 and 4 KC groups for postoperative BCVA, K mean , CT, spherical equivalent, and topographic astigmatism values (each P value >0.05). The effect of preoperative BCVA, K mean , CT, and refractive error values on postoperative BCVA could not be demonstrated ( P = 0.264). In addition, no statistically significant correlation was found between postoperative and preoperative values (each P value > 0.05). Although intraoperative Descemet membrane perforation and postoperative early suture loosening were observed more frequently in stage 4 KC than in stage 3 KC, the 2 groups were statistically similar for these and other complications (each P value >0.05).

CONCLUSIONS

The preoperative KC stage and the parameters used in classification are not useful in predicting postoperative deep anterior lamellar keratoplasty outcomes. The timing of the surgery should be planned with the awareness that the progression of the disease will not have a negative effect on outcomes.

Keratoconus: exploring fundamentals and future perspectives - a comprehensive systematic review

Background

New developments in artificial intelligence, particularly with promising results in early detection and management of keratoconus, have favorably altered the natural history of the disease over the last few decades. Features of artificial intelligence in different machine such as anterior segment optical coherence tomography, and femtosecond laser technique have improved safety, precision, effectiveness, and predictability of treatment modalities of keratoconus (from contact lenses to keratoplasty techniques). These options ingrained in artificial intelligence are already underway and allow ophthalmologist to approach disease in the most non-invasive way.

Objectives

This study comprehensively describes all of the treatment modalities of keratoconus considering machine learning strategies.

Design

A multidimensional comprehensive systematic narrative review.

Data sources and methods

A comprehensive search was done in the five main electronic databases (PubMed, Scopus, Web of Science, Embase, and Cochrane), without language and time or type of study restrictions. Afterward, eligible articles were selected by screening the titles and abstracts based on main mesh keywords. For potentially eligible articles, the full text was also reviewed.

Results

Artificial intelligence demonstrates promise in keratoconus diagnosis and clinical management, spanning early detection (especially in subclinical cases), preoperative screening, postoperative ectasia prediction after keratorefractive surgery, and guiding surgical decisions. The majority of studies employed a solitary machine learning algorithm, whereas minor studies assessed multiple algorithms that evaluated the association of various keratoconus staging and management strategies. Last but not least, AI has proven effective in guiding the implantation of intracorneal ring segments in keratoconus corneas and predicting surgical outcomes.

Conclusion

The efficient and widespread clinical translation of machine learning models in keratoconus management is a crucial goal of potential future approaches to better visual performance in keratoconus patients.

Trial registration

The article has been registered through PROSPERO, an international database of prospectively registered systematic reviews, with the ID: CRD42022319338.

Comparison of Deep Anterior Lamellar Keratoplasty and Penetrating Keratoplasty in Keratoconic Eyes With Previous Hydrops-Related Corneal Scar

PURPOSE

This study aimed to compare the outcomes of deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) procedures in keratoconic eyes with a previous hydrops-related corneal scar.

METHODS

In this retrospective study, the medical records of patients who had hydrops-related corneal scarring and underwent keratoplasty surgery were reviewed. Patients treated with DALK were classified as group 1, and patients treated with PK as group 2. Preoperative and postoperative best-corrected visual acuity, central corneal thickness, keratometry (K), and refractive error values of each group were recorded and compared.

RESULTS

Seventy-eight eyes (41 in group 1 and 37 in group 2) were included in this study. The mean follow-up period of the patients was 37.7 ± 30.0 months in group 1 and 51.2 ± 29.4 months in group 2 ( P = 0.06). The preoperative and postoperative best-corrected visual acuity and central corneal thickness values were statistically similar in both groups (each P value >0.05). Keratometry values (K1 and mean keratometry) were significantly steeper in group 1 ( P1 = 0.02 and P2 = 0.03, respectively). Descemet membrane perforation was experienced in 7 (4 macroperforation and 3 microperforation; 15.6%) of 45 eyes that planned to perform DALK. These 4 eyes with macroperforation underwent PK and were excluded from the study. When all postoperative complications were assessed, although the total complication rate was 21% after DALK, it was 43% after PK ( P = 0.04).

CONCLUSIONS

DALK with a big-bubble technique is a feasible surgery in eyes with corneal scarring due to previous hydrops and is comparable with PK in terms of visual and refractive outcomes. This study suggests that DALK, which is safer than PK with less postoperative complication rates, should be the primary surgical option to avoid serious complications in keratoconic eyes with hydrops-related corneal scarring.

Clinical Performance and Patient Satisfaction of Hybrid Contact Lenses in Patients with Keratoconus

Objectives

The aim of the study was to evaluate the fitting process, clinical performance, and patient satisfaction of hybrid contact lenses (HCL) in patients with keratoconus (KC).

Materials and Methods

Sixty-eight KC patients (35 female, 33 male) who were prescribed HCL were included in the study. Corneal topographic parameters, best corrected visual acuity (BCVA) with eyeglasses, the number of HCL trials, prescribed HCL base curve (BC), and visual acuity with HCL were recorded from hospital records. A contact lens satisfaction survey was sent to the patients via email or WhatsApp and the data was statistically analyzed using IBM SPSS Statistics version 22.0.

Results

The study included 110 eyes of 68 patients with a mean age of 27.34±8 years (range: 12-48 years). According to the Amsler-Krumeich classification, 35.5% of the eyes were stage 1, 50.9% were stage 2, and 13.5% were stage 3 or 4. Mean K1, K2, and Kmean values were 7.14±0.50 mm (range 5.72-8.30 mm), 6.63±0.49 mm (range 5.07-7.84 mm), and 6.89±0.48 mm (range 5.39-8.06 mm), respectively. The average number of lens trials was 1.59±0.82 (range 1-4). The mean BC of the prescribed HCL was 6.84±0.50 mm (range 5.60-8.00 mm). BCVA with glasses was 0.36±0.2 (range 0.05-0.8), and 0.80±0.14 (range 0.3-1.0) with HCL (p<0.0001). The overall survey score was 3.54 out of 5, the overall satisfaction score was 3.27, the average vision satisfaction score was 3.62, the average satisfaction score for lens insertion and removal was 3.01, and the average satisfaction score for lens comfort was 2.97.

Conclusion

Prescribed HCL BC is usually close to the topographic Kmean value and in most of the patients, fitting was successful with the first or second CL trial. The overall satisfaction score was moderate to good and the disadvantages were low comfort compared to soft CL, difficulty with insertion and removal, short lens life, and high cost.

Vision-related quality of life among patients with keratoconus: a cross sectional study

Purpose

The present study aimed to evaluate the quality of life of keratoconus patients residing in Nablus city, Palestine. Furthermore, we investigated the possible correlation between Pentacam topographic indices and the quality of life of patients with keratoconus.

Methods

This cross-sectional study evaluated keratoconus patients at An-Najah University Hospital in 2019, diagnosed through clinical examination and corneal tomography. A control group was randomly selected from non-keratoconus patients with normal tomography. The NEI-VFQ-25 questionnaire was administered during face-to-face interviews to compare both groups. NEI-VFQ-25 assesses vision-related quality of life and is a validated tool.

Results

Keratoconus patients' quality of life is significantly impacted, mainly in near and distant vision, general vision, mental health, and social health, but not in general health, ocular pain, color vision, role difficulties, or dependency. Visual acuity is significantly affected in both eyes of keratoconus patients.

Conclusion

Patients with keratoconus exhibit a decreased quality of life related to vision, with physical, emotional, and social impairments demonstrated by the NEI-VFQ-25 when compared to controls. Since keratoconus patients are typically young adults in their productive years, understanding their concerns about their future is an important public health aspect that can aid in modifying their treatments. By addressing the specific needs of this patient population, healthcare providers can better support their long-term well-being and quality of life.

Lutfi Kirdar Training and Research Hospital, Health Science University, Semsi Denizer Caddesi, E-5, Kartal Istanbul 34890, Turkey, Department of Ophthalmology, Fatih Sultan Mehmet Training and Research Hospital, Health Science University, E-5, Icerenkoy 34752, Istanbul, Turkey. Efficacy of custom-made soft keratoconus lenses on corneal aberrations and photic phenomena in patients with keratoconus: a corneal topography imaging based study

AIM

To evaluate the efficacy of custom-made soft keratoconus (KC) lenses on corneal aberrations and photic phenomena in two different optical zones in patients with KC.

METHODS

Sixty eyes of 42 patients with KC were examined at baseline and after fitting HydroCone (Toris K) soft silicone hydrogel lenses. Best spectacle-corrected visual acuity (BSCVA) and contact lens-corrected visual acuity (CLCVA) were recorded. Lower- and higher-order corneal aberrations (LOAs and HOAs) were measured with and without Toris K lenses and compared in central 4.5 mm and 7 mm zones. Mesopic pupil diameter and subjective photic phenomena were also assessed.

RESULTS

Mean CLCVA was significantly improved compared to BSCVA (P<0.0001). Corneal curvature and refractive measurements were found to be significantly reduced by the use of Toris K lenses, except for posterior corneal curvature values. In the 4.5 mm central optical zone, all wavefront aberrations decreased significantly after lens fitting (P<0.0001). In contrast, in the 7 mm (peripheral) optical zone, values for HOAs, spherical and residual aberrations, and optical path differences were increased, while LOAs, trefoil, and quadrifoil coefficients were decreased. The rate of photic phenomena was significantly higher in participants with a pupil size >6.00 mm (85.7%).

CONCLUSION

Toris K lenses provide good visual results and a significant reduction in central corneal aberrations in patients with KC but could cause an increase in peripheral aberrations. This practical and nonsurgical approach appears to be an effective method for the visual management of KC.

Short-term visual outcome with sclerocorneal contact lens on irregular cornea

PURPOSE

The purpose is to study the change in visual acuity obtained with sclerocorneal contact lens (SCL) in patients with irregular corneal astigmatism.

METHODS

A prospective pre-post observational study was designed to include consecutive consenting patients with irregular corneal astigmatism and best-corrected visual acuity worse than 6/12 and fitted with SCL. Visual acuity was assessed using Snellen charts before fitting SCL and 1 week after the fit and converted to the equivalent logMAR units for analysis.

RESULTS

We included 51 eyes of 41 patients with a mean age of 26.31 ± 8.86 of which 32 (78%) were men. Keratoconus was the most common indication (n = 42 eyes, 82.35%), followed by corneal scar (n = 3, 4%), post keratoplasty (n = 2, 4%), high myopia (n = 2, 4%), pellucid marginal degeneration (n = 1, 2%), and aphakia (n = 1, 2%). The mean overall uncorrected visual acuity improved significantly (P < 0.001) with SCL from 1.18 ± 0.34 logMAR (6/120 Snellen's equivalent) to 0.27 ± 0.15 (6/9 Snellen's equivalent) at 1-week post-SCL fitting. The mean overall best spectacle-corrected visual acuity improved from 0.89 ± 0.45 logMAR (6/36 Snellen's equivalent) to 0.26 ± 0.15 (6/9 Snellen's equivalent) at 1-week post-SCL fitting.

CONCLUSION

Sclerocorneal contact lens improves visual acuity significantly in patients with irregular corneal astigmatism and reduces the need for corneal transplantation.

Effects of a new-generation hybrid contact lens on visual performance and vision-related quality of life in patients with keratoconus

PURPOSE

The aim of this study was to evaluate the efficacy of a new-generation hybrid contact lens for improving visual outcomes and vision-related quality-of-life performance in patients with keratoconus who had intolerance or treatment failure of conventional correction methods such as the use of soft silicone-hydrogel or rigid gas-permeable contact lenses.

METHODS

Twenty-eight patients with keratoconus (42 eyes) were enrolled in this prospective cross-sectional study. Airflex (Swisslens) lenses were fitted in the patients' eyes in accordance with the manufacturer's instruction. Ophthalmologic examinations, including manifest refraction, best-corrected distance visual acuity, slit-lamp biomicroscopy, and National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25) assessment, were performed at baseline and the 6-month visit.

RESULTS

An adequate fit was achieved in 39 eyes (92.9%) of 26 patients. Six eyes of 3 patients were excluded from the study owing to discontinuation of lens wearing. The mean age of the successful wearers was 20.3 ± 4.9 years. The mean best-corrected distance visual acuity was statistically significantly improved from 0.62 ± 0.30 to 0.11 ± 0.06 logMAR with the Airflex hybrid contact lenses (p<0.001). The mean overall composite NEI-VFQ-25 score statistically significantly increased with the Airflex hybrid contact lenses at the 6-month visit as compared with that at baseline (from 77.1 ± 16.3 to 90.9 ± 7.3, p=0.036). Statistically significantly better scores were obtained with the Airflex hybrid contact lenses in all the NEI-VFQ-25 subscale items (all p<0.05). No significant adverse effects were observed.

CONCLUSIONS

New-generation hybrid contact lenses can be used as an effective alternative for correction of irregular astigmatism in patients with keratoconus who have intolerance or treatment failure of conventional methods. Significant improvement in vision-related quality-of-life in patients with keratoconus can be achieved with these lenses.

Post-Bader procedure: a long-term follow-up case study

Keratoconus is a progressive disorder that manifests as a cone-like steepening of the central or paracentral inferior cornea and irregular stromal thinning. There is a gradual decrease in visual acuity due to corneal asymmetry, irregular astigmatism, and increased optical aberrations, consequently impacting the quality of life. Several procedures have been developed in an attempt to slow or reverse the progression. The Bader procedure, which includes a pattern of incisions around the circumference of the cornea and at the base of the protruding cone, is one such surgery. These incisions penetrate 70-90% of the cornea's depth. Its goal is to flatten the topography and reduce corneal asymmetry and irregular astigmatism. Though prior research found these to be highly promising, we report a patient who was given contact lenses to restore and maintain his vision while his corneal ectasia and thinning progressed over the following decade.

Impact of rigid gas-permeable contact lens on keratometric indices and corneal thickness of keratoconus eyes examined with anterior segment optical coherence tomography

Purpose/Aim

Detecting keratoconus (KC) progression helps determine the surgical indication for corneal cross-linking (CXL). This retrospective observational study aimed to examine changes in keratometric indices and corneal thickness in patients with KC who used rigid gas-permeable (RGP) contact lenses.

Materials and methods

This study involved 31 eyes (31 patients) diagnosed with KC. No patient had used RGP or any other type of contact lenses for at least 1 month. Corneal topographic data were obtained using three-dimensional anterior segment optical coherence tomography before and after >1 month of RGP lens use.

Results

The average and maximum keratometry values changed after using an RGP lens (-1.05 ± 1.92 D, p < 0.01 and -1.65 ± 4.20 D, p = 0.04, respectively); the spherical component of the anterior corneal surface became significantly smaller (p = 0.02). No change was observed in the central or thinnest corneal thickness values. Keratometric changes were greater in eyes with severe KC than in those with moderate KC (p = 0.014).

Conclusions

Keratometry and spherical components of the anterior corneal surface values decreased after RGP lens use; keratometric changes were greater in eyes with severe KC than in those with moderate KC. Corneal progression indices, including corneal thickness, posterior keratometry, and irregular astigmatism values, mostly remained unchanged. It is important to consider these findings when evaluating corneal topography of KC and preparing CXL.

Role of therapeutic contact lenses in management of corneal disease

PURPOSE OF REVIEW

The current review highlights areas of innovation and research in the use of contact lenses in the treatment of corneal ectasia and ocular surface disease.

RECENT FINDINGS

A series of academic reports were published by a committee of experts reviewing evidence-based practice patterns of contact lens use. There continues to be active research in the use of contact lenses in the management of keratoconus, including mini-scleral lenses, custom impression-based scleral lenses and wavefront-guided scleral lenses. Recent reports on contact lenses for ocular surface disease were primarily reviews, retrospective case reports or case series, with publications on contact lens use in corneal epithelial defects, graft-vs.-host disease, limbal stem cell deficiency and neurotrophic keratitis. There are recent publications on advances in drug-eluting contact lenses.

SUMMARY

Corneal specialists should be aware of current advances in the field of contact lens expanding their use in corneal ectasia and ocular surface disease.

Indications for keratoplasty in management of corneal ectasia

PURPOSE OF REVIEW

The current review aims to describe recent advancements in treatment of corneal ectasias and its effect on indications for corneal transplantation.

RECENT FINDINGS

The majority of patients affected by ectatic corneal disease use contact lenses to correct resulting astigmatism. Patients who are intolerant of contact lenses or cannot achieve acceptable vision through conservative measures could consider keratoplasty. However, continuing advancements in both nonsurgical and surgical treatments are either reducing or delaying the need for keratoplasty in patients affected by ectatic corneal disease.

SUMMARY

Corneal transplantation has been the mainstay of treatment for patients with advanced ectatic corneal disease. In the past decade, numerous improvements have been occurred to make contact lenses not only more effective for visual correction, but also more comfortable. Although corneal cross-linking is the only proven treatment known to prevent progression of disease, several other therapies show early potential for those in which cross-linking is contraindicated. Patients now have access to a wider range of therapies before considering keratoplasty.

Keratoconus: An updated review

Keratoconus is a bilateral and asymmetric disease which results in progressive thinning and steeping of the cornea leading to irregular astigmatism and decreased visual acuity. Traditionally, the condition has been described as a noninflammatory disease; however, more recently it has been associated with ocular inflammation. Keratoconus normally develops in the second and third decades of life and progresses until the fourth decade. The condition affects all ethnicities and both sexes. The prevalence and incidence rates of keratoconus have been estimated to be between 0.2 and 4,790 per 100,000 persons and 1.5 and 25 cases per 100,000 persons/year, respectively, with highest rates typically occurring in 20- to 30-year-olds and Middle Eastern and Asian ethnicities. Progressive stromal thinning, rupture of the anterior limiting membrane, and subsequent ectasia of the central/paracentral cornea are the most commonly observed histopathological findings. A family history of keratoconus, eye rubbing, eczema, asthma, and allergy are risk factors for developing keratoconus. Detecting keratoconus in its earliest stages remains a challenge. Corneal topography is the primary diagnostic tool for keratoconus detection. In incipient cases, however, the use of a single parameter to diagnose keratoconus is insufficient, and in addition to corneal topography, corneal pachymetry and higher order aberration data are now commonly used. Keratoconus severity and progression may be classified based on morphological features and disease evolution, ocular signs, and index-based systems. Keratoconus treatment varies depending on disease severity and progression. Mild cases are typically treated with spectacles, moderate cases with contact lenses, while severe cases that cannot be managed with scleral contact lenses may require corneal surgery. Mild to moderate cases of progressive keratoconus may also be treated surgically, most commonly with corneal cross-linking. This article provides an updated review on the definition, epidemiology, histopathology, aetiology and pathogenesis, clinical features, detection, classification, and management and treatment strategies for keratoconus.