International Journal of Keratoconus and Ectatic Corneal Diseases

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Volume 10, Number 1--2, January-December 2023
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EDITORIAL

Cosimo Mazzotta

It is time for a Turning Point in Keratoconus

[Year:2023] [Month:January-December] [Volume:10] [Number:1--2] [Pages:2] [Pages No:iv - v]

   DOI: 10.5005/ijkecd-10-1-iv  |  Open Access | 

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Original Article

Rashid Al Saidi

Transepithelial (Epi-on) Corneal Collagen Cross-linking with Supplemental Oxygen as a Treatment for Patients with Progressive Keratoconus in Oman: 1-year Results

[Year:2023] [Month:January-December] [Volume:10] [Number:1--2] [Pages:7] [Pages No:1 - 7]

Keywords: Corneal biomechanics, Corneal collagen cross-linking, Epi-on corneal collagen cross-linking, Keratoconus, Supplemental oxygen, Transepithelial, Visual acuity

   DOI: 10.5005/jp-journals-10025-1197  |  Open Access |  How to cite  | 

Abstract

Objectives: This prospective study aimed to assess the 1-year outcomes of transepithelial [epithelium-on (Epi-on)] corneal collagen cross-linking (CXL) with supplemental oxygen in patients with progressive keratoconus (KC) in Oman. The study sought to assess efficacy, and effectivity associated with this modified CXL technique. Methods: A total of 50 eyes of 35 patients with progressive KC underwent Epi-on CXL with supplemental oxygen. Clinical evaluations were performed at various time intervals over 1 year, assessing parameters including uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), corneal thickness, and keratometry. The demarcation line depth was also measured. Results: The results revealed non-significant improvements in UCVA, modest enhancements in BCVA, and corneal thickness stabilization. Notably, keratometry parameters showed initial increases followed by reductions, with a significant decrease in K-mean. The demarcation line reached an average depth of 333.18 microns, signifying deep cross-linking equivalent to conventional CXL. Conclusion: Transepithelial cross-Linking with supplemental oxygen shows promise in halting the progression of KC. The approach, which avoids epithelial removal, proves effective in stabilizing corneal shape and improving visual acuity. Particularly beneficial for younger patients, this modified CXL technique offers a less invasive alternative to conventional methods, thereby enhancing the management of progressive KC. While further research is needed for validation, current evidence positions transepithelial CXL as a valuable advancement with the potential to significantly impact the treatment landscape for KC.

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Original Article

Adel Barbara, Joseph Pikkel, Jorge L Alio, Ramez Barbera, Michael Mimouni

Variable Thickness Intracorneal Ring Segment for the Treatment of Keratoconus

[Year:2023] [Month:January-December] [Volume:10] [Number:1--2] [Pages:5] [Pages No:8 - 12]

Keywords: Intracorneal, Keratoconus, Ring, Segment, Thickness, Variable

   DOI: 10.5005/jp-journals-10025-1198  |  Open Access |  How to cite  | 

Abstract

Aim: To report outcomes of a new variable thickness intracorneal ring segment (VT-ICRS) for the treatment of keratoconus. Methods: This was a retrospective interventional case series of consecutive keratoconus eyes that underwent VT-ICRS implantation from January 2018 to December 2020 with a minimum follow-up time of 3 months. Primary outcomes included best spectacle-corrected visual acuity (BSCVA), uncorrected distance visual acuity (UCVA) and adverse events. Secondary outcomes included keratometry and manifest refraction. Results: Overall, 9 eyes of 7 patients with a mean age of 30.22 ± 8.58 (range, 21–49 years) of which 85.7% (n = 6) were of male gender were included. The mean follow-up time was 9.0 ± 5.3 (range, 4–17) months. No intraoperative or postoperative adverse events were identified during the follow-up period of these patients. At final follow-up, there was significant improvement in logMAR UCVA (from 0.95 ± 0.21 to 0.34 ± 0.31, p < 0.001), manifest sphere (from 1.11 ± 1.69 to −0.13 ± 0.35 D, p = 0.05), manifest cylinder (from −6.61 ± 2.83 to −2.44 ± 2.26 D, p < 0.001), K2 (51.94 ± 5.43 to 49.20 ± 5.78 D, p = 0.01), and logMAR BSCVA (from 0.35 ± 0.10 to 0.15 ± 0.14, p = 0.002). The mean safety index was 1.68 ± 0.53 (range, 1–2.50) and the mean efficacy index was 1.24 ± 0.69 (range, 0.39–2.25). Alpins refractive vector analysis revealed a mean surgically induced astigmatism (SIA) of 4.99 ± 1.20 D (range, 3.79–7.12 D) with a mean SIA axis of 96.3 ± 42.5° (range, 25.1–142°). Conclusion: The initial results of VT-ICRS for the treatment of keratoconus are encouraging. Future studies should compare VT-ICRS to classic ICRSs for the treatment of keratoconus.

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Original Article

Roberto Albertazzi, Carlos Rocha-de-Lossada, Leonardo Ferlini, Franco A Perrone

Treatment of High Astigmatism after Penetrating Keratoplasty in Patients with Keratoconus with 800 µm Base Intrastromal Corneal Ring Segments: A Retrospective Study

[Year:2023] [Month:January-December] [Volume:10] [Number:1--2] [Pages:7] [Pages No:13 - 19]

Keywords: Astigmatism, Cornea, Intrastromal corneal ring segments, Keratoconus, Penetrating keratoplasty

   DOI: 10.5005/jp-journals-10025-1199  |  Open Access |  How to cite  | 

Abstract

Purpose: To evaluate the efficacy and stability of implantation of 5 mm diameter intrastromal corneal ring segments (ICRS) with a modified base (800 µm) in the treatment of astigmatism after penetrating keratoplasty (PK). Materials and methods: A retrospective case-series study was performed in a cornea-keratoconus service in Buenos Aires (Argentina). We included patients with a history of keratoconus who underwent PK and had residual high astigmatism (>5.0 diopters [D]) after 2 years. These patients had undergone 800 µm width ICRS implantation between 2002 and 2019, with at least 2 years of postoperative follow-up. The main outcomes were uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) and topographic astigmatism, evaluated before ICRS implantation and 2 years postoperatively. Results: Twelve eyes underwent ICRS implantation. The mean topographic astigmatism was 12.9 ± 3.8 D (6.9–19.6) at baseline, which decreased (p < 0.001) to 4.2 ± 2.3 D (0.4–8.8) after ICRS implantation. The baseline UDVA was 1.00 ± 0.21 logarithm of the minimum angle of resolution (LogMAR) (0.6–1.3), whereas the postoperative UCVA was 0.32 ± 0.17 LogMAR (0.1–0.7). The baseline CDVA was 0.63 ± 0.15 LogMAR (0.2–0.8), whereas the postoperative CDVA was 0.12 ± 0.05 LogMAR (0–0.2). The improvement in visual acuity was statistically significant (p < .0.001). Conclusion: The high postoperative astigmatism after PK in eyes with keratoconus decreased following the implantation of ICRS with an 800 µm base width, improving the UDVA and CDVA and achieving refractive stability for at least 2 years postoperatively. Complications were not detected, although a larger cohort should be evaluated in a multicentric setting to confirm these results. Clinical significance: This series clinically proves that ICRS with a base of 800 µm can be an effective option for managing high post-PK astigmatism.

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Original Article

Rashid Al Saidi, Haithem Almahroqi, Ashoka Bandara, Devdatta Deschmukh

Prevalence of Keratoconus among Young Adults in Oman: A Cross-sectional Study Using Retinoscopy and Corneal Tomography

[Year:2023] [Month:January-December] [Volume:10] [Number:1--2] [Pages:6] [Pages No:20 - 25]

Keywords: Keratoconus, Retinoscopy, Tomography

   DOI: 10.5005/jp-journals-10025-1195  |  Open Access |  How to cite  | 

Abstract

Objective: This cross-sectional study aimed to determine the prevalence of keratoconus (KC) among young individuals in the Omani population, covering the entire country. Additionally, the severity of keratoconus was investigated after detection of the disease. Materials and methods: A total of 2750 participants were included in the study. The screening was conducted using retinoscopy (Phase 1) by well-trained optometrists, and those with a positive scissoring reflex underwent further assessment with corneal tomography to confirm the presence of keratoconus and assess its severity (Phase 2). Visual acuity and demographic data, such as age, sex, governorate, and village of residence, were collected during Phase 1, while corneal curvature parameters (K-Max, K-Mean, corneal thickness, back elevation) and keratoconus staging data were collected during Phase 2. Results: Out of the 2750 participants screened, 184 individuals between the ages of 20 and 34 were found to have a positive scissoring reflex. Among them, 96 cases were confirmed to have keratoconus in one or both eyes through corneal tomography, regardless of the severity stage. This yielded a prevalence rate of 3.49% among the study population. Among the positive keratoconus cases, 38 were males and 58 were females, with only 15 individuals aware of their keratoconus condition. Analysis of positive cases revealed the highest prevalence in the Al Batinah North governorate. Severity analysis based on topographic keratoconus classification displayed five eyes in stage 3–4, indicating advanced disease. Additionally, 75 cases had corneal parameters suspected of keratoconus on corneal tomography but did not meet the diagnostic criteria (based on the KSS score, This system grades the severity of keratoconus from 0 (suspect) to 5 (severe) based on two corneal topographic indices (i.e., anterior corneal higher order aberration RMS error and mean central keratometry), and 13 cases were confirmed as false-positive scissoring reflex. Conclusion: This study revealed a significant prevalence of keratoconus among young individuals in the Omani population. Compared with similar studies conducted in other parts of the world and neighboring countries, Oman appears to have a higher prevalence. Notably, a significant proportion of cases were already in advanced stages upon detection. Certain regions in Oman showed a higher prevalence, suggesting a potential relationship with geographic location and environmental factors. These findings warrant further investigation into the causative factors of keratoconus among the Omani population in the planned Phase 3 of the study. Close follow-up is recommended for cases suspected of having keratoconus but not meeting diagnostic criteria. Additionally, the lack of awareness among individuals with keratoconus, even in advanced stages, highlights the importance of population-based educational programs to promote early detection and intervention, ultimately preventing permanent visual disability.

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Original Article

Miltos Balidis, Spyridon Koronis, Penelope Burle de Politis, Georgios Sidiropoulos, Achilleas Rasoglou

Two-year Outcomes of Transepithelial Customized Cross-linking for Mild to Moderate Keratoconus

[Year:2023] [Month:January-December] [Volume:10] [Number:1--2] [Pages:6] [Pages No:26 - 31]

Keywords: Corneal collagen cross-linking, Keratoconus, Transepithelial cross-linking

   DOI: 10.5005/jp-journals-10025-1196  |  Open Access |  How to cite  | 

Abstract

Background/Aim: Corneal cross-linking remains the only treatment option capable of halting keratoconus progression. Customized cross-linking is a new topographically-guided protocol consisting of irradiating different corneal treatment zones with variable energy beam profiles. In this study cohort, customized cross-linking was combined with sustained oxygen delivery and high-energy pulsed UV-A irradiation at the apex of the cone, without epithelial debridement. This paper presents outcomes through 24 months postoperatively in keratoconus patients treated with this tailored cross-linking procedure. Materials and methods: This study involves 54 eyes of 43 patients with keratoconus. Visual acuity and corneal topography were recorded preoperatively. Every patient was examined at 1, 6, 12, and 24 months postoperatively and corneal topography and anterior optical coherence tomography were performed. Corrected distance visual acuity (CDVA), Kmax values, anterior and posterior elevation, and demarcation line depth were recorded. Results: Median CDVA improved from 0.14 to 0.01 logMAR (p < 0.001) at the 24-month visit. Kmax was successfully reduced from 53.2 ± 8.2 D to 51.5 ± 9.0 D (p < 0.001). Median anterior elevation decreased from 16 to 15 μm (p = 0.01), while median posterior elevation remained stable at 40 μm (p = 0.35), at 12 months. In the first postoperative month, the mean demarcation line depth was 344.6 ± 62.8 μm, equating to 72.7 ± 10.9% of corneal thickness. Conclusion: Customized corneal cross-linking is a safe and effective procedure for the management of keratoconus, customized and less invasive than cross-linking with epithelial removal. Our encouraging results and minimal complication rates point to a very promising technique that may change the standards for cross-linking. What is already known on this topic • Transepithelial cross-linking previously has been found to have lower effectiveness than standard cross-linking with epithelial debridement. • Customized high-energy pulsed UV-A delivery profiles and oxygen supplementation, as in the present procedure, may enhance the effectiveness of transepithelial cross-linking. What this study adds • At 2 years of follow-up, customized transepithelial oxygen-supplemented cross-linking appears to be an effective procedure for keratoconus, with results generally comparable to the Dresden protocol. • This high-energy procedure was well-tolerated, with minimal adverse events. How this study might affect research, practice, or policy • This study may contribute to the establishment of customized corneal cross-linking as a gold-standard treatment for the stabilization of keratoconus.

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CASE REPORT

Ramez Barbara, Eran Berkowitz, Beatrice Tiosano, Adel Barbara

Superior Keratoconus: A Case Report and Review of Literature

[Year:2023] [Month:January-December] [Volume:10] [Number:1--2] [Pages:3] [Pages No:32 - 34]

Keywords: Acute hydrops, Allergic conjunctivitis, Case report, Superior keratoconus

   DOI: 10.5005/jp-journals-10025-1194  |  Open Access |  How to cite  | 

Abstract

Superior keratoconus (SKC) is a rare subtype of KC characterized by corneal steepening in the superior region, which may mimic other ocular surface irregularities. These irregularities can arise from contact lens warpage, upper lid ptosis, superficial corneal scars, Terrien's marginal degeneration (TMD), and dry eyes. Accurate diagnosis of superior KC can be challenging, but newer tomographic modalities can aid in differentiating it from other conditions. This review highlights the clinical features of superior KC and discusses the role of advanced imaging techniques in improving diagnostic accuracy.

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