Wan Haslina Wan Abdul Halim

This study investigated the 12-month impact of orthokeratology (Ortho-K) treatment on eyeball dimensions using magnetic resonance imaging (MRI). Results were compared with single-vision spectacle wearers (SVS). A total of 70 Chinese schoolchildren (mean age: 8.31 ± 0.47 years) with myopia were assigned to Ortho-K (n = 45) and SVS (n = 25). Baseline spherical equivalent (SE), visual acuity (VA), and flat keratometry (FK) were measured. MRI was performed at baseline and at 12 months to measure three-dimensional ocular dimensions, including longitudinal axial length (LAL), horizontal width (HW), and vertical sagittal height (VSH). Standard slit-lamp examinations ensured ocular health at all follow-up visits. At 12 months, the Ortho-K group showed significant reductions in SE and FK (p < 0.001), whereas the SVS group exhibited a significant increase (p < 0.05). LAL was significantly shorter in the Ortho-K group compared to SVS (p < 0.05). Although individual HW and VSH did not reach independent significance, repeated measures analysis of variance confirmed significant between-group differences in global eyeball shape over 12 months (p < 0.05). Correlation analysis revealed a significant association between SE and LAL in the SVS group (p < 0.05). In the Ortho-K group, SE showed no significant correlation with ocular dimensional changes (p > 0.05). In contrast, FK in the Ortho-K group demonstrated significant correlations with all dimensional parameters (p < 0.05), a pattern not observed in the SVS group. Findings indicate that myopic progression in the SVS group is primarily driven by axial elongation, whereas refractive changes in the Ortho-K group arise from corneal reshaping. Over 12 months, Ortho-K wear modifies ocular dimensions and inhibits AL elongation more significantly than SVS, providing a structural basis for controlling myopic progression.

This scoping review aims to focus on the association between topical anti-glaucoma medication and limbal stem cell deficiency through a comprehensive analysis from the available relevant case reports, research articles and experimental studies. By understanding the potential risks associated with long-term anti-glaucoma medication use and their impact on corneoscleral limbus, precautions can be taken to balance between the risk of glaucoma progression and limbal stem cell deficiency. All relevant publications from 2000 to 2023 were included and evidence of strong emerging potential link between topical glaucoma eyedrops and the disruption of limbal stem cell homeostasis were found. Prolong use of topical glaucoma medication with preservatives were found to have a negative effect on limbal stem cells. The frequent use of topical preservative-free prostaglandin analogues and beta-blockers, commonly prescribed for glaucoma, is associated with morphological alterations in the corneoscleral limbus. These changes appear to be mediated through an inflammatory process, leading to disruption of the corneoscleral limbal niche which eventually results in limbal stem cell deficiency. With the advancement of glaucoma surgical treatment, it is possible for glaucoma treatment to shift towards earlier surgical modality to reduce topical anti-glaucoma burden leading to limbal stem cell deficiency.

Purpose: This study assessed corneal tomographic, biomechanical, and pachymetry using 3 multimodal imaging (MMI) diagnostic capabilitiesto detect keratoconus in first-degree relatives (FDR) of patients with keratoconus and normal populations. Methods: This was a prospective cross-sectional study. A total of 118 eyes from 78 patients with keratoconus, 96 eyes from 54 FDR subjects, and 126 eyes from 63 healthy individuals were analyzed using the Oculus Pentacam HR, Oculus Corvis ST, and Cirrus OCTA 5000. Corneal tomography, biomechanics, and pachymetry were performed and compared between the 3 groups. Results: Notable disparities in corneal tomography, biomechanics, and pachymetry were observed between FDR and healthy subjects. FDR exhibited a thinner cornea and reduced corneal biomechanical strength compared with normal eyes. In distinguishing keratoconus in FDR, the diagnostic capabilities of B.Ele.Th (back elevation at thinnest), BAD (Belin/Ambrósio Enhanced Ectasia Display), and TBI (tomographic biomechanics index) proved to be highly effective with area under the curve (AUC) beyond 0.90. Stepwise logistic regression (SLR) model combination of corneal tomography and biomechanics of IHD, CBI, and TBI showed an excellent accuracy of AUC:0.999 for detecting keratoconus in FDR than using single MMI alone. Conclusions: FDR with keratoconus indeed have an increased likelihood of developing corneal ectasia, including keratoconus itself. MMI screening of asymptomatic relatives can facilitate early stage or subclinical keratoconus detection.

PURPOSE: To evaluate and identify the ability of the Oculus Pentacam parameters to distinguish subclinical keratoconus (SCKC) and clinical keratoconus (CKC) at different stages in normal eyes. METHODS: SCKC ( n = 28), KC Stage I ( n = 25), KC Stage II ( n = 40), KC Stage III ( n = 35), KC Stage IV ( n = 26), and normal eyes ( n = 46) were analyzed using the Oculus Pentacam HR. Comparisons between groups were assessed using Kruskal–Wallis and pairwise comparison Dunn tests. Receiver operating characteristic curves were used to determine the predictive accuracy of each parameter, as described by the area under the curve (AUC). The AUCs were compared using the DeLong method. RESULTS: The SCKC group demonstrated a notable decrease in corneal thickness compared with the normal group. Index Surface Variance (ISV) had the highest ability to distinguish SCKC from normal (AUC: 0.897, sensitivity: 78.57%, specificity: 95.74%), followed by Ambrósio-Relational Thickness (ARTmax). ISV and index vertical asymmetry showed perfect discrimination ability to distinguish KC Stage I from normal eyes. Most of the Pentacam parameters had sufficient strength to differentiate between Stage II and normal eyes. CONCLUSION: The ISV from Pentacam was the most sensitive parameter for detecting SCKC, Stage I KC, and Stage II KC. Pentacam indices related to corneal thickness may be particularly valuable for identifying early signs of corneal ectasia when no abnormalities in topography are observed.

A 72-year-old man with a history of multiple keratoplasty graft failures presented with acute left eye blurring of vision for 2 weeks. Polymerase chain reaction (PCR) of aqueous showed persistent cytomegalovirus (CMV) infection despite treatment with oral valganciclovir and topical ganciclovir. This led to another penetrating keratoplasty, which failed due to the reactivation of CMV endotheliitis. After achieving CMV negativity on viral PCR, the patient underwent a penetrating keratoplasty followed by postoperative management with a prolonged course of oral valganciclovir and topical ganciclovir. Consequently, the patient was able to achieve graft survival for over a year with a best-corrected vision of 6/12. This case underscores the challenges of managing CMV endotheliitis in corneal grafts, emphasizing the importance of prolonged antiviral therapy with vigilant monitoring to ensure long-term graft success.

The retrocorneal membrane is a rare but serious complication of intraocular surgery, presenting in varied forms. This case series highlights three patients who developed retrocorneal membranes following different ocular procedures. The first case involves a 67-year-old man with a history of right open globe rupture. He underwent multiple surgeries and developed corneal decompensation, for which Descemet stripping automated endothelial keratoplasty (DSAEK) was performed. He later developed a recurrent epithelial downgrowth (EDG) membrane. The second case presents a 79-year-old man who presented with a worsening vision to 3/60, one year after a complicated cataract surgery, due to a temporally growing fibrous downgrowth. The third describes a 70-year-old man who experienced blurred vision with visual acuity (VA) of 6/60, caused by a nasally growing fibrous downgrowth 10 months post-endothelial keratoplasty. All patients underwent retrocorneal membrane peeling combined with intracameral 5-fluorouracil (5-FU) treatment. This report discusses their clinical presentations, ocular imaging, treatment approaches, and histopathological findings. Retrocorneal membranes, particularly EDG, are difficult to manage and often result in poor visual outcomes despite treatment. While histopathology (HPE) remains the gold standard for diagnosis, clinical evaluation, anterior segment optical coherence tomography (AS-OCT), and regular follow-up are essential in guiding management. Further research is needed to improve the understanding and treatment of this rare condition.

Background: High astigmatism (HA) can be misinterpreted as keratoconus (KCN), is highly prone to developing KCN and is normally reconfirmed using corneal topography. Aim: To determine the diagnostic value of corneal biomechanical parameters in distinguishing HA and normal eyes from mild KCN. Setting: This is a comparative retrospective study. Methods: This study assessed 55 eyes with mild KCN (stages I and II), 56 eyes with HA (> 2.0 DC) without KCN and 55 normal healthy eyes. Corneal biomechanical and tomography parameters were measured using the Corvis ST and Pentacam HR (Oculus Optikgeräte GmbH, Germany). Keratoconus was diagnosed through slit lamp examination and abnormal corneal tomography patterns. The Kruskal–Wallis test evaluated each parameter’s distinguishing capability, and the receiver operating characteristic curve (ROC) analyzed the ability to differentiate high astigmatism and normal eyes from mild KCN. Results: The Corvis biomechanical index (CBI) between HA and mild KCN reflected a lower area under the curve (AUC) of 0.859, with a sensitivity of 92.7% and specificity of 65.4%, than CBI between normal and mild KCN, with an AUC of 0.896. The AUC for the Belin / Ambrósio enhanced ectasia deviation index (BAD-D) was 0.993, while the tomographical and biomechanical index (TBI) achieved an AUC of 0.99. Conclusion: Scheimpflug-derived biomechanical parameters effectively differentiated suspected HA and normal corneas from mild KCN corneas, indicating that corneal stiffness decreases at the early KCN stage. Contribution: Oculus Corvis ST effectively screens for ectasia risk, enabling early detection of KCN in individuals with high astigmatism and asymmetric curvature.

Allergic conjunctivitis (AC) comprises a group of conditions triggered by environmental allergens, substantially diminishing the quality of life, particularly among children and adolescents. The mechanical impact of eye rubbing in patients with AC is known to induce biomechanical alterations in the cornea. Modern instruments enable the detection and quantification of these corneal biomechanical changes. The ocular response analyzer and CorVis ST have become standard tools for assessing corneal biomechanical properties. We conducted a review of studies that have investigated corneal biomechanics in patients with AC using both devices to elucidate the association between corneal biomechanical changes and early ectasia development. Our analysis highlights significant findings regarding the tomographic biomechanical index parameter in corneal biomechanics among patients with AC. These findings underscore the importance of ocular screening for all patients to promptly detect subclinical keratoconus changes, thereby improving disease management and outcomes.

Purpose: To evaluate the demography, clinical characteristics, and risk factors of keratoconus (KCN) patients attending a tertiary eye center in Kuala Lumpur, Malaysia. Methods: This prospective cross-sectional study included KCN patients who visited Ophthalmology Clinic, Hospital Canselor Tuanku Muhriz UKM, Kuala Lumpur, Malaysia between January 2022 and October 2023. Their demographic details, best-corrected visual acuity (BCVA), clinical findings, refraction, and risk factors were recorded. Topographical data and KCN classification were obtained through Oculus Pentacam (Wetzlar, Germany). Results: Out of 71,862 cases, 78 KCN patients were identified, with the majority having bilateral KCN (75.6%). The patients were 27.90 ± 7.37 years old on average and were predominantly male (55.1%) and Malay (70.5%). The KCN severity also varied between patients (12.8% mild, 43.6% moderate, and 43.6% severe). No significant association was found between the patient’s demographics and KCN severity (P > 0.05). The patients had a mean BCVA of 0.39 ± 0.48 and a mean spherical equivalent of −5.30 ± 4.45. Eye rubbing (85.9%) and atopy (80.77%) were identified as the most common risk factors for KCN, contrary to family history (12.8%). Meanwhile, Scissors Movement, Vogt Striae, and Munson’s Sign were among the highest percentages of clinical findings presented. Furthermore, 68.7% of KCN cases also reported ocular allergies (papillae). Conclusion: Patients’ demographics were not a determinant of KCN severity. Eye rubbing and atopy were the most significant risk factors for KCN in Malaysia. Thus, KCN screening for patients with atopy and ocular allergies is vital for KCN prevention.