![]() Detailed refraction, slit-lamp, and biomicroscopic examinations were done for all patients prior to inclusion in the study. Patients presenting to the hospital for correction of refractive errors and cataract surgery were included in the study. ![]() The age completed at last birthday was considered while including the subject in the study. We aimed to recruit at least 50 subjects in each group to have a predetermined convenient sample of 200 subjects (400 eyes). 5–20 years (group 1), 21–35 years (group 2), 36–50 years (group 3), and more than 51 years (group 4), to have comparable representation. Stratified sampling technique was used by dividing the subjects into four age groups, viz. Informed consent was obtained from the parents/guardians of the children and minor subjects. The adult subjects provided written informed consent to participate in the study. Clearance from the institutional review board and ethics committee was obtained prior to the commencement of the study. This was a prospective, cross-sectional observational study carried out in a tertiary care eye hospital in western India over an 18-month period from August 2017 to February 2019. In this study, we aim to compare the CET parameters in various age groups, measured using a 9-mm-wide OCT scan, including a comparable representation of the pediatric population. Furthermore, the studies that aimed to compare the CET in various age groups did not include pediatric subjects. This leads to poor assessment of extreme peripheral CET and can have a bearing on the assessment of CET changes in peripheral ectasias, wider ablation zones in kerato-refractive surgery, and orthokeratology lenses. ![]() Most studies that aimed to assess the CET in normal individuals using optical coherence tomography (OCT) have been limited by having a scan diameter of only 6 mm. However, having a normative database is essential prior to understanding and analyzing effects secondary to disease entity or treatment modalities. Combined treatments and improved screening could eliminate the need for surgical management in most cases of PMD.Corneal epithelial thickness (CET) parameters and their changes are a subject of interest vis-à-vis ectasia diagnosis and treatment, orthokeratology lenses, and advanced surface ablations for correction of refractive errors. Corneal collagen cross-linking is especially exciting because it halts disease progression. Combining treatments such as ICRS, CXL, toric PIOL implantation, and refractive surgery is promising, but additional studies are needed to investigate their efficacy and safety.Īlthough little is understood about the etiology, pathophysiology, epidemiology, and genetics of PMD, new treatments are improving visual outcomes and reducing complications. CXL demonstrates effectiveness without complications, although data are limited and long-term results are needed. ICRS implantation can delay penetrating keratoplasty and improve contact lens tolerance, but does not treat the underlying process. Toric PIOL implantation is effective, but ectasia progression is a concern. Crescentic lamellar keratoplasty and TILK are effective, but technically difficult and without long-term results. CLWR is effective, but lacks long-term results. FTCWR has good visual outcomes, but with significant astigmatic drift. DALK provides visual outcomes similar to penetrating keratoplasty without the risk of immune-mediated graft rejection, but its complexity and relative novelty limit its acceptance. Penetrating keratoplasty is the treatment of last resort in PMD and is effective, but with considerable complications. Reported data for each treatment is presented. This is the first review article looking at the literature specific to PMD. To review and evaluate current and future directions in the diagnosis and surgical management of pellucid marginal degeneration (PMD), including penetrating keratoplasty, full-thickness crescentic wedge resection (FTCWR), deep anterior lamellar keratoplasty (DALK), crescentic lamellar wedge resection (CLWR), crescentic lamellar keratoplasty, tuck-in lamellar keratoplasty (TILK), toric phakic intraocular lens (PIOL) implantation, intrastromal corneal ring segment implantation (ICRS), corneal collagen cross-linking (CXL), and combined therapies.
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