RESUMEN
Background: In the general population, 1 in 2000 people has keratoconus. Indians and other people from Southeast Asia have a higher incidence of keratoconus. Children with keratoconus typically present earlier in life and with a more severe disease. Rubbing the eyes has been identified as a risk factor. Children have a higher incidence and a faster rate of keratoconus progression. Visual rehabilitation in children with keratoconus is challenging. They have a low compliance with contact lens use. Many of these children require penetrating keratoplasty at an early age. Therefore, stopping the progression of keratoconus in children is of paramount importance. Main text: Compared to treatment, keratoconus progression prophylaxis is not only preferable, but also easier. Corneal collagen cross-linking has been shown to be safe and effective in stopping its progression in children. The Dresden protocol, which involves central corneal deepithelization (7-9 âmm), saturation of the stroma with riboflavin (0.25%), and 30 âmin UV-A exposure, has proven to be the most successful. Two significant disadvantages of the typical Dresden regimen are the prolonged operating time and the significant post-operative pain. Accelerated-CXL (9 âmW/cm2 x 10 âmin) has been studied to reduce operative time and has been shown to be equally effective in some studies. Compared to accelerated CXL or traditional CXL, epi-off procedures, transepithelial treatment without the need for de-epithelialization and without postoperative discomfort, have been shown to be safer but less effective. Corneal crosslinking should only be performed after treating children with active vernal keratoconjunctivitis. Corneal opacity, chronic corneal edema, sterile infiltrates, and microbial keratitis have been reported after cross-linking of corneal collagen. Conclusions: The "Dresden protocol", also known as the conventional corneal cross-linking approach, should be used to halt the progression of keratoconus in young patients. However, if the procedure needs to be completed more rapidly, accelerated corneal crosslinking may be considered. Transepithelial corneal cross-linking has been proven to be less effective at stabilizing keratoconus, although being more safer.
RESUMEN
Purpose: The purpose of the study is to investigate the effects of combined 0.8% tropicamide and 5% phenylephrine on the corneal parameters using Pentacam. Methods: The study was performed on 200 eyes of 100 adult patients visiting the ophthalmology clinic for evaluation of refractive errors or cataract screening. Mydriatic drops (Tropifirin; Java, India) containing tropicamide 0.8%, phenylephrine hydrochloride 5%, and chlorbutol 0.5% (as a preservative) were instilled into the eyes of the patients three times every 10 minutes. The Pentacam was repeated after 30 minutes. The measurement data of various corneal parameters from different Pentacam displays (keratometry, pachymetry, densitometry, and Zernike analysis) was manually compiled on an Excel spreadsheet and analyzed using Statistical Package for the Social Sciences (SPSS) 20 software. Results: Analysis of Pentacam refractive maps revealed a statistically significant increase (P < 0.05) in the values of radius peripheral (cornea front), pupil center Pachymetry, pachymetry apex, thinnest location Pachymetry, and cornea volume. However, pupil dilation did not affect the Q-value (asphericity). Analysis of the densitometry values revealed significant increase in all zones. Aberrations maps revealed statistically significant increase in the value of spherical aberration after the induction of mydriasis, but the values of Trefoil 0º, Trefoil 30º, Koma 90º, and Koma 0º were not affected significantly. We did not observe any untoward effect of the drug, except transient blurring of vision. Conclusion: The current study showed that routine mydriasis in the eye clinics leads to a significant increase in various corneal parameters including corneal pachymetry, cornea densitometry, and spherical aberration as measured by Pentacam, which can influence the decision-making in the management of various corneal diseases. The ophthalmologists should be aware of these issues and make adjustments in their surgical planning accordingly.
