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J and Inflammation ResearchResearch Article Article OpenOpen Access Access Recent Advancements in Corneal Ectatic Conditions and their Management: A Mini Review Zeeshan Akhtar, Gaurav Kumar Bhardwaj and Phani Krishna Athreya* Department of Optometry and Vision Sciences, Amity Medical School, Amity University Haryana, Behind Gwalior Village, Haryana, India

Abstract Background: Recent advancements in the corneal diagnostics have helped us a lot in effective management of ectatic conditions of the cornea. This article gives a brief overview about the developments in management and various ways of vision rehabilitation for the condition of corneal ectasia. Methods: After reviewing several studies in the field of ophthalmology and optometry, we tried to understand the various techniques and management plans for improving vision in the ectatic corneal conditions effectively and to update them in this article. Conclusion: During recent years, there are various combination strategies which can be combined to give a productive outcome to these patients who are suffering with ectasia disorders. Procedures like C3R or DALK in conjunction with contact lens can help us achieve better visual outcomes. In severe conditions, it is judicious to check the visual outcome with a scleral lens before planning for a corneal transplant which can avoid the waiting time for the donor cornea and other complications of the surgery beforehand.

Keywords: Ectasia; Penetrating keratoplasty; Corneal collagen cross tests like keratometry, Placido’s disc, pachymetry, slit scanning linking; Riboflavin; Keratoconus; Keratoglobus; Pellucid marginal topography, scheimpflug tomography, optical coherence tomography, degeneration; Post LASIK ectasia; corneal rehabilitation; Kerasoft IC corneal biomechanics will help us reveal the underlying cause and nature of the ectatic disorder. Based on the parameters like simulated Introduction Keratometry reading, Anterior Steeper curvature, Inferior-superior In the recent years, technology has developed in many folds so is value and other parameter analysis will reveal the category and type of the diagnostic, rehabilitation and surgical aspects of eye care system. corneal disorder. Predisposing factors like connective tissue disorders, Cornea being avascular, transparent structure covering the one third vernal kerato-conjunctivitis, chronic marginal blepharitis and other anterior surface of the eye is one of the important vision contributing observations like frequent rubbing of the eyes are to be noted to rule structure not only for accounting the major refracting power, but also out the cause of corneal ectasia [3]. by acting as a primary interface for the light that is entering our eyes. Keratoconus being the most common condition is usually bilateral This article mainly discusses about the recent advancement in the in nature with an age of onset in Puberty, which usually leaves a scar in management of corneal ectatic conditions and vision rehabilitation with the later stages. Pellucid marginal degeneration and Terrine’s marginal the help of contact lenses and some surgical interventions. In normal degeneration are rare with the onset of age around 20 to 40 years and are conditions, Cornea being a strong layer of the eyeball has the strength usually bilateral in nature with a thinning of the inferior and superior and ability to withstand the pressure of intraocular contents excreting corneal areas respectively [1]. Keratoglobus is a rare condition which on it, however, there are few ectatic conditions which will distort the shows bilateral thinning and globular protrusion in the cornea with shape of the cornea leading to unclear image to fall on the retina making increased fragility due to the extreme thinning with unclear genetic a patient to complain about his unstable and unclear vision even after origin. Based on the origin, keartoglobus has primarily been a congenital wearing a standard spectacle correction. disorder in nature with no genetic or inherited patterns defined. Recent Types of ectasia studies reveal an acquired type of keratoglobus too exists [3-6]. Conditions of ectasia are primary and secondary in origin. After ultrastructure observations of corneal ectatic tissue, a Primary conditions like keratoconus, keratoglobus, pellucid marginal significant decrease in the collagen lamellae in the ectatic region and degeneration and terrien’s marginal degeneration, which have shown accumulation of lamellae in the surrounded non-ectatic regions were a few characteristics like progressive thinning (stroma), bulging and noted, indicating a change in the normal anatomical structure of the irregular astigmatism [1]. Secondary reasons are acquired in nature cornea [7,8]. due to corneal diseases or reshaping procedures like refractive surgery procedures are noted. *Corresponding author: Phani Krishna Athreya, Department of Optometry and Etiology and stages of ectasia Vision Sciences, Amity Medical School, Amity University Haryana, Behind Gwalior village, Haryana 122413, India, Tel: 0124-2337015; E-mail: [email protected] In the initial stages, these ectatic disorders are undiagnosed and are usually managed by a common spectacle correction. Decreased quality Received: January 01, 2018; Accepted: January 22, 2018; Published: January of vision achieved by the patient spectacles, frequent change in the 25, 2018 spectacle prescriptions and intermittent contrast or glare problems are Citation: Athreya PK (2018) Recent Advancements in Corneal Ectatic Conditions a few common complaints seen in the initial stages of ectasia [2]. and their Management: A Mini Review. J Ocul Infect Inflamm 2: 101. Copyright: © 2018 Athreya PK. This is an open-access article distributed under With the increasing severity of ectasia gradually patient will have a the terms of the Creative Commons Attribution License, which permits unrestricted clinically significant decrease in best corrected, pin hole and uncorrected use, distribution, and reproduction in any medium, provided the original author and visual acuities. To investigate the cause of the vision loss, the diagnostic source are credited.

J Ocul Infect Inflamm, an open access journal Volume 2 • Issue 1 • 1000101 Citation: Athreya PK (2018) Recent Advancements in Corneal Ectatic Conditions and their Management: A Mini Review. J Ocul Infect Inflamm 2: 101.

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Advancements in management of ectasia in the topography, collagen cross linking with riboflavin is the first mode of treatment which is usually advised to improve the biomechanical With newer imaging and topography techniques, more accurate strength and to delay the corneal changes. This is a 30-minute-long and early diagnosis is possible leading to a significant decrease in procedure which involves the exposure to ultra violet rays of 370 nm the chances of post refractive ectasia. Studies show a reduced rate of on the debrided central corneal epithelium of 6 to 7 mm diameter complications post lasik and, ectasia is a very rare vision deteriorating of riboflavin (vit B2) exposed epithelium to generate covalent bonds complication when not diagnosed or detected in time [9]. between stromal collagen fibrils. Recent advancements have made During histopathology and ultrastructure examination of corneal this procedure safer to endothelium by replacing dextran with HPMC etatic zone reveal few common signs like epithelial hypoplasia with rare and to increase comfort by adopting trans-epithelial cross linking by hyperplasic foci, breaks in Bowman’s membrane, reduction in number suing Benazalconium Chloride (BAK) or Ethylendiaminatetetraacetic of stromal lamellae and thin residual stromal bed and thin collagen acid (EDTA) as a component making the Epithelium-On procedure fibrils are a few corelated signs in explaining the pathophysiology of possible [19-22]. ectatic disorders [10]. Enhancing the riboflavin penetration by using a mild electricity, Use of femto second laser for a most predictive flap removal and in which can help the riboflavin penetrate deeper layers into the stroma smile LASIK are more common strategies which surgeons are adopting which is referred as iontophoresis, in a lesser duration is explored with for preserving the residual stromal bed which help them in reducing epi-on it will be more comfortable with [23]. post LASIK ectatic complications and predictable visual outcomes. However, in rare cases, post LASIK corneal ectatic complications can Observations like using Pulsed oxygen during the treatment occur. These ectatic complications are observed as early as a weekday improved efficacy of postoperative outcome. The basic requirement to after surgery can be seen. But, majority of these ectasia signs are qualify for C3R was a minimum thickens of 400 microns which was identified as surgical complications within the first and second year tweaked by using a hypotonic saline to swell the corneal thickness of a after surgery [11]. person by which most of the patients who were diagnosed with a later stage of ectatic disorders can be benefitted with this novel treatment. The pathophysiology of the post lasik corneal ectasia is due to The chances of reduction in the time duration of the procedure were incomplete or splits seen in the interweaving of stromal lamellar fibrils also explored by using high intensity UV lamps increasing the UV layer which are a result of fracture between stromal lamellae of anterior exposure level to a safer level like 7 mw/cm2 for 15 minutes and 18 mw/ stroma. Similar biomechanical catastrophe is observed even in the cm2 for 5 minutes which are safer without affecting the endothelial cell cases of primary ectatic conditions like keratoconus which goes in to a chronic phase making the condition worsen with time because of this density and limbal stem cell function [24]. phenomenon called interfibrillar slippage which is thought to be the Even after undergoing C3R procedure, for retaining the corneal reason for observing Vogt’s striae more easily visible during the slit shape most of the times, an RGP or Rose K series designs, or Kerasoft lamp examination for most of the ectactic corneas [12-14]. IC based on the severity of the condition can be indicated. The use of Correction of ectasia with contact lenses these speciality design lenses makes the wearer comfortable and gives a stable vision. A decreased visual performance with ophthalmic spectacle lenses if noted or when spectacle lenses doesn’t give a satisfactory visual Intra-stromal corneal rings outcome, there is a need for a trial of soft toric contact lenses to enhance A surgical intervention which was primarily invented for myopia the visual acuity of the eyes till the astigmatism is regular and is within control is later adopted for controlling the astigmatism because of the available prescription range. If it exceeds the range, a rigid gas ectasia and to improve rigidity of the cornea by implanting stromal rings permeable lens with a tri-curve design can be given as a trial. If vision, which have varying sizes and thickness with single or dual segments. lens stability and comfort are still not achieved with a generalized RGP Most successful implants are done in patients with 450 microns corneal lens design, a speciality contact lens with a variable design can be used. thickness and smaller mesopic pupil size. Patients who want to delay Rose K, Rose K2 and Rose K2 NC comes with variable designs that their corneal ectasia, who have contact lens intolerance and who wants can be fitted to the patients with a better comfort and vision than a to postpone penetrating keratoplasty procedure can undergo this traditional RGP lens. procedure. These rings can effectively control the asymmetry in cornea and can able to give better unaided and best corrected vision. Piggy back is another option to try, but due to the structural complexity, thickness and the complex maintenance, storage issues Based on the nomograms followed in this procedure, smaller lead it to be an uncommon option. Hybrid lenses with a combination optical zone of 5 mm and a zone of 7 mm are implanted in the stromal of Silicone hydrogel and an RGP can be a mode of correction which layer of the peripheral cornea. Two segmented rings are usually are commercially available too (KeraSoft IC) which can able to correct inserted in each eye. Asymmetric rings can be used in which thicker an astigmatism up to 12 D in a quarterly disposable modality that can segments are implanted in the steeper parts of the cornea and thinner ensure comfort, health and hygiene of the user [15]. segment in the other portion. Ring segments which are Alike are inserted in cases where the cone is centrally located, which can reduce In recent times the usage of corneo-scleral contact lenses like the steepness of the cornea helping the uncorrected and best corrected Rose K2 XL lenses and scleral lenses have been increased with some vision to be improved. In mild ectatic cases, this procedure can help the promising results in the category of enhancing vision if the previous patients regain their vision with spectacles itself. Recently few studies smaller diameter designs are not giving sufficient vision to the patient, have concluded that a single segment implant can able to correct if the cost factor is not a barrier [16-18]. astigmatism and double segments can reduce the spherical ametropias Cornea collage crosslinking with riboflavin effectively [25]. If the cornea is found to have a significant thinning or rapid changes A study shows that a reduction of mean corneal power by 3.7 diopters

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J Ocul Infect Inflamm, an open access journal Volume 2 • Issue 1 • 1000101