aio vol 1 issue 1 sep 2013
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DESCRIPTIONThis journal is the official scientificpublication of the Al SalamaInstitute of Ophthamology & itsallied hospitals with two issuesbeing published every year. Itwelcomes original articles, reviews,case reports, book reviews & othermaterials of academic interest inophthalmology & medicine
AIO Journal of Ophthalmology 1
Know Thy Instrument
Chief EditorDr. K. Preetha
Editorial CommitteeDr. Priya NambiarDr. Divya MenonDr. Dolly Nazia P.M.
Editorial BoardDr. J. MuthiahDr. Rajesh P.Dr. M.A. SafarullaDr. Kunal KumarDr. Manish ShyamkulDr. Syed BasheerDr. Dheeresh KadukanvelliDr. Shaji Hussain
Advisory BoardDr. Muhammed Swadique
Dr. K. PreethaConsultant Ophthalmologist
Al Salama Eye Hospital, Arayidathupalam Junction, Calicut - 673004Emai l : email@example.comMobile : 9895878764Landline : 0495 3930123
This journal is the official scientific
publication of the Al Salama
Institute of Ophthamology & its
allied hospitals with two issues
being published every year. It
welcomes original articles, reviews,
case reports, book reviews & other
materials of academic interest in
ophthalmology & medicine.
AIO Journal of OphthalmologyVolume I, Issue I, September 2013
Address for correspondence
AIO Journal of Ophthalmology 3
OriginalArticle7 Role of corneal wavefront guided LASIK treatment in highly aberrated corneas MuhemmedSwadique,PadmajaKrishnan
20 Recurrent corneal erosion DivyaMenon
25 Contracted socket
28 Phakic Intraocular Lens
Cuttingedgeophthalmology31 Refractive lenticule extraction (ReLEx)
4 AIO Journal of Ophthalmology
CaseKorner34 Posterior embryotoxon and its significance
36 Ankyloblepharon filiforme adenatum
KnowThyInstrument38 Optical coherence biometry: How coherent is the master ?
Eureka!45 This is all about smart phone-o-graphy
TheOphthalmicParaphernalias48 Oculocardiac reflex an overview
AIO Journal of Ophthalmology 5
Greetings from the editorial desk!
In your hands is the maiden issue of AIO JOURNAL OF OPHTHALMOLOGY. As the tag line states this journal is the official scientific journal of the Al Salama Institute of Ophthalmology (AIO) & its allied hospitals. Envisaged as a half yearly journal with a minimum of two issues a year, we plan to make this journal a forum for ophthalmic interactions of the highest quality.
Ophthalmology is in the midst of a knowledge boom with quite a few journals coming out every year. The fate of most of these publications is that the ophthalmologist flips through most of them cursorily without actually going through the material. Our endeavor is to make this journal interesting enough so that the reader is enticed to read it thoroughly.
Inside this issue, The Review Section features articles on Ptosis, RCES, Contracted Socket & Phakic IOL. The section Original Articles features an interventional study on the role of corneal wave front guided lasik treatment in highly aberrated corneas . The results are promising with a significant reduction in corneal higher order aberrations with coma components.
The section Cutting Edge Ophthalmology focuses on the latest innovation in refractive surgery- ReLex. Case Korner features two interesting cases seen in our hospital. In Know Thy Instrument the focus is on the IOL Master recently acquired at our Calicut branch. Our guest column Ophthalmic paraphernalias features a writeup on oculocardiac reflex a nemesis for surgeons; Eureka features a brilliant innovation to use smart phones for slit lamp photography, Potpourri is an aviyal of ophthalmology information while funtastica is the dessert after the feast. We finally wind off with a Ready Reckoner on the present day modalities for managing Keratoconus.
Here is hoping that this information collage is as interesting for you to peruse as it was for us to assemble. Please feel free to give your reviews, opinions & criticism about this issue & also about any novel ideas you want incorporated in the journal.
AIO Journal of Ophthalmology 7
Dr. Muhemmed Swadique, FRCS, Prof. Padmaja Krishnan, MS
Laser in situ keratomileusis (LASIK), is developed to correct refractive errors. It involves moulding of corneal surface with the help of excimer laser. It is a safe and effective procedure.1 Even though the un aided acuity of vision improves, the quality of vision decreases after LASIK procedure. This is due to the increase in the in-duced aberrations which reduces the contrast sensitivity2-4 and also causes photic phenomena like glare and halos. The optical aberrations may be the cause for non attain-ment of maximal acuity of retinal limit of 6/35.
The aim of refractive surgery has shifted to maintain or even improve the quality of vision6. This target can be attained by decreasing the induced aberrations and also by decreasing the pre-existing aberrations6. This can be at-tained by the use of Corneal wavefront guided LASIK treat-ment.
This study aims at evaluating the safety and efficacy of Corneal wavefront guided LASIK treatment in highly aber-rated corneas. Also it evaluates the changes in the higher order aberrations, glare, halos and contrast sensitivity.
Materials and MethodsThis non randomised, interventional, prospective study comprised 76 consecutive symptomatic eyes of 38 pa-tients with a hyperopic or myopic spherical equivalent (SE). Inclusion criteria were symptomatic myopia, hyperopia, or astigmatism and a significant level of primary corneal coma aberration. The level of corneal coma was considered significant when the associated root mean square (RMS) for the corneal primary coma (measured over a pupil of 6.0 mm) was higher than 0.5 m.
This criterion was chosen based on previously reported physiologic levels of corneal HOAs16; that is, the 0.5 m cut-off point was selected because the associated probability of it being a normal value was less than 1%.16 Exclusion cri-teria were formal contraindication to LASIK.
Patients wearing contact lenses to correct the residual error were instructed to discontinue lens use for at least 4 weeks before the preoperative examination. Before
surgery, patients received a complete explanation of the surgery and its risks and benefits and signed an informed consent in accordance with the Declaration of Helsinki. No treatment was performed if the refraction was not stable at 2 consecutive examinations performed at least 3 weeks apart. The target postoperative refraction was emmetropia in all cases. The postoperative follow-up was 6 months.
Preoperative ExaminationThe preoperative examination included uncorrected deci-mal visual acuity (UCVA); best spectacle-corrected decimal visual acuity (BSCVA); manifest and cycloplegic refractions; slitlamp biomicroscopy; applanation tonometry; ultrasonic pachymetry; scotopic, low, and high mesopic pupillome-try; contrast sensitivity, corneal topography (Opticon Kera-ton Scout); and fundus evaluation.
Corneal aberrations were derived from corneal topog-raphy following the protocol described below in Corneal Aberrations. In addition, patients were asked to evaluate the levels of halos and glare they perceived at night using the following qualitative scale: none, low, moderate, high, or severe.
Ablation ProfileThe corneal wavefrontguided customized ablation was designed and calculated using commercially available ORK-CAM software. With this system, after the Opticon Keraton Scout corneal topography file is imported into the ORK-CAM software and clinical information (eg, patient age, subjective spherocylindrical refraction, central corneal pachymetry, flap thickness) is introduced, the software au-tomatically designs the ablation profile to best minimize all corneal aberrations.
The calculation requires a topographic examination during which at least 7.0 mm of corneal area is analyzed in all meridians. Then, the optical zone is modified accord-ing to the pachymetry and the more significant or disturb-ing terms from the Zernike decomposition are chosen for inclusion in the calculation of the customized ablation.
8 AIO Journal of Ophthalmology
The main goal of the designed ablation in all cases was to minimize the primary coma aberration Z(3,1). Therefore, the ablation profile was designed according to the corneal shape and refractive error and by modifying the optical zone and number of Zernike terms treated.
The aim was to create a corneal surface with an el-evation profile that would generate a minimally distorted wavefront. In addition, all treatments were designed to leave an expected residual stromal bed thicker than 300 m in the central cornea.
Surgical TechniqueAll LASIK procedures were performed by the same surgeon at Al Salama Eye Hospital, Perinthalmanna, Kerala, India. First, the treatment designed using ORK-CAM software was loaded into the computer of the excimer laser (Esiris, Schwind eye-tech-solutions). The surgeon then reviewed and confirmed the data. The Esiris is a flying-spot laser with a para-Gaussian spot of 0.8 mm diameter.
The laser incorporates an eye-tracker system with a frequency of 330 Hz. The temperature and humidity condi-tions were maintained within the ranges indicated by the laser manufacturer. The optical zone of the treatment was selected according to the preoperative scotopic pupil size. Depending on the pachymetry, optical zones w