R. Gary Lane, MD 1, J. Michael Jumper, MD 1, Yu Hyon Kim, MD 1, John Taboada, PhD 2 1 Wilford Hall Medical Center, San Antonio, TX, 2 Brooks AFB, San Antonio,

Slides:



Advertisements
Similar presentations
Theoretical Optical Performance of an Equal Conic Intraocular Lens and Comparison to Spherical and Aspheric IOLs Edwin J. Sarver, PhD.
Advertisements

Self induced ocular surface injuries caused by careless handling of topical agents Faik Oruçoğlu (Orucov) Kudret Eye Hospital / Istanbul.
Physiological optics 5th lecture
The Eye By Michael J. Harman . Lacrimal Apparatus.
Basic Illuminating Light Paths and Proper Microscope Alignment E. D. Salmon University of North Carolina at Chapel Hill.
The Human Eye
Eye- Structure and Refraction
Evaluation of the Mature Cataract Baxter McLendon MD FACS Clinical Professor of Ophthalmology Medical University of South Carolina Charleston, South Carolina.
In-the-Bag Toric IOL for Correction of Astigmatism in Keratoconus and after Corneal Surgery Bart T.H. van Dooren, M.D., Ph.D Ilse E.M.A. Mol, M.D. Department.
The Human Eye. The human eye is similar to a camera!! Light enters through an opening, is focused through a lens, passes through a light-tight (dark)
Jeffrey Levenson, MD, Levenson Eye Associates Farrell Tyson II, MD, Cape Coral Eye Center William Flynn, MD, Rashid, Rice & Flynn Eye Associates The authors.
Clinical evaluation of foldable acrylic phakic IOL (fP) implantation ASCRS, San Diego, 2011 A.John Kanellopoulos, MD Professor NYU Medical School, NY Director,
The Eye: Structure & Function
Measuring cells.
The Canadian Association of Optometrists
1 Eye Optics and Refractive Errors By: John J. Beneck MSPA, PA-C.
Lenses Chapter 30.
Bryan Y Kim 1, Shintaro Kanayama MD PhD 1, Tueng T Shen MD PhD 1, Thomas E Gillette MD 2 1 University of Washington Department of Ophthalmology, 2 Eye.
Identification of minerals with the petrographic microscope
W. A. Maxwell, MD, PhD ASCRS 2008 Comparison of the Optical Image Quality for Presbyopia Correcting IOLs using Modulation Transfer Function Testing W.
Copyright 2002, Delmar, A division of Thomson Learning Chapter 12 Eyes.
W. Maxwell, MD, PhD California Eye Institute Fresno, California
Human Visual Perception The Human Eye Diameter: 20 mm 3 membranes enclose the eye –Cornea & sclera –Choroid –Retina.
Evaluation of Systane® versus Placebo in Corneal Epithelial Healing Following Photorefractive Keratectomy (PRK) Lt Col Charles D. Reilly Major Vasudha.
Lecture on eye ball For B.D.S. students only By Prof. Ansari
Laboratory Tips and Microscope Use. Setting Up: Microscope Carrying and Bench Layout Always hold the arm of the microscope while supporting the base with.
Learning question: what conditions can arise from an aged NS? Title: The effects of aging on the nervous system Homework: You have your class test next.
Spook Fish. Eyes How We See Eye Anatomy Nocturnal Eye.
Metallic Foreign Body Embedded in the Posterior Lens Capsule Helen R. Moreira, MD; Michele S. Todman, MD; Paul J. Botelho, MD Division of Ophthalmology,
Financial Disclosure: None
Phototoxic Maculopathy After Scleral Sutured IOL Implantation NC CHO, DW LEE, EY KWEON, MJ KIM Department of Ophthalmology, Chonbuk National University.
Direct ophthalmoscopy
VISION.
The Effect of Corneal Anterior Surface Eccentricity on Astigmatism after Cataract Surgery Choul Yong Park MD 1 Sung Jun Lee MD 1 Prabjot Channa MD 2 Roy.
Open Globe Injuries Maddy Alexeeva PGY-1.
Urrets-Zavalia Syndrome After Lamellar Corneal Transplant: Two Case Reports Timothy Y. Chou, MD, Sujata P. Prabhu, MD, Justin Dexter, MD Department of.
Adriana S. Forseto1, MD Walton Nosé1,2, MD
Light Notes. Light can be visible or not-visible, visible light is only a small part of the electromagnetic spectrum.
Human Vision Outcome C4 – Explain how human vision works.
AcrySof ® ReSTOR ® Apodized Diffractive IOL. What is the AcrySof ® ReSTOR ® IOL? The AcrySof ® ReSTOR ® IOL incorporates an apodized diffractive optic.
Eye anatomy.
Ophthalmic Surgery Chapter 16. Anatomy of the Eye Sensory organ of sight Sensory organ of sight Main function is to convert environmental light energy.
Dorota Tarnawska, MD Dariusz Dobrowolski, MD Dominika Janiszewska
Clinical Outcomes Post AcrySof Toric IOL Implantation In 231 Consecutive Eyes Johnny L. Gayton, MD, FSEE Eyesight Associates 216 Corder Road 216 Corder.
Elmira Baghdasaryan1,2, M.D. Sophie X. Deng1, M.D., Ph.D.
Comparing Factors Affecting Surgically Induced Astigmatism
Science in Primary 4 Master Nopphadol Panyadee. A guide to the many parts of the human eye and how they function.
9-Month Results after Implantation of a new accommodative IOL that works with one focus Mark Tomalla M.D.* Clinic for Refractive and Ophthalmic Surgery,
How to choose best eye Surgeon In India. What is Eye Eyes are the one of the most sensitive organ in your body which functions like the camera. Each part.
The Eye.
Microscopic Observation of Cells Part One. The majority of cells are too small to be seen by the naked eye. We need to use a microscope to observe them.
Comparison of Endothelial Cell Loss After Phacoemulsification Performed by Third Year Residents and Anterior Segment Surgeons Alexandra Braunstein, MD.
Authors have no any financial interest in the subject matter
Direct Ophthalmoscopy
OPTO 4101: Contact lens1- lab L01: Slit lamp microscope
Retina Surgery Tips
Early Experience with Descemet’s Stripping Automated Endothelial Keratoplasty Combined with Phacoemulsification: Clinical and Refractive Outcome University.
Comparison of corneal powers obtained from four different devices
Cataracts and Cataract Operations (Second of Two Parts)*
Eric Dai MD, Pawan Prasher MD, James McCulley MD, R. Wayne Bowman MD.
Direct Ophthalmoscopy
Optics.
The Eye Chapter 8.
Eye- Structure and Refraction
Microscopy.
The Effect of Corneal Thickness on Ocular Drug Penetration
Michael Goodman, Alexandra Paul and Andrew Hsu
Presentation transcript:

R. Gary Lane, MD 1, J. Michael Jumper, MD 1, Yu Hyon Kim, MD 1, John Taboada, PhD 2 1 Wilford Hall Medical Center, San Antonio, TX, 2 Brooks AFB, San Antonio, TX Authors have no financial Interest.

 Operating microscope induced photic maculopathy after cataract surgery was first reported in  Has been observed in other procedures, including glaucoma, refractive, corneal, and retinal surgeries.  Photic maculopathy remains an important problem in ophthalmic surgery  Duration of surgery closely correlates with injury:  Less than 100 minutes – 0.9% risk  Greater than 100 minutes – 39%

 Cheapest and most common method for prevention of light toxicity.  Especially important for microscopes without oblique lighting or an eclipse feature.  Light shields may directly block light headed for the macula.  Defocus the light which is concentrated onto a macular “hot spot” by the cornea and the lens.  Although various light shields have been described and used for many years, there have been no clinical measures of their effectiveness.  We compare the ability of various corneal light shields to block light from reaching the macula.  We also describe the ability of shields to diffuse light and prevent the formation of a “hot spot”.

 A cadaveric model was prepared using 20 porcine eyes mounted on glass slides with a surgically created posterior scleral window to allow light transmission through the ocular media.  Four commonly used ad hoc materials were fashioned into corneal light shields of 6.0mm and 8.5mm. Two commercially available light shields were also examined.  Radiometric measurements were made with a UDT silicone photodiode detector placed behind the eye..  Light intensities were recorded with and without each shield in place with unfiltered light from an operating microscope at full intensity focused on the iris plane and also with a 505nm filter in place.

Four commonly used ad hoc materials were fashioned into corneal light shields of 6.0mm and 8.5mm as well as two commercially available light shields (Hessburg and Linstrom).

Using a trephine, a 10mm window was surgically created in the macula to allow light transmission through the ocular media. The eyes were mounted on a glass microscope slide with putty to block stray light contamination Anterior view of the eye model with the back of the eye cut away, showing the clear path from the cornea to the scleral window, where the light detector will sit.

 Assessed the ability of corneal light shields to defocus light and prevent the formation of a “hot spot”, a red glow in the sclera.  A non-surgically altered, intact pig eye was placed under the operating microscope.  The corneal light shields were placed on the cornea.  The size of the “hot spot” was measured.

The actual amount of light attenuation (mV) for each shield is shown on the x- axis. A percentage attenuation was also calculated after subtracting out background illumination. ANOVA (p<0.001)

Attenuation of light (mV) in the blue-green region is shown in the x axis. Also shown are percentage of the reduction of the voltages after placement of the corneal shields. ANOVA (p<0.001).

Before and after photos of pig eyes using a 1000 drape corneal shield. The shield defocuses the hot spot slightly and its dimensions increased to 3x5mm. 8.5mm instrument wipe completely darkens the hot spot.

 Highest attenuation levels:  Hessburg 8.5mm shield  8.5mm brown surgical glove  Several shields ineffective  Less than 10% total light (5/9)  Less than 75% 505nm light (6/9)  8.5mm shields are more effective.

 Not all corneal light shields are created equal.  The overall percentage of light blocked by the shields was lower than expected.  Ranges from 25 to 75% for the filtered and lower for the unfiltered light.  Increases dramatically with increasing diameter  Choose a minimum of 8.5 mm when working with dilated pupils.  Several commonly used shields provide unacceptably low levels of protection.  Brown surgical gloves work just as well as the commercially available Hessburg shield.  4mm Lindstrom keratoplasty shield was not effective in our study.  Do not become complacent after placing a light shield