Looking deep into retina : indirect ophthalmoscopy and fundus drawing

LOOKING DEEP DOWN : EXAMINING RETINA

Dr Prachir Agarwal

Moderator : Dr Pradeep Kumar Panigrahi3/6/2013

• Indirect Ophthalmoscopy is essential for a detailed, panoramic and complete examination of the fundus

CR Keeler, A Brief History of the Ophthalmoscope, Optometry in Practice ,Vol 4 (2003) :137-45.

Introduction

1851

Direct Helmholtz

1852

Indirect

Mono-ocular Independent light source

Ruete

1861

Indirect

Binocular Independent light source

Giraud - Teulon

1951

Indirect

BinocularHeadmounted

Integrated, clinically useful

Charles Schepens

Outline

Optical principle of Indirect Ophthalmoscopy

Comparison between different lenses used

Comparison of Direct and Indirect Ophthalmoscope

Advantages & Disadvantages of Indirect Ophthalmoscope

Technique of Indirect Ophthalmoscopy & Scleral Depression

Documentation of findings (THE FUNDUS DRAWING)

Optics of Indirect Ophthalmoscopy

The technique is called Indirect because the fundus is seen through a condensing lens.

The image is formed close to the principle focus of the lens, between the lens and the observer

If the retina could light up….

Emmetropic eye

Image of retinaon distant surface

GTT 04

Fundamental Principle of the Indirect Ophthalmoscope

Condensing lens

Aerial image of retina

Fundamental Principle ofIndirect Ophthalmoscope

GTT 04

Viewing the aerial image with a magnifier

GTT 04

Image is Real and Inverted

The power of the condensing lens determines:

• Working distance • Magnification• Field of view

Lens Power (D)

Static Field of View*

Magnification

Working Distance from

Cornea+14 22 4.17 72 mm

+20 30 3.25 47 mm

+30 40 1.97 26mm

Comparison with Direct Ophthalmoscopy

Retinal Detachment: Principles and Practice, Third Edition Daniel A. Brinton and C. P. Wilkinson

Advantages of Indirect system

• Image not affected by the patients refractive power

• In children

• In eyes with nystagmus

• Delivery of LASER

• Binocular examination of fundus up-to the periphery.

• Large field of view allow for the panoramic view.

• Better Resolution.

• Use in operating room for cryo/scleral buckling.

• Better view in presence of media opacities.

• Increased illumination .

• Reduced distortion.

An additional advantage is that the doctor is at a distance from the patient.

• Difficult to master.

• Small movements alter significantly the size and

clarity.

• Inverted and reversed image.

• Relative lack of magnification.

Disadvantages

Technique of Indirect ophthalmoscopy

Adjusting the instrument

Positioning of the patient

The examination proper & scleral indentation

The fundus drawing

Adjustment of Eye piece, Head band

IPDIPD knob

Adequately adjusted IPD – at arms length

Adjusting IPD

Aperture setting

Filter knob

Rheostat

Technique

Ideal position of the ophthalmoscope

Axis perpendicular to the visual axis of examiner

The scope not resting on the nose of the examiner

The eyepiece as close to the examiners pupils as possible

Adequately adjusted IPD

IDEAL POSITION

Head flexed

Head Extended

Positioning the patient

• Proprioception helps patient to look in cardinal gazes

• Patient should be urged to keep the other eye open

Examination Proper

Holding the lens

Pivot

Scleral Depression Technique

Holding the depressor

• A – Patient looks down, depressor on margin of sup tarsal plate

• B – Depressor advanced into the orbit as patient looks up but no depression applied as yet

• C – Scleral depression applied gently to area of interest

Scleral Depression technique

Critical in obtaining a binocular (stereoscopic) view

Technique of indirect ophthalmoscopy

Scleral Depression technique

Video Presentation

Fundus drawing-Amsler Dubois chart

Junction of P Plicata &

P Plana

The Ora

The Equator

Fundus drawing

Tips for drawing

Disregard Sup/Inf and Temp/Nasal while drawing

What ever appears closer to the observer in the condensing lens is peripheral (anterior)

Observe the disc and follow a vessel to the periphery

Observe the macula at the end for best patient co-operation

Fundus drawing

Fundus drawing

• Right Eye – Localized RD with HST at 11° clock and Lattice at 1° clock

FUNDUS DRAWINGDraw as you see the lesion in the condensing lens

• Retinal arterioles

• Neovascularization

• Vascular anomalies

• Attached retina

• Vascular tumors

FUNDUS DRAWING – RED SOLID

• Hemorrhages ( Pre and retinal)

• Open interior of retinal breaks (tears, holes)

• Open interior of outer layer holes in retinoschisis

•

FUNDUS DRAWING – RED SOLID

• Open portion of GRT or large dialyses

• Inner portion of CRA

• Inner portion of thin areas of retina

• Open portion of retinal holes in inner layer of retinoschisis

FUNDUS DRAWING- RED CROSSED

• Detached retina

• Retinal veins

• Outlines of retinal breaks

• Outlines of ora serrata

FUNDUS DRAWING – BLUE SOLID

FUNDUS DRAWING – BLUE SOLID

• VR traction tuft

• Outline of lattice

degeneration (inner X)

• Outline of thin area of

Retina

•Inner layer of retinoschisis

•White with or without pressure (label)

•Detached parsplana epithelium anterior to separation of ora serrata

•Rolled edges of retinal tears / inverted flap in GRT (curved lines)

FUNDUS DRAWING – BLUE CROSSLINES

• Cystoid degeneration

• Outline of change in area or folds of detached retina because of shifting fluid

FUNDUS DRAWING BLUE CIRCLE/INTERRUPTED LINES

• Opacities in the media

• Vitreous hemorrhage

• Vitreous membranes

• Hyaloid ring

• IOFB

FUNDUS DRAWING- GREEN SOLID

• Retinal operculum

• Outline of elevated Neovascularisation

• Vitreous Substitute – Silicone Oil, Gas

FUNDUS DRAWING – GREEN SOLID

• Asteroid hyalosis

• Frosting or snowflakes on Retinoschisis or lattice degeneration

FUNDUS DRAWING – GREEN DOTTED

• Uveal tissue

• Pigment beneath detached retina

FUNDUS DRAWING – BROWN SOLID

• Pigment epithelial Detachment

• Choroidal melanomas

• Nevus

• Choroidal detachment

FUNDUS DRAWING- BROWN SOLID

• Edge of buckle beneath detached retina

• Outline of Posterior Staphyloma

FUNDUS DRAWING – BROWN OUTLINE

• I/R, S/R hard exudate

• S/R gliosis

• Deposits in the RPE

FUNDUS DRAWING – YELLOW SOLID

• Post-PHC /cryo retinal edema

• Substance of long & short ciliary N

• Retinoblastoma Yellow – stippled-• Drusen Yellow Crossed• Chorioretinal coloboma

FUNDUS DRAWING- YELLOW SOLID

• Hyperpigmentation as a result of previous Rx with cryo/PHC/Diathermy

• Completely Sheathed vessels

• Pigment within detached retina (Lattice, HST)

FUNDUS DRAWING- BLACK SOLID

• Pigment within choroid or pigment epithelial hyperplasia within attached retina (e.g. RP)

• Pigment demarcation line at margin of attached

and detached retina

FUNDUS DRAWING- BLACK SOLID

• Edge of buckle beneath attached retina

• Outline of CRA

FUNDUS DRAWING – BLACK OUTLINE

Thankyou