How To Examine A Corneal

Pathology

Dr. Pooja Bandivadekar

Senior Resident

Dr. R. P. Center for Ophthalmic Sciences

AIIMS

Examination Of Corneal Pathology-

Overview

Evaluation Of Visual Potential And Prognostication

Laboratory Investigations And Corneal Imaging

Bedside Tests

Clinical Evaluation Of Cornea And External Eye

Clinical History

Examination Of Corneal Pathology-

Clinical History

• Age of onset

• Mode of onset

• Unilateral or bilateral

• History of trauma or

chemical injury

• Previous ocular

surgery

• Use of medications

Examination Of Corneal Pathology-

Clinical Assessment

• Assessment of vision,

Refraction

• Systemic Evaluation

• Torch Light Examination

– Ocular Movements

– Fixation

– Deviations

Examination of Corneal Pathology-

Clinical Assessment

Cornea And Adnexal

Examination

Evaluation Of The Lid

Slit lamp Biomicroscopy

Tear Film Evaluation

Corneal Pathology- Adnexal

Evaluation

Corneal Pathology-

Slit lamp Examination

Direct Illumination

Diffuse Illumination

Focal Illumination

Indirect Illumination

Sclerotic scatter

Retro illumination

Specular Reflection

Slit Lamp Examination-

Diffuse Illumination

Slit Lamp Examination-

Diffuse Illumination

Slit Lamp Examination-

Focal Illumination

Slit Lamp Examination-

Retro Illumination

Slit Lamp Evaluation-

Sclerotic Scatter

• Corneal

opacities

• Interstitial

deposits

• Perforating scars

Slit Lamp Examination-

Specular Reflection

• Morphology of

endothelial cells

• Guttae and

excrescences

• Assessment for

corneal

decompensation

Slit Lamp Examination-

Fluorescein staining

Examination of Corneal Pathology-

Documentation Of Corneal Opacity

Examination of Corneal Pathology-

Documentation Of An Ulcer

Examination of Corneal Pathology-

Documentation of Decompensation

Examination of Corneal Pathology-

Tear Film Evaluation

Tear Film Function Test

TBUT

Schirmer’s test

Tear Meniscus Height

Tear Clearance rate

Tear OsmolarityAnd

Composition

Tear Film Evalaution-

Schirmer’s Test

• Tear production –

Aqueous component

• Basal Schirmer Test

• Schirmer I - < 15 mm

• Schirmer II- < 10 mm

• < 5 mm -

Tear Film Evalaution-

Tear Film Breakup Time

Tear Film Stability

Tear Film Evaluation-

Tear Meniscus Height

• Pathological <0.3 mm height

• Aqueous deficiency

• Poor lid to globe apposition

• Raised if naso-lacrimal obstruction

Esthesiometry

Examination Of Corneal Pathology

Assessment Of Intraocular Pressure

• Irregular mires on

applanation tonometry

• Effect of – Scarring

– Edema

– High astigmatism

• Tonopen

Examination Of Corneal Pathology

Assessment Of Fundus

• Optic nerve status-

Pupillary reactions,

Consensual reactions

• Ultrasound examination-

– Endophthalmitis

– Retinal Detachment

– Optic nerve head cupping

Examination of Corneal Pathology-

Laboratory Investigations

Keratometry

Pachymetry

Impression Cytology

Corneal Scraping

Laboratory Investigations-

Keratometry

• Assessment of

astigmatism

• Planning of surgery-

– DSAEK v/s PKP

– Triple procedures

• Contact lens trials for

visual rehabilitation

Laboratory Investigations-

Pachymetry

• Methods– Ultrasonic

– ASOCT based

– Scheimflug and scanning

slit

– UBM

• Indications– Corneal opacities

– Keratoconus and ectatic

disorders

– Ocular surface disorders-

Laboratory Investigations-

Impression Cytology• Non-invasive

• Indications– Limbal stem cell

deficiency and dry eye -cell morphology and goblet cells

– Diagnosis and monitoring ocular surface neoplasia-metaplasia

Laboratory Investigations-

Corneal Scraping

Corneal Scraping

Smear

Gram’s stain

10% KOH mount

Culture

Bacterial

Fungal

Others

PCR

Viral

Acanthamoeba

Examination of Corneal Pathology

Advanced Diagnostic Techniques

Advanced Diagnostic Techniques

Corneal Topography

Confocal Scan

Specular Count

ASOCT

UBM

Advanced Diagnostic Techniques

Videokeratography• Placido disc based

• Surface topography of entire cornea

• Indications– Corneal astigmatism

– Selective suture removal in keratoplasty

– Contact lens rehabilitation of patients with corneal scars

Advanced Diagnostic Techniques

Slit Scanning Imaging

• Combined with placido

disc imaging

• Elevation based

topography

• Indications

– Corneal ectatic disorders-

keratoconus, PMD

– Post- LASIK ectasia

– Progression analysis

Advanced Diagnostic Techniques

Scheimflug Imaging

• Elevation based

• Pachymetric values

• Good repeatability

• Indications– Corneal ectatic disorders-

keratoconus, PMD

– Post- LASIK ectasia

– Progression analysis

Advanced Diagnostic Techniques -

ASOCT

Indications

• Monitoring of corneal ulcers

• Lasik flaps

• Pannus morphology

• Planning and management of

lamellar keratoplasties

• Descemet membrane

detachment

Advanced Diagnostic Techniques

Ultrasonic Biomicroscopy• Indications

• Keratoplasty work-up-

• Limbal mass– Dermoids

– OSSN

• Ocular surface diseases-– Evaluation

– Planning of surgery

Advanced Diagnostic Techniques

Specular Count

• Indications– Fuch’s endothelial dystrophy

– Posterior polymorphous

dystrophy

– Follow-up of keratoplasty

– Eyes with glaucoma, uveitis,

pseudo-exfoliation

• Assessment of

contralateral eye

important

Examination of Corneal Pathology

What Next?

Diagnosis

Prognosis

Management

Examination Of Corneal Pathology

Visual Potential Assessment

• Macular function tests

• Laser Interferometry

• Potential Acuity Meter

• Visually evoked potentials

Summary

• Accurate elicitation of history is important

• Detailed slit lamp examination is

necessary

• Fluorescein staining in all the cases

• Thorough assessment of corneal

sensations

• Tailored laboratory and imaging

techniques