2. Definitions
Pathology is the study of disease conditions
using scientific methods
Disease - Structural or functional
abnormality in a cell, tissue, organ or system
Ocular Pathology - Scientific study of
diseases that affect the eye.
3. .
Pathology gives explanations of a disease by studying the
following four aspects of the disease.
1.Aetiology (the cause, set of causes, or manner of causation
of a disease or condition)
2. Pathogenesis (mechanism through which the cause
produces the pathological and clinical manifestations)
3. Morphologic changes (structural alterations)
4. Functional derangements and clinical significance.
In other to understand pathology, the normal function of the
cell, tissue etc. must be understood
4. CLASSIFICATION of Diseases
Topographical i.e. by bodily region or systems, eg,
Vascular diseases, GIT diseases, Ocular diseases
Anatomical i.e. by organ of tissue, eg. Corneal disease.
etc.
Physiological i.e. by function or effect.eg. Inflammatory
disease, etc
Pathological i.e. by nature of disease process ( same as
above
Aetiological i.e based on the cause.eg staphlococcus
infection
Epidemiological i.e. based on the prevalence
Any single disease may fall within several of these
categories
5. The causes of disease
Diseases can be caused by either
Genetic/congenital factors,
Acquired (environmental) factors,
or a combination of the two
or indirect causes
6. Genetic conditions
Genetic: These are hereditary factors that are
inherited genetically from one’s parents i.e. An
abnormality in the base sequence of the DNA
inherited from the parents Eg. Albinism, Colour
blindness, trisomy 21 (Hypertelorism,
Keratoconus, Iris hyperplasia)
Congenital: Congenital means “born with.” It may
be genetic, eg Down’s syndrome, or it may be
acquired, eg, transmission of Rubella infection
from mother to foetus. Injestion of certain drugs
during prenancy, etc. These changes occur when
the foetus is still in the womb, They manifest at
birth or shortly after. Eg. Congenital glaucoma,
congenital cataract, Rubella
7. Acquired disease
Acquired diseases are due to Environmental
factors
Environmental causes of disease are many and
may be due to
1. Physical agents
2. Chemicals
3. Nutritional deficiencies and excesses
4. Infections and infestations
5. Immunological factors
6. Psychogenic factors
8. Common diseases of the eye
Inflammatory conditions
Infectious conditions
Immunological conditions
Neoplasms
Degenerative conditions
Others i.e. Dystrophies, Traumatic conditions
nutritional, etc
9. Inflammatory conditions
Inflammation is a local response (reaction) of living vasculaized
tissues to endogenous and exogenous stimuli.
The aim of Inflammation is to localize and eliminate the causative
agent and to limit tissue injury.
Occurs when a living tissue is injured.
The body’s response to injury, invading pathogens, anything
perceived as injurious
There is an extensive array of powerful defense responses which
try to eliminate the effect of the injury and bring about healing
Five cardinal signs of acute inflammation are Redness, Swelling,
Heat, Pain, Loss of function
Inflammation can occur in any tissue of the eye
inflammatory lesion are usually indicated by the suffix 'itis to the
name of the tissue involved
10. Inflammatory conditions of the
eye
Eyelid Blepharitis
Cornea Keratitis
Conjunctiva Conjunctivitis
Sclera Scleritis
Cornea/ Conjunctiva Keratoconjunctivitis
Sclera/ Cornea Sclerokeratitis
Episclera Episcleritis
Iris Iritis
Ciliary body Cyclitis
Iris and ciliary body Iridocyclitis, Anterior
Uveitis
Ciliary body and Choroid posterior uveitis
11. Iris, CB, Choroid Uveitis
Choroid Choroiditis
Retina Retinitis
Choroid and Retina Chorioretinitis
Optic nerve Optic Neuritis
Optic nerve head alone Papillitis
Lacrimal sac Dacryocystitis
Lacrimal gland Dacryoadenitis
All parts of the eye
(inside andouter coat) Panophthalmitis
All vascular structures Endophthalmitis
Exudase in the anterior chamber Hypopion
Blood in the anterior chamber Hyphema
12. Infectious conditions
Diseases caused by infectious agents.
The presence of microorganisms in tissues,
invading, multiplying and causing clinically
apparent disease
Fatal not only to the host but also to the organism
involved
Major cause of inflammation
May be caused by bacteria, Viruses, fungi,
parasites
May be Exogenous or Endogenous
13. Immunological conditions
The immune system identifies invading material and
repels or evades them
Due to the presence of genetically determined
biological marker on the cell, the host is able to
recognize and develop a wide array of defenses
against it
If it invades again, a more vigorous reaction against it
occurs
However, the immune system can be abnormal, which
can lead to diseases. The abnormalities of the immune
system include:
A. Hypersensitivity reaction - This is exaggerated
immune response to an antigen.
B. Immunodeficiency - deficiency of a component of
the immune system
14. Neoplastic conditions (Tumours)
• Uncoordinated growth of an abnormal mass of cells
which are
Purposeless
No regard for surrounding tissues
Continues to grow after cessation of the stimulus
that initiated it
• Tumours can be classified in several ways
In terms of tissue of origin
In terms of their products
In terms of microscopic or macroscopic appearance
In terms of behaviour
THE MOST IMPORTANT CLASSIFICATION IS IN
TERMS OF BEHAVIOUR WHERE THEY ARE EITHER
MALIGNANT OR BENINGN
15. Degenerative conditions
Changes that occur as a result of aging or
decrease in metabolic efficiency of the tissue
Due to deterioration and loss of specialized
function of the cells
16. Others
Trauma – External force that cause injury. These
include, Physical agents, radiation, extremes of
temperature, and electric power. These agents apply
excess physical energy, in any form, to the body.
Chemicals burns - With the use of an ever-increasing
number of chemical agents such as drugs, in industrial
processes, and at home, chemically induced injury has
become very common
Nutritional – Deficiencies or excesses
Dystrophies - Disorders of an organ due to impaired
nourishment, usually bilateral, genetic and often
progressive Eg. Corneal dystrohies -resulting in
abnormal deposition of material in the cornea
17. Diseases of the eye based on the
tissue involved
Diseases of the orbit
Diseases of the Eyelids and adnexia
Diseases of the Lacrimal apparatus
Diseases of the Conjunctiva
Diseases of the Sclera and Episclera
Diseases of the Cornea
Diseases of the anterior uvea
18. Important considerations
In clinical assessment of eye diseases, it is
important to consider the following
1. Epidemiology(distribution of the disease, i.e.
age, sex, occupation etc)
2.Risk factors (attributes that increase the
likelihood of the disease)
3. Aetiology
4. Pathophysiology
5. Symptoms (evidence of a disease as described
by the patient, eg, Headaches, Diplopia)
6. Chief complaint
19. 7. History of present illness (intensity,
duration, severity)
8.Sgns (evidence of a disease that is
observed or elicited or discovered by the
doctor)
9. Complications
10. Differential diagnosis ( the process of
differentiating between two or more conditions
which have similar signs and symptoms)
20. 11. Pathognomonic ( A particular sign that is
peculiar to a disease whose presence
provides a definitive diagnosis for the
condition)
12.Treatment/management
13. Evidence based medicine ( Optimizes
decision making by the use of modern best
evidence from well designed and well
conducted researches)
21. Patient Care considerations
SOAP format
S – Subjective assessment
Case history
Chief complaint
History of present illness
Risk factor analysis
O – Objective assessment
Observe patients general behaviour
Entry VA (monocular/binocular, distant/near, Pinhole etc
External examination (Slitlamp biomicroscope/Penlight)
Use a systematic approach
Internal examination (Ophthalmoscopy)
Others (Tonometry, gonioscopy, Keratometry, etc)
Document findings thoroughly using standard
abbreviations
22. SOAP continued
Assessment
Rule out other involvements (systemic disease, EOM
involvement, Drugs etc)
Consider other laboratory assessments an clinical tests
Do a differential diagnosis
Plan - May involve any of
Counseling only
Observation and monitoring
Prescription of placebos
Referral for further consultation
Use of pharmaceutical agents
Emergency care and hospitalization
WHICH EVER YOU CHOSE, COUNSEL, COUNSEL,
COUNSEL!!!
