HIV is a virus that attacks the immune system and can lead to AIDS if not treated. It was first reported in 1981 and has since infected over 60 million people worldwide. There are two types - HIV-1, which is more prevalent, and HIV-2, which progresses more slowly. HIV infects and kills CD4+ T cells, weakening the immune system. It enters cells by binding to CD4 receptors and integrating its RNA into the host cell's DNA. This reprograms the cell to produce more HIV viruses that then infect other cells, leading to lower CD4 counts and immunodeficiency. Ocular manifestations may be the first sign of HIV infection, with eye involvement seen in up to 90% of autopsy

1. Ocular manifestations of HIV
INTRODUCTION
( incidence & virology)
ETIOPATHOGENISIS

2. History
• 1st reported on June 5, 1981 when the U.S
Centers for Disease Control recorded a cluster
of Pneumocystis carinii pneumonia in five
homosexual men in Los Angeles
• Its cause HIV was identified in the early 1980s
2

3. • Human immunodeficiency virus (HIV) is a blood-
borne, sexually transmissible virus.

4. Global prevalence
• In 2014, WHO estimated 33.4 million people
worldwide living with HIV/AIDS,
• with 2.7 million new cases of HIV infection per
year
• and 2.0 million deaths due to AIDS
4

5. • According to UNAIDS report, 60 million people
have been infected since the start of
pandemic , with 25 million deaths, and 14
million orphaned children in southern Africa
alone
5

7. NACO 2015

8. Classification of HIV
• Two serological types
• HIV – 1 (world wide)
• HIV – 2 (West Africa & Portugal)
• HIV – 1 • HIV – 2
1.Type M 1. Type A, B,C,D and E
2. Type O
8

9. • HIV is a member of the genus Lentivirus, part of
the family Retroviridae .
• it is composed of two copies of positive single-
stranded RNA
• the single-stranded RNA is tightly bound to
nucleocapsid proteins, p7, and enzymes needed
for the development of the virion such as reverse
transcriptase, proteases, ribonuclease and integra
se.

10. • the viral envelope contains proteins from the
host cell and relatively few copies of the HIV
Envelope protein, which consists of a cap
made of three molecules known
as glycoprotein (gp) 120,

11. Type 1…
• HIV-1 probably originated from one or more
cross-species transfers from chimpanzees in
central Africa.
• HIV-2 is closely related to viruses that infect
sooty mangabeys in western Africa.
• Genetically, HIV-1 and HIV-2 are superficially
similar, but each contains unique genes and its
own distinct replication process.

12. Type 2…
• HIV-2 carries a slightly lower risk of transmission, and HIV-2
infection tends to progress more slowly to acquired immune
deficiency syndrome (AIDS).
• This may be due to a less-aggressive infection rather than a
specific property of the virus itself.
• Persons infected with HIV-2 tend to have a lower viral load
than people with HIV-1, and a greater viral load is associated
with more rapid progression to AIDS in HIV-1 infections
• HIV-2 is rare in the developed world. Consequently, most of
the research and vaccine and drug development has been
(perhaps unfairly) focused on HIV-1

14. etiopathogenesis
• Mode of infection

15. HIV Transmission
Requires:
1. Infected body fluid
AND
2. Entry into body

16. Mode of transmission
• Sexual contact – 70% of cases
• IV drug use – 27%
• Blood transfusion – 2-3%
• Perinatal transmission – 1%
16

17. 3. Infected body fluids
Four Fluids, if infected, can transmit HIV
a. Blood
b. Semen
c. Vaginal Secretions
d. Breast Milk
If these enter the body

18. 4. Which Fluids are safe?
Four Fluids that can’t transmit HIV
a. Spit/saliva
b. Pee/Urine
c. Sweat
d. Tears

19. How Does HIV get into a T Cell?
1. attaches to infection fighting T4 cell
2. Locks on to two entry areas of the T4 cell
at once. (Keys in lock)
3. Tricks T4 cell to allow Virus RNA to enter

20. What Does HIV do inside a T Cell?
1. Virus’s RNA changes into
DNA
2. Enters Cell nucleus &
becomes part of Host’s
DNA!
3. Programs T cell to produce
virus in abundance
4. New viruses bud off Host T
cell, killing T cell, & enters
bloodstream
5. New HIV viruses infect more
T cells

21. Flowchart
Binding to CD4 Internalization Uncoating
Reverse transcriptase
Integrated proviral DNA
Productive infection Latent infection
Mature HIV production
Cell lysis
21

22. New HIV viruses leaving a cell

23. Pathophysiology
• HIV attaches to T-cells & monocytes
/macrophage that display a membrane Ag-
complex known as CD4.
• The target cells of HIV show different cytopathic
effects
• CD4 + helper T-cells – decrease in number –
immunodef. – opportunistic infections
23

24. * Macrophage –
> decreased migration response to
chemoattractants
> defective intracellular killing of mircroorg.
(eg. Toxo. , Candida.)
> impaired Ag presentation
*excessive production of TNF-alpha –leads to
dementia , wasting , unexplained fever.

25. 6. What is the “Window Period?”
The time period between a person’s exposure
& actual infection with HIV and until antibodies
are detectable in the body.
• After three months there are usually enough
antibodies to show on an AIDS test.
Nearly all people (99%) develop antibodies by
THREE months.

26. • Th pressence of any two major signs
associated with atleast one minor sign is
considered to be an indiaction of AIDS

27. Major signs include
• Loss of more than 10% of body weight
• Chronic fever
• Chronic diarrhoea of over 1 months duration

28. Minor signs include
• Chronic cough
• Itchy dermatitis
• Recurrent herpese zoster
• Oropharyngeal candidiasis
• Chronic progressive herpes simplex infection
• Generalised lymphadenopathy

29. • Eye involvement seen in 90% Autopsy cases
• Ocular complication in 75% of pts with AIDS
• Visual morbidity & blindness is the leading
cause of suicide in pt. with AIDS
• May be the first sign of HIV infection this shows
the Role of Eye consultant to make a sight
saving & life sustaining Diagnosis
29

30. To be continued…