9. Lens and cataract.pdf by delta University

Ophthalmology in medicine

2. Level 5
Semester 9
Module (SS931)

3. MD,PhD,MRCS-Ed
Lecturer of Ophthalmology
Faculty of Medicine, Delta university
E-mail: [email protected]
Dr. RamyAwadElbassiouny
MD, PHD, MRCS-ED
Lecturer of Ophthalmology
Faculty of Medicine –Delta University
E-mail:[email protected]
Phone:[phone]

4. ةيلكلا ةلاسر:
م
ز
تلتةیلكبطلاي
ر
شبلا–ةعماج اتلدلامولعلل ایجولونكتلاومیدقتبجمانرب

میلعتت

لماك
ز
تمتمموقیلع
ةراـھملاةـفرعملاوفدـھــیولىاجــــیرختءاـبطأنیرداـقلعءاـفولامھتاـبجاوبةـینھملاةـیقلاخلأاو،میلعتلاو
بطلا
رمتسملاةكراشملاوةلاعفلا

ز
فثحبلا

ملعلاةمدخوعمتجملا.
ةيلكلا ةيؤر:
عىستةیلكبطلاي
ر
شبلا-ةعماج اتلدلامولعلل ایجولونكتلاونمللاخقیبطتجمانربتلاملعمئاقلالعباــستكا
تارادجلانأنوكت

ز
فةمدقمتاسسؤملاةیبطلاةیمیلعتلاة
ز
تمتملالعىوتسملا

لحملامىوقلاو

ملاعلاو.
Mission and Vision

5. The lens
and
Cataract

6. By the end of the lecture, the students will be able to:
Learning Outcomes
Have an overview of anatomy and physiology of the lens
Identify the common types of cataract
Determine the clinical picture of cataract
Get an idea about management of cataract

7. Introduction

8. Anatomy

9. The Crystalline lens
Crystal-clear biconvex lens.
Lies in the pupillary area behind the iris.
Divides the eyeball into anterior and posterior
segments.
Attached to the ciliaryprocesses of the ciliary
body by suspensory ligaments (zonules).
covered by a tough capsule that is divided into
the anterior capsule and posterior capsule, joining
each other at the equator.
Anterior capsule is thicker than posterior and
lined from its inner surface by anterior
subcapsularepithelium.
The posterior capsule is not lined by epithelium.

10. The Crystalline lens
The center of the anterior capsule is termed the
anterior pole of the lens while that of the
posterior capsule is the posterior pole.
The line joining both poles is the lens axis.
The posterior pole of the lens is the thinnest
The equator is the thickest
The lens cortex formed from the anterior
subcapsularepithelium and represents the soft
fibers lying inner to the anterior and posterior
capsules.

11. The Crystalline lens
The epithelium proliferation is a continuous
process throughout life forming new cortical
fibers.
The lens fibers come together to meet at lens
sutures.
The lens sutures in front of the nucleus take an
erect (Y) shape, while the one behind the lens
nucleus is inverted (Y) shape

12. The Crystalline lens
The lens has 3 nuclei:
oEmbryonic nucleus
oFoetal/Infantile nucleus
oAdult Nucleus

13. Embryology
The lens develops embryologicallyfrom the
surface ectoderm forming a lens placode.
Separates later on forming a lens vesicle.
The lens nucleus present at birth is the embryonic
nucleus formed partly by migration of the
posterior subcapsularepithelium.
The lens has no blood vessels and no nerve
endings.
It was vascular during early embryonic life
supplied by the posterior hyaloidartery.
With development, the posterior hyaloidartery
obliterates forming tunica vasculosalentis

14. Function
Refraction:aboutone-third
oftherefractivepowerof
theeye.
Accommodation:thatcan
assistinnearvision.
Protection:itprotectsthe
retinafrom harmful
ultraviolet(UV)rays

15. Dimensionsofadultlens:
Lensdiameterisabout10mm.
Lensthicknessisabout4mm.
Theradiusofcurvature:
Anteriorsurfaceis10mm.
Posteriorsurfaceis6mm(morecurved)
Refractiveindex:
Cortex:1.38.
Nucleus:1.42.
Dioptricpower:
Insidetheeye:16-18D.
Outsidetheeye:70D.

16. Examination

17. Lens Displacement

18. Lens Displacement
DislocationSubluxation
Etiology
Congenital:Connectivetissuediseases.
Aquired:
oTrauma
oHypermaturecataract
oAnterioruvealtumour
oLargeglobe(Myopia,Congenitalglaucoma)

19. Symptoms Signs
Monocular diplopia??!!
Visual impairment??!
Lenticular myopia
Changing astigmatism
Prismatic effect
1.Deep anterior chamber
2.Tremulous iris
3.Possible visualization of
the lens edge or zonules
4.Refraction
Lens Displacement

20. Lens Displacement
DislocationSubluxation
Management
Opticalcorrection(Glassesorcontactlenses).
SurgicalRemoval

21. Aphakia

22. Aphakia
Absence of the lens from the pupillary area
Congenital
Surgical
Lossthroughperforatedcornealulcer
Posteriordislocation
Etiology

23. Aphakia
Optical conditions
1. Strong hypermetropia
+10 to +11 if previously emmetrope
>+11 if previously hypermetrope
<+10 if previously myope
2. Loss of accommodation

24. Aphakia
Optical conditions
3. Astigmatism 4. Increase in size of image

25. Aphakia
Clinical picture
1. Decreased VA
2. Deep AC
3. Tremulous iris
4. Jet black pupil
5. Absence of Purkinje images

26. Aphakia
Management
1. Glasses 2. Contact lens 3. IOL implantation
For bilateral cases
Thick, heavy, Ugly
Decrease field of vision
Increase size of image
(25-30%)
Unilateral or bilateral
Used with care
Increase size of
image (7-8%)
Primary or secondary
Posterior chamber
Anterior chamber
Scleral fixation

27. Aphakia
IOL implantation
Investigations to
determine the power
A-Scan US
IOL Master

28. Aphakia
Change in size of image

29. Cataract

30. Cataract
Opacificationof the lens
Congenital & Developmental Acquired
Senile Traumatic
Complicated Toxic

31. Cataract
Congenital and developmental
Etiology
Infections
Drugs
Irradiation
nutritional
Trauma
Metabolic
disorders
With ocular
anomalies

32. Congenital & Developmental Cataract
Lamellar
Nuclear
Polar
Total
Blue dot
Sutural
Coronary
Membranous

33. Cataract
Congenital and developmental
Clinical presentations
Leucocoria .. DD
Squint and amblyopia
Nystagmus
Most common
Unilateral dense cases
Bilateral dense cases

34. Cataract
Congenital and developmental
Diminution of vision
Sever
Moderate
Mild or No
Complete
Membranous
Posterior polar
Lamellar and nuclear
Blue dot
Coronary
Anterior polar

35. Cataract
Congenital and developmental
Management
Evaluation
Indications
Surgical technique
Unilateral
Dense
Bilateral
Dense
Less
Dense
Most Urgent
Lensectomy

36. Cataract
Congenital and developmental
1. Glasses 2. Contact lens 3. IOL implantation
For bilateral cases
Thick, heavy, Ugly
Decrease field of vision
Increase size of image
(25-30%)
Unilateral or bilateral
Used with care
Increase size of
image (7-8%)
Primary or secondary
Posterior chamber
Anterior chamber
Scleral fixation
Correction of Aphakia

37. Cataract
Opacificationof the lens
Congenital & Developmental Acquired
Senile Traumatic
Complicated Toxic

38. Cataract Acquired
Toxic
Causedbytoxinsordrugs
ThemostcommonexampleisSteroidinduced

39. Cataract Acquired
Secondarytooculardiseasee.g
oHighmyopia
oCornealulcer
oIridocyclitis
oChronicglaucoma
oRD
oRetinitisPigmentosa
Complicated

40. Cataract Acquired
SecondarytoSystemicdiseasee.g
oDM
oHypothyroidism
oHypoparathyroidism
oSeveranaemia
Complicated

41. Cataract Acquired
Characterizedby
oPresenceofocularcause,
oPoly-chromaticluster
Complicated

42. Cataract
Effects of DM On the lens??
Weaknessofaccommodationandearlypresbyopia
Changeinrefractiveindexoflenscortex
oHyperglycemialeadstomyopicshift
oHypoglycemialeadstohyperopicshift
Cataractof2types
oPresenile:senilecataractthatoccursatearlierage
oComplicatedcataract:Snow-flakecataract

43. Cataract Acquired
Traumatic
Blunttraumaleadsto:
oRosette-shapedcataract
oVossiousring
oLensdisplacement

44. Cataract Acquired
Traumatic
Penetratingtraumaleadsto:
oDirectimpact
oLenticulo-cornealtouch
oTraumatolenscapsule

45. Cataract Acquired
Traumatic
Chemicalinjuries:
oAlkalies>Acids

46. Cataract Acquired
Traumatic
Radiationinjury:
oUltraviolet
oMicowave
oIonizing
oInfrared
True exfoliation of lens capsule
“Glass blowers cataract”

47. Cataract Acquired
Traumatic
Electricinjuryleadsto:
oCoagulationoflensproteins

48. Cataract Acquired
Traumatic
IOFB:
oIronleadtosidrosis
oCopperlidtoChalcosisandSunflower’scataract

49. Cataract Acquired
Senile Traumatic
Complicated Toxic

50. Senile cataract
Nuclear
Cortical Posterior
Subcapsular
Cataract
Due to nuclear sclerosis and yellowing
Increase RI of lens nucleus
Leads to 2ry sight (Presbyopecan see without reading glasses)
Affect far vision>near
Late may be brown (Brounescent) or black/Nigra)

51. Senile cataract
NuclearCortical Posterior
Subcapsular
Cataract
Usually axial
Affect near vision more than far
Affect vision more in bright lightening conditions

52. Senile cataract
Nuclear
Cortical Posterior
Subcapsular
Precataractous
changes
Incipiant
Cataract
Immature
Cataract
Mature
Cataract
Hypermature
Cataract
Cataract

53. Senile cataract
Nuclear
Cortical Posterior
Subcapsular
Precataractous
changes
Cataract

54. Senile cataract
Nuclear
Cortical
Posterior
Subcapsular
Incipiant
Cataract
Cataract
Incipiantmeans early
Wedge like opacities near the periphery
Affect night vision more than day vision
Leads to mono-ocular diplopia or even polyopia
Leads to haloes around light

55. Senile cataract
Nuclear
Cortical
Posterior
Subcapsular
Immature
Cataract
Mature
Cataract
Opacity
Visual acuity
Iris shadow
RR
Colour
Cataract
Not total
CF or better
Present
Dim
Grey
Total
HM
Absent
Absent
White

56. Senile cataract
NuclearCortical Posterior
Subcapsular
Hypermature
Cataract
Cataract
Morgagianor Shrunken
In shrunkeiris shadow and iridodenesisare present

57. Cataract
Lens induced glaucoma
Lens induced uveitis
Lens displacement

58. Management of cataract
in adults

59. Management of cataract
1
2
3
To improve vision
To treat underlying complications
To treat underlying retinal disease
Indications of cataract surgery

60. Management of cataract
LocalSystemic
Evaluation before surgery

61. Management of cataract
Evaluation before surgery
Fundus
examination

62. Management of cataract
Evaluation before surgery
Ultrasound

63. Management of cataract
Evaluation before surgery
IOL power
calculation
Using A-Scan US
+Keratometry

64. Management of cataract
Anesthesia
Local
General

65. Management of cataract
Operative procedure
ICCE
Performed now in
luxatedcataract

66. Management of cataract
Operative procedure
ECCE
Less vitreous loss
Capsule stand as barrier
between aqueous and vitreous
Capsule serve as bag for IOL
Less risk of RD
Less risk of macular edema

67. Management of cataract
Operative procedure
Phacoemulsification

68. Management of cataract
Operative procedure
Phacoemulsification
Performed using US

69. Management of cataract
Operative procedure
Phacoemulsification
Earlier rehabilitation
Less induced astigmatism

70. Management of cataract
Complications of surgery
Vitreous loss
Expulsive Hemorrhage
Posterior capsule
opacification
Endophthalmitis
Corneal edema
Astigmatism
Iris prolapse
IOL decentration
RD
CME
Intraoperative Postoperative

71. Management of cataract
Posterior capsule opacification(PCO)

72. •TheWillsEyeManual:OfficeandEmergencyRoomDiagnosis
andTreatmentofEyeDisease,8
th
Edition,WoltersKluwer,2016.
•Kanski'sClinicalOphthalmology,9thEdition,Elservier,2021.
•https://youtube.com/playlist?list=PL8OVtyCOyQr_FguqyPQma
wa_KcOuyXnGU&si=MmehRyTzp 5FsyLr0(Dr.AdelAbdelshafik
channel).
•https://www.clinicalkey.com/student/institution-login
References & recommended readings