Ophthalmic Education:

Principles and Guidelines of a Curriculum for Ophthalmic Education of Medical Students: Chapter IV: Lens and Cataract

On this page:

• Educational Goal
  
  
• Anatomy of lens
  
  
• Symptoms attributable to cataract
  
  
• Examination of the lens by direct ophthalmoscopy
  
  
• Treatment of cataract
  
  
• When to refer patient to an ophthalmologist
  
  
• Clinical Competencies

Educational Goal: 

Students should recognize the symptoms and ophthalmic signs of cataract as a cause of decreased central visual acuity. They should understand the general principles of cataract surgery and correction of aphakia with intraocular lenses, contact lenses, or aphakic spectacles.

A. Anatomy of lens.*  

1. Intraocular location of lens behind the iris plane.*

2. Optical clarity of normal lens.*

3. Suspension of normal lens in retroiridic position by zonules.*

B. Symptoms attributable to cataract.*

(REF. 2B. Slide 10, 51) (REF. 22 Fig. A01, A02, A03, A04, A05, A06)

1. Slowly progressive blurring of vision.*

2. Painless progressive loss of vision.*

C. Examination of the lens by direct ophthalmoscopy.*

1. Evaluation of red reflex.* (REF. 4 Fig. 3.9-3.11)

D. Abnormal lens features by direct ophthalmoscopy.*

1. General.*  

a. Loss of normal red reflex.* (REF. 4 Fig. 3.9-3.11)   

b. Dark spots in red reflex.* (REF. 2B Slide 50)

c. Abnormal color of red reflex.*

2. Lens abnormalities found in important systemic diseases.*  

a. Marfan’s syndrome – spontaneous dislocation of lens.* (REF. 15 Fig. 4-15A, B) (REF.  22 Fig. H38)

3. Lens abnormalities found in important ocular diseases.**

a. Cataract (clouding or opacification of lens).** (REF. 22 Fig. A07, A10)

b. Implanted artificial intraocular lens.** (REF. 22 Fig. A24, A26, A27)

E. Treatment of cataract.**

(REF. 3 Case 6, Cataract, p.12)

1. Surgical removal of lens (cataract extraction).***(REF. 2B Slide 52) (REF. 22 Fig. A19, A20, A21, A22, A23)

2. Implantation of artificial lens in eye.*** (REF. 2B Slide 54)

F. When to refer patient to an ophthalmologist.**  

1. Examination reveals abnormal red reflex, lens clouding, or opacity.**

2. Patient reports progressive visual loss or blurring.**

Clinical Competencies

Students should:

• Describe presbyopia.**
  • definition and symptoms**
• Diagnose cataract.*  
  • definition and symptoms.*  
  • red reflex.*  
  • slit lamp findings.***
• Understand importance of lens dislocation in association with systemic conditions, such as Marfan’s syndrome and homocystinuria.***
• Describe management of cataract.***  
  • surgery.***
  • intraocular lens.***

* Basic Level: Necessary in the education of medical students worldwide.

** Standard Level: A higher level of ophthalmic understanding than the basic curriculum of most international medical students.

*** Advanced Level: Advanced cognitive and clinical skills more appropriate for students who seek further training in ophthalmology, which may be covered in an ophthalmology elective in medical school.

(Also see: More on Educational Priorities)

Next: V. Neuro-Ophthalmology

Also see:

• Table of Contents of the "Principles and Guidelines of a Curriculum for Ophthalmic Education of Medical Students"
  
  
• Education of Medical Students in Ophthalmology
  
  
• Resources for Ophthalmic Education of Medical Students