OPT506 Course Overview

Recording Information

• The lecture will be recorded and available via Panopto on the module DLE pages.
• Questions asked during the lecture may appear on the recording.
• Students can ask the lecturer to pause the recording if they do not wish their question to be recorded.

Module Information

• The module is OPT506 Specialist Optometry Skills.
• The module focuses on introducing Slit lamp biomicroscopy.
• The module is a full-year course (terms 1 and 2).
• The module includes 20 credits (200 hours of work).
• Lectures: 30 hours
• Practical sessions: 48 hours
• Independent study: 122 hours

Assessments

• 50% Written exam on May 13, 2025.
  • The exam includes 50 multiple-choice questions.
• 50% Practical exam on December 3, 2024.
  • The exam consists of 3 OSCE stations and 1 ISCE station.
  • Station 1: Slit lamp techniques
  • Station 2: Keratometry and baseline measurements
  • Station 3: RGP fit assessment(passive)
  • ISCE (May 27-28, 2025): SCL Aftercare routine

Ground Rules

• Be respectful.
• Be ready.
• Be safe.

Specialist Optometry Skills Breakdown

• Optometry is a general skill.
• Specialist skills include:
• Binocular vision
• Pediatric vision
• Contact Lens
• Low Vision

Lecture Structure

• 1 lecture per week (2 hours each)
• Lecture outlines are uploaded 48 hours before lecture.
• Lecture slides are uploaded after the lecture.
• Lecture content:
  • L1 - L5: Initial CL assessment
  • L6 - L9: Rigid Gas Permeable Lenses (RGP)
  • L10 - L11: Optics and CL material
  • L12 - L16: Soft Contact Lens (SCL)
  • L17 - L18: Low Vision
  • L19 - L20: CL care and complications

Practical Sessions

• 1 practical session per week (2 hours each).
• Briefing/Demo/Q&A duration: 50 minutes.
• Group 1: 11:05-11:15am; 11:15am – 12:05pm
• Group 2: 9:00-9:10am ; 9:10 - 10:00am; 10:00am - 10:50am
• Students should arrive 10 minutes early.
• Set up the bay if you are first in your pair- don't wait.

Practical Session Guidelines

• All sessions have demo videos
• Hand hygiene is critical!
• Dress code is smart casual, with a name tag.
• No long nails or nail varnish.
• Clinical workbook and pen are required.
• Optometry equipment and stationery are to be placed in locker code 2244.
• No cell phones in the practical sessions.
• Turn off equipment after use (such as keratometer, SL, bay lights).
• Log out of PC before leaving the session.
• Leave the session bay tidy.

Intended Learning Outcomes

• Use a variety of instruments and techniques to assess the anterior eye.
• Understand the manufacturing process of contact lenses.
• Evaluate and select suitable contact lenses for various refractive issues.
• Perform appropriate contact lens aftercare.
• Understand magnification and alternative methods for managing visual impairment.
• Assess and select appropriate optical and non-optical aids.
• Develop a management plan for contact lens wearers.

Slit Lamp Biomicroscopy 1

• Slit lamp biomicroscopy is a critical skill.
• Understanding the anatomy of the anterior eye is key.
• The slit lamp is a crucial tool for assessing the anterior segment of the eye.
• It delivers excellent image quality and provides a stereoscopic view.
• Flexible illumination and magnification enhance its versatility.

Slit Lamp Components

• Patient support (chin rest and forehead rest)
• Illumination system
• Observation system

Observation System Components

• Eyepiece
• Magnification control

Magnification Levels

• Levels of magnification are critical in ophthalmology procedures:
  • Low (6x): overview of the eye (lids, conjunctiva, cornea, limbus)
  • Medium (10-16x): detailed examination of the anterior structures.
  • High (20-25x): deeper examination of corneal layers (epithelium, stroma, endothelium)
  • Very High (30-40x): detailed examination, identifying vacuoles, microcysts and dystrophies.

Slit Beam Height Setting

• The height of the slit beam can be adjusted using a dial on the illumination arm.
• A mm gauge display can be used for setting the correct height.

Diffuser Filters

• The diffuser filter is essential to prevent a focused beam from damaging the eye.
• Ground glass filters are often implemented to achieve diffuse illumination.

Slit Lamp Filters

• Heat reduction filter
• Neutral density filter
• Cobalt blue + Wratten filter
• Red free filter

Wratten 12 Filter

• A yellow filter used in conjunction with the observation system to enhance fluorescein's contrast.
• Commonly hand-held, though some slit lamps have inbuilt options.

Slit Lamp Uses

• Pachymetry
• Gonioscopy
• Fundoscopy
• Laser photocoagulation
• Contact tonometry
• Anterior eye assessment

Contact Lens Fitting Routine

• History & symptoms
• Baseline measurements: key step to determine the initial status.
• Keratometry: Measurement of corneal curvature. Vital for contact lens selection.
• Anterior eye assessment
• Selection of lens: based on the initial data.
• Insertion of lens: placing the lens onto the eye.
• Fit assessment: evaluating if the lens fits well to the eye. Crucial to ensuring a comfortable wearing experience.
• Over refraction: further adjustment of the spectacle or contact lens prescription.
• Prescribe/refit: finalising the contact lens prescription.

Slit Lamp and Contact Lens Fitting Procedures

• Patient suitability assessment
• Recording baseline measurements
• Monitoring the contact lens fitting process, including scheduled and unscheduled visits.
• Assessing the contact lens' condition, including surface properties and wetting.
• Assessing ocular integrity.

Things to Remember

• Wipe down the slit lamp.
• Maintain effective hand hygiene.
• The focusing of fully corrected emmetropic individuals should be within +/-0.50D.

Slit Lamp Examination Techniques Overview (Techniques and Purpose)

• Direct illumination: Basic overview, fit assessment
• Diffuse illumination: General overview
• Parallelepiped: Detailed corneal observation, no endothelium assessment needed
• Optic section: Detailed corneal observation
• Indirect illumination: Detailed endothelium assessment, tear film, lens surface -Specular reflection: Endothelium, tear film, crystalline lens surface -Sclerotic scatter: Corneal surface -Conical beam: Anterior chamber -Retro-illumination: Corneal oedema and pathological changes. -Van Herick's technique: Anterior chamber angle assessment

Diffuse Illumination Setup

• Angle: 30-45° between the microscope and illumination.
• Slit Width: Widest setting.
• Filter: Diffusing filter.
• Magnification: Low to medium.
• Illumination: Medium to high.

Diffuse Illumination Observation

• Good overall view of the eye (lids, lashes, conjunctiva, sclera, redness, iris, pupil, gross pathology, and media opacities).
• No fine details.
• Useful for a general survey.

Parallelepiped Setup

• Angle: 40-60° from the straight ahead position.
• Slit: Narrow, 1-2mm width.
• Filter: No filter initially.
• Magnification: 16x.
• Illumination: Medium.
• Microscope directly in front of the cornea.

Parallelepiped Observation

• Detect and examine corneal structures or defects.
• Wider beam illumination is necessary to evaluate the depth and extent of corneal scarring or foreign bodies.
• Corneal nerve features, appearing as fine white threads.

Optic Section Setup

• Angle: 45-60°
• Slit: Narrowest possible (careful to avoid turning the illumination off).
• Magnification: Medium to Maximum.
• Illumination: Maximum.

Optic Section Observation

• Localize: Nerve fibers, blood vessels, infiltrates, cataracts.
• Assess: Corneal thickness, thinning, foreign bodies, opacities (percentage of thickness).
• Visualize: Wide slices of the stroma.

Decoupling - Indirect Observation

• Separate rotation points for the illumination and observation systems.

Illumination Techniques

• Sclerotic scatter: -Beam focused on the limbus. -Angle(45-60°). -Slit: Narrow slit of 0.5 mm. -Filter: No filter -Magnification: 10-16x. -Illumination: Highest setting.
• Conical beam: -Angle(45-60°) -Slit: Parallelepiped, 1-2mm height. -Filter: No filter initially. -Magnification: Medium(10x) to maximum. -Illumination: Maximum -Focusing beam between the cornea and anterior lens surface and dark zone between cornea and anterior lens observed. -Useful for assessing anterior chamber transparency, floating cells and flare in anterior uveitis

Retro Illumination Overview

• Techniques specifically used for corneal edema and pathological changes.
• Used to assess vessels and neovascularizations.

Direct Retro Illumination Setup

• Angle: 30-50° for iris/lens; 0 - 10° for retina.
• Slit: Parallelepiped max height; parallelepiped, pupil size.
• Magnification: 16x initially, and increase
• Illumination: Medium-high; Low-medium setting

Direct Retro Illumination Observation

• Assess objects close to the cornea.
• Identify infiltrations, small scars, corneal vessels, microcysts, and vacuoles.

Indirect Retro Illumination Observation

• Infiltrations, small scars, corneal vessels, micro cysts, and vacuoles.
• Corneal features seen against a dark background.

Anterior Chamber Angle Assessment

• Assessment of ACA
• Assessment of ACD
• Van Herrick's grading system for assessing the anterior chamber angle (ACA).
• Grades 0 -4 based on the relative width of the anterior chamber and visible corneal structures (with the relationship between cornea and iris)