Lecture Notes: Monocular Estimation Method in Retinoscopy

• Topic: Monocular Estimation Method (MEM) for evaluating accommodative response
• Type: Near Retinoscopy (Dynamic Retinoscopy)

Overview of MEM

• MEM is used to measure the dynamic accommodative response. It is objective and usually perform after subjective refraction.
• Also known as dynamic retinoscopy.

Equipment Required

• MEM Card: Necessary for the procedure.
• Retinoscope Attachment: Clip needed to attach the MEM card to the retinoscope.

Procedure

Setup

• Ensure the room is normally illuminated; do not switch off lights.
• Distance for Testing:
  • Adults: 40 centimeters
  • Pediatric (Harmon's Distance): From elbow to knuckle

Steps

1. Patient Preparation:
   • Patient should be fully corrected for refractive error.
   • Patient reads a MEM card at the specified distance.
2. Examiner's Task:
   • Look inside the patient's eye.
   • Neutralize the reflex seen.
3. Neutralization:
   • Perform MEM in the horizontal meridian by placing the streak vertically.
   • Identify movement (e.g., "with movement or against movement") and quickly place lens to neutralize.
   • With motion = LAG of accommodation
   • Against motion = LEAD of accommodation
   • Use plus lens (e.g., +0.50) to neutralize with movement and minus lens (eg. -0.50) to neuturalize against movement.
   • Avoid keeping lenses in front of the eye for prolonged periods as it may alter the accommodative response.
   • Record the lens used to neutralize accommodation ONLY.

Expected Results

• MEM Range: +0.25 to +0.50
• Standard Deviation: ±0.25
• Anomalies: Values below plano or above +0.75 may indicate accommodative anomalies.

Conclusion

• This method helps in identifying issues with accommodation.