A Study on Range of Near Visual Acuity in Children with Pseudophakia NC01-NC03
Dr. Deepa John,
Associate Professor, Department of Ophthalmology, Christian Medical College, Vellore, Tamil Nadu, India.
Introduction: Accommodation is the ability to see over a range of distances by changing the power of the natural lens. With cataract surgery, this ability is partially or completely abolished. Apparent accommodation or pseudo-accommodation is the potential of pseudophakic eyes to sustain a good amount of near vision.
Aim: To measure near vision in children with pseudophakia unaided, with distance vision correction alone (mono focal lens) in-situ and to measure the minimum near add (bifocal near segment power) required to read 1M (normal reading print size) at 30 cm and 40 cm.
Materials and Methods: A cross-sectional study was conducted among children between 5-15 years of age with pseudophakia. Vision assessment was done using Lea symbol chart, at 3 metres for distance and at 30 cm and 40 cm for near. Near vision assessment was done unaided and with distant vision correction alone in place. Minimum spherical power needed to read 1M and child’s class textbooks were also assessed.
Results: Sixty-four children were included in the study. Mean age was 10.5 (±3.12) years. Refractive status showed spherical power ranging from -7.00 DS to +1.00 DS (-0.8 Mean, (±1.33 SD), astigmatism ranging from -4.50 DC to +3.00 DC (-1.29 mean, ±1.37 SD). Unaided near vision assessment showed that 41 (64%) could read <2M at 30 cm. Nine children could read 1M at 30 cm and three children could read 1M at 40 cm with distant vision correction alone in place.
Conclusion: Sixteen (25%) children in our study were independent of spectacles for reading 1M at a reading distance of 30 cm. Nine children (14.1%) read 1M at 30 cm with monofocal spectacles. Twenty-three children (35.9%) had good functional near vision and did not require any add for near work. Forty-six children (71.8%) required only 2 D or less near add for their classwork at 30 cm. Thus, monofocal or reduced near add can give these children a better quality of vision.