A new specialized visual acuity chart for amblyopic children aged 3-5 years old:development and its clinical applications

AIM:To Introduce a new specialized visual acuity chart for amblyopic children aged 3-5 years old and its clinical applications.METHODS:The new visual acuity chart and notations were designed based on Weber-Fechner law.The optotypes were red against a white background and were specially shaped four basic geometric symbols:circle,square,triangle,and cross.A regular geometric progression of the optotype sizes and distribution was employed to arrange in 14 lines.The progression rate of the optotype size between two lines was 1.2589 and the testing distance was 3m.Visual acuity score could be recorded as logMAR notation or decimal notation.Agestratified diagnostic criteria for amblyopia established by consensus statement on diagnosis of amblyopia(2011)among members of the Strabismus and Pediatric Ophthalmology Group,Ophthalmology Society,Chinese Medical Association(SPOGOSCMA)were illustrated in the new visual acuity chart.RESULTS:When assessing visual acuity in children aged 3-5 years old,this new visual acuity chart that consists of four symmetrical shapes(triangle,square,cross,and circle)overcame an inability to recognize the letters of the alphabet and difficulties in designating the direction of black abstract symbols such as the tumbling’E’or Landolt’C’,which the subjects were prone to lose interest in.The visual acuity score may be recorded indifferent notations:decimal acuity and logMAR.These two notations can be easily converted each other in the new eye chart.The measurements of this new chart not only showed a significant correlation and a good consistency with the international standard logarithmic visual acuity chart(r=0.932,P【0.01),but also indicated a high test-retest reliability(89%of retest scores were within 0.1 logMAR units of the initial test score).CONCLUSION:The results of this study support the validity and reliability of distance visual acuity measurements using the new eye chart in children aged3 to 5 years over a wide range of visual acuities,and the new eye chart is great for early detection of amblyopia.It can be applied in various clinical settings.

A near-vision chart for children aged 3-5 years old:new designs and clinical applications

AIM:To introduce a new near-vision chart for children aged 3-5 years old and its clinical applications.METHODS:Thenewnear-visionchartwhichcombined the Bailey-Lovie layout with a newly devised set of symmetry symbols was designed based on WeberFechner law.It consists of 15 rows of symmetry symbols,corresponding to a visual acuity range from 1.3 to 0.1logMAR.The optotypes were red against a white background and were specially shaped four basic geometric symbols:circle,square,triangle,and cross,which matched the preschool children’s cognitive level.A regular geometric progression of the optotype sizes and distribution was employed to arrange in 15 lines.The progression rate of the optotype size between two lines was 1.2589 and two smaller groups of optotypes ranging from 0.7 to-0.1 logMAR were included for repetitive testing.A near visual acuity was recorded in logMAR or decimal,and the testing distance was 25 cm.RESULTS:This new near-vision chart with pediatric acuity test optotypes which consists of 4 different symbols(triangle,square,cross,and circle)met the national and international eye chart design guidelines.When performing the near visual acuity assessment in preschoolers(3-5y old).It overcame an inability to recognize the letters of the alphabet and difficulties in designating the direction of black abstract symbols such as the tumbling’E’or Landolt’C’,which the subjects were prone to lose interest in.Near vision may be recorded in different notations:decimal acuity and logMAR.These two notations can be easily convertedeach other in the new near-vision chart.The measurements of this new chart not only showed a significant correlation and a good consistency with the Chinese national standard logarithmic near-vision chart(r=0.932,P【0.01),but also indicated good test-retest reliability(89%of retest scores were within 0.1 logMAR units of the initial test score)and a high response rate.CONCLUSION:The results of this study support the validity and reliability of near visual acuity measurements using the new near-vision chart in children aged 3-5y over a wide range of visual acuities,and the new eye chart was especially suitable for the detection of amblyopia risk factors and low vision examination in children(3-5y of age).It can be applied in routine clinical practice.