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Both in medicine and optometry, clinical guidelines have become a relevant part of clinical practice decision making process. In our study, we aimed to refer to potential limitations related to specific undefined guidelines used in optometry that suggest near addition (add) values based on patient age. We measured near add binocularly at 40 cm distance with plus build up technique in 216 adults aged 35 to 80 years. Baseline subjective refraction, near visual acuity with and without add was analysed in a relation to age and the amount of near add. For further analysis, we randomly selected 30 patients and performed five different near add estimation techniques. Our results support that there is a positive, linear relationship of moderate strength between age and amount of near add (r = 0.73, P < 0.05). Relationship is positive and fairly strong (r = -0.78, P < 0.05) between near visual acuity without add and near add amount and moderate (r = -0.51, P < 0.05) between near visual acuity without add and patient age. Differences between plus build up technique is not statistically significant if compared with other clinical near add estimation techniques (P > 0.05). Guideline based technique (P < 0.01) provided 0.29 D higher near add while technique based on calculations from amplitude of accommodation (P < 0.01) provided 0.65 D lower near add. Based on our results, we highlight that usability of age expected near add in clinical environment is limited because of large individual differences.
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