Abstract
Purpose::
If sustained near work with high cognitive demand is an environmental precursor for myopic progression, entry into optometry school may present a marked increase in these factors. Measurement of myopes who are stable (SMs) vs. those who progress (PMs)between their first and second year of optometry school may elucidate risks factors for myopia progression.
Methods::
On two occasions, separated by 7 mos, an open field autorefractor (SRW-5000) was used to determine distance refraction and accommodative responses (AR) to a near target (33cm) and to minus lenses (-3D,-5D). Subjects wore autorefraction results for the accommodation tests. Subjects also completed 3 surveys: Adult Manifest Anxiety (AMAS-C), Self Perception Profile (SPP) and CI Symptom Survey (CISS-15). Two additional symptoms, "Far Blur" and "Far Blur after Near Work" were also ranked. In addition, baseline phorias and axial length[AL] (IOL master) were measured. PMs ( refractive shift≥ -0.25D, x=-0.41D, n=11) and SMs (shift<-0.25D, x=0.05D, n=28) are compared.
Results::
At BASELINE: 1) PMs are more myopic (Sph Equiv =-4.7D vs-3.2D, p=0.04) with longer ALs (25.7mm vs. 24.7mm, p=0.02); 2)PM’s have more aesthenopia: "eyes sore", "eyes hurt" & "eyes pulling" (p<0.05); 3) No differences in far or near phorias or in AR; 4)On the AMAS-C, PMs have less social concerns (p=0.05); on the SPP, no differences. At TIME 2: 1)PMs' aesthenopia decreases ("eyes sore", p=0.03); 2) SMs' AR to the 33cm target increases (change=0.39D, p=0.02); 3)"Far Blur after Near Work" decreases in SMs (p=0.01) ; 4)PMs have less social concerns (p=0.002); 5)SMs' feelings of social acceptance are reduced (p=0.002).
Conclusions::
PMs' started out with more axial myopia and greater aesthenopia than SMs. At 7 mos., PMs' myopia increased significantly (x=-0.41D) while their aesthenopia was reduced. Since they had not yet had their second year annual eye exam, this increase in myopia likely went uncorrected. The resultant near add may have reduced the aesthenopia. While there were no differences at either baseline or time 2 between the groups in accommodative responses, SMs did have a significant increase in their AR to a real target at 7mos., as well as a significant reduction in the symptom "Far Blur after Near Work" suggesting reduction in NITM (low AR and high NITM are possible risk factors for myopia progression).We will continue to investigate these initial differences in PMs' and SMs' responses to the near work demands of optometry school as they progress in their program.
Keywords: myopia • stress response • vergence