what's the frequency of the letter "h" in:
commercial relationships m. malen, none; p. lai, none.
m. malen, p. lai; effects of slt on iop in poag on maximum medical therapy. invest. ophthalmol. vis. sci. 2008;49(13):1235. doi: https://doi.org/.
purpose: : to evaluate the effects of selective laser trabeculoplasty (slt) on intraocular pressure in the treatment of primary open-angle glaucoma (poag) on maximum medical therapy. in this retrospective chart review, all of the slt procedures were performed by residents.
methods: : 29 eyes with poag on maximum medical therapy were treated with a frequency-doubled, q-switched nd:yag laser (532 nm). a total of 100 spots were placed over 360° of the tm at energy level 0.8 mj/pulse. no changes were made to the medication pre and post slt. iop was obtained via goldman applanation preoperatively, 2 weeks, 3 months, 6 months, 9 months and 12 months after treatment.
results: : the mean pretreatment iop was 18.97 mm hg (sd 5.49). after 2 weeks of follow-up the iop was reduced by a mean of 1.86 mm hg (sd 0.78, p=0.04); after 3 months, iop was reduced by a mean of 0.97 mm hg (sd 2.12, p=0.47); after 6 months of follow-up, iop was reduced by a mean of 0.86 mm hg (sd 0.78, p=0.50); after 9 months of follow-up, iop was reduced by a mean of 1.41 mm hg (sd 1.02, p=0.24); after 12 months of follow-up, iop was reduced by a mean of 2.48 mm hg (sd 0.37, p=0.03). 2 weeks and 1 year after treatment were significantly lower than pre-treatment values in both groups (t-test, p < 0.05).
conclusions: : slt in a resident setting showed statistically significant lower iop 1 year after treatment with no addition of medication for poag on maximum medical therapy.

user
The total number of "h"s in that passage is 40.
assistant