Abstract
Purpose. To use Doppler ultrasound for evaluating the effect of vascular therapy and hyperbaric oxygenation (HBO) on ocular hemodynamics in patients with recurrent herpetic stromal keratitis (HSK).
Material and Methods. Totally, 60 patients with unilateral HSK (mean age, 39.4 ± 9.5 years) were included in the study. They were divided into groups of 20 based on the treatment scheme. Group 1 was treated conventionally with anti-inflammatory and etiopathogenetic therapy only, group 2 received conventional treatment plus vascular therapy (vinpocetine) only, and group 3, conventional treatment plus vascular therapy and HBO (ten 45-minute sessions at 1.5 atmospheres). A Doppler ultrasound machine (Toshiba Nemio-20) was used to determine peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive index (RI) in the ophthalmic artery (OA) and central retinal artery (CRA), and PSV in the central retinal vein (CRV). Fellow eyes were used as controls. An integral vascular response index (IVRI) was calculated based on relative post-treatment changes (Δ%) in major Doppler parameters and was employed for evaluating hemodynamic response to treatment. Cohen's d was used for evaluating effect sizes.
Results. Vascular therapy, when used as an adjunct to conventional treatment, resulted in a significant improvement in OA hemodynamics, with increases in Δ% PSV (25.3–34.1%; p<0.0001) and Δ% EDV (40.4–41.0%; p<0.0001) compared to anti-inflammatory therapy only. Improvements in PSV and RI were most pronounced when vascular therapy was combined with HBO. Vascular therapy, when combined with HBO, resulted in a significant improvement in CRA hemodynamics, with sequential reductions in Δ%PSV (to –29.6%) and Δ%EDV (to –24.6%), reflecting the normalization of retinal blood flow. Among the three treatment groups, group 3 showed the PSV and EDV values closest to those in the fellow eyes, which reflected the most pronounced hemodynamic effect. The increase in IVRI reflected an additive response to reduced inflammation, normalized vascular tone, improved microcirculation and corrected tissue hypoxia in group 3.
Conclusion. Anti-inflammatory treatment combined with vascular therapy and HBO allowed for the best effect on and OA and CRA hemodynamics. IVRI values indicated that, HBO, when used as an adjunct to combination treatment for recurrent HSK, was associated with an additional improvement in ocular hemodynamics (most notable, OA hemodynamics).