Clinical observation of subretinal injection of compound electrolyte intraocular irrigation solution in the treatment of diabetic macular edema with hard exudate

Jiangling LI; Lu CHANG; Jie ZHANG; Rongyu GAO; Qing DAI; Xianyong SUN

ABSTRACT

Objective:

To observe the clinical effect of vitrectomy, inner limiting membrane (ILM) peeling, subretinal injection of compound electrolyte intraocular irrigation solution (CEIIS) and conbercept in the treatment of diabetic macular edema (DME) with hard exudate (HE) (DME-HE).

Methods:

A prospective clinical study. Thirty-three patients with DME-HE diagnosed by examination in Weifang Eye Hospital from June 2020 to February 2022 were included in the study. Among them, there were 15 males (16 eyes) and 18 females(20 eyes), with the mean age of (62.00±6.54) years. All patients underwent the examinations of best corrected visual acuity (BCVA), scanning laser ophthalmoscope, optical coherence tomography (OCT), and multifocal electroretinography (mf-ERG). Snellen visual acuity chart was used for BCVA examination, which was converted into logarithm of the minimum angle of resolution (logMAR) BCVA for statistic analysis. Macular foveal retinal thickness (CMT) and macular volume (MV) were measured by OCT. The 1 ring P1 wave amplitude density was measured by mf-ERG. The patients were randomly divided into group A and group B, with 17 patients (18 eyes) and 16 patients (18 eyes), respectively. There were no significant differences in age, logMAR BCVA, HE area, CMT, MV, and 1 ring P1 wave amplitude density between the two groups ( t=0.403, 0.972, 0.291, 0.023, -0.268, -0.206; P>0.05). Group A was treated with vitrectomy, ILM peeling, and subretinal injection of CEIIS and conbercept (combined therapy). Group B was treated with intravitreal injection of conbercept (IVC). Follow-up was 12 months after treatment. The changes of BCVA, HE area, CMT, MV, 1 ring P1 wave amplitude density were compared between groups and groups after treatment. The times of injection and complications after treatment were observed. Independent sample t test was used for comparison between the two groups.

Results:

At 12 months after treatment, compared to before treatment, there were significant differences in logMAR BCVA ( F=14.837), HE area ( χ2=94.522), CMT ( χ2=199.212), MV ( χ2=81.914) and 1 ring P1 wave amplitude density ( F=8.933) in group A ( P<0.05); there were significant differences in CMT ( F=5.540) and MV ( F=7.836) in group B ( P<0.05). Compared between the two groups, logMAR BCVA 1 week and 6 and 12 months after treatment, the difference was statistically significant ( t=2.231, -2.122, -3.196; P<0.05); HE area except 1 week after treatment, there were statistically significant differences at other times after treatment ( t=-2.422, -3.107, -3.540, -4.119; P<0.05). CMT, MV, 1 ring P1 wave amplitude density 12 months after treatment, the differences were statistically significant ( t=-2.653,-2.455, 2.204; P<0.05). During the follow-up period, the injection times of group A and group B were (3.06±1.89) and (5.56±2.04), respectively, and the difference was statistically significant ( t=-3.815, P<0.05). Macular hole and vitreous hematoma were found in 1 eye in group A and 1 eye in group B.

Conclusion:

Vitrectomy, ILM peeling, subretinal injection of CEIIS and conbercept to treat DME-HE can effectively remove HE, alleviate macular edema, improve BCVA, and reduce CMT and MV. Combination therapy can reduce the number of IVC re-treatments.