Abstract: Objective To compare the efficacy and safety of 2 mg and 3 mg ganciclovir intravitreal injection on cytomegalovirus retinitis (CMVR) in patients with acquired immunodeficiency syndrome (AIDS). Design Prospective comparative case series. Participants 63 cases (86 eyes) of patients with AIDS complicated with CMVR in Beijing Ditan Hospital from 2016 to 2020. Methods All patients were randomly divided into 2 mg group (41 eyes) and 3 mg group (45 eyes) and received ganciclovir intravitreal injection of 2 mg or 3 mg based on the systemic ganciclovir treatment. Before vitreous injection, aqueous humor was extracted for PCR detection of cytomegalovirus. Intravitreous injection was given once a week until the fundus lesion was controlled and cytomegalovirus PCR in the aqueous humor was negative. Main Outcome Measures The fundus statues, cytomegalovirus (CMV) load in aqueous humor[log（CMV DNA）], the frequencies of the injection, visual acuity, complications. Results All the active retinal necrosis lesions were controlled and gradually transformed into atrophy lesions. Viral load in aqueous humor decreased weekly and eventually turned negative. The viral loads of CMV in the 2 mg group was 3.90±0.73 copies/ml, 3.88±0.82 copies/ml, 3.06±0.93 copies/ml, 2.85±0.75 copies/ml and 2.32±0.50 copies/ml respectively before initial treatment, and at the first, second, third and fourth weeks of treatment (F=28.54，P<0.01). In 3 mg group, the viral loads of CMV was 4.10±0.94 copies/ml, 3.76±0.90 copies/ml, 3.50±0.81 copies/ml, 2.90±0.91 copies/ml, 2.57±0.79 copies/ml, respectively (F=18.21，P<0.01). Initial CMV viral load was positively correlated with the frequency of injection in both 2 mg groups (r=0.69, P<0.01) and 3 mg groups (r=0.82, P<0.01). Visual acuity improved or remained unchanged in 31 of 41 eyes in the 2 mg group and 33 of 45 eyes in the 3 mg group (χ2=0.06，P=0.81). No serious complications occurred in any of the patients. There were no significant differences in lesion recovery rate, viral load in aqueous humor, number of injections, complications between the two groups (all P>0.05). Conclusion Intravenous ganciclovir combined with ganciclovir intravitreal injection of 2 mg or 3 mg can effectively treat CMVR. In order to reduce retinal toxicity, 2 mg of intravitreal ganciclovir is a relatively safe and effective dose for the treatment of CMVR. (Ophthalmol CHN, 2021, 30: 227-231)

Key words: acquired immunodeficiency syndrome, cytomegalovirus retinitis, intravitreal injection, ganciclovir