Next-generation nanomaterials: advancing ocular anti-inflammatory drug therapy

Ophthalmic inflammatory diseases, including conjunctivitis, keratitis, uveitis, scleritis, and related conditions, pose considerable challenges to effective management and treatment. This review article investigates the potential of advanced nanomaterials in revolutionizing ocular anti-inflammatory drug interventions. By conducting an exhaustive analysis of recent advancements and assessing the potential benefits and limitations, this review aims to identify promising avenues for future research and clinical applications. The review commences with a detailed exploration of various nanomaterial categories, such as liposomes, dendrimers, nanoparticles (NPs), and hydrogels, emphasizing their unique properties and capabilities for accurate drug delivery. Subsequently, we explore the etiology and pathophysiology of ophthalmic inflammatory disorders, highlighting the urgent necessity for innovative therapeutic strategies and examining recent preclinical and clinical investigations employing nanomaterial-based drug delivery systems. We discuss the advantages of these cutting-edge systems, such as biocompatibility, bioavailability, controlled release, and targeted delivery, alongside potential challenges, which encompass immunogenicity, toxicity, and regulatory hurdles. Furthermore, we emphasize the significance of interdisciplinary collaborations among material scientists, pharmacologists, and clinicians in expediting the translation of these breakthroughs from laboratory environments to clinical practice. In summary, this review accentuates the remarkable potential of advanced nanomaterials in redefining ocular anti-inflammatory drug therapy. We fervently support continued research and development in this rapidly evolving field to overcome existing barriers and improve patient outcomes for ophthalmic inflammatory disorders.

Presenting Features, Treatment and Clinical Outcomes of Cytomegalovirus Retinitis: Non-HIV Patients Vs HIV Patients

PURPOSE

To compare clinical features, complications, and outcomes of CMV retinitis in non-HIV immunocompromised patients with HIV infected patients.

METHODS

A retrospective study of patients diagnosed with CMV retinitis with or without HIV infection was performed. Results: Thirty-five eyes from 27 patients (median follow up 26 months) were included. Six patients had HIV infection, the others were immunocompromised from a range of causes. The baseline visual acuity (VA) was similar in the two groups. Prevalence of different types of retinitis (fulminant/indolent) was similar in the two groups. Presence of vitreous haze ≥1+ (p = .041), presence of arteritis, (p = .016) and widespread vascular occlusion (p = .003) were more common in the non-HIV group.

CONCLUSION

CMV retinitis can present with different features depending on the cause of immunocompromise. Evidence of intraocular inflammation such as vitritis, retinal arteritis, and vascular occlusions was more common in HIV-negative subjects.

Initial intravitreal injection of high-dose ganciclovir for cytomegalovirus retinitis in HIV-negative patients

BACKGROUND

The purpose of this study is to examine the clinical outcomes achieved by using initial high-dose intravitreal ganciclovir injections to treat cytomegalovirus retinitis in patients without human immunodeficiency virus (HIV) infection.

METHODS

Twenty-four eyes (24 patients) with cytomegalovirus retinitis received multiple intravitreal injections of ganciclovir in weekly intervals. A higher dose (6 mg) of ganciclovir was applied at the first intravitreal injection, and a lower dose was used for maintenance. Anterior aqueous humour was obtained before each injection. The best-corrected visual acuity and cytomegalovirus loads in the anterior aqueous humour were measured.

RESULTS

The mean cytomegalovirus DNA load in aqueous humour decreased significantly from (2.59 ± 2.28) × 10⁵ copies/mL at baseline to (1 ± 1.76) × 10⁴ copies/mL one month later. The aqueous cytomegalovirus DNA load was negative in 17 eyes (70.8%) one month later. No obvious improvement of best-corrected visual acuity was found during the treatment. A positive correlation was proven between initial cytomegalovirus DNA titers in aqueous humour and the total number of intravitreal injections of ganciclovir, as well as between the baseline and final best-corrected visual acuities. No severe complications developed.

CONCLUSIONS

An initial high dose of ganciclovir (6 mg) and continuous intravitreal injections of ganciclovir could significantly decrease the cytomegalovirus load in HIV-negative patients with cytomegalovirus retinitis.

TRIAL REGISTRATION

http://clinicaltrials.gov, NCT03598452, retrospectively registered on 24 July 2018.

Cytomegalovirus retinitis in HIV-negative patients - associated conditions, clinical presentation, diagnostic methods and treatment strategy

In recent years, numerous reports have tied cytomegalovirus retinitis (CMVR) with multiple systemic conditions in the absence of human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS). These range from reports in apparently healthy individuals, through conditions rendering limited immune dysfunction such as advanced age and diabetes mellitus, and finally severe immune dysfunction such as in haematological and rheumatological conditions. Reports are also emerging, suggesting that induced local ocular immunosuppression is a risk factor for CMVR. We herein present a comprehensive collection of the accumulated findings regarding CMVR in non-HIV patients. We summarize the spectrum of underlying morbidity that has been associated with CMVR, its clinical presentation, diagnostic methods and treatment choice in the attempt to suggest the optimal treatment strategy in this complicated and diverse patient population which is still currently lacking a consensus.

Comparison of intravitreal ganciclovir monotherapy and combination with foscarnet as initial therapy for cytomegalovirus retinitis

AIM

To compare the effectiveness between multiple intravitreal injections of ganciclovir alone and combined with foscarnet as initial treatment for patients with newly-onset cytomegalovirus retinitis (CMVR).

METHODS

The retrospective study observed 37 patients (58 eyes) who suffered from CMVR onset between 2013 and 2015. Among them, 35 eyes underwent 4 weekly intravitreal injections of 3.0 mg ganciclovir, and 23 eyes underwent 4 weekly injections of 3.0 mg ganciclovir combined with 2.4 mg foscarnet. Visual acuity, intraocular pressure and viral load of cytomegalovirus (CMV) in aqueous humor measured by real-time polymerase chain reaction were compared before and after each injection.

RESULTS

CMV-DNA copies in aqueous humor decreased remarkably in both groups. The average of CMV-DNA copies in patients' aqueous decreased from 38.3×10⁴ copies/mL at baseline to 2.2×10⁴ copies/mL after the 4^th injection in patients who were treated with ganciclovir monotherapy, and decreased from 76.9×10⁴ copies/mL to 11.3×10⁴ copies/mL after 4 continuous injections of ganciclovir combined with foscarnet. No significant difference was found in reduction of viral load, change of visual acuities or intraocular pressures between monotherapy or combined therapy.

CONCLUSION

Results of this study show that the initial effectiveness of treating CMVR after 4 weekly intravitreal injections is not significantly different from ganciclovir alone or combined with foscarnet. Continuous injection of ganciclovir alone is sufficient in treating immunosuppressive patients with newly-onset CMVR.

Cytomegalovirus Retinitis in a Human Immunodeficiency Virus-negative Cohort: Long-term Management and Complications

PURPOSE

To examine the clinical outcomes achieved by using intravitreal ganciclovir injections combined with systemic anti-viral therapy in treating cytomegalovirus (CMV) retinitis in patients without human immunodeficiency virus (HIV) infection.

METHODS

Twenty-three eyes of 15 HIV-negative patients diagnosed with CMV retinitis were included in this retrospective study.

RESULTS

The median follow-up was 68 weeks (range, 12-156), and median number of injections was 10 (range, 2-22). The retinal lesions stopped progressing within 1-2 weeks following treatment. All of the eyes showed either unchanged or ≥2 line improvements of BCVA at last visit. There was no development of CMV retinitis in a fellow eye, or recurrence in a studied eye. Systemic complications such as neutropenia were not detected.

CONCLUSIONS

Intravitreal ganciclovir injections combined with systemic anti-viral treatment is a good therapeutic option for treating CMV retinitis without HIV infection. Such treatment provided favorable visual outcomes, with minimal ocular and systemic complications.

Synthesis and Characterization of Ganciclovir Long Chain Lipid Prodrugs

Ganciclovir (GCV) is indicated for the treatment of human cytomegalo virus (HCMV) retinitis in immunocompromised patients. Sub-optimal physicochemical properties prevent GCV from reaching therapeutic concentrations in back of the eye (retina) tissue after oral and intravenous administration. Chronic high dose administration results in systemic toxicity. Local intravitreal injections suffer from poor ocular bioavailability and require repeated administration which can cause retinal detachment, retinal/vitreal hemorrhage and endophthalmitis. In the current study, we synthesized long chain acyl ester derivatives of GCV to improve lipophilicity and bioavailability. Ester conjugates (C₅, C₁₀ and C₁₃ mono- and di-(O-acyl)) of GCV were synthesized in one step reaction following conventional esterification reaction. Purity of the novel prodrugs was determined with reversed phase high performance liquid chromatography. Conjugation of long lipid chain to GCV was confirmed with proton (¹H) and carbon (¹³C) nuclear magnetic resonance and mass spectroscopy. Also, melting point and lipophilicity for the prodrugs and GCV were determined. MTS assay was used to assess in vitro toxicity of GCV and its long chain lipid prodrugs on human retinal pigment epithelial cell line (ARPE-19) cells. Results indicated that long chain lipid GCV prodrugs are nontoxic, safe and well-tolerated by ARPE-19 cells. These results suggest that novel long chain lipid GCV prodrugs may be further evaluated for ocular delivery and treatment of HCMV retinitis.

Outcome of cytomegalovirus retinitis in immunocompromised patients without Human Immunodeficiency Virus treated with intravitreal ganciclovir injection

PURPOSE

To study the outcomes of treatment with intravitreal ganciclovir injection for cytomegalovirus (CMV) retinitis in patients without Human Immunodeficiency Virus (HIV) infection.

METHODS

In this retrospective cohort study, demographic and clinical characteristics of patients with CMV retinitis without HIV were noted. Patients received intravitreal ganciclovir injection (2 mg/0.1 ml) alone until quiescence. The outcome measures were time taken for the lesions to heal, number of injections, change in best-corrected visual acuity (BCVA), recurrence of retinitis, occurrence of immune recovery uveitis (IRU) or injection-related complications and retinal detachment (RD).

RESULTS

18 eyes of ten patients (six males) with mean age of 33.7 years from June 2004 to March 2013 were included. Thirteen eyes with active lesions (mean BCVA of 0.51 ± 0.41) received 5.54 ± 3.36 intravitreal ganciclovir injections with complete healing within 1.81 ± 1.25 months. The final BCVA was 0.43 ± 0.52. IRU was observed in six eyes (33.33%) and RD developed in one eye. One eye had recurrence 1 month after stopping ganciclovir injections. The rest of the patients had recurrence-free follow-up at 9.46 ± 12.42 months.

CONCLUSIONS

Non-HIV patients with CMV retinitis can be successfully treated with intravitreal ganciclovir injection alone, avoiding the systemic side effects of systemic anti-CMV therapy.