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An in depth description of the cytomegalovirus retinus cmv and what it causes

Cytomegalovirus retinitis

Can J Infect Dis. Telephone 613-737-8218, fax 613-737-8836, e-mail ac. All patients received intravitreal ganciclovir therapy, and half of the patients began HAART as well. Secondly, instantaneous hazards for outcomes such as CMV retinitis progression, ocular complications and mortality were compared. Tertiary care centre in Ottawa, Ontario. Five of eight patients receiving HAART discontinued intravitreal ganciclovir after a mean treatment period of 428 days.

Subsequently, none of these patients experienced retinitis progression during follow-up periods lasting up to 820 days mean of 617 days. Progression of CMV retinitis was 11. However, the development of potent antiretroviral chemotherapeutic agents has led to a significant decrease in the incidence of CMV retinitis 2. Before HAART, treatment of CMV retinitis consisted of lifelong treatment with specific anti-CMV compounds, with relapse of retinitis occurring within two to three weeks after discontinuation of maintenance therapy 6.

Three antiviral drugs - ganciclovir, foscarnet and cidofovir - are currently in use 12 - 14. Ganciclovir, a guanosine analogue, was the first of these proven to be effective in halting the progression of CMV retinitis 15. Initial therapy with this drug generally involves intravenous administration; however, maintenance therapy has been effective via intravenous, oral and intravitreal routes.

Intravitreal drug delivery can be accomplished via an intravitreal implant device or through repeated intravitreal injection 1617. In Canada, the injection option has been widely employed, because intravitreal implants are not funded by provincial health insurance programs.

Therefore, the primary objective of the present study was to describe the course and outcome of CMV retinitis among patients treated with intravitreal ganciclovir injections and HAART.

A secondary objective was to evaluate the impact of HAART on such outcomes as CMV retinitis progression, ocular complications of intravitreal treatment and mortality among CMV retinitis patients receiving intravitreal ganciclovir. Patients younger than 18 years of age at the time of diagnosis and those followed for less than two weeks were excluded from the present study. Hence, the study included 21 eyes from 16 patients.

Diagnosis and covariates measured: All ophthalmological data were obtained from detailed ophthalmology clinic notes and drawings, with the additional support of fundus photographs. The diagnosis of CMV retinitis was based on well established clinical criteria 18. The baseline threat to central vision was assessed by determining the invasion of retinitis into three distinct retinal zones as previously delineated 19.

Treatment of CMV retinitis with intravitral ganciclovir in the HAART era

Follow-up and outcomes measured: All patients underwent fundus examination at one-month intervals during intravitreal ganciclovir therapy. If ganciclovir was discontinued after HAART-induced immune recovery, the frequency of fundus evaluation was slowly decreased, with a maximum time between examinations of six months.

Subjects were followed until August 1999. The primary outcomes were retinitis progression, ocular complications and death. Subjects were censored at the time of discontinuing intravitreal injections, except in the case of survival measurements, in which all patients were included until the end of the study period.

Ocular complications consisted of retinal detachment and endophthalmitis. Date of death was established using hospital patient files and records from the infectious diseases clinic at the Ottawa Hospital. Using these resources, all subjects were accounted for at the end of the study period. Because the impact of intravitreal ganciclovir is local, each eye was evaluated independently for the ophthalmological outcomes. However, each subject was counted only once in survival calculations.

Immediately after the diagnosis of CMV retinitis, all patients received induction therapy consisting of 14 days of daily intravenous ganciclovir infusions. After this period, patients received maintenance therapy in the form of weekly intravitreal injections of ganciclovir 2 mg in 0. HAART consisted of the combination of at least one protease inhibitor with at least two reverse transcriptase inhibitors.

However, two patients in this group began HAART much later, commencing at 298 and 313 days after the diagnosis. Finally, progression, ocular complication and mortality rates were compared using a censored Cox proportional hazards analysis. Subsequently, after cessation of intravitreal ganciclovir, none of these patients experienced CMV retinitis recurrence during a mean follow-up period of 617 days range 408 to 820 days.

  1. Follow-up and outcomes measured.
  2. For patients with esophagitis, colitis, or rectal ulcers, improvement in clinical symptoms is usually noted during the first week of therapy with valganciclovir, ganciclovir, or foscarnet.
  3. Patients might also wish to consider methods to reduce infection or reinfection by practicing safe sex, avoiding infected needles, and receiving only blood products that have been determined to be CMV free or have been filtered.
  4. Disease is usually recognized unilaterally at first but may present bilaterally.
  5. Diagnosis and covariates measured.

Among the other three individuals in the HAART group, one developed bacterial endophthalmitis and, after resolution, failed to return for ongoing ophthalmic assessment.

This complication was felt to be secondary to the intravitreal injections. One of these patients was eventually switched to intravitreal foscarnet because of ongoing CMV retinitis progression, which was felt to be secondary to ganciclovir resistance.

This subject continued to receive intravitreal ganciclovir for a further 158 days, during which time no CMV retinitis progression occurred. Overall, three patients who originally presented with uniocular disease subsequently developed CMV retinitis in the second eye with a mean time of 175 days between diagnoses.

While all patients in both groups displayed initial stabilization of CMV retinitis with intravenous ganciclovir induction therapy, subsequent progression during intravitreal ganciclovir therapy was 11.