Abstract
Purpose::
To assess changes of retinal nerve fiber layer (RNFL) thickness measured by Optical Coherence Tomography (OCT) in patients with HIV related to viral load, CD4 cell count and HAART (Highly Active Antiretroviral Therapy) treatment before and after 1 year of follow up.
Methods::
A prospective clinic study with twelve months of follow-up. The study has been designed according to Guidelines for Good Clinical Practice in Clinical Trials (MRC, 1998) and Helsinki Declaration (MRC, Appendix 1, 1998) about ethical principles in human investigation. Each patient has been informed in detail about the purpose of this study and we have obtained the informed consent of all of them.The study included 40 eyes of 20 patients in one center. Thickness of RNFL along 3,4 mm diameter circle centered on the optic nerve head and macular thickness were evaluated with Stratus OCT (Zeiss version 4.0.2) . Patients were assessed baseline, before beginning HAART therapy and every three months.
Results::
19 patients were male and 1 female. Age ranged between 19 and 55 years old (38,4 ± 9). Baseline viral load was between 3.000-580000 copies/ml ( range 95449 ± 20534) and CD4 cell count was 21-501 cels/ml (range 152 ±134). After six months of HAART therapy, viral load became indetectable with <50 cels/ml in all patients , and CD4 cell count improved with a range of 368±208 cels/ml. Average of foveal thickness were analysed in both eyes before and after HAART therapy. In baseline visit the mean foveal thickness was ranged 210±25µ in the right eye and 213±21µ in the left eye. After twelve months this mean rised up with a range 214±24µ and 214±19µ. respectively. Superior and inferior area average of the optic nerve were also analysed with a range improvement in the RNFL thickness from 120±26 to 136,16 ±16,22µ in the superior region of right eye and 128,18±18,86µ in the superior region of the left eye.
Conclusions::
HIV is a neurotropic virus which leads to a significant RNFL thinning in HIV patients with low CD4 count compared with patients with CD4 count increased to above 100 and HIV-negative control subjects. Ours results show an improvement in the RNFL thickness, most prominent in the superior area of the optic nerve, in HIV patients after 1 year of treatment with HAART therapy. Therefore, a decrease of viral load and an improvement of CD4 cell count lead to changes in the RNFL thickness.
Keywords: AIDS/HIV • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • nerve fiber layer