الفهرس 
Aim of the StudyOnly 14 pages are availabe for public view
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Abstract
Hydroxy chloroquine (HCQ), originally an anti -malarial drug, is used in treatment
of various rheumatological diseases, such as rheumatoid arthritis (RA), systemic lupus
erythematosis (SLE) and some autoimmune dermatological conditions (1). Despite lesser
systemic toxicity compared to other drugs, it can cause severe retinal dysfunction and
loss of vision in approximately 3% of the patients on chronic use (2).
Although HCQ retinopathy may be asymptomatic early, patients with advanced
disease have vision problems and paracentral scotoma (3). the clinical sign of HCQ retinal
toxicity is typically characterized by bilateral pigmentary change of the macula sparing
the foveal centre known as bull‗s eye maculopathy (4).
The initial pathological changes were observed in the retinal ganglion cells in the
form of membranous cytoplasmic bodies that leads to cellular degeneration which
affects also the photoreceptors and retinal pigment epithelium cells, respectively, at a
later stage (5). This occurs here secondary to alterations of protein synthesis and lipid
peroxidation (6) .The structural and functional damage at this stage becomes irreversible
(7). Discontinuing the drug in early stages of HCQ retinopathy can prevent the
permenant structural and functional damage so the screening for early detection of HCQ
retinal toxicity is critical (8-10).
The screening of HCQ retinopathy includes a complete ophthalmological
examination with dilated fundus examination, amsler grid test and visual field testing.
Other methods include color vision, fundus photography and Flourescein angiography.
In the recent years, multifocal electroretinogram, fundus auto fluorescence and high
resolution spectral domain optical coherence tomography (SD-OCT) prove to be
valuable in early detection of HCQ retinal toxicity (11).
Cirrus high definition optical coherence tomography (HD-OCT) can early
characterize changes in the macular ganglion cell complex thickness (GCC) in patients
treated with HCQ (12-14).
This study aimed to evaluate the role of the ganglion cell complex using cirrus
HD-OCT in the screening of early hydroxy chloroquine maculopathy in rheumatoid
arthritis patients as early as possible before it becomes clinically visible.
This study is a case control study included 128 eyes of 64 rheumatoid arthritis
patients treated with HCQ and128 eyes of 64 age matched controls. All patients were
subjected to detailed history taking, full ophthalmological examination and SD-OCT
examination of the macular GCC thickness and photoreceptor layer (PL) integrity
assessment. Moreover, the correlation between the GCC thickness and duration of HCQ
use, PL integrity, uncorrected visual acuity and best corrected visual acuity in the HCQ
group were analyzed.
A statistically significant difference between the patients treated with HCQ
compared to their age matched control as regard to the photoreceptor layer integrity was
detected. Moreover, no statistical significant between the two studied groups as regard
to average, minimum and sectorial macular GCC thickness had been found. The
duration of treatment with HCQ, uncorrected visual acuity, best corrected visual acuity
and the photoreceptor layer integrity were associated with the average GCC thickness in
the HCQ treated patients in the univariate analysis. On the other hand, the multivariate analysis revealed that only the photoreceptor layer integrity was the highest variable that
was independently associated with the average GCC thickness followed by the duration
of treatment with HCQ and lastly the uncorrected visual acuity.
The conclusion of the study is that unique SD OCT findings in the retina can
identify early HCQ retinopathy before it becomes clinically visible.