International Journal of Retina (IJRETINA) 2023.
Volume 7.
Number 1.
P-ISSN.
E-ISSN.
ASSESSMENT OF EARLY AND LATE FEATURES OF DRY AGE-RELATED
MACULAR DEGENERATION WITH SPECTRAL-DOMAIN OPTICAL
COHERENCE TOMOGRAPHY AND FUNDUS AUTOFLUORESCENCE
Archana Singh1.
Mohini Agrawal2.
Harikrishnan Vannadil3.
Sunandan Bhatta4 Department of Ophthalmology.
INHS Asvini.
Mumbai.
India Department of Ophthalmology.
Military Hospital.
Jalandhar.
India Department of Ophthalmology.
Eyeris Eye Care Hospital,Hyderabad.
India Department of Ophthalmology.
Military Hospital.
Agra.
India Abstract Introduction: To assess early and late features of dry age-related macular degeneration (ARMD) using spectral-domain optical coherence tomography (SDOCT) and fundus autofluorescence (FAF).
Method: Observational cross-sectional study conducted from January-2022 to December-2022 in a tertiary eye care center.
India.
Patients >55 years and clinically diagnosed dry ARMD underwent SDOCT and FAF.
OCT and FAF were assessed and correlated with best-corrected visual acuity (BCVA).
Results: 106 eyes of 60 cases were included.
Mean age was 65.
80 years.
Mean BCVA was 4A0.
24 LogMAR.
Among clinically evident drusen, hard drusen (>63AA.
6% .
=94 eye.
, confluent soft-drusen 9% .
=10 eye.
and pigmentary changes at macula in 2 eyes only.
In the OCT, 65% .
eyes showed RPE irregularity, which was there in all the cases with soft drusen, whereas it varied in cases with hard drusen.
In the FAF, hypo/hyper was observed in 81 eyes .
%).
When correlated with BCVA.
RPE irregularity was not seen in cases with BCVA>6/12.
An abnormality in macular autofluorescence was evident in 62% .
= .
in cases with vision >6/12.
whereas in cases with vision<6/18, it was seen in 80% .
A strong correlation was found between the OCT findings and abnormal FAF .
appa=0.
, suggesting comparable results by both the modalities in ARMD.
Conclusion: OCT and FAF show good correlation in assessing early and late dry ARMD, thereby explaining the correlation between anatomical and biochemical changes.
Thus, these can be used as a progression predictor, when used together.
Keywords: Dry.
Age-related macular degeneration.
Spectral Domain.
Optical Coherence Tomography.
Fundus Autofluorescence.
Retinal pigment epithelium Cite This Article: SINGH.
Archana et al.
Assessment of early and late dry age-related macular degeneration with spectral-domain optical coherence tomography and fundus autofluorescence.
International Journal of Retina, [S.
ISSN
Available <https://w.
com/index.
php/ijretina/article/view/264>.
Date accessed: 26 feb.
https://doi.
org/10.
35479/ijretina.
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Correspondence to:
the RPE layer may be of immense prognostic value.
Mohini Agrawal.
Department of Ophthalmology.
Military Hospital.
Jalandhar.
India.
RPE over drusen in histological examination can be stretched and thin, thus drusen might be associated with alterations in the distribution of lipofuscin in the overlying RPE.
15@gmail.
INTRODUCTION
Age
(ARMD)
accounts for 8.
7% of all blindness in developed countries and increases with ageing eyes.
1-2 In the early stages, lipid material accumulates and deposits beneath the retinal pigment epithelium (RPE) and within the BruchAos membrane, referred to as The purpose of this study was to assess features of early and late dry ARMD on SDOCT and FAF, to prognostication and to correlate with BCVA levels as METHODS AoDrusenAo.
With advanced disease.
RPE undergoes This was an observational cross-sectional study morphological changes and develops geographic carried out over a period of one year from January atrophy/ or exudative disease leading to irreversible 2022 to December 2022.
It was approved by vision loss.
Institutional Ethics Committee and conducted in The diagnosis of ARMD is usually by clinical examination using a high-definition fundus lens for stereo-biomicroscopy.
4 Several imaging modalities accordance with the AoDeclaration of HelsinkiAo.
written informed consent was taken from all the study subjects.
have been found useful in studying the disease, in Patients attending the outpatient clinic of the department of ophthalmology at a tertiary care spectral-domain optical coherence tomography (SD- centre.
Western Maharashtra.
India were taken.
All OCT).
These modalities show specific changes which the clinically diagnosed cases of early to late dry can be used as prognostic indicators for the ARMD of >55 years age was identified, based on the 5,6 FAF along with SD-OCT has made it easier presence of drusen (>63AA.
with or without to diagnose ARMD, as these imaging modalities can pigmentary changes at the macula were included in reveal abnormal areas that may not be clinically the study.
It was done by biomicroscopy with slit- visible on biomicroscopy.
SD-OCT is widely used lamp and dilated fundus examination using slit lamp for the diagnosing early or late ARMD.
It has great and indirect ophthalmoscope.
The diagnosis was role in revealing structural abnormalities up to a confirmed by a vitreoretinal specialist.
(FAF)
resolution of 5-to-10 microns.
10 OCT used with FAF is the current standard diagnostic and monitoring modality to detect dry ARMD and follow-up on its Both of these modalities are complementary in diagnosing ARMD and their correlation can be of diagnostic importance.
Also, the correlation between the biochemical changes and structural changes in Based on AREDS classification, early dry ARMD was defined as patients with <20 medium-size drusen .
Intermediate dry ARMD was defined as patients with geographic atrophy (GA) that did not extend to macula or those with large drusen .
, or at least 20 medium-size, or at least 65 medium-size defined drusen.
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Late ARMD included geographic atrophy involving The results of the two tests were recorded by two independent observers to eliminate observerAos bias neovascularisation .
et ARMD) or evidence of and finally the results were correlated with each neovascular maculopathy .
ubretinal haemorrhage, other and with BCVA levels.
ry ARMD) serous retinal or RPE detachmen.
Patients with wet ARMD, hereditary retinal disease, glaucoma, inflammatory choroidopathies, retinal detachment, ocular trauma, media opacity and cases who had undergone vitreoretinal surgeries were excluded from the study.
All selected cases underwent visual acuity testing by SnellenAos chart, anterior and posterior segment examination by slit lamp biomicroscope and on confirming the diagnosis as dry ARMD, were taken up for FAF by using a fundus camera (Carl Zeiss FF 450 plu.
with an excitatory filter of 488nm and SDOCT (Carl Zeiss Cirrus 4.
Sample size calculation Kappa value of 0.
73 was taken as reference from previous studies.
The definition of is:
K = P0 Ae Pe = 1 - 1 Ae Po 1 Ae Pe 1 Ae Pe Where Po is the relative observed agreement among Raters, and Pe is the hypothetical probability of chance agreement.
If the Raters are in complete agreement, then K = 1.
If there is no agreement among the Raters other than what would be expected by chance .
s given by P.
K < 0.
If we assume that the two Raters agree more than 50% of Authors stratified visual acuity into three groups- the times .
appa coefficient 0.
with 20 % relative Ou6/12, <6/18-6/36 and <6/36.
error and confidence interval of 95% the minimum Spectral-domain OCT is a commercially available device with a scan speed of 27,000 axial scans/ second and an axial resolution of 5AAm.
Macular scan was acquired using macular cube 200x200 scan and 5-line raster protocol.
IS-OS junction disruption or bumps in the RPE layers were considered suggestive of anatomical changes at the RPE level caused by dry ARMD.
OCT
RPE
irregularities were present in the macular area and was negative in absence of the same.
FAF was considered positive in cases with hypo/ hyper autofluorescence in the macular area, while a normal fluorescence was considered negative.
sample size required is 100.
Statistical analysis Data was analyzed using SPSS for Windows .
Qualitative data variables were expressed as frequency and percentage while quantitative data variables expressed as Mean.
SD and Median.
t-test was applied to see the difference between different groups.
A confidence level of 95% and p<0.
05 was considered significant.
RESULTS
One-hundred and six eyes of 60 cases were included in the study.
Mean age at the presentation 80 years.
Majority .
%) of the cases belonged to the age group between 60 to 70 years .
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Table 1.
Distribution Of Patients with Dry ARMD Stratified Based on Age showed RPE irregularity, which was there in all the cases with soft drusen, whereas it varied in cases with Age group Number of patients Percentage (%) O 60 years FAF was observed in 81 eyes .
%) .
61 Ae 70 years 71 Ae 80 years Table 2.
Distribution Of Eyes Based on ARMD Patterns in Optical Coherence Tomography and Corresponding Fundus Autofluorescence and Correlation.
> 80 years Total There were 33 .
%) males and 27 .
%) females.
Mean visual acuity was 0.
4A0.
24 LogMAR.
Among clinically evident drusen, hard drusen (>63AA.
was 6% .
=94 eye.
, confluent soft drusen was evident in 9% .
=10 eye.
and pigmentary changes hard drusen.
In the FAF, be it hypo or hyper, macular abnormal FAF
Pattern
Abnormal
SD(Hypo & Normal
OCT
Hype.
Active .
Total Kappavalue Smooth Total at macula in 2 eyes only.
In the OCT, 66 eyes .
%) Figure 1 to 3 depicts various types of clinically evident drusen and corresponding OCT and FAF Figure 1: Image depicting .
Colour fundus photo, .
spectral-domain optical coherence topography image and .
fundus autofluorescence in a case of confluent soft drusen Published by: INAVRS https://w.
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Figure 2: Image depicting .
Colour fundus photo, .
spectral-domain optical coherence topography image and .
fundus autofluorescence in a case of intermediate hard drusen Figure 3: Image depicting .
spectral-domain optical coherence topography image and .
fundus autofluorescence in a case of pigment change at macula When correlated with BCVA.
RPE irregularities were more prevalent in the cases with BCVA between 6/186/36.
An abnormality in macular autofluorescence was evident in 62% .
= .
in cases with vision >6/12, whereas in cases with vision <6/18- 6/36, it was seen in 80% .
= .
Table 3.
Correlation Between ARMD Patterns on Optical Coherence Tomography and Corresponding Fundus Autofluorescence When Stratified Based on Best-Corrected Visual Acuity.
Best-corrected visual acuity Pattern on SDOCT
FAF
Total
Abnormal
Normal
Active
Smooth
Active
Smooth
Active
Smooth
>6/12
<6/18-6/36
<6/36
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Fundus autofluorescence findings showed a slight visual acuity groups.
RPE irregularities were noted deviation from the clinically evident changes in cases more in the group with vision between 6/18-6/36.
of ARMD.
Cases with evident discrete hard drusen This construct a fact that anatomical disruption at did not show obvious FAF findings, while a few the level of RPE and BruchAos layer is associated with patients with subtle pigmentary changes at the photoreceptors damage and responsible for the macula showed abnormal FAF.
However, when vision loss.
compared to OCT.
FAF was more sensitive in the group with good BCVA >6/12.
A strong correlation was found between the positive OCT findings of RPE irregularity and abnormal FAF .
appa=0.
, modalities in cases of early and late dry ARMD.
ARMD is a multifactorial disease affecting the macula resulting in progressive and irreversible 13 Dry ARMD presents with very slowly progressive loss of vision which is irreversible due to accumulation of debris and metabolic by-products between the RPE and BruchAos membrane.
14 Various treatment modalities like anti-vascular endothelial growth factor and laser therapy, have been shown to result in improvement in wet ARMD15.
treatment of dry ARMD still remains at a nascent stage with prescription of multivitamins and antioxidant supplements to prevent the progression.
Dry ARMD is also known to progress to wet ARMD, however features predisposing for the progression are not clearly identified.
17 This study was an attempt to find factors suggestive of poor prognosis of the disease and also factors leading to early progression of dry ARMD to wet ARMD.
morphology of drusen in dry ARMD were in Studies suggested that RPE disruption is less commonly seen over intermediate hard drusen whereas confluent drusen at the macula and hypofluoresence in late stages with RPE atrophy.
FAF showed various patterns in early ARMD which were observed in this It was strikingly observed that a few cases with clinically evident hard drusen did not show obvious FAF abnormality, while a few patients with subtle pigment changes at macula showed abnormal FAF.
This is in accordance with the earlier studies which suggested that FAF was not merely dependent upon the size and number of drusen, but also on the composition of the drusen and the status of the RPE above and adjacent to the drusen.
In this study.
RPE irregularities on SDOCT and abnormal FAF strongly correlated .
appa=0.
in cases of dry ARMD.
Hence, both the investigation modalities gave comparable results in dry ARMD An interesting observation was made that a few cases with clinically evident drusen did not show significant OCT or FAF changes as depicted in figure 2, whereas cases with subtle pigment changes at the macula showed equivocal changes in both the investigation modalities as shown in figure 3.
The results in our study on the prevalence and the in the form of hyperfluorescence in clinically evident study as well.
DISCUSSION
Abnormal autofluorescence, found in 81 eyes, was RPE irregularities18 as seen in figure 1.
Our study also showed a similar pattern.
When compared within the A previous study Brar et al also showed a significant correlation between these two modalities with a comparable kappa value of 0.
20 Our study showed similar results but it differed in the inclusion criteria which included cases of both early and late dry ARMD.
Our study included the whole spectrum of the disease with a sufficient sample size.
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When this observation was correlated with BCVA of diagnosed cases of dry ARMD.
The study also the respective cases, it exposed that the group with suggests that, there is a strong association between good BCVA was not showing changes on either OCT changes seen in these two investigative modalities or FAF, even in the presence of clinically evident and can be used as a progression predictor when used together.
However, the study doesnAot show any This study was limited by its single-center, crosectional design with a small sample size.
In the clinical practice, finding drusen at the macula is an important diagnostic criterion to label a case as dry ARMD.
However, this finding hardly has any prognostic value.
A serial observation of the patient and starting him/her on antioxidant therapy is not significant difference between the two modalities and does not prove which modality is better.
Further longitudinal studies may be required to understand the progression of the disease and specific changes which can predict the prognosis of the disease.
REFERENCES