Choroidal and retinal thickness variations in ocular albinism

Purpose: To study the retinal and choroidal thickness variations on enhanced depth imaging optical coherence tomography scans in ocular albinism (OA) and compare with age?matched healthy subjects. Methods: This retrospective observational study had 48 eyes of 24 patients diagnosed clinically as OA and age, sex, and axial length?matched control healthy subjects. All patients underwent detailed ophthalmic examination and a single?line horizontal?raster enhanced depth imaging – optical coherence tomography scan (Spectralis, Heidelberg Engineering). Retinal and choroidal thickness was measured, compared, and analyzed between the two groups. Mann–Whitney U test was used for analysis between the two groups. P < 0.05 was considered significant. Results: The mean age was 28.3 ± 11.6 and 29.9 ± 10.6 years in the OA group and control group, respectively. Spherical equivalents ranged from ?8.5D to +10.5D in the OA group and from ?8.0D to +10.0D in the control group. The mean axial length between the two groups (P = 0.652) were comparable. The average retinal thickness (272 ± 34.3 vs. 213 ± 13.8 ?m; P < 0.001) was greater in the OA group as compared to controls. The mean choroidal thickness (184 ± 78.4 vs. 287 ± 46.4 ?m; P < 0.001) was significantly thinner in the OA group. Conclusion: Acquisition of OCT scans in OA can be challenging. This study showed that the subfoveal retinal thickness and choroidal thickness measured across the scans were significantly different in the OA group compared to controls. In the future, more studies are required to evaluate the role of the choroid and its relationship to emmetropization in albinism.

Correlation between retinal sensitivity and cystoid space characteristics in diabetic macular edema.

Purpose: To evaluate the correlation between retinal sensitivity and cystoid space characteristics in eyes with diabetic macular edema (DME). Materials and Methods: Prospective cross‑sectional study of 22 subjects with DME (32 treatment‑naïve eyes). All study subjects underwent complete ophthalmic examination, including slit‑lamp biomicroscopy and dilated fundus examination. All subjects underwent spectral domain optical coherence tomography (SD‑OCT) and microperimetry (MP). Intraretinal cystoid space (ICS) volume was generated after manual delineation of cystoid space boundaries using the three‑dimensional‑OCT software. Various SD‑OCT parameters, including retinal thickness, retinal volume, cystoid space volume, cystoid space intensity, and outer retinal structure integrity, were correlated with MP parameters and best‑corrected visual acuity (BCVA). Results: Subject’s mean age was 57 ± 9 years. The mean logarithm of minimum angle of resolution BCVA was 0.4 ± 0.2. The intraclass correlation coefficient for inter‑ and intra‑grader assessment of cystoid space volume by manual delineation was 0.99 and 0.99, respectively. Mean total ICS volume was 0.4 ± 0.4 mm3 and for the foveal center, subfield was 0.1 ± 0.1 mm3. Mean retinal sensitivity was 12.89 ± 10 dB; however, foveal retinal sensitivity was 12.3 ± 11.1 dB. We found no significant correlation between BCVA and total cystoid space volume (r = 0.33, P = 0.06). Correlation between total retinal sensitivity and total ICS was negative and nonsignificant (r = −0.17, P = 0.36). Correlation between foveal retinal sensitivity and foveal cystoid space intensity was moderate and marginally significant (r = −0.43, P = 0.05). Conclusion: Total cystoid space volume was not significantly correlated with BCVA or total retinal sensitivity in subjects with DME. Foveal cystoid space optical intensity was negatively correlated with foveal retinal sensitivity. These findings suggest further investigation of cystoid space characteristics in the setting of DME may be of value.

Evidence‑based review of diabetic macular edema management: Consensus statement on Indian treatment guidelines.

The purpose of the study was to review the current evidence and design a diabetic macular edema (DME) management guideline specific for India. The published DME guidelines from different organizations and publications were weighed against the practice trends in India. This included the recently approved drugs. DME management consisted of control of diabetes and other associated systemic conditions, such as hypertension and hyperlipidemia, and specific therapy to reduce macular edema. Quantification of macular edema is precisely made with the optical coherence tomography and treatment options include retinal laser, intravitreal anti‑vascular endothelial growth factors (VEGF), and implantable dexamethasone. Specific use of these modalities depends on the presenting vision and extent of macular involvement. Invariable eyes with center‑involving macular edema benefit from intravitreal anti‑VEGF or dexamethasone implant therapy, and eyes with macular edema not involving the macula center benefit from retinal laser. The results are illustrated with adequate case studies and frequently asked questions. This guideline prepared on the current published evidence is meant as a guideline for the treating physicians.

Choroidal thickness in diabetic patients of Indian ethnicity.

Purpose: To evaluate choroidal thickness (CT) change in various grades of diabetic retinopathy (DR) in comparison to age‑matched healthy subjects. Methods: This prospective observational study included 227 eyes of 125 subjects with diabetes (study group: 58 females) and 197 eyes of 110 age‑matched healthy subjects (control group: 66 females). Collected data included age, gender, duration of diabetes, glycemic control, comprehensive ocular examination, fundus photography, and CT measurement on spectral domain ocular coherence tomography using enhanced depth imaging. Results: Mean age in the study group was 57.0 ± 9.37 years (43–73 years). The mean age was 41.48 ± 5.43 years in the control group. Subjects with diabetes with (252.8 ± 55.6 microns) and without (261.71 ± 51.8 microns) retinopathy had significantly thinner choroids when compared to the control group (281.7 ± 47.7 microns; P = 0.032). Seventy‑four of 227 eyes did not have any evidence of DR, 89 eyes had features of nonproliferative diabetic retinopathy (NPDR), and 33 eyes had treatment naïve proliferative diabetic retinopathy (PDR). Thirty‑one PDR eyes had received previous laser photocoagulation. Subjects with diabetes without retinopathy had a greater subfoveal choroidal thickness (SFCT) than subjects with diabetes with retinopathy (P < 0.001). Eyes with PDR (243.9 ± 56.2 microns) had thinner SFCT than those with NPDR (238.98 ± 111.23 microns). There was no difference in the SFCT between treated (laser photocoagulation done; 251.784 ± 103.72 microns) and treatment naïve PDR (258.405 ± 89.47 microns, P = 0.23). Conclusions: Control eyes had greater SFCT compared to subjects with diabetes, with and without retinopathy. The thinning progressed with increasing severity of DR. Choroidal thinning may contribute to DR pathogenesis.

Retrospective hospital‑based analysis of age‑related macular degeneration patterns in India: 5‑year follow‑up.

Purpose: To provide a detailed analysis of age‑related macular degeneration (AMD) with a 5‑year follow‑up at a Tertiary Eye Care Center in India. Methods: In this retrospective institutional study, 408 eyes of 204 subjects (100 males) with a diagnosis of AMD with minimum 5‑year follow‑up were included. Data collected included demographics, details of the ocular exam, special investigations performed, treatment offered, complications, and systemic diseases, if any. Results: The median age was 74.24 ± 8.23 years. Median follow‑up was 5.77 years. The visual acuity (VA) at baseline and last visit was 0.74 ± 0.12 (Snellen’s equivalent 20/100) and 0.54 ± 0.12 logarithm of the minimum angle of resolution (Snellen’s equivalent 20/50; P = 0.032) in patients with choroidal neovascular membrane (CNVM). The most common complaint was decreased vision (94.5%). AMD (any stage) was found to be bilateral in 93% of patients at baseline and 197 patients (96.56%) at 5 years. Seventeen eyes had active CNVM (12 of these were occult) at presentation. At baseline, 43 eyes had a disciform scar. Three hundred twenty‑one eyes had dry AMD at baseline (geographic atrophy ‑ 12 [3.7%] eyes). Five‑year conversion rate into wet AMD and geographic atrophy was 2.87% and 3.12%. Median number of anti‑vascular endothelial growth factor injections administered per patient was 2.8 ± 1.2. CNVM bilaterality was low (7.5%). Conclusion: Patients with AMD in India presented later in the course of the disease. Bilateral advanced AMD and geographic atrophy were uncommon. Five‑year conversion rate into wet AMD and geographic atrophy was 2.87% and 3.12%.

Choroidal thickness profile in healthy Indian children.

Purpose: The purpose was to study choroidal thickness and its profile based on location in healthy Indian children using enhanced depth spectral‑domain‑optical coherence tomography (SD‑OCT). Methods: In this cross‑sectional observational study 255 eyes of 136 children with no retinal or choroidal disease were consecutively scanned using enhanced depth SD‑OCT. Eyes with any ocular disease or axial length (AXL) >25 mm or < 20 mm were excluded. A single observer measured choroidal thickness from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction at 500‑microns intervals up to 2500 microns temporal and nasal to the fovea. Generalized estimating equations were used to evaluate the correlation between choroidal thickness at various locations and age, AXL, gender and spherical equivalent (SEq). Results: Mean age of the subjects was 11.9 ± 3.4 years (range: 5–18 years). There were 62 Females and 74 males. The mean AXL was 23.55 ± 0.74 mm. Mean subfoveal choroidal thickness was 312.1 ± 45.40 μm. Choroid was found to be thickest subfoveally, then temporally. Age, AXL and SEq showed a significant correlation with choroidal thickness, whereas gender did not affect choroidal thickness. Conclusion: Our study provides a valid normative database of choroidal thickness in healthy Indian children. This database could be useful for further studies evaluating choroidal changes in various chorioretinal disorders. Age and AXL are critical factors, which negatively correlated with choroidal thickness.

Choroidal thickness profile in inherited retinal diseases in Indian subjects.

Purpose: To evaluate changes in choroidal thickness (CT) in inherited retinal diseases and its relationship with age, spherical equivalent, visual acuity, and macular thickness. Methods: Retrospective analysis of 51 eyes with features of retinal dystrophy of 26 subjects, who underwent enhanced depth imaging using spectral domain (SD) optical coherence tomography (OCT), were included. The CT measurements were made at the fovea and at 5 points with an interval of 500 microns in both directions, nasal and temporal from the fovea and were compared with age‑matched healthy subjects. Step‑wise regression was used to find the relationship between age, spherical equivalent, best‑corrected visual acuity (BCVA), central macular thickness (CMT), and subfoveal CT. Results: Disease distribution was as follows: Stargardt’s disease 18 eyes (9 subjects); Best disease 5 eyes (3 subjects); cone‑rod dystrophy 26 eyes (13 subjects); and Bietti’s crystalline dystrophy 2 eyes (1 subject). Mean subfoveal CT was 266.33 ± 76 microns. On regression analysis, no significant correlation was found between subfoveal CT and any other variable such as age (P = 0.9), gender (P = 0.5), CMT (P = 0.1), spherical equivalent (P = 0.3) and BCVA (P = 0.6). While comparing with age‑matched healthy subjects, no significant statistical difference was noted (P < 0.05) among all age groups. Conclusion: Our study reports quantitative changes in CT in various common inherited retinal diseases seen in Indian populations. To validate changes in choroid, a longitudinal study with larger sample size is warranted.

Clinical applications of choroidal imaging technologies.

Choroid supplies the major blood supply to the eye, especially the outer retinal structures. Its understanding has significantly improved with the advent of advanced imaging modalities such as enhanced depth imaging technique and the newer swept source optical coherence tomography. Recent literature reports the findings of choroidal changes, quantitative as well as qualitative, in various chorioretinal disorders. This review article describes applications of choroidal imaging in the management of common diseases such as age‑related macular degeneration, high myopia, central serous chorioretinopathy, chorioretinal inflammatory diseases, and tumors. This article briefly discusses future directions in choroidal imaging including angiography.

En-face optical coherence tomography in the diagnosis and management of age-related macular degeneration and polypoidal choroidal vasculopathy.

Optical coherence tomography (OCT) is a noninvasive imaging modality providing high‑resolution images of the central retina that has completely transformed the field of ophthalmology. While traditional OCT has produced longitudinal cross‑sectional images, advancements in data processing have led to the development of en‑face OCT, which produces transverse images of retinal and choroidal layers at any specified depth. This offers additional benefit on top of longitudinal cross‑sections because it provides an extensive overview of pathological structures in a single image. The aim of this review was to discuss the utility of en‑face OCT in the diagnosis and management of age‑related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV). En‑face imaging of the inner segment/outer segment junction of retinal photoreceptors has been shown to be a useful indicator of visual acuity and a predictor of the extent of progression of geographic atrophy. En‑face OCT has also enabled high‑resolution analysis and quantification of pathological structures such as reticular pseudodrusen (RPD) and choroidal neovascularization, which have the potential to become useful markers for disease monitoring. En‑face Doppler OCT enables subtle changes in the choroidal vasculature to be detected in eyes with RPD and AMD, which has significantly advanced our understanding of their pathogenesis. En‑face Doppler OCT has also been shown to be useful for detecting the polypoid lesions and branching vascular networks diagnostic of PCV. It may therefore serve as a noninvasive alternative to fluorescein and indocyanine green angiography for the diagnosis of PCV and other forms of the exudative macular disease.

Choroidal thickness profile in healthy Indian subjects.

Purpose: The aim was to study choroidal thickness (CT) and its profile based on location in healthy Indian subjects using Cirrus high definition (HD) optical coherence tomography. Materials and Methods: A total of 211 eyes of 115 healthy subjects with no retinal or choroidal disease were consecutively scanned using Cirrus HD 1 line raster scan mode without pupillary dilation. Eyes with any ocular disease or axial length (AXL) >24 mm or <20 mm were excluded. Experienced technician measured CT from the lower border of the retinal pigment epithelium (RPE) to the lower border of choroid. CT was measured from the posterior edge of the RPE to the choroid/sclera junction at 500‑μm intervals up to 3000 μm temporal and nasal to the fovea. Generalized estimating equations were used to evaluate the correlation between CT at various locations and age, AXL, spherical equivalent, and macular thickness. Results: Mean age was 42.8 ± 13.6 years. Mean AXL was 22.84 ± 0.78 mm. Median spherical equivalent was 0.16 ± 0.64 D. Mean central macular thickness was 216.4 ± 30.03 μm. Choroidal was thinnest nasally and thickest subfoveally. On multivariate regression, age was the most significant factor affecting subfoveal CT (P = 0.000). Regression analysis showed an approximate decrease in CT of 1.18 μm every year. Conclusions: Our study provides CT profile in Indian healthy subjects in various age groups. CT depends on its location, subfoveal being the thickest and nasal being the thinnest. Age is a critical factor, which is negatively correlated with CT.

Different treatment modalities for choroidal neovascularization in two eyes of one patient with bilateral type 2A parafoveal telangiectasia.

A 60-year-old diabetic man presented with a history of decrease in vision in both eyes since 2 weeks. At presentation, best corrected visual acuity (BCVA) in the right eye (RE) was 20/30 and that in the left eye (LE) was 20/80. The right fundus revealed a grayish reflex, yellowish crystalline deposits and retinal pigment epithelial hyperplasia at the macula. The left fundus showed subretinal fluid and temporal subretinal hemorrhage near a grayish reflex at the macula. A diagnosis in both eyes of idiopathic macular telangiectasia (IMT) type 2A with RE stage 4 and LE stage 5, choroidal neovascularization (CNVM) was made. The patient was treated with photodynamic therapy (PDT) in LE. The visual acuity improved to 20/40 over the next 6 months. At a 4-year follow-up, he developed decreased vision in RE diagnosed as IMT with CNV and was treated with intravitreal ranibizumab. At 6-month follow-up post injection, the vision was 20/40p.

Smartphones in ophthalmology.

The potential usefulness of smartphones in the medical field is evolving everyday. This article describes various tools available on smartphones, largely focusing on the iPhone, for the examination of an ophthalmic patient, for patient and physician education, as well as reference tools for both ophthalmologists and vision researchers. Furthermore, the present article discusses how smartphones can be used for ophthalmic photography and image management, and foremost, the usefulness of the applications such as the Eye Handbook for the ophthalmologist and interested students, patients, physicians, and researchers, currently available in the iPhone.

Delayed inflammation associated with retained perfluorocarbon liquid.

A 55-year-old woman, with history of cataract surgery 1 year back, presented with features of ocular inflammation for last 3 months. She had no history of any other intraocular surgery. On examination, anterior segment showed frothy material in the inferior angle with moderate anterior chamber reaction (cells+/flare+) and sulcus intraocular lens with large posterior capsule rent. Fundoscopy showed multiple, small to medium-sized transparent bubbles of perfluorocarbon liquid (PFCL) with membranes in the vitreous cavity. Ultrasonography confirmed the presence of PFCL in the vitreous cavity. Pars plana vitrectomy with anterior chamber wash was done which led to good visual recovery. To conclude, retained PFCL can cause late onset fibrinous inflammation after a quiescent period but surgical intervention may lead to good visual outcome.