Effects of Sickle Cell Disease on the Eye: Clinical Features and Treatment

Laser therapy for retinopathy in sickle cell disease

BACKGROUND

Sickle cell disease (SCD) includes a group of inherited haemoglobinopathies affecting multiple organs including the eyes. Some people with SCD develop ocular manifestations. Vision-threatening complications are mainly due to proliferative sickle retinopathy, which is characterised by proliferation of new blood vessels. Laser photocoagulation is widely applicable in proliferative retinopathies. It is important to evaluate the efficacy and safety of laser photocoagulation in the treatment of proliferative sickle retinopathy (PSR) to prevent sight-threatening complications.

OBJECTIVES

To evaluate the effectiveness of various techniques of laser photocoagulation therapy in SCD-related proliferative retinopathy.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Date of last search: 4 July 2022. We also searched the following resources (26 June 2022): Latin American and Caribbean Health Science Literature Database (LILACS); WHO International Clinical Trials Registry Platforms (ICTRP); and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials comparing laser photocoagulation to no treatment in children and adults with SCD.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and risk of bias of the included trials; we extracted and analysed data, contacting trial authors for additional information. We assessed the certainty of the evidence using the GRADE criteria.

MAIN RESULTS

We included three trials (414 eyes of 339 children and adults) comparing the efficacy and safety of laser photocoagulation to no therapy in people with PSR. There were 160 males and 179 females ranging in age from 13 to 67 years. The trials used different laser photocoagulation techniques; one single-centre trial employed sectoral scatter laser photocoagulation using an argon laser; a two-centre trial employed feeder vessel coagulation using argon laser in one centre and xenon arc in the second centre; while a third trial employed focal scatter laser photocoagulation using argon laser. The mean follow-up periods were 21 to 32 months in one trial, 42 to 47 months in a second, and 48 months in the third. Two trials had a high risk of allocation bias due to the randomisation method for participants with bilateral disease; the third trial had an unclear risk of selection bias. One trial was at risk of reporting bias. Given the unit of analysis is the eye rather than the individual, we chose to report the data narratively. Using sectoral scatter laser photocoagulation, one trial (174 eyes) reported no difference between groups for complete regression of PSR: 30.2% in the laser group and 22.4% in the control group. The same trial also reported no difference between groups in the development of new PSR: 34.3% of lasered eyes and 41.3% of control eyes (very low-certainty evidence). The two-centre trial using feeder vessel coagulation, only presented data at follow-up for one centre (mean period of nine years) and reported the development of new sea fan in 48.0% in the treated and 45.0% in the control group; no statistical significance (P = 0.64). A third trial reported regression in 55% of the laser group versus 28.6% of controls and progression of PSR in 10.5% of treated versus 25.7% of control eyes. We graded the evidence for these two primary outcomes as very low-certainty evidence. The sectoral scatter laser photocoagulation trial reported visual loss in 3.0% of treated eyes (mean follow-up 47 months) versus 12.0% of controlled eyes (mean follow-up 42 months) (P = 0.019). The feeder vessel coagulation trial reported visual loss in 1.14% of the laser group and 7.5% of the control group (mean follow-up 26 months at one site and 32 months in another) (P = 0.07). The focal scatter laser photocoagulation trial (mean follow-up of four years) reported that 72/73 eyes had the same visual acuity, while visual loss was seen in only one eye from the control group. We graded the certainty of the evidence as very low. The sectoral scatter laser trial detected vitreous haemorrhage in 12.0% of the laser group and 25.3% of control with a mean follow-up of 42 (control) to 47 months (treated) (P ≤ 0.5). The two-centre feeder vessel coagulation trial observed vitreous haemorrhage in 3.4% treated eyes (mean follow-up 26 months) versus 27.5% control eyes (mean follow-up 32 months); one centre (mean follow-up nine years) reported vitreous haemorrhage in 1/25 eyes (4.0%) in the treatment group and 9/20 eyes (45.0%) in the control group (P = 0.002). The scatter laser photocoagulation trial reported that vitreous haemorrhage was not seen in the treated group compared to 6/35 (17.1%) eyes in the control group and appeared only in the grades B and (PSR) stage III) (P < 0.05). We graded evidence for this outcome as low-certainty. Regarding adverse effects, only one occurrence of retinal tear was reported. All three trials reported on retinal detachment, with no significance across the treatment and control groups (low-certainty evidence). One trial reported on choroidal neovascularization, with treatment with xenon arc found to be associated with a significantly higher risk, but visual loss related to this complication is uncommon with long-term follow-up of three years or more. The included trials did not report on other adverse effects or quality of life.

AUTHORS' CONCLUSIONS

Our conclusions are based on the data from three trials (two of which were conducted over 30 years ago). Given the limited evidence available, which we assessed to be of low- or very low-certainty, we are uncertain whether laser therapy for sickle cell retinopathy improves the outcomes measured in this review. This treatment does not appear to have an effect on clinical outcomes such as regression of PSR and development of new incidences. No evidence is available assessing efficacy in relation to patient-important outcomes (such as quality of life or the loss of a driving licence).  Further research is needed to examine the safety of laser treatment compared to other interventions such as intravitreal injection of anti-vascular endothelial growth factors (VEGFs) . Patient-important outcomes as well as cost-effectiveness should be addressed.

The Impact of Optical Coherence Tomography in the Early Identification of Children with Sickle Cell Retinopathy

INTRODUCTION

Sickle cell disease is characterized by the production of abnormal hemoglobin, which affects hemoglobin molecule stability during hypoxia and leads to the formation of sickle cells, resulting in increased hematic viscosity, hemolysis, and microvascular blockage. Vasoocclusion is assumed to be the primary cause of vision-threatening retinopathy in sickle cell disease. The aim of this study was to improve the early detection of sickle cell retinopathy (SCR) in children with sickle cell disease (SCD) and investigate the link between systemic and ocular symptoms.

METHODS

This cross-sectional study comprised children with SCD. The patient files provided a detailed medical history. The laboratory tests included a blood count, reticulocyte count, and Hb electrophoresis. The slit lamp, fundus, optical coherence tomography (OCT), and optical coherence tomography angiography (OCTA) were all part of the ophthalmological examination.

RESULTS

The study comprised 15 children with sickle cell disease who met the inclusion and exclusion criteria, with a mean age of 11.15 ± 1.29 years. Nine of the children were males (60%) and six were females (40%). 8 (53.3%) of the children had Hb SS, three (20%) had Hb SC, three (20%) had Hb SB⁺, and one (6.7%) had Hb SB⁰. Four children (26.7%) had poor visual acuity. A fundus examination revealed significant abnormal findings in 12 of the 7 children's eyes (40 percent). Macular thinning was detected by OCT in 10 eyes of 7 children (33.3%). Flow voids at the deep retinal capillary plexus were detected by OCTA in 10 eyes of 7 children (33.3%). Longer disease duration, higher reticulocytic percent, more painful crises, and noncompliance with hydroxyurea medication were all linked to the existence of eye abnormalities on fundus examination and OCT.

CONCLUSION

OCTA can show early retinal damage in sickle cell patients with macular changes. Sickle cell retinopathy is usually associated with more severe disease.

Quantifying Areas of Vascular Leakage in Sickle Cell Retinopathy Using Standard and Widefield Fluorescein Angiography

BACKGROUND AND OBJECTIVE

To evaluate neovascular surface area change in sickle cell retinopathy following scatter photocoagulation treatment in wide- and standard-field fluorescein angiography (FA) scans using ImageJ software.

PATIENTS AND METHODS

Images of 11 patients with wide- or standard-field FA scans pre- and post-treatment for sickle cell retinopathy were evaluated retrospectively by two graders using ImageJ. Graders traced lesions in the late arteriovenous phase and calculated the lesion area and intensity relative to the optic disc. Changes in area and intensity pre- to post-treatment were assessed using dependent t-tests.

RESULTS

Pre- to post-treatment, lesion area decreased by 3.34 ± 2.43 to 3.66 ± 3.72 disc areas (P < .001), whereas intensity decreased by 11.36 ± 25.87 to 22.97 ± 69.25 units (P = .104). Neovascular area declined status post-aphotocoagulation by 3.83 ± 3.65 disc areas (P = .003) for widefield images and by 2.81 ± 3.55 discs areas (P = .034) for standard fluorescein images. No statistical difference in area reduction was appreciated between imaging modalities (P = .652) CONCLUSION: Neovascular area decreased significantly following scatter photocoagulation in both standard-field and widefield FA scans without an appreciable difference between imaging modalities. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:153-158.].

Acute Soft Head Syndrome (Subgaleal Haematoma) with Periorbital Oedema as a Rare Presentation in Sickle Cell Disease

Background

Sickle cell disease is a genetic condition frequently found in Africa and the Arabian Peninsula. Uncommon complications include subgaleal haematoma (soft head syndrome) and periorbital oedema.

Case presentation

A 17-year-old male patient presented with body aches and progressive right parieto-temporal and frontal head swelling. Physical examination revealed puffiness of the right eye that progressed rapidly to reddish periorbital oedema sparing the extraocular muscle and pupil response to light. CT and MRI of the brain suggested multiple subgaleal haematomas (soft head syndrome) and right periorbital oedema.

Conclusion

Subgaleal haematoma (soft head syndrome) and periorbital oedema are uncommon complications of sickle cell disease. Management is conservative rather than surgical.

LEARNING POINTS

Subgaleal haematoma concurrently with periorbital oedema is a rare presentation of sickle cell disease.There are no guidelines on treatment, but the conditions in our patient resolved with conservative management.

Optical coherence tomography (OCT) and OCT angiography allow early identification of sickle cell maculopathy in children and correlate it with systemic risk factors

PURPOSE

To determine the presence of sickle cell retinopathy and maculopathy and to identify associations between markers of hemolysis and systemic and ocular manifestations in children affected by sickle cell disease.

METHODS

Eighteen children with sickle cell disease, aged 5-16 years, underwent complete eye examination including best-corrected visual acuity, slit-lamp biomicroscopy, ophthalmoscopy after pharmacological mydriasis, spectral-domain optical coherence tomography (SD-OCT), and optical coherence tomography angiography (OCTA). Blood test results and clinical history information were collected for each child, including fetal hemoglobin (HbF), hemoglobin (Hb), hematocrit (Htc), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), reticulocytes percentage (%ret), lactic dehydrogenase (LDH), total and direct bilirubin, glomerular filtration rate, number of painful crises, acute chest syndromes, and splenic sequestration. Therapeutic regimen and transfusion therapy were also evaluated.

RESULTS

Sixteen of 36 eyes (44.4%) had non-proliferative sickle cell retinopathy on ophthalmoscopic evaluation. No patients had proliferative sickle cell retinopathy. In 13 of 36 eyes (36.1%), SD-OCT and OCTA detected signs of sickle cell maculopathy. Nine eyes (25%) presented sickle cell retinopathy and maculopathy, 7 eyes (19.4%) sickle cell retinopathy alone, and 4 eyes (11.1%) sickle cell maculopathy alone. A statistically significant association was found between sickle cell retinopathy; lower levels of HbF, Hb, and Htc; and higher MCV and percentage of reticulocytes. Sickle cell maculopathy was associated with lower values of H and Htc and higher levels of reticulocytes and total bilirubin.

CONCLUSIONS

We identified early signs of sickle cell retinopathy and maculopathy in a pediatric population with SD-OCT and OCTA. These two retinal complications were more frequent in children with higher hemolytic rates.

Recurrent orbital bone sub-periosteal hematoma in sickle cell disease: a case study

BACKGROUND

Sickle cell disease is a common inherited hemoglobinopathy and is associated with high morbidity and mortality. Vaso-occlusive crises commonly occur in individuals with SCD that results in high morbidity due to end-organ ischemia and infarction. These include splenic infarction, pulmonary involvement, acute chest syndrome, and orbital compression syndrome. Ocular manifestations of SCD include anterior segment ischemia, secondary glaucoma, angoid streaks, retinopathy, and retinal artery occlusion. Commonly reported causes for the incidence of sickle cell disease are extreme temperatures, wind speed, and rainfall. This study has conducted an investigation of recurrent orbital bone sub-periosteal hematoma in a sickle cell patient that was exposed to high altitude areas.

CASE PRESENTATION

A 12-year-old boy with SCD developed a recurrent sudden periorbital pain and swelling during a visit to high altitude area. The family reported two similar attacks previously. The patient recovered completely with timely initiated conservative treatment. The case study is about homozygous SCD with previous history of similar attack of painful periorbital swelling that resolved after conservative management. This condition was associated with proptosis, diplopia, and restriction of eye movement. Magnetic resonance imaging of the orbits showed right orbital roof subperiosteal mass adjacent to the orbital wall, which was identified as a subperiosteal haematoma, inducing proptosis. The patient was discharged after 7 days with follow up.

CONCLUSIONS

Infarction of orbital bones during vaso-occlusive crises in SCD presented acutely with a rapidly progressive painful periorbital swelling. Hematomas frequently complicate the condition, along with the inflammatory swelling that may lead to the orbital compression syndrome. The condition is sight-threatening and necessitates prompt diagnosis along with appropriate management. This condition mandates prompt initiation of conservative treatment and close monitoring of the optic nerve functions to prevent permanent visual loss in young patients.

Bilateral Subperiosteal Hematoma and Orbital Compression Syndrome in Sickle Cell Disease

A 14-year-old boy with sickle cell disease presented with preseptal cellulitis findings as proptosis, eyelid edema, and hyperemia. His best corrected visual acuity in the right eye was 20/20 and 16/20 in the left eye. He had limited ductions in vertical and lateral gazes in both eyes. Bilateral venous tortuosity was observed in posterior segment examination. Orbital bone infarction and subperiosteal hematoma were seen in magnetic resonance imaging. He was diagnosed as having orbital compression syndrome secondary to vaso-occlusive crisis of sickle cell disease and was treated with intravenous ampicilin-sulbactam and methylprednisolone.

New Ways to Detect Pediatric Sickle Cell Retinopathy: A Comprehensive Review

Sickle retinopathy reflects disease-related vascular injury of the eye, which can potentially result in visual loss from vitreous hemorrhage or retinal detachment. Here we review sickle retinopathy among children with sickle cell disease, describe the epidemiology, pediatric risk factors, pathophysiology, ocular findings, and treatment. Newer, more sensitive ophthalmological imaging modalities are available for retinal imaging, including ultra-widefield fluorescein angiography, spectral-domain optical coherence tomography, and optical coherence tomography angiography. Optical coherence tomography angiography provides a noninvasive view of retinal vascular layers that could previously not be imaged and can be quantified for comparative or prospective analyses. Ultra-widefield fluorescein angiography provides a more comprehensive view of the peripheral retina than traditional imaging techniques. Screening for retinopathy by standard fundoscopic imaging modalities detects a prevalence of approximately 10%. In contrast, these more sensitive methods allow for more sensitive examination that includes the retina perimeter where sickle retinopathy is often first detectable. Use of these new imaging modalities may detect a higher prevalence of early sickle pathology among children than has previously been reported. Earlier detection may help in better understanding the pathogenesis of sickle retinopathy and guide future screening and treatment paradigms.

Method for quantitative assessment of retinal vessel tortuosity in optical coherence tomography angiography applied to sickle cell retinopathy

Tortuosity is an important geometric vessel parameter and among the first microvascular alterations observed in various retinopathies. In the current study, a quantitative vessel tortuosity index (VTI) based on a combination of local and global centerline features is presented. Performance of VTI and previously established tortuosity indices were compared against human observers' evaluation of tortuosity. An image-processing pipeline was developed for application of VTI in retinal vessels imaged by optical coherence tomography angiography (OCTA) in perifoveal (6 mm × 6 mm) and parafoveal (3 mm × 3 mm) regions centered on the fovea. Forty-one subjects (12 healthy control (NC) and 29 sickle cell retinopathy (SCR)) and 10 subjects (5 NC and 5 SCR) were imaged in the perifoveal and parafoveal regions, respectively. The relationship between VTI and age was examined in the perifoveal regions in NC subjects. VTI was measured from the OCTA images and compared between NC and SCR subjects using generalized least square regression with and without adjusting for age and race. VTI was found to correlate better than the 4 previous indices with performance of human observers. In the perifoveal region, a significant correlation was observed between VTI and age (r = -0.4, P<0.001, N = 12). VTI was higher in SCR than NC subjects in perifoveal and parafoveal regions (P≤0.001). The results demonstrate that the proposed method shows promise for detection of increased tortuosity in vessels due to retinal disorders.

Laser therapy for retinopathy in sickle cell disease

BACKGROUND

Sickle cell disease includes a group of inherited haemoglobinopathies affecting multiple organs including the eyes. Some people with the disease develop ocular manifestations due to vaso-occlusion. Vision-threatening complications of sickle cell disease are mainly due to proliferative sickle retinopathy which is characterized by proliferation of new blood vessels. Laser photocoagulation is widely applicable in proliferative retinopathies such as proliferative sickle retinopathy and proliferative diabetic retinopathy. It is important to evaluate the efficacy and safety of laser photocoagulation in the treatment of proliferative sickle retinopathy to prevent sight-threatening complications.

OBJECTIVES

To evaluate the effectiveness of various techniques of laser photocoagulation therapy in sickle cell disease-related retinopathy.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Date of last search: 21 September 2015.We also searched the following resources (24 March 2015): Latin American and Carribean Health Science Literature Database (LILACS); WHO International Clinical Trials Registry Platforms (ICTRP); and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials comparing laser photocoagulation to no treatment in children and adults.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility, the risk of bias of the included trials and extracted and analysed data. We contacted the trial authors for additional information.

MAIN RESULTS

Two trials (341 eyes of 238 children and adults) were included comparing efficacy and safety of laser photocoagulation to no therapy in people with proliferative sickle retinopathy. There were 121 males and 117 females with an age range from 13 to 67 years. The laser photocoagulation technique used was different in the two trials; one single-centre trial employed sectoral scatter laser photocoagulation using an argon laser; and the second, two-centre trial, employed feeder vessel coagulation using argon laser in one centre and xenon arc in the second centre. The follow-up period ranged from a mean of 21 to 32 months in one trial and 42 to 47 months in the second. Both trials were at risk of selection bias (random sequence generation) because of the randomisation method employed for participants with bilateral disease. One study was considered to be at risk of reporting bias.Using sectoral scatter laser photocoagulation, one trial (174 eyes) reported that complete regression of proliferative sickle retinopathy was seen in 30.2% in the laser group and 22.4% in the control group (no difference between groups). The same trial reported the development of new proliferative sickle retinopathy in 34.3% of laser-treated eyes and in 41.3% of eyes given no treatment; again, there was no difference between treatment groups. The second trial, using feeder vessel coagulation, did not present full data for either treatment group for these outcomes.There was evidence from both trials (341 eyes) that laser photocoagulation using scatter laser or feeder vessel coagulation may prevent the loss of vision in eyes with proliferative sickle retinopathy (at median follow up of 21 to 47 months). Data from both trials indicated that laser treatment prevented the occurrence of vitreous haemorrhage with both argon and xenon laser; with the protective effect being greater with feeder vessel laser treatment compared to scatter photocoagulation.Regarding adverse effects, the incidence of retinal tear was minimal, with only one event reported. Combined data from both trials were available for 341 eyes; there was no difference between the laser and control arms for retinal detachment. In relation to choroidal neovascularization, treatment with xenon arc was found to be associated with a significantly higher risk, but visual loss related to this complication is uncommon with long-term follow up of three years or more.Data regarding quality of life and other adverse effects were not reported in the included trials.

AUTHORS' CONCLUSIONS

Our conclusions are based on the data from two trials conducted over 20 years ago. In the absence of further evidence, laser treatment for sickle cell disease-related retinopathy should be considered as a one of therapeutic options for preventing visual loss and vitreous haemorrhage. However, it does not appear to have a significant different effect on other clinical outcomes such as regression of proliferative sickle retinopathy and development of new ones. No evidence is available assessing efficacy in relation to patient-important outcomes (such as quality of life or the loss of a driving licence). There is limited evidence on safety, overall, scatter argon laser photocoagulation is superior in terms of adverse effects, although feeder vessel coagulation has a better effect in preventing vitreous haemorrhage. Further research is needed to examine the safety of laser treatment compared to other interventions such as intravitreal injection of anti-vascular endothelial growth factors. In addition, patient-important outcomes as well as cost-effectiveness should be addressed.

Beyond the definitions of the phenotypic complications of sickle cell disease: an update on management

The sickle hemoglobin is an abnormal hemoglobin due to point mutation (GAG → GTG) in exon 1 of the β globin gene resulting in the substitution of glutamic acid by valine at position 6 of the β globin polypeptide chain. Although the molecular lesion is a single-point mutation, the sickle gene is pleiotropic in nature causing multiple phenotypic expressions that constitute the various complications of sickle cell disease in general and sickle cell anemia in particular. The disease itself is chronic in nature but many of its complications are acute such as the recurrent acute painful crises (its hallmark), acute chest syndrome, and priapism. These complications vary considerably among patients, in the same patient with time, among countries and with age and sex. To date, there is no well-established consensus among providers on the management of the complications of sickle cell disease due in part to lack of evidence and in part to differences in the experience of providers. It is the aim of this paper to review available current approaches to manage the major complications of sickle cell disease. We hope that this will establish another preliminary forum among providers that may eventually lead the way to better outcomes.

Sickle cell disease: an opportunity for palliative care across the life span

Sickle cell disease is a chronic illness that affects patients physically and emotionally and can do so at an early age. An ecological model of palliative care that involves improved communication among the health care team, patients, and their families can be beneficial. Open and honest communication regarding advance care planning, disease management, relief of pain and other symptoms, and bereavement and grief are all important for the patient, family, and health care team. Given the multiple acute and chronic complications of sickle cell disease, an approach to care that is holistic and comprehensive may help to improve a patient's biologic function and the perceived health, functional status, and quality of life of the patient and family.

Health status and healthcare use in a national sample of children with sickle cell disease

BACKGROUND

There is a paucity of population-based data describing health status and use of health services among children with sickle cell disease (SCD).

PURPOSE

This study provides estimates of co-occurring conditions, health impact and utilization, and barriers to care for a national sample of children with SCD.

METHODS

Data were derived from the 1997-2005 National Health Interview Survey Child Sample Core. The study included 192 children aged 0-17 years with SCD whose race was reported as black or African-American, and 19,335 children without SCD of the same age and race. Parents or other knowledgeable adults reported on medical and developmental conditions, health status, and healthcare use and access.

RESULTS

After adjusting for demographic characteristics, black children with SCD had higher odds of frequent severe headaches or migraines, intellectual disabilities, regular use of prescription medication, and fair or poor health status compared with black children without SCD. While healthcare and special education services use were generally higher for black children with SCD than for black children in the general population, those with SCD also had higher odds of reporting delays in accessing health care.

CONCLUSIONS

The health burden for children with SCD and their families is profound and may be exacerbated by barriers to accessing comprehensive medical care. Additional study of the extent of unmet needs for U.S. children with SCD is warranted.