Natural history of untreated proliferative sickle retinopathy

Visual outcome of treating proliferative sickle cell retinopathy in 108 eyes

AIM

To report treatment methods and visual outcome of treating proliferative sickle cell retinopathy (PSCR).

DESIGN

Retrospective interventional.

METHODS

Review of PSCR eyes treated between 2017 to 2022. Patient demographics, fundus findings at presentation, genotype, PSCR stage, treatment used, and visual outcome were assessed.

RESULTS

108 eyes of 88 consecutive patients were studied. Male: Female 48:40. Mean age: 38.91 (SD:12.52) years. Genotype: sickle cell haemoglobin C (SC) 83 eyes (76.9%), sickle cell haemoglobin S (SS) 19 eyes (17.6%), and sickle cell trait (AS) 6 eyes (5.5%). PSCR stages: 3: 15 eyes (11.0%), 4: 74 eyes (67.0%), and 5: 19 eyes (22.0%). Treatment methods: Intravitreal Injection (IVI) of anti-vascular endothelial growth factor (VEGF) only (27 eyes,25%), scatter retinal laser photocoagulation (SRLP) only (7 eyes, 6.5%), Vitrectomy + SRLP (29 eyes, 26.9%), IVI + SRLP (25 eyes, 23.1%), and Vitrectomy + IVI + SRLP (20 eyes, 18.5%). The treatment used correlated with PSCR stage (p = 0.000). IVI only was mostly used to treat stage 4 (81.4%), and SRLP only was used for stages 3 (42.9%) and 5 (57.1%). IVI + SRLP treated eyes had the best pre- and post-treatment vision. Vitrectomy + SRLP treated eyes had the most improved vision. SRLP only had least visual improvement. Fundus findings correlated with visual outcome (p = 0.003); but stage of PSCR, genotype and treatment used had no correlation (P > 0.05).

CONCLUSION

Several options effectively treat PSCR. Visual outcome improved or remained same in 90.7% of treated eyes. Randomized controlled trials will determine the optimum treatment for each distinct presentation of PSCR. Treatment guidelines and a disease classification system of prognostic value are unmet needs.

Proliferative Sickle Cell Retinopathy: Outcomes of Vitreoretinal Surgery

PURPOSE

To report the clinical presentation and outcomes in patients who underwent surgery for proliferative sickle cell retinopathy (PSCR).

DESIGN

Retrospective, consecutive case series.

SUBJECTS

All patients who underwent vitreoretinal surgery for complications secondary to PSCR between January 1, 2014, and December 31, 2021, at a university referral center.

METHODS

Retrospective consecutive case series.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA), single operation anatomic success rate.

RESULTS

The study included 65 eyes of 61 patients. Disease distribution included 24 (44.4%) eyes with hemoglobin SC disease, 14 (25.9%) with hemoglobin SS disease, 13 (24.1%) with sickle cell trait, and 3 (5.6%) with sickle cell-β thalassemia. Preoperative transfusion was not performed in any study patients. Regional anesthesia with monitored anesthesia care (RA-MAC) was utilized in 58 (89.2%) eyes and general anesthesia in 7 (10.8%). In eyes that underwent surgery for retinal detachment (RD; N = 52) the rate of single operation anatomic success was 72.4% with combined scleral buckling/pars plana vitrectomy (SB/PPV; N = 29) compared with 47.8% with PPV alone (N = 23; P = 0.07). Mean BCVA at the last follow-up examination was 1.27 (20/372) in the SB/PPV group and 1.05 (20/226) in the PPV group (P = 0.48). In all SB cases, an encircling band was utilized and there were no known cases of anterior segment ischemia. All eyes that had surgery for vitreous hemorrhage (N = 13) underwent PPV with endolaser and mean BCVA improved from 1.67 (20/944) preoperatively to 0.45 (20/56) at last follow-up examination (P < 0.001). Mean preoperative BCVA, indication for surgery, single operation success rate, and mean BCVA at last follow-up examination did not differ based on sickle cell disease type (P > 0.05).

CONCLUSIONS

In patients with RD, SB/PPV achieved slightly higher rates of single operation anatomic success compared with PPV alone. Visual acuity outcomes were similar in the 2 groups. The majority of patients received RA-MAC anesthesia and preoperative transfusions were not performed. There were no cases of postoperative anterior segment ischemia. Hemoglobin SC disease was the most common disease type in the current study and surgical outcomes did not differ between sickle cell disease types.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Widefield oct-angiography-based classification of sickle cell retinopathy

PURPOSE

To assess the capillary non-perfusion in different concentric sectors on widefield optical coherence tomography angiography (WF-OCTA) and to correlate the ratio of non-perfusion (RNP) to the severity of sickle cell retinopathy (SCR).

METHODS

This retrospective, cross-sectional study included eyes of patients with various sickle cell disease (SCD) genotypes having undergone WF-OCTA and ultra-widefield color fundus photography (UWF-CFP). Eyes were grouped as no SCR, non-proliferative SCR or proliferative SCR. RNP was assessed on WF-OCTA montage in different field-of-view (FOV) sectors centered on the fovea: 0-10-degrees circle excluding the foveal avascular zone, the 10-30-degrees circle excluding the optic nerve, the 30-60-degrees circle, and the full 60-degrees circle.

RESULTS

Forty-two eyes of twenty-eight patients were included. Within each SCR group, mean RNP of the FOV 30-60 sector was higher than all other sectors (p < 0.05). Mean RNP of all sectors were significatively different between no SCR group and proliferative SCR group (p < 0.05). To distinguish no SCR versus non-proliferative SCR FOV 30-60 had a good sensitivity and specificity of 41.67% and 93.33%, respectively (cutoff RNP > 22.72%, AUC = 0.75, 95% CI 0.56-0.94, p = 0.028). To differentiate non-proliferative versus proliferative SCR, FOV 0-10 had good sensitivity and specificity of 33.33% and 91.67%, respectively (cutoff RNP > 18.09, AUC = 0.73, 95% CI 0.53 to 0.93, p = 0.041). To discern no SCR versus proliferative SCR, all sectors had optimal sensitivity and specificity (p < 0.05).

CONCLUSION

WF OCTA-based RNP provides non-invasive diagnostic information regarding the presence and severity of SCR, and correlates with disease stage in certain FOV sectors.

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.

Temporal macular thinning and vessel density correlation in children and young adults with sickle cell disease

Optical coherence tomography angiography (OCTA) is a recent noninvasive imaging technology that has proved to provide a comprehensive evaluation of retinal vascular abnormalities in adult patients with sickle cell disease (SCD). However, the pediatric population remains less studied. The purpose of this study is to evaluate the correlation between temporal vessel density (VD) in OCTA and temporal macular thinning in optical coherence tomography (OCT) in children and young adults with SCD. We reviewed medical records, OCT and OCTA (Spectralis®) scans from a sample of 32 eyes from 16 patients (7 female + 9 male) under 25 years old. The OCT macular thickness data and OCTA image data were processed using Python 3.9 programming language, and statistical analysis was performed. Pearson Correlation Coefficient between macular thickness and VD for inner and outer temporal areas was 0.47 (p-value = 0.006) and 0.74 (p-value < 0.001), respectively. A t-test was also performed to prove that there is a statistically significant VD difference in patients with higher and lower macular thickness (p < 0.001). These results show that children with outer temporal macular thinning on OCT have lower outer temporal VD on OCTA suggesting that microvascular insults may lead to chronic ischemic changes in the inner retinal layers.

Risk factors associated with sickle cell retinopathy: findings from the Cooperative Study of Sickle Cell Disease

Background

Sickle cell retinopathy (SCR) is one of the most important ocular manifestations of sickle cell disease (SCD). This study aims to assess the prevalence of SCR in SCD, identify risk factors for its development and progression to proliferative sickle cell retinopathy (PSCR), and evaluate the potential implications of these results on clinical practice.

Methods

This research is a secondary analysis of patients diagnosed with SCD from the epidemiological, multicenter Cooperative Study of Sickle Cell Disease (CSSCD). We included all patients who completed a full ophthalmic evaluation. We identified clinical and laboratory SCD characteristics associated with SCR using multivariate logistic regression models. Proliferative sickle cell retinopathy (PSCR) was diagnosed according to the Goldberg classification system.

Results

Of the 1904 study participants with SCD who met the inclusion criteria, 953 (50.1%) had retinopathy; of which 642 (67.3%) had bilateral disease. SCR was associated with older age (p < 0.001), history of smoking (p = 0.001), hematuria (p = 0.050), and a lower hemoglobin F (HbF) level (p < 0.001). PSCR risk increased with smoking (p = 0.005), older age (p < 0.001) higher hemoglobin level (p < 0.001) and higher white blood cell count (p = 0.011). Previous blood transfusion (p = 0.050), higher reticulocyte count (p = 0.019) and higher HbF level (p < 0.001) were protective factors against the development of PSCR. Ocular symptoms were associated with progression to PSCR in patients with SCR (p = 0.021).

Conclusion

In this cohort of individuals with SCD, half of the participants had signs of SCR. Smoking and blood hemoglobin level were the two modifiable risk factors associated with increased retinopathy progression. Screening to identify the different stages of retinopathy, actively promoting smoking cessation, and optimizing the hematological profile of patients with SCD should guide treatment protocols designed to prevent the vision-threatening complications of the disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40942-022-00419-8.

Salmon patch-associated vitreous hemorrhage in non-proliferative sickle cell retinopathy masquerading as infectious uveitis

PURPOSE

To report three cases of non-proliferative sickle cell retinopathy (NPSR) with vitreous hemorrhage masquerading as infectious uveitis.

OBSERVATIONS

Three patients were referred from ophthalmologists to our practices with clinical findings suggestive of infectious uveitis. The first patient was referred for new-onset floaters in both eyes, bilateral vitritis and dome-shaped lesions on B-scan ultrasound. He was initially treated for tuberculosis uveitis due to a positive purified protein derivative test. The second patient was referred with floaters and hazy vision in the setting of recent fever and headache and was also reported to have vitritis and unilateral yellow vitreoretinal lesions on fundoscopy. She was initially treated for toxoplasmosis and endogenous endophthalmitis. The third patient presented with flashes, floaters, and decreased vision four months after a ring-enhancing lesion was found on brain imaging, and was found to have unilateral vitritis with yellow vitreoretinal lesions. He was initially started on topical steroids and cycloplegics empirically for uveitis. All patients were ultimately diagnosed as having manifestations of NPSR, including vitreous hemorrhage, and dehemoglobinized salmon patch hemorrhages.

CONCLUSIONS AND IMPORTANCE

NPSR can occasionally masquerade as infectious uveitis. Obtaining a detailed history with relevant ancillary testing, along with performing a careful physical exam to recognize important clues, can help the physician arrive at the correct diagnosis in these equivocal cases.

Topographic Variation of Retinal Vascular Density in Normal Eyes Using Optical Coherence Tomography Angiography

Purpose

To establish a continuous topography of retinal vessel density in normal eyes using optical coherence tomography angiography (OCTA).

Methods

A retrospective chart review was performed, and 8-mm × 8-mm OCTA images from 22 normal eyes were analyzed. Vessel density was plotted as a continuous function of distance from the foveal center (radial vessel density) and directional meridians (directional vessel density) for the superficial capillary plexus and deep capillary plexus.

Results

Continuous radial and directional vessel density plots for the superficial and deep capillary plexus were generated. Radial vessel density analysis revealed transition points at 657 microns (95% confidence interval [CI], 619-696) and 950 microns (95% CI, 903-997) from the foveal center for the superficial plexus and deep plexus, respectively. Directional vessel density analysis demonstrated significant vessel density variations in these vascular layers and provided greater detail compared to traditional quadrant analysis.

Conclusions

There are significant topographic variations of retinal vessel density in normal eyes. Continuous vessel density analysis offers greater sensitivity in detecting topographic vessel density changes compared to traditional methods of analysis.

Translational Relevance

This study establishes a normative continuous vessel density topography that may help elucidate the role of the vascular bed in different chorioretinal diseases.

Hemoglobinopathies: ocular manifestations in children and adolescents

Hemoglobinopathies are genetic disorders that lead to abnormal structure of the hemoglobin molecule. Sickle cell disease, the most common inherited blood disorder, is characterized by defective oxygen transport. Almost every part of the eye can be affected by sickle cell disease; however, proliferative sickle cell retinopathy is the primary cause of vision loss, either from vitreous hemorrhage or retinal detachment. Here we review the various manifestations of hemoglobinopathies on the eyes of children and adolescents, with a specific focus on sickle cell disease and its different phenotypes. Newer, more sensitive ophthalmological imaging modalities, including ultra-widefield fluorescein angiography, spectral-domain optical coherence tomography, and optical coherence tomography angiography, are available. These sensitive modalities allow for a more thorough examination of the retinal periphery where sickle cell retinopathy is often present. Utilization of such modalities will help with the early detection of the disease in children, which provide a better understanding of the pathogenesis of the disease and guide future screening and treatment regimens.

Longitudinal assessment of quantitative ultra-widefield ischaemic and vascular parameters in sickle cell retinopathy

PURPOSE

To evaluate longitudinal quantitative ischaemic and vasculature parameters, including ischaemic index, vessel area, length and geodesic distance in sickle cell retinopathy (SCR) on ultra-widefield fluorescein angiography (UWFA).

METHODS

Optimal UWFA images from two longitudinal timepoints of 74 eyes from 45 patients with SCR were aligned and a common region of interest was determined. A deep-learning augmented ischaemia and vascular segmentation platform was used for feature extraction. Geodesic distance maps demonstrating the shortest distance within the vascular masks from the centre of the optic disc were created. Ischaemic index, vessel area, vessel length and geodesic distance were measured. Paired t-test and linear mixed effect model analysis were performed.

RESULTS

Overall, 25 (44 eyes) patients with HbSS, 14 (19 eyes) with HbSC, 6 (11 eyes) with HbSthal and other genotypes were included. Mean age was 40.1±11.0 years. Mean time interval between two UWFA studies was 23.0±15.1 months (range: 3-71.3). Mean panretinal ischaemic index increased from 10.0±7.2% to 10.9±7.3% (p<0.005). Mean rate of change in ischaemic index was 0.5±0.7% per year. Mean vessel area (p=0.020) and geodesic distance (p=0.048) decreased significantly. Multivariate analysis demonstrated baseline ischaemic index and Goldberg stage are correlated with progression.

CONCLUSION

Longitudinal ischaemic index and retinal vascular parameter measurements demonstrate statistically significant progression in SCR. The clinical significance of these relatively small magnitude changes remains unclear but may provide insights into the progression of retinal ischaemia in SCR.

Sickle Cell Maculopathy: Prevalence, Associations and Impact on Visual Acuity

AIMS

To investigate the prevalence of sickle cell maculopathy (SCM), and associations with age, sex, genotype, proliferative sickle cell retinopathy (PSR) stage, and the impact on visual acuity.

METHODS

Age, sex, and visual acuity were recorded and spectral domain OCT and ultra-wide-field images of the macula and retina were reviewed in a consecutive series of 74 adults with sickle cell disease.

RESULTS

The median age was 37 years (range 19-73 years) and 36 cases (48.6%) were male. SCM was present in at least 1 eye of 40 cases (54.1%) or in 67 of all eyes (42.3%). SCM prevalence was 54.8%, 62.5%, and 25% for the HbSS, HbSC, and HbS/BThal or other genotypes, respectively. SCM was observed in 41 (39.4%) of the eyes with PSR stages 0, 1, and 2, and in 21 (51.2%) of the eyes with PSR stages 3, 4, and 5, respectively. Mild visual impairment or worse was present in 3 eyes (4.8%) with SCM but this was secondary to other pathology.

CONCLUSION

SCM is a frequent finding in the eyes of adults with sickle cell disease. The prevalence is similar for the HbSS and HbSC genotypes and is not related to the PSR stage. High-contrast distance visual acuity is typically preserved.

Retinal ultra-wide-field colour imaging versus dilated fundus examination to screen for sickle cell retinopathy

PURPOSE

To compare ultra-wide-field colour fundus imaging (UWFI) to dilated fundus examination (DFE) for the screening of sickle cell retinopathy (SCR).

DESIGN

This study is a prospective, blinded, multicentre case series.

PARTICIPANTS

This study included two groups: an adult group (n=268 eyes) and a paediatric group (n=168 eyes). Sickle cell disease (SCD) types included haemoglobin S homozygous (HbSS), haemoglobin S and C (HbSC) and Hb S with β-thalassaemia (HbSß-Thal).

METHODS

Participants underwent DFE and UWFI. Each eye received three independent grades (1-4), documented by three graders: clinical grader, image grader 1 and image grader 2. Three clinically relevant diagnostic thresholds were determined. Based on these thresholds, the sensitivity, specificity, positive predictive value and negative predictive value for all three graders were calculated relative to each other as reference tests.

RESULTS

HbSC was associated with the most advanced SCR grades. When compared to the clinical grader, image grader 1 and image grader 2 consistently detected more SCR and higher SCR grades in both adult and paediatric groups. In both groups, image grader 1 and image grader 2 identified twice as many cases of capillary occlusion/anastomosis than clinical grader. To detect the presence of any proliferative SCR, image grader 1 and image grader 2 had a sensitivity of 82%, 71% in the paediatrics group and 90% and 72% in the adult group. The clinical grader sensitivity was 52% in the paediatrics group and 53% in the adult group.

CONCLUSION

The UWFI is a sensitive tool to screen for SCR. It is superior to DFE in detecting capillary occlusion or anastomosis.

Hemoglobin S/OArab: Retinal Manifestations of a Rare Hemoglobinopathy

Hemoglobin S/O_Arab (Hgb S/O_Arab) disease is a rare hemoglobinopathy which presents similarly to sickle cell retinopathy, with only three prior reports that describe associated retinal findings. In this report, we present ophthalmic examination findings in 2 patients with Hgb S/O_Arab. One patient exhibited peripheral ischemia and sunburst lesions without neovascular disease, and the other patient developed proliferative retinopathy of both eyes and multiple posterior-pole branch retinal artery occlusions in one eye. To our knowledge, this is the first case of retinal arterial occlusive disease in Hgb S/O_Arab, and the first report of fundus autofluorescence and OCT angiography in Hgb/O_Arab retinopathy.

Interocular asymmetry of foveal avascular zone morphology and parafoveal capillary density in sickle cell retinopathy

OBJECTIVES

To examine interocular asymmetry of foveal avascular zone (FAZ) and parafoveal capillary density metrics in sickle cell retinopathy (SCR) using optical coherence tomography angiography (OCT-A).

METHODS

This cross-sectional, retrospective study evaluated SCR patients and unaffected controls who underwent 3x3mm macular OCT-A imaging using a spectral domain-OCT system. FAZ (area, perimeter, and acircularity index) and parafoveal capillary density metrics were computed for both eyes of each participant. In unaffected controls, interocular difference in FAZ and parafoveal capillary density metrics were evaluated using Bland-Altman plots. SCR patients with interocular difference outside the upper 97.5% and lower 2.5% limits of agreement from controls were defined as having interocular asymmetry. Area under receiver operating characteristic curve (AROC) was also performed to determine the ability of the absolute interocular difference to differentiate between subjects with SCR-including non-proliferative SCR (NP-SCR) and proliferative SCR (P-SCR)-and unaffected controls.

RESULTS

Thirty-one patients with SCR (21 NP-SCR and 10 P-SCR) and 14 race-matched and age-matched controls were included for analysis. Interocular asymmetry was seen for all FAZ and parafoveal capillary density metrics in NP-SCR and P-SCR subjects. SCR subjects showed greater disease severity in the left-eye for FAZ and parafoveal capillary density metrics.

CONCLUSIONS

NP-SCR and P-SCR patients demonstrated quantifiable interocular asymmetry in FAZ and parafoveal capillary density metrics compared to unaffected subjects, with left-eye predominance in disease severity.

Sensitivity and Specificity of Ultrawide-Field Fundus Photography for the Staging of Sickle Cell Retinopathy in Real-Life Practice at Varying Expertise Level

Purpose: To evaluate the sensitivity and specificity of ultrawide-field fundus photography (UWF-FP) for the detection and classification of sickle cell retinopathy (SCR) by ophthalmologists with varying degrees of expertise in retinal disease. Methods: Patients presenting with sickle cell disease (SCD) in the Créteil University Eye Clinic, having undergone UWF-FP and ultrawide-field fluorescein angiography (UWF-FA) on the same day, were retrospectively included. Eyes with previous retinal photocoagulation were excluded. SCR was graded independently by UWF-FP and UWF-FA using Goldberg classification by two ophthalmologists with varying expertise levels. Results: Sixty-six eyes of 33 patients were included in the study. The sensitivity of UWF-FP for the detection of proliferative SCR was 100%, (95% confidence interval [CI95%] 76.8–100) for the retinal specialist and 100% (CI95% 71.5–100) for the ophthalmology resident. The specificity of UWF-FP for the detection of proliferative SCR was 100% (CI95% 92.7–100) for the retinal specialist and 98.1% (CI95% 89.7–100) for the ophthalmology resident. Conclusions: UWF-FP is a valuable exam for proliferative SCR screening, with excellent sensitivity and specificity and a good inter-grader agreement for ophthalmologists with various degree of skills, and is easy to use in a real-life setting.

Longitudinal Study of Peripapillary Thinning in Sickle Cell Hemoglobinopathies

PURPOSE

To determine the rate of retinal nerve fiber layer (RNFL) thinning in patients with sickle cell hemoglobinopathies.

DESIGN

This was a prospective cohort study.

METHODS

Sixty-seven patients averaging 35.8 ± 11.5 years of age at enrollment with electrophoretically confirmed sickle cell hemoglobinopathies followed by the University of Illinois at Chicago retina clinic for ≥1 year were included. Exclusion criteria included a history of diabetes, uncontrolled hypertension, glaucoma, ocular opacities, other retinopathies, and previous retinal procedures. The optic nerve head RNFL thicknesses were measured with spectral-domain optical coherence tomography (Heidelberg Engineering, Inc) at enrollment and subsequent follow-ups. Linear mixed models were used to estimate rates of thinning.

RESULTS

A total of 122 eyes were followed for 3.8 ± 2.0 years (range 1-8 years). Mean global peripapillary RNFL thickness was 100.9 ± 13.0 μm at baseline. Global peripapillary RNFL thickness decreased at a rate of 0.98 μm per year (95% confidence interval [CI] 0.77-1.19 μm/year). A history of stroke was associated with a faster rate of global RNFL thinning (1.72 ± 0.20 vs 0.79 ± 0.12 μm/year, P < .001), whereas a history of hypertension was associated with a slower rate of thinning (0.33 ± 0.27 vs 1.14 ± 0.12 μm/year, P = .002).

CONCLUSIONS

Peripapillary RNFL thinning in patients with sickle cell hemoglobinopathies occurred faster in patients with a history of stroke and slower in patients with controlled hypertension. Future studies will compare these rates to those of healthy age- and race-matched individuals.

Sickle cell disease: Clinical presentation and management of a global health challenge

Sickle cell disease is an autosomal recessive, multisystem disorder, characterised by chronic haemolytic anaemia, painful episodes of vaso-occlusion, progressive organ failure and a reduced life expectancy. Sickle cell disease is the most common monogenetic disease, with millions affected worldwide. In well-resourced countries, comprehensive care programs have increased life expectancy of sickle cell disease patients, with almost all infants surviving into adulthood. Therapeutic options for sickle cell disease patients are however, still scarce. Predictors of sickle cell disease severity and a better understanding of pathophysiology and (epi)genetic modifiers are warranted and could lead to more precise management and treatment. This review provides an extensive summary of the pathophysiology and management of sickle cell disease and encompasses the characteristics, complications and current and future treatment options of the disease.

Clinical and Ophthalmic Factors Associated With the Severity of Sickle Cell Retinopathy

PURPOSE

To identify associations between severity of sickle cell retinopathy (SCR) and other clinical, laboratory, or treatment factors relevant to sickle cell disease (SCD).

DESIGN

Retrospective cohort study.

METHODS

We investigated clinical, laboratory, and demographic associations with the severity of SCR in 296 patients seen at both our SCD specialty clinic and our retina clinic. Multivariate multinomial logistic regression was used to estimate the association between each clinical variable and severity of SCR.

RESULTS

Multivariate analysis showed that in patients with sickle cell anemia (SCA) genotypes, older age (95% confidence interval [CI], 1.04-1.15; P < .001) and male sex (95% CI, 0.13-0.87; P = .02) were associated with proliferative sickle cell retinopathy (PSR). In patients with genotypic variants, visual symptoms (95% CI, 1.36-21.62; P = .02) were associated with PSR. Laser photocoagulation and vitrectomy surgery, the standard interventions for PSR, were associated with older age (95% CI, 1.05-1.13; P < .001), visual symptoms (95% CI, 1.48-7.40; P = .004), higher hemoglobin level (95% CI, 1.14-1.65; P = .001), and no chronic transfusion (95% CI, 0.16-1.09; P = .08) across the whole cohort.

CONCLUSIONS

These findings may inform clinicians of the symptoms, systemic findings, and disease-modifying therapies most frequently associated with SCR in SCD patients. Visual symptoms such as blurred vision or floaters were associated with progression of SCR and may be criteria for referral for retinal examination. Chronic transfusion therapy may be protective against the need for retinal laser photocoagulation or vitrectomy. Prospective studies are necessary to further explore risk factors for SCR and to identify which individuals with SCD are at risk for incident or progression of retinopathy.

The past, present and future management of sickle cell retinopathy within an African context

Sickle cell retinopathy is a potentially blinding condition that affects young people in the working age group. This review looks at the past, present and future management of sickle cell retinopathy within an African context. After Sickle cell disease was first reported in 1910, some reports from Africa were pivotal in describing the retinal changes associated with the disease. It soon became obvious that there was a varied clinical picture and clinical course. Several landmark studies were carried out in Jamaica to help elucidate the complexities of the disease and outline appropriate clinical management. In most of the developed world, the clinical management of sickle cell disease has improved with concurrent improvement in outcomes. Currently resource constraints in most Sub-Saharan African countries where there is a high burden of disease means that the management of sickle cell retinopathy is fraught with numerous challenges. Future large scale trials in Africa shall hopefully help to better elucidate the mechanisms behind proliferative sickle retinopathy and help in the development of new and improved therapeutic pathways. The use of technology can help immensely in the screening of patients with sickle cell to detect early proliferative changes and if necessary treat accordingly.

Retinal Photocoagulation for Proliferative Sickle Cell Retinopathy: A Prospective Clinical Trial with New Sea Fan Classification

Purpose

To compare the clinical outcome of stage III proliferative sickle cell retinopathy (PSR) treated by peripheral retinal scatter photocoagulation to natural course disease.

Methods

Long-term follow-up of 101 patients enrolled in a prospective trial of photocoagulation for PSR has been completed. Among 202 eyes of 101 patients enrolled at the University Eye Clinic of Créteil, 73 eyes showed a stage III PSR, which the authors further divided into five new grades (A, B, C, D, E) considering size, hemorrhage, fibrosis, and visible vessels. Grading was based on a three-mirror fundus examination, 360° color photographs, and fluorescein angiography. Mean follow-up was 4 years.

Results

Thirty-eight treated eyes and 35 untreated eyes were included in this study. The evolution was not statistically significant between treated and untreated groups concerning flat sea fan p<1 MPS disc area (grade A) or elevated sea fan with partial fibrosis (grade C). Progression and regression were compared between the two groups for grade B, resulting statistically significant (pp<0.05). Nine complications (13%) were observed, which only occurred in untreated patients with elevated sea fan and hemorrhage (grade B) or complete fibrosed sea fan with well defined vessels (grade E) (pp<0.05).

Conclusions

These data suggest that patients with grade A or C new sea fan classification should not be initially treated but observed.

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.

Optical Coherence Tomography Angiography and Ultra-widefield Fluorescein Angiography for Early Detection of Adolescent Sickle Retinopathy

PURPOSE

Based on standard screening techniques, sickle retinopathy reportedly occurs in 10% of adolescents with sickle cell disease (SCD). We performed a prospective, observational clinical study to determine if ultra-widefield fluorescein angiography (UWFA), spectral-domain optical coherence tomography (SD-OCT), and optical coherence tomography angiography (OCT-A) detect more-frequent retinopathy in adolescents with SCD.

DESIGN

Cross-sectional study.

METHODS

Setting: Institutional.

SUBJECTS

Sixteen adolescents with SCD, aged 10-19 years (mean age 14.9 years), and 5 age-equivalent controls (mean age 17.4 years).

OBSERVATION PROCEDURES

Examinations including acuity, standard slit-lamp biomicroscopy, UWFA, SD-OCT, and OCT-A were performed.

MAIN OUTCOME MEASURES

Sickle retinopathy defined by biomicroscopic changes, Goldberg stages I-V, Penman scale, flow void on OCT-A, or macular thinning on SD-OCT.

RESULTS

While 22 of 32 SCD eyes (68.8%) had retinopathy on biomicroscopy, by UWFA 4 of 24 (16.7%) SCD eyes had peripheral arterial occlusion (Goldberg I), and 20 of 24 eyes (83.3%) had peripheral arteriovenous anastomoses (Goldberg II) in addition. No patients had Goldberg stages III-V. By SD-OCT and OCT-A, thinning of the macula and flow voids in both the superficial and deep retinal capillary plexus were found in 6 of 30 (20%) eyes.

CONCLUSIONS

All 24 eyes with adequate UWFA studies demonstrated sickle retinopathy. SD-OCT and OCT-A, which have not been previously reported in the adolescent population, detected abnormal macular thinning and flow abnormalities undetected by biomicroscopy. These findings suggest that pediatric sickle retinopathy may be more prevalent than previously suspected. If these findings are confirmed with larger cross-sectional and prospective analyses, these approaches may enhance early screening for sickle retinopathy.

Sickle cell disease and the eye

PURPOSE OF REVIEW

To review recent literature pertaining to sickle cell retinopathy (SCR) and, in particular, sickle cell maculopathy.

RECENT FINDINGS

Several recent studies suggest that macular perfusion abnormalities seen in patients with sickle cell disease of various genotypes may affect both the superficial and deep capillary plexi, with a predilection for the deep capillary plexus. Further, these changes may be associated with areas of macular thinning, as well as with peripheral retinal ischemia, even in individuals without visual symptoms, contrary to what has previously been described in both diabetic retinopathy and retinal vein occlusion. Several cases also suggest that paracentral acute middle maculopathy may be the pathophysiologic mechanism by which microvascular occlusion leads to macular thinning.

SUMMARY

Sickle cell disease can manifest in a number of ways within the orbit as well as intraocularly because of its nonspecific vasoocclusive episodes. However, SCR is the most common ophthalmic manifestation of this disease. Historically, SCR has been considered a peripheral retinopathy, but the development and use of spectral-domain optical coherence tomography and optical coherence tomography angiography suggest that significant macular vascular changes occur early in this disease, even in asymptomatic individuals.

Evaluation of Macular Vascular Abnormalities Identified by Optical Coherence Tomography Angiography in Sickle Cell Disease

PURPOSE

To evaluate macular vascular flow abnormalities identified by optical coherence tomography angiography (OCT-A) in patients with various sickle cell genotypes.

DESIGN

Prospective, observational case series.

METHODS

This is a single-institution case series of adult patients with various sickle cell genotypes. All patients underwent macular OCT-A (Avanti RTVue XR). Images were analyzed qualitatively for areas of flow loss and quantitatively for measures of foveal avascular area, parafoveal flow, and vascular density. The findings were compared by sickle cell genotype and retinopathy stage and correlated to retinal thickness and visual acuity.

RESULTS

OCT-A scans of 82 eyes from 46 patients (60.9% female, mean age 33.5 years) were included. Sickle cell genotypes included 27 patients with hemoglobin SS (58.7%), 14 SC (30.4%), 4 beta-thalassemia (8.7%), and 1 sickle trait (2.2%). Discrete areas of flow loss were noted in 37.8% (31/82) of eyes overall and were common in both SS (40.0%, 20/50 eyes) and SC (41.7%, 10/24 eyes). Flow loss was more extensive in the temporal and nasal parafoveal subfields of the deep plexus with sickle SC or proliferative retinopathy. Retinal thickness measurements correlated with vascular density of the fovea, parafovea, and temporal and superior subfields. Visual acuity correlated with foveal avascular zone area and parafoveal vascular density in the superficial and deep plexi.

CONCLUSIONS

Areas of abnormal macular vascular flow are common in patients with various sickle cell genotypes. These areas may be seen at any retinopathy stage but may be more extensive with sickle SC or proliferative retinopathy.

Temporal Macular Atrophy as a Predictor of Neovascularization in Sickle Cell Retinopathy

BACKGROUND AND OBJECTIVE

To evaluate the association between temporal macular atrophy and the presence of neovascularization in eyes with sickle cell disease (SCD).

PATIENTS AND METHODS

Retrospective, case-controlled study identifying 64 eyes from 38 consecutive patients with SCD. Dilated funduscopic examination and wide-field fluorescein angiography were used to identify the Goldberg stage of proliferative sickle cell retinopathy. Spectral-domain optical coherence tomography images were analyzed for the presence of temporal macular atrophy. The association between temporal macular atrophy and neovascularization was then evaluated.

RESULTS

Temporal macular atrophy had a sensitivity of 27%, a specificity of 67%, a positive predictive value of 83%, and a negative predictive value of 13% for identifying neovascularization.

CONCLUSION

Although the presence of temporal macular atrophy is not sensitive enough to be used as a screening test, if seen in a patient with SCD, the physician should be alerted to the strong possibility that peripheral neovascularization may be present.

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.

Cohort study of adult patients with haemoglobin SC disease: clinical characteristics and predictors of mortality

Haemoglobin (Hb) SC disease is the second most common subtype of sickle cell disease and is potentially fatal. This study aimed to determine the clinical characteristics, outcome and predictors of mortality in HbSC disease patients, and to compare these findings with patients followed-up in different centres. Clinical, laboratory and outcome data were collected from a cohort of adult patients with HbSC disease followed between 1991 and 2103. Cox regression multivariate analysis was used to determine predictors of mortality. One hundred and fifty-five patients were followed-up over 20 years: 9% died and 70·8% had at least one complication. The most common complications were: painful crises (38·3%), retinopathy (33·8%), cholelithiasis (30·3%), osteonecrosis (24·8%) and sensorineural hearing disorders (9·7%). Frequency of chronic complications was similar in most studies. In multivariate analysis, hearing disorders remained an independent predictor of mortality (Odds Ratio 9·26, 95% confidence interval 1·1-74·8; P = 0·03). It was concluded that patients with HbSC disease receive a late diagnosis and there is remarkable similarity between the studies conducted in different centres around the world. Sensorineural hearing disorders were an independent predictor of mortality, suggesting that it may be useful to implement routine diagnostic screening.

Vitreoretinal management and surgical outcomes in proliferative sickle retinopathy: a case series

PURPOSE

To report the outcomes of current vitreoretinal surgical management of proliferative sickle retinopathy and to compare current methods to previous studies.

DESIGN

A retrospective, interventional case series.

METHODS

Fifteen eyes of 14 patients with proliferative sickle retinopathy were managed with vitreoretinal surgery over a 12-year period at a single institution.

RESULTS

Nine patients had a sickle cell-hemoglobin C (SC) profile, 1 was sickle cell-beta(+) thalassemia (S beta(+)-thal), and 4 were sickle cell trait (AS). All 15 eyes underwent pars plana vitrectomy (PPV): 6 for vitreous hemorrhage (VH), 1 for epiretinal membrane (ERM), and an additional 8 for tractional retinal detachment (RD) and/or rhegmatogenous RD. In addition, an encircling scleral buckle (SB) was used in 2 cases. In 7 cases, 20 gauge PPV was used; 23 gauge was used in 3; and 25 gauge was used in 5. All 7 eyes with VH or ERM had improved vision postoperatively. Four of the 8 patients with traction and/or rhegmatogenous RD developed recurrent detachments and required a second operation. All retinas were attached at last follow-up, and visual acuity was 20/400 or better in all eyes. No cases of anterior segment ischemia were encountered.

CONCLUSIONS

Anterior segment ischemia is no longer a common occurrence in eyes undergoing surgery for proliferative sickle retinopathy. Although PPV has replaced the use of SB in many situations, an encircling SB may still be used in this population when necessary. Surgery for VH and ERM generally results in favorable outcomes, but eyes undergoing surgery for traction/rhegmatogenous RD carry a more guarded prognosis.

Sickle cell disease, vasculopathy, and therapeutics

Sickle cell disease (SCD) is caused by a mutation in both beta globin genes, resulting in chronic hemolysis and multiorgan disease that ultimately leads to premature death. Although hemoglobin S (HbS) polymerization and vaso-occlusion are central to the pathogenesis of SCD, overlapping pathways implicated in SCD-related endothelial dysfunction include hemolysis, defects in nitric oxide metabolism, ischemia-reperfusion injury, oxidative stress, increased cell-to-cell adhesion, and proinflammatory and coagulation mediators. Progression of organ-specific vasculopathy often precedes organ dysfunction and may provide targets for therapeutic intervention. SCD-related vasculopathies include, but are not limited to, moyamoya that often precedes cerebral infarcts or hemorrhage, proliferative retinopathy prior to loss of eyesight, pulmonary vasculopathy associated with pulmonary hypertension, and renal vasculopathy prior to the onset of chronic renal disease. This review evaluates evidence that SCD vasculopathy is a harbinger for organ dysfunction and reviews the potential for targeted antivasculopathy therapies.

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.

The eye in haematological disease

The eye allows living functioning blood vessels to be observed and is thus ideal for the study of haematological disease. Disorders of the blood have significant ocular manifestations and pose a real threat to vision, making knowledge of the subject essential to ophthalmologists, haematologists, oncologists and general physicians.

Clinical and laboratory factors associated with the severity of proliferative sickle cell retinopathy in patients with sickle cell hemoglobin C (SC) and homozygous sickle cell (SS) disease

Proliferative sickle cell retinopathy (PSCR) is the most frequent vision-threatening complication of sickle cell disease (SCD). We investigated the relationship between the severity of sickle cell retinopathy in heterozygous (SC) or homozygous (SS) adult SCD patients and the clinical and laboratory data obtained during visits to a national SCD referral center. This retrospective longitudinal analysis included 942 SCD patients (313 patients with SC and 629 with SS disease) with ophthalmologic evaluations who were followed over a 19-year period by a multidisciplinary team in a referral center. PSCR was graded using the Goldberg classification. We identified patient and SCD characteristics associated with sickle cell retinopathy severity using multinomial logistic-regression models. Multivariate analysis associated severe PSCR forms (stages III-V) with older age (p=0.032), pulmonary involvement (documented pulmonary hypertension with pulmonary arterial pressure≥40 mm Hg, restrictive syndrome>20%, or previous history of pulmonary embolism diagnosed by vascular imaging) (p=0.029), deafness or tinnitus (p=0.026), and no history of osteomyelitis (p=0.013) for SC patients; and with older age (p<0.001), male sex (p=0.003), and acute pyelonephritis (p=0.04) for SS patients. The model of severe PSCR versus no PSCR showed good calibration and discrimination for SC and SS patients. Awareness of the clinical and laboratory factors significantly associated with severe PSCR in patients with SC or SS SCD may contribute to improved preventive strategies.

Pediatric sickle cell retinopathy: correlation with clinical factors

BACKGROUND

Sickle cell disease (SCD) occurs in 1 of every 500 African American births and 1 of every 36,000 Hispanic American births. Of children with SCD, 16.7% to 96.3% develop sickle retinopathy (SR). This study was designed to determine whether certain factors are associated with SR and whether SR is correlated with a greater incidence of other SCD manifestations.

METHODS

A retrospective analysis was performed of 258 children with SCD seen in the ophthalmology clinic at a large urban children's hospital. Of these, 54 children with SR were matched for age and sickle variant with 54 children with normal examinations. Data extracted included demographics, type of retinopathy, presence of glucose-6-phosphate dehydrogenase (G6PD) deficiency, and history of acute chest syndrome, transfusions, pulmonary hypertension, renal disease, cerebrovascular accident, aplastic crisis, splenic sequestration, priapism, osteonecrosis, gallstones, pneumonia, leg ulcers, vaso-occlusive pain crises, and death.

RESULTS

Of the children with SR, 11 (20.3%) had active proliferative disease, 32 (56.1%) had hemoglobin SS, 18 (31.6%) had hemoglobin SC, and 4 (7.0%) had hemoglobin S-beta thalassemia. Several factors were correlated with retinopathy: pain crisis (odds ratio [OR], 5.00; p=0.011), male sex (OR, 4.20, p=0.004), and splenic sequestration (OR, 4.00; p=0.013). G6PD deficiency was more common in patients with retinopathy, although this was not statistically significant (OR, 4.20; p=0.054). No other factors, including frequency of pain crisis, were statistically significant.

CONCLUSIONS

Patients with pain crisis and splenic sequestration should be considered for early ophthalmic evaluation. Those with G6PD deficiency may also deserve early screening. By identifying patients at high risk for SR, we can refine screening protocols to safeguard patients from vision loss.

[Epidemiology and prognostic factors for sickle cell retinopathy in Ouagadougou (Burkina Faso)]

INTRODUCTION

The frequency of sickle cell disease varies from 5% to 20% in Africa.

PATIENTS AND METHOD

This retrospective study investigated 173 patients in an ambulatory setting from August 2000 to July 2006. The study included 98 women and 75 men, aged 15-62 years, with a mean age of 26.7 years.

RESULTS

Only 89 patients (71 SC and 18 SS) were seen in ophthalmology, 44 (49%) had sickle cell retinopathy with 26 (29%) cases nonproliferative and 18 cases proliferative (20%). Among the 71 SC patients, 35 (50%) had sickle cell retinopathy, with 40% the proliferative form. Of the 18 SS patients, nine had a retinopathy (50%), with four cases proliferative.

DISCUSSION

Retinopathy is a frequent complication of sickle cell disease, which can lead to blindness, and its management better accessibility to the ophthalmologic examination and preventive treatment by laser photo coagulation.

[Sickle cell beta-thalassemia leading to serious ischemic retinopathy: a study of 18 patients in Abidjan]

The authors in this study intended to demonstrate that S-beta thalassemia can lead to severe ocular hemorrhagic risks, as is true of the sickle cell form. Both forms are also comparable in terms of the risk of aseptic necrosis of the femoral head. Out of the 18 patients studied, 13 (72.2%) had sickle cell retinopathy. Three of 13 patients had already developed new vessels and risked intravitreous hemorrhage. The authors recommend that more vigilance be mounted for the detection of S-beta thalassemia so as to benefit from rigorous and systematic follow-up and early treatment. Retinal argon laser photocoagulation is only effective if a clear diagnosis is made early.

Risk factors for conjunctival and retinal vessel alterations in sickle cell disease

PURPOSE

The aim of this study was to clarify whether the clinical, laboratory and genetic aspects of sickle cell disease (SCD) influence the occurrence of vessel alterations in the conjunctiva and retina.

METHODS

A total of 102 SCD patients underwent biomicroscopical and retinal examination, in addition to evaluations of haemoglobin (Hb) and haematocrit (Ht) levels, fetal haemoglobin (HbF) estimations, serum creatinine and albuminuria levels, glomerular filtration rate (GFR) values, phenotypes, beta-globin gene haplotypes and alpha-thalassaemia. The relationship between ocular vessel alterations and clinical, laboratory and genetic features were evaluated using chi-squared or Fisher tests and logistic regression analysis. In 13 patients on enalapril treatment, a second ophthalmological evaluation was performed after a 12-month period to evaluate the longitudinal effect of the drug on ocular vessels.

RESULTS

Conjunctival vessel alteration (CVA) was not influenced by age, gender, HbF estimation, serum creatinine and albuminuria levels, GFR values, beta-globin gene haplotypes or alpha-thalassaemia. However, increased frequencies of CVA were found in patients with Hb </= 9.0 g/dl, Ht </= 26.7% and sickle cell anaemia (SS) phenotype. Retinal vessel alteration (RVA) was identified only in patients aged 17 years or older. Enalapril did not demonstrate ocular vessel amelioration after 12-months of daily use.

CONCLUSION

The results indicate that lower Hb and Ht levels and SS phenotype are risk factors for CVA, and age over 17 years may be risk factors for RVA in SCD patients.