Review Article

Corneal neurotization: a narrative review of techniques, outcomes, and surgical considerations

:22-33
 
Background and Objective: Corneal neurotization is a novel surgical technique used to restore corneal sensation in patients with neurotrophic keratopathy. Neurotrophic keratopathy is a disorder characterized by dysfunction of the ophthalmic division of the trigeminal nerve, which provides sensory innervation to the cornea. Without sensation, the cornea is at risk of infection, ulceration, perforation, and ultimately, vision loss. Corneal neurotization has emerged as an innovative technique to reinnervate anesthetized corneas by transferring a healthy donor nerve to the affected eye around the corneoscleral limbus. As the field of corneal neurotization rapidly grows, there is a need to synthesize the existing body of literature on corneal neurotization and identify important areas for further research. In this review, we will discuss neurotrophic keratopathy and its current management strategies, followed by an overview of corneal neurotization techniques, outcomes, surgical considerations, and future directions. Methods: PubMed and Google Scholar searches were conducted to retrieve and analyze relevant original papers and reviews on neurotrophic keratopathy and corneal neurotization up until April 2022.Key Content and Findings: Currently, numerous techniques for corneal neurotization exist, including direct nerve transfers, as well as indirect neurotization via interposition nerve grafts. So far, corneal neurotization has been shown to be highly successful in restoring corneal sensation, improving visual acuity,and improving corneal epithelial health. To date, there have been no significant differences in outcomes between direct versus indirect neurotization techniques, different donor nerves, or autologous versus allogeneic interposition grafts. However, there is some evidence that corneal neurotization procedures may be more successful in pediatric patients.Conclusions: Corneal neurotization shows great promise in treating neurotrophic corneas and represents the first management option to date that addresses the underlying pathophysiological mechanism of neurotrophic keratopathy by restoring corneal sensation. As the use of corneal neurotization continues to broaden, additional studies will become important to compare techniques in a systematic manner, with larger sample sizes, as well as standardized outcome measures and follow-up time.
Editorial
Original Article

Comparison of ocular biometry in Chinese patients using two swept-source optical coherence tomography devices

:22-77
 
Background: To compare two swept-source optical coherence tomography (SS-OCT) biometers,IOLMaster 700 and ANTERION.
Methods: This is a retrospective study. Biometric measurements of cataract patients performed between March and July 2021 in the Department of Ophthalmology, United Christian Hospital, Hong Kong, were reviewed. Patients scheduled for cataract surgery were measured with both SS-OCT devices on the same day.The following biometry parameters were compared: keratometry (K), total keratometry (TK), axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), white-to-white (WTW) and the predicted intraocular lens (IOL) power to achieve emmetropia. To assess the agreement between the devices, Bland-Altman analysis with 95% limits of agreement (LoA) were used.
Results: In total, 92 eyes of 47 subjects were measured with both devices. There were statistically significant differences between the two biometers for most measurements (P<0.05) except for flat K, AL and IOL power when using the right eyes for analysis. For the left eyes, there were statistically significant differences in the measurements from the two biometers in all parameters except for flat and steep K. The ANTERION did not obtain ACD, AL and LT in 2 (2.17%), 1 (1.09%) and 5 cases (5.43%) respectively.
Conclusions: The two biometers showed a clinically acceptable agreement in most parameters. Comparisons showed significant differences in most parameters but not clinically relevant except for the TK and WTW, and these two parameters should not be used interchangeably between the devices.
Review Article

Pregnancy and diabetic retinopathy—considerations for evaluation and treatment: a review

:22-82
 
The prevalence of diabetic retinopathy (DR) continues to increase in pregnant females; these individuals are also at a higher risk of disease progression. The lack of evidence regarding the safety and efficacy of current treatment options in pregnancy makes disease management particularly challenging.All pregnant women with diabetes should have a prenatal DR screening, as well as receive counseling regarding the progression and management of DR during pregnancy. Optimal blood glucose and blood pressure control should be encouraged. For patients with proliferative diabetic retinopathy (PDR) in the absence of visually significant diabetic macular edema (DME), panretinal photocoagulation (PRP) remains a safe and effective treatment option. Visually significant DME can be treated with focal laser if areas of focal leakage are identified in the macula on fluorescein angiogram, intravitreal steroids or anti-vascular endothelial growth factor (VEGF) agents, The theoretical risk of anti-VEGF agents to the fetus should be considered and the patients should be extensively counselled regarding the risks and benefits of initiating anti-VEGF therapy before initiating treatment. When the decision is made to treat with anti-VEGF agents, Ranibizumab should be the agent of choice. In conclusion, ophthalmologists should make treatment decisions in pregnant patients with DR on a case-by-case basis taking into consideration disease severity, risk of permanent threat to vision, gestational age, and patient preferences.
Original Article

Changes in crystalline lens parameters during accommodation evaluated using swept source anterior segment optical coherence tomography

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Backgrounds: To assess changes in anterior segment biometry during accommodation using a swept source anterior segment optical coherence tomography (SS-OCT).

Methods: One hundred-forty participants were consecutively recruited in the current study. Each participant underwent SS-OCT scanning at 0 and ?3 diopter (D) accommodative stress after refractive compensation, and ocular parameters including anterior chamber depth (ACD), anterior and posterior lens curvature, lens thickness (LT) and lens diameter were recorded. Anterior segment length (ASL) was defined as ACD plus LT. Lens central point (LCP) was defined as ACD plus half of the LT. The accommodative response was calculated as changes in total optical power during accommodation.

Results: Compared to non-accommodative status, ACD (2.952±0.402 vs. 2.904±0.382 mm, P<0.001), anterior (10.771±1.801 vs. 10.086±1.571 mm, P<0.001) and posterior lens curvature (5.894±0.435 vs. 5.767±0.420 mm, P<0.001), lens diameter (9.829±0.338 vs. 9.695±0.358 mm, P<0.001) and LCP (4.925±0.274 vs. 4.900±0.259 mm, P=0.010) tended to decreased and LT thickened (9.829±0.338 vs. 9.695±0.358 mm, P<0.001), while ASL (6.903±0.279 vs. 6.898±0.268 mm, P=0.568) did not change significantly during accommodation. Younger age (β=0.029, 95% CI: 0.020 to 0.038, P<0.001) and larger anterior lens curvature (β=?0.071, 95% CI: ?0.138 to ?0.003, P=0.040) were associated with accommodation induced greater steeping amplitude of anterior lens curvature. The optical eye power at 0 and ?3 D accommodative stress was 62.486±2.284 and 63.274±2.290 D, respectively (P<0.001). Age was an independent factor of accommodative response (β=?0.027, 95% CI: ?0.038 to ?0.016, P<0.001).

Conclusions: During ?3 D accommodative stress, the anterior and posterior lens curvature steepened, followed by thickened LT, fronted LCP and shallowed ACD. The accommodative response of ?3 D stimulus is age-dependent.

Case report

Case report: simultaneous femtosecond laser astigmatic keratotomy and toric intraocular lens implantation in femtosecond laser-assisted cataract surgery in a patient with surgically induced high corneal astigmatism

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Background: Femtosecond laser astigmatic keratotomy (FSAK) and toric intraocular lens (IOL) implantation have been studied individually for comparison to treat astigmatism at cataract surgery. We report a case of surgically induced high corneal astigmatism by laser thermal keratoplasty (LTK) in a patient with cataract who was successfully treated with simultaneous combination of FSAK and toric IOL implantation with femtosecond laser-assisted cataract surgery (FLACS). This is the first report of both procedures combined simultaneously, with or without history of LTK.

Case Description: A 68-year-old male presented with a history of LTK with two enhancements each eye in 2004, with subsequent surgically induced high corneal astigmatism, and with age-related nuclear cataract of both eyes. IOL master demonstrated +7.71 diopters of astigmatism at 163 degree right eye and +3.29 diopters of astigmatism at 4 degree left eye. After extensive discussion of the risks and benefits, the patient agreed to undergo FLACS with FSAK with two 61 degrees of relaxation incisions (RIs) and toric IOL (Alcon SN6AT9) right eye; FLACS with toric IOL (Alcon SN6AT7) alone left eye. At 2-year follow-up, uncorrected visual acuity was 20/30 right eye, 20/25 left eye. His best corrected visual acuity was 20/25 (+0.25 +1.00 axis 21) right eye and 20/20 (plano +0.25 axis 90) left eye; his best corrected near visual acuity was J1+ with add +2.50 diopters right eye and left eye.

Conclusions: Patients with age-related cataract and LTK induced high corneal astigmatism can hardly be sufficiently treated with FSAK or toric IOL alone at the time of cataract surgery. An effective way is to combine large FSAK and toric IOL of the highest cylindrical power of T9, in our case, simultaneously, which can achieve an excellent long term visual outcome.

Original Article

Supracapsular implantation with optic capture of posterior chamber intraocular lens in Chinese children with aphakic after traumatic cataract

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Background: To assess the safety and efficacy of supracapsular implantation with optic capture of the posterior chamber intraocular lens in Chinese children with aphakic after traumatic cataract.

Methods: It was a retrospective case series study. Fifteen cases (15 eyes) Chinese children received supracapsular implantation with optic capture of the posterior chamber intraocular lens. Pre- and post-operative visual acuities were recorded. Intra- and post-operative complications were observed. The follow-up period ranged from 7 to 43 (28.7±7.2) months.

Results: Implantation of optic capture of the posterior chamber intraocular lens was successfully performed in 15 eyes. The best corrected visual acuity (BCVA) ranged from 0.3 to 1.0 (0.61±0.19). No optic axis opaque was found in 15 eyes with optic capture. The major complications of optic capture were iris posterior synechia and intraocular lens (IOL) precipitates. Intraocular dislocation was found in one case three weeks after the operation.

Conclusions: Supracapsular implantation with optic capture of the posterior chamber intraocular lens is safe and effective for the treatment of traumatic cataract in Chinese children.

Review Article

How to screen diabetic retinopathy within communities

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Abstract: Diabetic retinopathy (DR) remains a leading cause of irreversible vision loss in adult populations around the globe. Despite growing evidence of the effectiveness of routine assessments and early intervention, DR screening strategies are not widely implemented largely due to an inadequate availability of resources to cope with the growing burden of diabetes. Advances in technology in the field of DR screening are clearly warranted and the recent emergence of deep learning-based artificial intelligence (AI) grading of retinal pathology offers significant potential benefits including an increased efficiency, accessibility and affordability of screening programmes.

Case Records of the Zhongshan Ophthalmic Center

Case 02-2017—Discussion of clinical pearls derived from 4 challenging and unusual retinal cases

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Abstract: Four challenging and unusual retinal cases: (I) 11-year follow-up for retinal hemangioblastoma with von Hippel-Lindau (VHL) disease; (II) treatment for central serous chorioretinopathy (CSC)—observation, half does photodynamic therapy (PDT) or micropulse laser photocoagulation; (III) diagnosis and treatment for a child with optic nerve defect; (IV) the optional treatment for retinal detachment (RD) with iridolenticular choroidal coloboma, were presented and discussed by three international retinal specialists at a retinal clinical round in Fundus Diseases Center of Zhongshan Ophthalmic Center (ZOC). The discussion helps us a better understanding of the pathogenesis and managements of these four retinal diseases and their association with systemic conditions.

Review Article

Genetic epidemiology of diabetic retinopathy

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Abstract: The disease burden of diabetic retinopathy (DR) is tremendous around the world. While DR is correlated with hemoglobin A1c (HbA1c) and duration of diabetes, genetic differences likely account for variation in susceptibility to DR. DR is a polygenic disorder with demonstrated heritability. However, linkage and admixture analyses, candidate gene association studies, and genome-wide association studies (GWAS) have not identified many loci for DR that can be consistently replicated. Larger, collaborative, multi-ethnic GWAS are needed to identify common variants with small effects. Rigorous defining of controls groups as patients with a long duration of diabetes without DR, and case groups as patients with severe DR will also aid in finding genes associated with DR. Replication in independent cohorts will be key to establishing associated loci for DR. Investigations of mitochondrial DNA and epigenetics in DR are ongoing. Whole exome sequencing presents new opportunities to identify rare variants that might be implicated in DR development. Continued research in the genetic epidemiology of DR is needed, with the potential to elucidate pathogenesis and treatment of an important disease.

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  • 眼科学报

    主管:中华人民共和国教育部
    主办:中山大学
    承办:中山大学中山眼科中心
    主编:林浩添
    主管:中华人民共和国教育部
    主办:中山大学
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  • Eye Science

    主管:中华人民共和国教育部
    主办:中山大学
    承办:中山大学中山眼科中心
    主编:林浩添
    主管:中华人民共和国教育部
    主办:中山大学
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