Retinal Argon Laser Research Articles

Diabetic corneal neuropathy and its relation to the severity of retinopathy in patients with type 2 diabetes mellitus: an in vivo confocal microscopy study.

To investigate corneal neuropathy and corneal nerve alterations in type 2 diabetes mellitus (DM) patients with different diabetic retinopathy (DR) status. A total of 87 eyes of 87 patients with DM and 28 eyes of 28 healthy control subjects were included in the study. DM patients were further classified into 3 groups: patients without DR (NDR), patients with non-proliferative DR (NPDR), and patients with proliferative DR (PDR). PDR patients were classified into 2 groups regarding having undergone retinal argon laser photocoagulation treatment (ALP). Ocular surface disease index score (OSDI), average tear break-up time (A-BUT), corneal sensitivity and cornea nerve fiber length (CNFL), cornea nerve fiber density (CNFD), and cornea nerve branch density (CNBD) of the cornea subbasal nerve plexus (SBNP) were measured using in vivo confocal microscopy (IVCM). OSDI scores increased and A-BUT decreased in DM patients compared to the control group, but no significant difference was found between DM patient groups. Corneal sensitivity decreased in DM patients who developed DR, compared to both the controls and the NDR group. CNFD and CNFL decreased in NPDR and PDR patients compared to controls. CNFD and CNBD decreased in patients who had developed PDR, compared to all three groups. All IVCM parameters decreased with DR progression. IVCM can detect early structural corneal nerve changes in diabetic patients. The presence of DM affects ocular surface parameters, especially in long-term DM patients. Corneal sensitivity loss is increased with the presence of DR. All IVCM parameters decrease with DR development and its progression.

Harmonizing ophthalmic residency surgical training across Europe: A proposed surgical curriculum.

One of the core aims of the European Union of Medical Specialists is to harmonize training across Europe by creating European Training Requirements for all medical specialties including Ophthalmology. The theoretical part is already defined by the EBO, however as ophthalmology also includes surgical skills, we herein propose a surgical minimum curriculum for ophthalmology residents in Europe. National and international ophthalmic training curricula which are publicly available in English were reviewed and compared. The final proposal was created from 5 criteria: 1. Disease prevalence; 2. Patient safety; 3. Case-trainee ratio; 4. Skill transfer; and 5. Technical difficulty. In total 7 different training curricula from across the world were compared. Among the surgical procedures, cataract surgery has the highest median number of procedures required to be completed during residency: 86 procedures (50-350). Followed by oculoplastics: 28 procedures (10-40) and panretinal photocoagulation: 27.5 procedures (10-49) Full procedural competence is proposed in 9 surgical skills, including YAG laser posterior capsulotomy, retinal argon laser, intravitreal injection, corneal foreign body removal, removal of corneal sutures, facial and periocular laceration repair, eyelid laceration repair, minor eyelid procedures, and punctal occlusion. These procedures are deemed essential and feasible for all ophthalmology residents in Europe to perform independently upon completion of their training. This proposal should be regarded as a recommendation based on comparable surgical curricula in use worldwide to establish standards across European countries and may serve as valuable insight to those responsible for compiling ETRs for ophthalmology, or their national curriculums.

Effect of fundus retinal argon laser photocoagulation combined with calcium dobesilate in the treatment of diabetic retinopathy

Effect of fundus retinal argon laser photocoagulation combined with calcium dobesilate in the treatment of diabetic retinopathy

Preclinical SPECT Imaging of Choroidal Neovascularization in Mice Using Integrin-Binding [99mTc]IDA-D-[c(RGDfK)]2.

Integrin ɑvβ3, an adhesion molecule overexpressed in neovascular endothelial cells, is involved in ocular angiogenesis. Integrin ɑvβ3-binding arginine-glycine-aspartic acid (RGD) peptide has been used to target and visualize new vessels. We explored the use of integrin ɑvβ3-targeted RGD peptide ([99mTc]IDA-D-[c(RGDfK)]2) for in vivo molecular imaging of choroidal neovascularization (CNV). To induce CNV in animals, the right eyes of C57BL/6 mice were treated with retinal argon laser photocoagulation. CNV formation was confirmed on immunohistopathological examination of retinal and choroidal tissues. To explore the association of integrin with angiogenesis, integrin mRNA expression in the retinal and choroidal tissues was measured using real-time reverse transcriptase-polymerase chain reaction. For in vivo imaging, mice were intravenously injected with [99mTc]IDA-D-[c(RGDfK)]2 and single-photon emission computed tomography (SPECT) images of [99mTc]IDA-D-[c(RGDfK)]2 were obtained before laser induction (baseline) and at 1, 3, 7, and 14days post-induction. CNV-induced regional alterations were measured using radiotracer uptake count. Immunohistopathological examination revealed that CNV lesions showed intense fluorescein isothiocyanate (FITC)-D-[c(RGDfK)]2 immunofluorescence, in contrast to the normal retina and choroid. Retinal integrin mRNA expression peaked at day 1 following CNV induction. On SPECT images using [99mTc]IDA-D-[c(RGDfK)]2, the radio-uptake count in eyes with CNV was significantly higher than in normal controls on days 1-7 (all p < 0.05), with a peak at day 3 representing the highest angiogenic activity. Our preclinical data demonstrated that [99mTc]IDA-D-[c(RGDfK)]2 can detect CNV and its associated angiogenesis in an animal model of CNV. SPECT imaging using an integrin ɑvβ3-targeted RGD peptide radiotracer may be a useful tool for in vivo functional molecular imaging of CNV.

Consensus on procedures to include in a simulation-based curriculum in ophthalmology: a national Delphi study.

The number of available simulation-based models for technical skills training in ophthalmology is rapidly increasing, and development of training programmes around these procedures should follow a structured approach. The aim of this study was to identify all technical procedures that should be integrated in a simulation-based curriculum in ophthalmology. Key opinion leaders involved in the education of ophthalmologists in Denmark including heads of departments, heads of clinical education, professors and board members of the society were invited to participate in a three-round Delphi process. Round 1 aimed at identifying technical procedures that physicians should be able to perform competently when completing specialty training; round 2 involved characterization of each procedure including frequency, number of operators, risk and/or discomfort for patients associated with an inexperienced physician, and feasibility of simulation-based training; round 3 included a priority ranking of procedures. The response rate for each round was 71%, 64% and 64%, respectively. Sixty-five procedures were reduced to 25 prioritized procedures during the three rounds. Two-thirds of the procedures that were identified and highly prioritized were therapeutic procedures such as intravitreal injection therapy, yttrium-aluminium-garnet laser iridotomy/capsulotomy, minor ocular surface procedures and retinal argon laser therapy. The diagnostic procedures that were prioritized were ocular ultrasound, superficial keratectomy and optical coherence tomography (OCT). The Delphi process identified and prioritized 25 procedures that should be practised in a simulation-based environment to achieve competency before working with patients. The list may be used to guide the development of future training programmes for ophthalmologists.

Refractive error after intravitreal bevazicumab for threshold disease in retinopathy of prematurity: Two‐years follow‐up

AbstractPurpose To examine the association between myopic refractive error at two years of life in infants who postnatally received an intravitreal bevacizumab injection or standard laser therapy for threshold retinopathy of prematurity (ROP) in fundus zone I or zone II.Methods In the retrospective non‐randomized interventional comparative study, infants who consecutively received a single intravitreal bevacizumab (0.375 mg) injection (study group) were compared with infants who had previously undergone standardized retinal argon laser therapy (control group). The follow‐up examination included cylcoplegic refractometry.Results The study group consisted of 7 children (13 eyes) and the control group included 14 children (27 eyes). Both groups did not differ significantly in gestational age and follow‐up. At the end of follow‐up of 24 months, refractive error (median:+1.00 diopters (D) (+4.0D to ‐10.00D) versus median:‐7.50D (+2.50D to ‐15.0D);P=0.001)), astigmatism (median:0.25D (0D to 2D) versus median:1.25 D (0D to 5.75D);P=0.001)) and prevalence of high myopia (≤‐6D) (15±10% versus 52±10%;P=0.04) were significantly less in the study group than control group. After adjusting for gestational age, follow‐up time, gender and birth weight, refractive error (P=0.007), astigmatism (P=0.01) and prevalence of high myopia (P=0.03; Odds Ratio:0.13) were significantly associated only with laser therapy versus bevacizumab therapy.Conclusion A single intravitreal bevacizumab injection as compared to conventional retinal laser coagulation was associated with a lower degree of myopization and less astigmatism at two year follow‐up.

Intravitreal Bevacizumab for Retinopathy of Prematurity: Refractive Error Results

To evaluate refractive error in infants who underwent intravitreal bevacizumab injection for treatment of threshold retinopathy of prematurity (ROP). Retrospective nonrandomized interventional comparative study. The study group included all infants who consecutively received a single intravitreal bevacizumab (0.375mg or 0.625mg) injection for therapy of threshold ROP in fundus zone I or zone II. The control group included infants who had previously undergone retinal argon laser therapy of ROP. The follow-up examination included refractometry under cycloplegic conditions. The study group included 12 children (23 eyes; mean birth weight: 622 ± 153 g; gestational age: 25.2 ± 1.6weeks) and the control group included 13 children (26 eyes; birth weight: 717 ± 197 g; gestational age: 25.3 ± 1.8weeks). Both groups did not differ significantly in birth age and weight and follow-up. At the end of follow-up at 11.4 ± 2.3months after birth, refractive error was less myopic in the study group than in the control group (-1.04 ± 4.24 diopters [median: 0 diopters] vs-4.41 ± 5.50 diopters [median:-5.50 diopters]; P= .02). Prevalence of moderate myopia (17% ± 8% vs 54% ± 10%; P= .02; OR: 0.18 [95% CI: 0.05, 0.68]) and high myopia (9% ± 6% vs 42% ± 10%; P= .01; OR: 0.13 [95% CI: 0.03, 0.67]) was significantly lower in the bevacizumab group. Refractive astigmatism was significantly lower in the study group (-1.0 ± 1.04 diopters vs 1.82 ± 1.41 diopters; P= .03). In multivariate analysis, myopic refractive error and astigmatism were significantly associated with laser therapy vs bevacizumab therapy (P=.04 and P= .02, respectively). In a 1-year follow-up, a single intravitreal bevacizumab injection as compared to conventional retinal laser coagulation was helpful for therapy of ROP and led to less myopization and less astigmatism.

In-vivo and ex-vivo characterization of laser-induced choroidal neovascularization variability in mice

Retinal argon laser coagulation is an established procedure for induction of choroidal neovascularization (CNV) in rodents. This study aimed to evaluate the in-vivo and ex-vivo morphology and variability of laser-induced CNV spots over time. Female C57/Bl/6 mice, 3-6months of age, were treated with five spots of retinal argon laser coagulation per eye (150mW, 100ms, 50μm). In-vivo fluorescein angiography (FA) and standard high-resolution spectral-domain optical coherence tomography (SD-OCT) were performed on day (d) 0, d1, d4, d7, d14 and d21. Ex-vivo histology, CD31 immunostaining, flatmount and confocal microscopy were also conducted. CNV size in the retinal and choroidal focus, CNV morphology, central retinal thickness (CRT) and FA CNV activity grading were assessed in-vivo at all times and compared to the ex-vivo assessments. SD-OCT revealed sub-retinal and intra-retinal fluid, and permitted evaluation of longitudinal morphologic changes of the induced CNV. Laser spot area in FA and CRT in SD-OCT did not differ in longitudinal evaluation. CNV could not be consistently outlined on SD-OCT images, and CNV volume as assessed on SD-OCT did not change over time. Significant CNV activity changes were only found in FA CNV activity grading, peaking on d4 and decreasing by d7. Non-invasive SD-OCT provides additional morphological information on laser-induced CNV. However, reliable evaluation of CNV requires FA. Spontaneous regression of CNV activity within 14days after induction has to be taken into account when utilizing this model for testing the efficacies of potential future treatments.

Maladie de Eales : à propos d’un cas au Burkina Faso

The authors report the first case of Eales disease described in Burkina Faso. A 21-year-old man presented myodesopsia with acute visual acuity decrease in the right eye at 1/50, vitreous haemorrhage, and retinal phlebitis of the large trunks. In the left eye, visual acuity was 10/10 P2, with phlebitis associated with retinal haemorrhages, vascular occlusion, and retinal ischaemia. Laboratory investigations found a positive TST at 20mm but the Koch bacillus was not isolated. The patient received treatment for tuberculosis, corticosteroids, retinal argon laser photocoagulation, and vitrectomy in the right eye. The clinical, immunopathological, and therapeutic aspects of Eales disease are discussed.

Is Rosiglitazone use associated with an increase in intensive eye treatment in diabetic patients? A community based study

Objective: To evaluate the effect of rosiglitazone on diabetic retinopathy in the usual care setting. Methods: Type 2 diabetic patients, aged over 40, who received rosiglitazone therapy for at least one year during the study period, were considered for the study group. All diabetic patients who had never received rosiglitazone or insulin were candidates for the control group. For each subject treated with rosiglitazone, up to five controls were randomly selected and matched on age, gender, and HbA1c%. We retrieved information about ophthalmologist visits, retinal argon laser therapy, vitrectomy and the date of the procedure. Time from the first rosiglitazone prescription to the first intervention was calculated. Results: A total of 6689 subjects, 1304 in the rosiglitazone group and 5385 in the control group were followed for a median of 3.6 years. The baseline level of HbA1C% was slightly higher in the rosiglitazone group (9.2 versus 8.8). There were more ophthalmologist visits in the rosiglitazone group compared to the control group. 115/1304 (8.8%) patients in the study group had an event compared to 379/5385 (7.0%) control group (P = 0.027). HR for the study group was 1.3 (95% CI: 1.08–1.64) for any event compared to control group (P = 0.008).Conclusion: Rosiglitazone was associated with increased laser treatments and vitrectomy. Caution may be needed when treating diabetic patients with rosiglitazone.

Effects of Photocoagulation on Intraretinal Po2in Cat

To test the hypothesis that intraretinal Po(2) increases after photocoagulation. Anesthetized cats underwent retinal argon laser photocoagulation. At least 4 weeks after treatment, Po(2)-sensitive microelectrodes were used to record intraretinal Po(2) profiles from healed photocoagulation lesions in anesthetized cats breathing air. Histopathologic examination of the retinas was used to confirm that the photoreceptors were destroyed and that the inner retinal layers were preserved, though somewhat disorganized, as in human panretinal photocoagulation (PRP). The retina and tapetum were thinner in the lesioned retina than in the nonphotocoagulated retina. Average Po(2) across the inner 50% of the retina was higher (22 +/- 10 mm Hg) in photocoagulated retina than in untreated retina (14 +/- 7 mm Hg; P < 0.01; n = 13 cats). The minimum Po(2) was also significantly higher, whereas choroidal Po(2) was significantly lower in the photocoagulated retina than in untreated retina. No significant difference was found in the preretinal vitreous. After lesions, inner retinal Po(2) could also be maintained above zero, even in the absence of retinal circulation. Previous measurements showed increased Po(2) in the preretinal vitreous of rabbits and pigs (but not cats) after photocoagulation of the outer retina. These intraretinal measurements in cats provide further evidence for a chronic increase in inner retinal Po(2) in lesioned areas during air breathing.

Les bêtathalasso-drépanocytoses pourvoyeuses de rétinopathies ischémiques graves: À propos de 18 patients étudiés à 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.

A new device for ocular surgical training on enucleated eyes

Objective To develop a reliable inexpensive device for teaching ocular surgical procedures and practicing experimental techniques on enucleated eyes. Design Teaching device trial. Participants Thirty enucleated porcine eyes. Methods A Plexiglas ocular bulb holder was secured with its base support to a polyvinylchloride pillar on a modified polystyrene trial head. Main outcome measure The convenience and reproducibility of both laser and surgical ocular techniques performed with this new device were evaluated. Results This model allows curvilinear capsulorrhexis and phacoemulsification of porcine lenses through a corneal tunnel incision and insertion of a soft foldable acrylic intraocular lens into the capsular bag. Argon and neodymium:YAG laser iridotomy and retinal argon laser photocoagulation can also be performed with this model. Conclusions This inexpensive device is useful for teaching both surgical and laser ocular procedures.