The Injection Practice Patterns of Retina Specialists in Managing Exudative Age-Related Macular Degeneration: A Retrospective Study

Purpose

To compare the PRN anti-VEGF injection patterns of four retina specialists with respect to the visual and anatomic outcomes in the management of wet age-related macular degeneration (AMD).

Methods

Medical records of patients who received bevacizumab, ranibizumab, and aflibercept anti-VEGF injections (years 2010-2020) by four retina specialists were reviewed for frequency, injection intervals, best corrected visual acuity (BCVA), and central macular thickness, center involved (CMT) for statistical analysis. Outcomes measured were change in logMAR BCVA and CMT from the first to last injection visit.

Results

Out of 137 AMD patients, 172 eyes were injected by four retina specialists in PRN fashion. Although all four specialists started the injection at similar baseline BCVA and CMT (p > 0.1), significant differences in mean injection number (9.0, p = 0.0001), injection intervals (5.06 weeks, p = 0.001), and total length of treatments (53.3 weeks, p = 0.0001) were observed. The mean change in logMAR BCVA between the first and last injection was -0.05, -0.22, 0.07, and 0.06 for the four specialists, respectively (p = 0.031), and the mean change in CMT was -53.3, -41.4, -72.7, and -21.9 µm (p = 0.41), respectively.

Conclusion

Despite similar baseline criteria for injections by the retina specialists, different anti-VEGF injection regimens were practiced resulting in variations in BCVA and CMT outcomes. This suggests a need in establishing a universally adoptable injection regimen with possible integration of the confounding factors to reduce burden on both patients and retina specialists.

Subfoveal choroidal thickness following pars plana vitrectomy in tractional diabetic macular edema

Purpose

To evaluate changes in subfoveal choroidal thickness (SCT) in cases of tractional diabetic macular edema (DME) after pars plana vitrectomy (PPV).

Methods

This prospective study included 31 eyes of 31 patients who underwent PPV for the management of tractional DME. Best-corrected visual acuity (BCVA), SCT, and central macular thickness (CMT) were measured before the operation, as well as one, three, and six months following the surgery in the operated eyes and at baseline, as well as six months in the fellow eyes.

Results

The SCT decline in eyes with tractional DME was statistically significant six months postoperatively (P = 0.009). A statistically significant decline was observed in the CMT values one, three, and six months postoperatively in eyes with tractional DME (P = 0.02, P < 0.001, and P < 0.001, respectively). There was a statistically significant improvement in the visual acuity of the affected eyes three (P = 0.047) and six months (P = 0.017) postoperatively.

Conclusion

After PPV for the treatment of tractional DME, a statistically significant decrease in the CMT values is detectable from the first month after surgery, followed by the improvement of BCVA from the third month. It is worth mentioning that a decrease was found in the SCT six months postoperatively.

Subretinal leakage of a retinal capillary macroaneurysm - a case report

BACKGROUND

Report a rare case of retinal capillary macroaneurysm with associated subretinal fluid.

CASE PRESENTATION

A 71-year-old male underwent full ophthalmic examination including Optical Coherence Tomography (OCT), Fluorescein Angiography (FA). Fundus examination showed moderate non-proliferative diabetic retinopathy of both eyes with scattered microaneurysms. On initial visit, FA displayed a hyperfluorescent lesion with leakage on late frames in the left eye. OCT revealed the lesion to be spheroid with a hyperreflective wall and hyporeflective lumen in the inner retina, corresponding to a capillary macroaneurysm. Intraretinal cystic fluid surrounded the lesion. On subsequent visit 7 months later, subretinal fluid in the location of the capillary macroaneurysm was noted on OCT. Vision was maintained at 20/30-2 OD, 20/40 OS throughout. No treatment was necessary.

CONCLUSION

Subretinal fluid from the capillary macroaneurysm likely developed from its juxtafoveal location and discontinuity of the external limiting membrane (ELM); a barrier preventing flow of intraretinal fluid to the outer retina.

Endogenous Endophthalmitis: Recommendation for Empiric Dual Antibacterial and Antifungal Therapy

Purpose:

This work compares clinical presentation and course of bacterial and fungal causes of endogenous endophthalmitis (EE).

Methods:

A single-institutional study of consecutive patients diagnosed with EE was conducted at the University of Pittsburgh Medical Center between September 2015 and September 2018. Exclusion criteria included history of ocular trauma, intraocular surgery or injection 6 months before presentation, or primary external ocular infection. Data included demographics, medical and ocular history, clinical examination, culture data, therapeutic interventions, final corrected visual acuity (VA), and mortality.

Results:

Thirty-six eyes of 26 patients were diagnosed with EE during a 3-year period. Median age at diagnosis was 55.5 years (range, 19-86 years). Based on ocular and systemic cultures, 19 patients had bacterial EE and 6 patients had fungal EE; findings from all cultures remained negative in 1 patient. All patients had risk factors for EE. Presenting VA, subjective symptom report, and objective measures of intraocular inflammation were similar between bacterial and fungal causes. Overall, EE presented indolently and was initially misdiagnosed in 19% of cases. Complications including final VA less than 20/200, retinal detachment, enucleation, or death within 6 months of diagnosis were equivalent between bacterial and fungal cases.

Conclusions:

The presentation of EE is remarkably different from that of exogenous endophthalmitis. Without a high index of suspicion, the indolent presentation of EE may lead to misdiagnosis. No clinical features reliably differentiated bacterial and fungal sources. This highlights the importance of considering empiric therapy for antibacterial and antifungal coverage on initial presentation.

PRN Treatment of Neovascular AMD with Cycles of Three Monthly Injections

Purpose

To report the one and two year outcome of cycles of three, monthly anti-VEGF injections given upon reactivation of the disease in eyes with neovascular age-related macular degeneration (nAMD).

Methods

Retrospective study of naïve nAMD cases with more than one year of follow-up, treated with a protocol of cycles of three monthly injections of anti-VEGF drugs upon reactivation. Visual acuity (VA) and central macular thickness (CMT) are the main outcome measures.

Results

Twenty-six patients with a mean age of 78.15 ± 9.29 years (57.7% female) were included. The mean follow-up was 30.89 ± 6.95 months. Treatment started with bevacizumab in all patients but in six patients was switched to aflibercept due to inadequate response to intravitreal bevacizumab injection. The mean VA at baseline and at 12 and 24 months was 53.87 ± 21.84, 60.54 ± 21.13, and 53.68 ± 27.16 ETDRS letters, respectively. Patients gained a mean of 6.67± 13.7 (p = 0.013, 95% CI= 0.60 to 12.65) and 0.77±15.21 (p = 0.4, 95% CI: –5.65 to 7.2) letters at 12 and 24 months. CMT at baseline, 12, and 24 months was 403.55 ± 147.59, 323.95 ± 79.58, and 298.59 ± 77.161 µm, respectively. The number of injections in the first and second years were 7.65 ± 2.64 and 5.52 ± 3.01, respectively. Three eyes (12.5%) lost >15 letters at 24 months.

Conclusion

This protocol can stabilize or improve vision in 87.5% of nAMD patients and can reduce the number of visits.

An Analysis of the Areas Occupied by Vessels in the Ocular Surface of Diabetic Patients: An Application of a Nonparametric Tilted Additive Model

(1) Background: As diabetes melllitus (DM) can affect the microvasculature, this study evaluates different clinical parameters and the vascular density of ocular surface microvasculature in diabetic patients. (2) Methods: In this cross-sectional study, red-free conjunctival photographs of diabetic individuals aged 30-60 were taken under defined conditions and analyzed using a Radon transform-based algorithm for vascular segmentation. The Areas Occupied by Vessels (AOV) images of different diameters were calculated. To establish the sum of AOV of different sized vessels. We adopt a novel approach to investigate the association between clinical characteristics as the predictors and AOV as the outcome, that is Tilted Additive Model (TAM). We use a tilted nonparametric regression estimator to estimate the nonlinear effect of predictors on the outcome in the additive setting for the first time. (3) Results: The results show Age (p-value = 0.019) and Mean Arterial Pressure (MAP) have a significant linear effect on AOV (p-value = 0.034). We also find a nonlinear association between Body Mass Index (BMI), daily Urinary Protein Excretion (UPE), Hemoglobin A1C, and Blood Urea Nitrogen (BUN) with AOV. (4) Conclusions: As many predictors do not have a linear relationship with the outcome, we conclude that the TAM will help better elucidate the effect of the different predictors. The highest level of AOV can be seen at Hemoglobin A1C of 9% and AOV increases when the daily UPE exceeds 600 mg. These effects need to be considered in future studies of ocular surface vessels of diabetic patients.

Long-Term Intraocular Pressure Changes after Pars Plana Vitrectomy: An 8-Year Study

Purpose:

To investigate the long-term changes of intraocular pressure (IOP) after pars plana vitrectomy (PPV).

Methods:

This was a retrospective historical cohort study. Patients with a history of vitrectomy in one eye by a single surgeon were enrolled. IOP of the operated eye was compared to the fellow eye. Previous scleral buckling, IOP rise due to surgical/anatomic complications, silicone oil (SO) emulsification, and contralateral ocular hypertension/glaucoma at recruitment were exclusion criteria. “Significant IOP rise” (>6.0 mmHg) and development of open angle glaucoma (OAG) were the main outcome measures.

Results:

Two hundred and twenty-five eyes were included. Mean and median follow-up duration were 20.6 and 9.0 months, respectively. Mean baseline IOP and mean final IOP were 13.53 ± 3.75 mmHg and 16.52 ± 6.95 mmHg, respectively (P < 0.001). Forty-three patients developed “significant IOP rise” with no statistically significant relation to the indication of vitrectomy, the postoperative lens status, and number of vitrectomies (P = 0.410, P = 0.900, and P = 0.160, respectively). SO injection raised the probability of IOP rise in the long-term (P = 0.028). OAG occurred in 17 patients (7.5%) with no association to SO tamponade (P = 0.840). “Significant IOP rise” and OAG occurred in 3 and 1 control eyes, respectively, significantly lower than the rates in study eyes (P < 0.001).

Conclusion:

Mean IOP slightly rose in the long-term after PPV. SO tamponade was associated with IOP rise in the long-term but not with the incidence of OAG. Both IOP rise and OAG were more probable after vitrectomy.

The Ocular Immune Response in a Rodent Model of Whole Eye Transplantation

Introduction

Approximately 36 million people are totally blind globally. Using a rodent whole eye orthotopic transplant model (WET), we are investigating a potential clinical treatment to restore vision. Typically, clinical transplantation involves allogeneic individuals and immune rejection is the first obstacle after surgery. Her--e, we use an MHC class I and II mismatched transplant model without immunosuppression to describe for the first time the features of the immune reaction in WET.

Methods

14-wk old male Brown Norway (BN) rats served as donor and recipient in the syngeneic group. 14-wk old male BN rats served as donors with age/sex matched Lewis rats used as recipient in the allogeneic group. Both groups underwent WET, subsequently the transplanted eye blood supply and structure were evaluated on post-operative day (POD) 2 by optical coherence tomography (OCT). Skin and cornea rejection at POD 2,4,5,6,8 were assessed separately by a scoring system. The progressive infiltration of immune cells into the eye was evaluated by flow cytometry and histology.

Results

At POD5 allogeneic corneas had transparency changes that coincided with skin rejection and Cornea thickness dramatically increased by 150% over syngeneic eyes. Also, the allogeneic group had significant CD4+, CD8+ T cells and NK cell infiltration in aqueous humor, iris, retina and choroid with no difference in cornea.

Conclusion

These preliminary results indicate that acute rejection in WET is T cell mediated and the blood ocular barrier is compromised post-operatively, where immune cells can access the eye. Rejection after WET can be potentially monitored by noninvasive measurement of the cornea thickness or easily accessible aqueous humor.

Optical Coherence Tomography Angiography in Eyes with Retinal Vein Occlusion

Optical coherence angiography (OCTA) is a noninvasive technique that has been introduced in recent years to detect ophthalmological pathology. The growing usage of OCTA to detect retinal abnormalities can be attributed to its advantages over the reference-standard fluorescein angiography (FA), although both of these techniques can be used in association. OCTA's advantages include its dye independency, its ability to produce depth-resolved images of retinal and choroidal vessels that yield images of different vascular layers of the retina, and the better delineation of the foveal avascular zone. OCTA's disadvantages include the lack of normalized patient data, artefactual projection issues, and its inability to detect low-flow lesions or pathologic conditions. Different OCTA platforms use unique algorithms to detect microvasculature, which are implemented in both spectral-domain (SD) and swept-source (SS) OCT machines. Microvascular changes in retinal vein occlusions (RVOs) are visible in both the superficial and deep capillary networks of the retina in OCTA. These visualizations include a decrease in foveal and parafoveal vascular densities, non-perfusion areas, capillary engorgement and telangiectasias, vascular tortuosity, microaneurysms, disruption of the foveal perivascular plexus, and formation of collateral vessels. The restricted field of view and inability to show leakage are important limitations associated with the use of OCTA in RVO cases. In this article, we present a brief overview of OCTA and a review of the changes detectable in different slabs by OCTA in RVO cases published in PubMed and Embase.

Vitreous changes after intravitreal bevacizumab monotherapy for retinopathy of prematurity: a case series

Purpose

Reporting a special clinical finding after intravitreal bevacizumab monotherapy for retinopathy of prematurity.

Methods

In a retrospective case series, the clinical courses of five premature infants with similar vitreous changes after a single dose of intravitreal bevacizumab (IVB) injection without additional laser therapy were reported.

Results

The mean post-conceptional age at IVB injection was 39.8 ± 2.2 (range 37–43) weeks. Localized vitreous syneresis and linear fibrotic vitreous condensation occurred 8.2 ± 2.3 weeks after IVB monotherapy in our patients (15.5% of injections). The mean last post injection visit was 61.6 ± 5.3 weeks (post-conceptional age). Further regression and complete retinal vascularization occurred in all patients.

Conclusions

Thread-like vitreous condensation with localized vitreous liquefaction may be related to involutional ROP disease itself, combined to anti VEGF therapy and may be a predictor factor for further regression and retinal vascularization. The case series describes a successful response to anti-VEGF monotherapy with no further complications.

Switching Anti-VEGF Drugs in the Treatment of Diabetic Macular Edema

Since their introduction in the late 2000s, anti-vascular endothelial growth factor (VEGF) agents have become the first-line choice for center-involved diabetic macular edema (DME). Even with its proven effectiveness, there are still cases that do not respond satisfactorily. In those cases, a treatment option is to change to another anti-VEGF drug. In this paper, the authors review studies on switching between different anti-VEGF drugs in the treatment of persistent DME. An extensive bibliographic review was done using PubMed, Embase, and Scopus. Fourteen studies published from March 2010 to April 2017 reporting switching from anti-VEGF drugs in DME treatment were included. All reported good anatomical results after conversion; however, visual acuity outcomes showed great variability between publications. Therefore, switching to other anti-VEGFs in patients with DME not responding to previous anti-VEGF therapy may be an option, but the results are still not well-known due to a lack of randomized clinical trials. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:748-754.].

Utility of 1% Tropicamide in Improving the Quality of Images for Tele-Screening of Diabetic Retinopathy in Patients with Dark Irides

PURPOSE

To compare the quality of fundus photographs taken before and after instillation of one drop of tropicamide.

METHODS

The 45º fundus photographs were taken with a non-mydriatic fundus camera in three conditions of the pupil; pre-mydriatic, 10 minutes after one drop of tropicamide, and fully dilated. Two photographs were taken in each condition; one centered on the macula and the other on the optic disc. Two vitreoretinal specialists graded the images.

RESULTS

A total of 1768 fundus photographs of 149 diabetic patients with dark irides were included. There were more ungradable images (38.1% and 50.3%, graders 1 and 2, respectively) in the non-mydriatic state than partially- (4.6% and 11.5%) or fully-dilated (15.4% and 10.0%) conditions (p < 0.001, both graders). Partially and fully dilated states had similar rates of ungradable images (p = 0.56 and p = 0.54, graders 1 and 2, respectively). Test-retest reliability (repeatability) was 92.5% and 74.3% for the two graders, respectively. Inter-grader agreement was moderate (Kappa = 0.50).

CONCLUSION

Non-mydriatic fundus photographs have a high rate of ungradable images in patients with dark irides. Instillation of only one drop of tropicamide improves the quality of fundus photographs, which is not furthered by adding more drops. This strategy can be used in tele-ophthalmology programs.

Distribution of Different Sized Ocular Surface Vessels in Diabetics and Normal Individuals

Purpose:

To compare the distribution of different sized vessels using digital photographs of the ocular surface of diabetic and normal individuals.

Methods:

In this cross-sectional study, red-free conjunctival photographs of diabetic and normal individuals, aged 30-60 years, were taken under defined conditions and analyzed using a Radon transform-based algorithm for vascular segmentation. The image areas occupied by vessels (AOV) of different diameters were calculated. The main outcome measure was the distribution curve of mean AOV of different sized vessels. Secondary outcome measures included total AOV and standard deviation (SD) of AOV of different sized vessels.

Results:

Two hundred and sixty-eight diabetic patients and 297 normal (control) individuals were included, differing in age (45.50 ± 5.19 vs. 40.38 ± 6.19 years, P < 0.001), systolic (126.37 ± 20.25 vs. 119.21 ± 15.81 mmHg, P < 0.001) and diastolic (78.14 ± 14.21 vs. 67.54 ± 11.46 mmHg, P < 0.001) blood pressures. The distribution curves of mean AOV differed between patients and controls (smaller AOV for larger vessels in patients; P < 0.001) as well as between patients without retinopathy and those with non-proliferative diabetic retinopathy (NPDR); with larger AOV for smaller vessels in NPDR (P < 0.001). Controlling for the effect of confounders, patients had a smaller total AOV, larger total SD of AOV, and a more skewed distribution curve of vessels compared to controls.

Conclusion:

Presence of diabetes mellitus is associated with contraction of larger vessels in the conjunctiva. Smaller vessels dilate with diabetic retinopathy. These findings may be useful in the photographic screening of diabetes mellitus and retinopathy.

Encircling Narrow Band versus Buckle for Retinal Detachments with Intrabasal or Unseen Retinal Breaks

Purpose:

To compare the results of narrow encircling band surgery with standard encircling scleral buckling for retinal detachments (RDs) with intrabasal or unseen breaks.

Methods:

In a retrospective study, eyes with intrabasal or unseen breaks underwent narrow band implantation (group N) or standard encircling buckling plus wide tire placement (group W) and were followed for at least one year.

Results:

A total of 112 eyes including 39 eyes in group N and 73 eyes in group W were studied. Preoperatively visual acuity of eyes in group N was significantly better (1.55 ± 0.9 vs. 1.93 ± 0.9 logMAR, P = 0.043). The two study groups (N and W) were comparable in terms of the extent of RD (2.8 ± 0.96 vs. 2.8 ± 0.93 quadrants), interval to surgery (88.3 ± 176.4 vs. 71.9 ± 135.4 days) and percentage of visible breaks (56.4% vs. 63%), respectively (all P values > 0.05). More atrophic holes were present in group W and more dialyses were reported in group N. The single operation success rate at 12 months was 69.2% in group N and 74% in group W (P = 0.1). The single operation success rate for eyes with unseen breaks was also comparable (66.7% vs. 85.7%, P = 0.157). Final corrected visual acuity was also similar (0.63 ± 0.44 vs. 0.85 ± 0.69 log MAR). The only factor influencing success rate was the type of retinal breaks (P = 0.04). Type of scleral buckling did not affect the single operation success rate (P = 0.460).

Conclusion:

Narrow encircling band surgery is a possible option with acceptable single operation success rate for RDs with intrabasal or unseen breaks.

Fully automated diabetic retinopathy screening using morphological component analysis

Diabetic retinopathy is the major cause of blindness in the world. It has been shown that early diagnosis can play a major role in prevention of visual loss and blindness. This diagnosis can be made through regular screening and timely treatment. Besides, automation of this process can significantly reduce the work of ophthalmologists and alleviate inter and intra observer variability. This paper provides a fully automated diabetic retinopathy screening system with the ability of retinal image quality assessment. The novelty of the proposed method lies in the use of Morphological Component Analysis (MCA) algorithm to discriminate between normal and pathological retinal structures. To this end, first a pre-screening algorithm is used to assess the quality of retinal images. If the quality of the image is not satisfactory, it is examined by an ophthalmologist and must be recaptured if necessary. Otherwise, the image is processed for diabetic retinopathy detection. In this stage, normal and pathological structures of the retinal image are separated by MCA algorithm. Finally, the normal and abnormal retinal images are distinguished by statistical features of the retinal lesions. Our proposed system achieved 92.01% sensitivity and 95.45% specificity on the Messidor dataset which is a remarkable result in comparison with previous work.

Higher titers of anti-Chlamydia pneumoniae IgG in diabetic retinopathy: a cross-sectional study

BACKGROUND

Chronic inflammation has a role in the pathogenesis of diabetic retinopathy. Infection with intracellular organisms may incite chronic inflammation. This study was conducted to investigate the association between previous infection with Chlamydia pneumoniae (an intracellular microorganism) and diabetic retinopathy.

METHODS

Patients with type 2 diabetes mellitus (30-60 years old) and age-matched normal controls were recruited. Patients with history of cardiovascular or cerebrovascular disease, recent pulmonary infection and the presence of age-related macular degeneration were excluded from the study. Complete ophthalmic examinations were performed. Fasting blood sugar and haemoglobin levels were measured in diabetic patients and controls, and HgbA1c , blood urea nitrogen, creatinine and 24-h urine protein were measured in diabetic patients. Anti-C. pneumoniae IgG (enzyme-linked immunosorbent assay) was measured in the sera of all participants.

RESULTS

A total of 215 type 2 diabetic patients and 243 normal healthy controls were included. Anti-C. pneumoniae IgG titers were higher in patients affected by diabetic retinopathy than participants without retinopathy (74.78 ± 33.38 vs 66.18 ± 31.40, p = 0.028). Diabetic patients with diabetic retinopathy also had higher titers than diabetic patients without diabetic retinopathy (74.78 ± 33.38 vs 66.11 ± 33.41, p = 0.042). Of different variables including age, body mass index, haemoglobin level, glycated haemoglobin level, fasting blood sugar, mean arterial pressure and blood urea nitrogen, only age (r = 0.17; p = 0.001) and body mass index (r = 0.15; p = 0.003) were correlated with anti-C. pneumoniae IgG levels. In regression analysis, the presence of diabetic retinopathy was still a determinant of the antibody level (p = 0.03).

CONCLUSION

Anti-C. pneumoniae IgG titers were higher in patients with diabetic retinopathy, which may indicate a role of this infection in the pathogenesis of diabetic retinopathy.

A Novel Curvature-Based Algorithm for Automatic Grading of Retinal Blood Vessel Tortuosity

Tortuosity of retinal blood vessels is an important symptom of diabetic retinopathy or retinopathy of prematurity. In this paper, we propose an automatic image-based method for measuring single vessel and vessel network tortuosity of these vessels. Simplicity of the algorithm, low-computational burden, and an excellent matching to the clinically perceived tortuosity are the important features of the proposed algorithm. To measure tortuosity, we use curvature which is an indicator of local inflection of a curve. For curvature calculation, template disk method is a common choice and has been utilized in most of the state of the art. However, we show that this method does not possess linearity against curvature and by proposing two modifications, we improve the method. We use the basic and the modified methods to measure tortuosity on a publicly available data bank and two data banks of our own. While interpreting the results, we pursue three goals. First, to show that our algorithm is more efficient to implement than the state of the art. Second, to show that our method possesses an excellent correlation with subjective results (0.94 correlation for vessel tortuosity, 0.95 correlation for vessel network tortuosity in diabetic retinopathy, and 0.7 correlation for vessel network tortuosity in retinopathy of prematurity). Third, to show that the tortuosity perceived by an expert and curvature possess a nonlinear relation.

A Simple Method for Removal of Particles from the Retinal Surface during Vitrectomy

Removal of particulate materials from the retinal surface is somewhat difficult during small gauge vitrectomy. Simple injection of balanced salt solution into the vitreous cavity in a controlled manner using a connector tubing between the syringe and needle can produce enough turbulence to float the deposited material and remove it.

Distribution of normal superficial ocular vessels in digital images

PURPOSE

To investigate the distribution of different-sized vessels in the digital images of the ocular surface, an endeavor which may provide useful information for future studies.

METHODS

This study included 295 healthy individuals. From each participant, four digital photographs of the superior and inferior conjunctivae of both eyes, with a fixed succession of photography (right upper, right lower, left upper, left lower), were taken with a slit lamp mounted camera. Photographs were then analyzed by a previously described algorithm for vessel detection in the digital images. The area (of the image) occupied by vessels (AOV) of different sizes was measured. Height, weight, fasting blood sugar (FBS) and hemoglobin levels were also measured and the relationship between these parameters and the AOV was investigated.

RESULTS

These findings indicated a statistically significant difference in the distribution of the AOV among the four conjunctival areas. No significant correlations were noted between the AOV of each conjunctival area and the different demographic and biometric factors. Medium-sized vessels were the most abundant vessels in the photographs of the four investigated conjunctival areas. The AOV of the different sizes of vessels follows a normal distribution curve in the four areas of the conjunctiva. The distribution of the vessels in successive photographs changes in a specific manner, with the mean AOV becoming larger as the photos were taken from the right upper to the left lower area.

CONCLUSIONS

The AOV of vessel sizes has a normal distribution curve and medium-sized vessels occupy the largest area of the photograph.

A distinct autosomal recessive ocular anomaly in Chaharborj, Islamic Republic of Iran

In Chaharborj, a village in north-eastern ofthe Islamic Republic of Iran, a high prevalence of congenital blindness (1.1%) has been reported. The clinical findings have not been fully described. We therefore assessed the clinical aspects of this condition in a case series of 20 congenitally blind patients and 24 of their parents. All patients had been blind since birth. There was anterior segment dysgenesis and retinal non-attachment in all patients. There were no systemic anomalies. Histopathologically, there was iridocorneal adhesion, normal angle structure and retinal dysplasia. No significant difference was found in the frequency of different HLA class I alleles compared with the general population. The anomaly causing congenital blindness in these patients has components of both anterior and posterior segment dysgenesis. It appears to be a distinct entity with an autosomal recessive pattern of inheritance.

Early decomposition of retained heavy silicone oil droplets

PURPOSE

To report a case of early decomposition of retained heavy silicone oil droplets.

CASE REPORT

The single highly myopic eye of a 16-year-old boy with history of scleral buckling and buckle revision developed redetachment due to inferior retinal dialysis. The patient underwent pars plana vitrectomy and injection of heavy silicone oil. Early emulsification of the silicone oil was observed following surgery, which was removed 4 weeks later in another operation. Retained heavy silicone droplets lost their heavier- than-water specific gravity within 2 months together with extensive iris depigmentation, and release of pigment granules into the anterior chamber and vitreous cavity.

CONCLUSION

This case report demonstrates that heavy silicone oil droplets can undergo in vivo chemical decomposition with possible toxic effects on ocular tissues.

Scleral fixation of intraocular lens in eyes with history of open globe injury

PURPOSE

To report the results and complications of scleral fixation of intraocular lens (SF-IOL) in traumatized eyes of children with iris defects and inadequate capsular support with technique customized to the condition of the eye.

METHODS

Retrospective review of pediatric eyes with a history of open globe injury and SF-IOLs. All eyes had undergone pars plana vitrectomy and lensectomy after primary repair of the laceration. Site of scleral fixation and limbal incision were selected according to the site of traumatic scar, remaining capsular support, and keratometry.

RESULTS

Ten patients with a mean age of 6.1 years were included. Mean duration of aphakia was 18.7 months. Five eyes had adequate capsular support for one haptic of the IOL. The only intraoperative complication was mild ciliary body hemorrhage. Mean follow-up was 11.8 months. Uncorrected visual acuity did not improve postoperatively in only one eye due to severe corneal astigmatism. Best-corrected visual acuity improved in 6 eyes. Mean postoperative sphere and cylinder were 1.8 and -3.05 diopters, respectively. The only postoperative complication was decentration of a sulcus-fixed haptic needing reoperation in one eye.

CONCLUSION

SF-IOL is a viable option for correcting traumatic aphakia and can have good results if customized to the condition of the eye.

Foveal Protection with Viscoelastic Material during Removal of Posterior Segment Foreign Bodies

Foreign bodies may drop during removal from the posterior segment and result in foveal damage. Due to high specific gravity and viscosity, ophthalmic viscosurgical devices (OVDs) can dampen and redirect the force of the dropping foreign body and therefore protect the fovea. Herein we describe our technique of foveal protection with OVDs and briefly demonstrate the results in five eyes with large posterior segment foreign bodies.

Anatomical and visual outcomes of three different scleral buckling techniques

PURPOSE

To compare the anatomical and visual outcomes of three different scleral buckling techniques and to explore the effect of cryotherapy and subretinal fluid drainage (SRFD) on outcomes of surgery.

METHODS

This retrospective study was performed on 111 eyes of 109 patients undergoing scleral buckling for rhegmatogenous retinal detachments (RRDs) by a single surgeon. Pre-, intra- and postoperative data were retrieved from hospital records.

RESULTS

Buckles were radial in 27 (24.3%), circumferential (segmental) in 16 (14.4%) and encircling in 68 (61.3%) eyes. Anatomical and visual results were comparable with all three buckling techniques. Application of cryotherapy, the spot number, and SRFD did not affect anatomical and visual results. The only preoperative factor associated with poorer anatomical results was the presence of multiple retinal breaks (P=0.006). The following preoperative factors affected visual outcomes on univariate analysis: extent of retinal detachment (r=0.417, P=0.011) and relative afferent pupillary defect (r=0.423, P=0.02). Preoperative macular status (attached vs detached) also had a significant effect on visual outcomes (P<0.001). Based on multivariate analysis however, only preoperative macular status was significantly correlated with visual results (P=0.022). Silicone sponges placed for non-encircling surgery were removed due to ocular dysmotility in 4 (3.6%) eyes, cosmetic reasons in 3 (2.7%) cases and extrusion in 2 (1.8%) eyes. One encircling tire was also removed due to extrusion.

CONCLUSION

Surgical technique and performing cryotherapy or SRFD do not seem to influence the anatomical and visual outcomes of scleral buckling. Postoperative complications seem to be more prevalent with non-encircling techniques.

Abnormal Cambridge low-contrast grating sensitivity results associated with diabetic retinopathy as a potential screening tool

Contrast sensitivity is proposed as a potential screening tool for the early detection of diabetic retinopathy. A cross-sectional study was performed in a tertiary referral university eye centre. A total of 80 diabetes patients were recruited and tests were performed on 154 eyes. Contrast sensitivity was checked using Cambridge low-contrast grating. Abnormal contrast sensitivity was observed in 27.1% of eyes with diabetic retinopathy, compared with 9.0% in unaffected eyes, a statistically significant difference. Cambridge low-contrast grating is a potential screening tool for early detection of diabetic retinopathy by non-ophthalmologists.

Vitreoretinal Disorders in Anterior Megalophthalmos

PURPOSE

To describe vitreoretinal abnormalities in patients with anterior megalophthalmos (AM) and to report the results of vitreoretinal surgery in these cases.

METHODS

In a retrospective, noncomparative case series, a diagnosis of AM was made according to the following criteria: megalocornea, iris hypoplasia, lens subluxation, cataract formation at an early age, and absence of congenital glaucoma. Vitreous biomicroscopy and funduscopy were performed in all patients. Patient records were also reviewed.

RESULTS

Twenty-four patients with AM (12 male, 12 female), aged 4 months to 64 years, were included in this study. Funduscopy was possible in 46 eyes. Vitreous degeneration was the most common abnormal posterior segment finding, present in 34 eyes (73.9%). Nine eyes (19.5%) had optically empty vitreous with strands. Lattice degeneration was seen in five eyes (10.8%). Spontaneous vitreous hemorrhage occurred in three eyes, and peripheral retinal neovascularization was detected in two. Retinal detachment occurred in 18 eyes (37.5%); retinal breaks were detected in eight of these before surgery. Thirteen eyes underwent a total of 18 procedures. Retinal reattachment was finally achieved in 12 of the 13 eyes.

CONCLUSIONS

Anterior megalophthalmic eyes seem to be affected by a type of vitreoretinopathy predisposing to retinal detachment. Current vitreoretinal surgical techniques usually achieve good anatomic results in these cases.

Removal of traumatic cyclitic membranes: surgical technique and results

BACKGROUND

As most patients with a history of open globe injury and judged to have cyclitic membrane are denied further surgery because of poor prognosis, a technique for creating radial cuts in traumatic cyclitic membranes and its results are described.

METHOD

This is a retrospective non-comparative interventional case series of eight eyes with history of penetrating eye injury with fibrovascular membrane over the pars plicata observed during vitrectomy. All eyes were hypotonic; two had undergone previous vitrectomy and had developed RD. During vitrectomy after penetrating trauma, lens and its capsule or IOL was removed, fibrovascular membrane was visualized over pars plicata with the aid of external compression and after removal of the center of anterior hyaloid face, radial cuts were placed over the membrane. The resulting pieces were removed with vitrectomy probe. An encircling buckling element was placed in all eyes. Best corrected visual acuity, IOP, and postoperative complications are described.

RESULTS

Eight eyes of eight patients (F: 3, M: 5) with an age range of 2-22 years (median: 11.5) with traumatic cyclitic membranes treated with the above technique were included in the study. They were followed for 6-18 months (median: 12 months). Seven patients had visual acuity of light perception to hand motion before operation . Preoperative IOP was low in all eyes (2-5 mmHg, median: 4 mmHg). One eye with a history of large foreign body removal was finally visually lost due to PVR. The other eyes had visual acuity of more than 20/100 (more than 20/60 in six eyes) and a normal IOP (8-20 mmHg, median 11 mmHg) in the last visit.

CONCLUSION

Placement of radial cuts over traumatic cyclitic membranes followed by removal of the pieces is well tolerated by the ciliary epithelium with good retaining of its secretory function and normalization of IOP.

Anatomic and visual outcomes of scleral buckling versus primary vitrectomy in pseudophakic and aphakic retinal detachment: six-month follow-up results of a single operation--report no. 1

PURPOSE

To compare the anatomic and visual results and complications of conventional scleral buckling versus primary vitrectomy for management of pseudophakic and aphakic retinal detachment.

DESIGN

Prospective, randomized, multicenter clinical trial.

PARTICIPANTS

Two hundred twenty-five eyes of 225 patients with pseudophakic or aphakic retinal detachment.

INTERVENTION

Eligible eyes were assigned randomly either to conventional scleral buckling or primary vitrectomy without any buckle.

MAIN OUTCOME MEASURES

Visual results, retinal reattachment rate, proliferative vitreoretinopathy, macular pucker, cystoid macular edema, choroidal detachment, intraocular pressure, extraocular muscle dysfunction, and anisometropia.

RESULTS

There were no statistically significant differences between the 2 treatment groups regarding the single-operation retinal reattachment rate at the 1-, 2-, 4-, and 6-month follow-up examinations. Patients in the buckle group had 28% greater likelihood of anatomic success compared with those in the vitrectomy group (odds ratio, 1.28; 95% confidence interval, 0.73-2.24), indicating no statistically significant difference. Proliferative vitreoretinopathy was the main cause of anatomic failure in both groups and occurred independent of the surgical technique used. Best-corrected visual acuity at the 1-, 2-, 4-, and 6-month postoperative follow-up examinations showed no statistically significant difference between the 2 groups. Six months after surgery, 12.8% of eyes in the buckle group and 11.3% of eyes in the vitrectomy group achieved visual acuity of 20/40 or better. The difference between the 2 groups was not statistically significant. Corresponding figures were 66.3% and 64.5% for visual acuity of 20/200 or better in the buckle and vitrectomy groups, respectively, again with no statistically significant difference. There were no statistically significant differences in rates of complications.

CONCLUSIONS

Scleral buckling and primary vitrectomy without an encircling band have comparable results in pseudophakic and aphakic retinal detachment. The choice of surgical technique depends on various factors, including patient compliance, cost of surgery, experience and capability of surgeons, and availability of appropriate instrumentation.