Treatment outcomes for maculopathy secondary to retinal vein occlusion in Afghanistan

OBJECTIVES

The objective of this study was to investigate the efficacy of intravitreal antivascular endothelial growth factor (VEGF) therapy in the treatment of macular edema secondary to retinal vein occlusion (RVO) in Afghanistan.

METHODS

A retrospective analysis was conducted of all RVO cases that underwent intravitreal ant-VEGF injection at the two leading hospitals in Kabul. The main outcome measures were visual acuity and central retinal thickness as determined by optical coherence tomography. Information was also collected on the distance traveled by each patient and the frequency of injections.

RESULTS

One hundred and twenty-five eyes of 121 patients (86 males) with RVO were identified as having undergone treatment, with a mean age of 53.1 years (range 20-80). The only agent used was bevacizumab. The mean central retinal thickness reduced from 624.2 ± 24.9 μm at the baseline to 257.8 ± 5.7 μm following treatment (P < 0.001). There was a small increase in visual acuity from 1.33 LogMAR at the baseline to 1.13 LogMAR following the most recent injection (P = 0.03, paired t-test). The mean distance traveled by patients was 173.9 km (range 2-447 km).

CONCLUSION

Despite the challenges of health-care provision in Afghanistan, this review shows that the use of intravitreal bevacizumab has provided an effective treatment for macular edema after RVO.

PHOTORECEPTOR DAMAGE IN TERSON SYNDROME

PURPOSE

To describe photoreceptor damage in patients with Terson syndrome as a potential cause for inconsistent clinical outcomes.

METHODS

Clinical evaluation and retinal imaging in six patients.

RESULTS

Four patients were women and two men, with an average age of 46.8 years (SD 8.9). Four patients suffered aneurysmal subarachnoid hemorrhage, one vertebral artery dissection, and one superior sagittal sinus thrombosis. In 11 eyes, a consistent pattern of outer retinal changes within the central retina affecting the ellipsoid zone and the outer nuclear layer was observed, indicating photoreceptor damage. Areas of photoreceptor damage showed poor spatial correlation with intraocular hemorrhage, particularly subinternal limiting membrane hemorrhage. The observed retinal abnormalities demonstrated incomplete recovery over long-term follow-up 3.5 to 8 years posthemorrhage, irrespective of surgical or conservative treatment strategy, and had variable impact on the patients' visual function.

CONCLUSION

The observations suggest that photoreceptor damage in Terson syndrome likely represents a distinct manifestation of this condition, which could be caused by transient ischemia of the outer retina secondary to acute rise in intracranial pressure.

Surgical outcomes in only eye cataract surgery

INTRODUCTION

Performing cataract surgery in the setting of only one seeing-eye has significant benefits but also potential negative consequences for both patient and surgeon. This study investigates the surgical outcomes in patients undergoing cataract surgery on their only seeing-eye.

METHODS

A retrospective analysis was conducted in a single tertiary centre of all adult patients who had undergone cataract surgery on their only eye, where the fellow eye had a vision of 1.0 LogMAR or worse. Complication rates and visual outcomes were compared against data from the National Ophthalmology Database (NOD) Audit.

RESULTS

918 patients underwent cataract surgery on their only seeing-eye and had their postoperative visual acuity recorded. The overall unadjusted complication rate was 4.0% (versus 2.5% from NOD data) with the rate of posterior capsule rupture (PCR) being 1.9% (versus 1.14% from NOD data). 72.5% (versus 91.5% from NOD data) of patients attained a post-operative visual acuity of 0.3 LogMAR or better. The grade of surgeon performing the surgery did not have a statistically significant effect on the risk of complications.

DISCUSSION

In this cohort of only-eye patients undergoing cataract surgery, there was a small increased risk of operative complications including an increased, unadjusted risk of PCR, and fewer eyes achieved 0.3 LogMAR vision post-operatively compared to the NOD audit data. Grade of surgeon did not have an impact on the complication rate, indicating that with appropriate supervision, trainee surgeons may gain experience in only-eye surgery without additional risk to the patient. Further multicentre studies are recommended to assess reproducibility across units.

Analysis of Early Cone Dysfunction in an In Vivo Model of Rod-Cone Dystrophy

Retinitis pigmentosa (RP) is a generic term for a group of genetic diseases characterized by loss of rod and cone photoreceptor cells. Although the genetic causes of RP frequently only affect the rod photoreceptor cells, cone photoreceptors become stressed in the absence of rods and undergo a secondary degeneration. Changes in the gene expression profile of cone photoreceptor cells are likely to occur prior to observable physiological changes. To this end, we sought to achieve greater understanding of the changes in cone photoreceptor cells early in the degeneration process of the Rho^−/− mouse model. To account for gene expression changes attributed to loss of cone photoreceptor cells, we normalized PCR in the remaining number of cones to a cone cell reporter (OPN1-GFP). Gene expression profiles of key components involved in the cone phototransduction cascade were correlated with tests of retinal cone function prior to cell loss. A significant downregulation of the photoreceptor transcription factor Crx was observed, which preceded a significant downregulation in cone opsin transcripts that coincided with declining cone function. Our data add to the growing understanding of molecular changes that occur prior to cone dysfunction in a model of rod-cone dystrophy. It is of interest that gene supplementation of CRX by adeno-associated viral vector delivery prior to cone cell loss did not prevent cone photoreceptor degeneration in this mouse model.

A Novel Achromatopsia Mouse Model Resulting From a Naturally Occurring Missense Change in Cngb3

Purpose

A local colony of inbred mice (129S6/SvEvTac origin), in isolation for over a decade, were found to have absent light-adapted electroretinogram (ERG) responses. We investigated the inheritance and genetic basis of this phenotype of cone photoreceptor function loss.

Methods

An affected 129S6/SvEvTac colony animal was outcrossed to a C57BL/6J mouse and intercrossed to investigate inheritance in the F2 generation. We performed ERG testing and targeted resequencing on genes of interest (Gnat2, Cnga3, Cngb3, Pde6c, Hcn1, Syne2). The eyes of a subset of animals underwent histologic immunostaining.

Results

All 129S6/SvEvTac colony animals tested lacked cone pathway function by ERG testing (n = 12), although rod pathway-based ERG responses remained unaffected. Outcross-intercross breeding showed a recessive inheritance pattern. A novel missense mutation was identified in the Cngb3 gene, which causes an amino acid substitution at a conserved residue (NM_013927)c.692G>A; p.(R231H). The recessive phenotype only affected homozygotes (χ2 = 39, P = 3.2e-10). Cones had normal morphology at postnatal day (PND) 70, but cone cell counts declined from PND 30 to PND 335 (P = 0.038), indicating progressive cone photoreceptor death.

Conclusions

We identified the spontaneous occurrence of a 10th model of cone photoreceptor function loss (cpfl10) in an isolated line of inbred mice. Our results indicate that this is caused by a novel missense mutation in the Cngb3 gene, with a fully recessive inheritance pattern. This mouse may provide a more appropriate background against which to assess CNGB3 achromatopsia gene therapy for missense mutations.

Transplanted photoreceptor precursors transfer proteins to host photoreceptors by a mechanism of cytoplasmic fusion

Photoreceptor transplantation is a potential future treatment for blindness caused by retinal degeneration. Photoreceptor transplantation restores visual responses in end-stage retinal degeneration, but has also been assessed in non-degenerate retinas. In the latter scenario, subretinal transplantation places donor cells beneath an intact host outer nuclear layer (ONL) containing host photoreceptors. Here we show that host cells are labelled with the donor marker through cytoplasmic transfer—94±4.1% of apparently well-integrated donor cells containing both donor and host markers. We detect the occurrence of Cre-Lox recombination between donor and host photoreceptors, and we confirm the findings through FISH analysis of X and Y chromosomes in sex-discordant transplants. We do not find evidence of nuclear fusion of donor and host cells. The artefactual appearance of integrated donor cells in host retinas following transplantation is most commonly due to material transfer from donor cells. Understanding this novel mechanism may provide alternate therapeutic strategies at earlier stages of retinal degeneration.

Previous studies have used fluorescently labelled cells to demonstrate the incorporation of transplanted photoreceptor precursors into the mouse retina. Here, the authors show that fluorescent proteins are passed between the host and transplanted cells rather than migration of donor cells into the retina.

Unsutured phakic implantation of a black intraocular lens in the sulcus to treat leukocoria

We describe a 40-year-old woman with von Hippel-Lindau syndrome, secondary chronic exudative retinal detachment, and white cataract with consequent leukocoria. Because the cataract was contracted and calcified, a black Morcher 85F poly(methyl methacrylate) IOL was implanted in the ciliary sulcus anterior to the lens to prevent posterior capsule rupture and potential destabilization of the retinal detachment with a risk for phthisis. Excellent centration of the black IOL was achieved with good cosmetic outcome and without postoperative uveitis or glaucoma. We suggest that this is a rare indication for implantation of an IOL designed for the sulcus but in the presence of the crystalline lens. This approach makes IOL removal, if necessary at a later date, relatively straightforward.

Financial Disclosure

No author has a financial or proprietary interest in any material or method mentioned.

Cone photoreceptor neuroprotection conferred by CNTF in a novel in vivo model of battlefield retinal laser injury

PURPOSE

To develop a reproducible laboratory model to simulate a battlefield foveal laser injury and to test potential neuroprotective effects of a single injection treatment that might be administered in a military setting.

METHODS

Frequency-doubled 532-nm Nd:YAG laser was used to induce a threshold retinal injury bilaterally in transgenic reporter mice that have fluorescent cones. Intravitreal injection of ciliary neurotrophic factor (CNTF) was then administered to the lasered eye and compared with a contralateral sham injection of saline. The effect on fluorescent cone cell survival was quantified using a confocal scanning laser ophthalmoscope (cSLO), TUNEL assays, and quantitative real-time PCR (qPCR).

RESULTS

At 3 weeks post-laser, cSLO imaging showed that the proportion of surviving cones expressing green fluorescent protein (GFP) was greater in CNTF-treated (54.1 ± 5.15% of baseline count) than in sham-injected eyes (28.7 ± 4.4%), which was accompanied by a reduction in TUNEL-positive cells. This difference in cone survival persisted at the 6-week point (treated, 39.6 ± 3.2% versus sham, 18.0 ± 3.8%). These changes were accompanied by a reduction in TUNEL-positive cells. The Bcl-2/Bax ratio was increased in CNTF-treated eyes at 1 week postlaser exposure relative to controls.

CONCLUSIONS

A single intravitreal injection of CNTF protein was shown to improve cone survival when administered immediately after laser exposure. Similar treatments with CNTF might also have a role in attenuating retinal laser damage sustained by combat personnel in the military setting.

Risk of iatrogenic peripheral retinal breaks in 20-G pars plana vitrectomy

PURPOSE

To estimate the frequency and risk factors for entry site and other peripheral iatrogenic retinal breaks in eyes undergoing standard 20-G 3-port pars plana vitrectomy.

DESIGN

Single-center, retrospective, interventional case series.

PARTICIPANTS

A total of 645 eyes undergoing pars plana vitrectomy at Moorfields Eye Hospital during the period June 1, 2005, to June 1, 2006, for indications excluding rhegmatogenous retinal detachment.

METHODS

Case note review. Exclusion criteria were preexisting retinal breaks or rhegmatogenous retinal detachment, previously vitrectomized eyes, and iatrogenic breaks posterior to the equator.

MAIN OUTCOME MEASURES

Frequency, anatomic location, and risk factors associated with iatrogenic peripheral retinal breaks and rate of postoperative rhegmatogenous retinal detachment.

RESULTS

Iatrogenic peripheral retinal breaks occurred in 98 of 645 eyes (15.2%) intraoperatively. Eleven of 645 cases (1.7%) experienced postoperative rhegmatogenous retinal detachment caused by undetected or new peripheral retinal breaks. Breaks were most common during surgery for tractional retinal detachment (22.2%), macular hole (18.1%), dislocated intraocular lens implants (16.7%), and epiretinal membrane (13.9%). Overall, breaks were more common in the superior retina (P<0.01), with 41.5% occurring in the 10 and 2 o'clock positions. Eyes requiring surgical induction of a posterior vitreous detachment had 2.9 times greater odds of developing iatrogenic peripheral retinal breaks (95% confidence interval, 1.8-4.7, P<0.001) than eyes with preexisting posterior vitreous detachment. Similarly, phakic eyes had 2.4 times higher odds (95% confidence interval, 1.42-3.96, P = 0.001) of break formation.

CONCLUSIONS

Iatrogenic peripheral retinal breaks caused by vitrectomy are more common than previously indicated. Approximately 4 in 10 breaks are related to traction at sclerotomy entry sites. Eyes undergoing surgery for tractional retinal detachment seemed to have the highest risk for break formation. Similarly, phakic eyes and eyes that require induction of a posterior vitreous detachment have more than double the risk for break formation.

Systemic tuberculosis presenting with acute transient myopia: a case report

INTRODUCTION

Transient myopia has been reported to occur in a number of conditions, either ocular in origin or associated with an underlying systemic cause. We present a rare case of this abnormality occurring in the setting of systemic tuberculosis.

CASE PRESENTATION

A 29-year-old Indian woman presented with sudden onset blurred distance vision and fever. Examination revealed visual acuity of counting fingers in both eyes improving to 6/9 with pinhole with N5 reading acuity. Anterior segment examination revealed narrow angles on gonioscopy. Posterior segments were normal. Systemic examination revealed a fluctuant mass in her left loin, aspiration of which yielded pus which was culture-positive for Mycobacterium tuberculosis. The Mantoux test elicited a strongly positive reaction. Chest X-ray and magnetic resonance imaging of the brain were unremarkable. Computed tomography scan and magnetic resonance imaging of the spine and abdomen revealed a large psoas abscess communicating with the loin mass. Two vertebrae were involved but not the spinal cord or canal.

CONCLUSION

Transient myopia is a rare presenting feature of systemic tuberculosis. A postulated mechanism in this patient is that development of a uveal effusion related to systemic tuberculosis caused anterior rotation of the iris-lens diaphragm, thereby inducing narrowing of the angle and acute myopia.

Undiagnosed type 2 diabetes mellitus presenting with orbital cellulitis

The authors describe the case of a 48 years old woman who presented with a one week history of a painful, swollen left eye with proptosis and diplopia. A computed tomography (CT) scan showed features of left orbital cellulitis, and blood tests and urinalysis confirmed the diagnosis of diabetes mellitus. The infection resolved following a course of intravenous antibiotics and with glycaemic control. To our knowledge, undiagnosed diabetes mellitus presenting with orbital cellulitis has not previously been reported.

Visual improvement after long-standing central serous macular detachment associated with an optic disc pit

BACKGROUND

Approximately 50% of cases of congenital optic disc pits are associated with serous macular detachment. Long-standing serous detachments (over 1 year) with poor initial presenting acuity are usually associated with cystic degeneration of the macula and loss of pigment from the underlying retinal pigment epithelium, with resultant poor visual outcome.

METHODS

A 43-year-old male presented with an optic disc pit and associated serous elevation of the macular region with cystic changes at the fovea.

RESULTS

Over the following 2 years, the patient was aware of an improvement in vision, and acuity improved from 1/60 to 6/18 with resolution of subretinal fluid, as evidenced on optical coherence tomography.

CONCLUSIONS

We report an unusual case of an optic disc pit associated with a long-standing serous macular detachment that resolved gradually over a 2.5-year period and, despite very poor presenting visual acuity, demonstrated eventual visual recovery.

Sub-Tenon's block complicated by subconjunctival cilia

We describe an unusual case of symptomatic eyelash entrapment in the subconjunctival space following a sub-Tenon's block. This case emphasizes the need for vigilance in patients reporting a persistent foreign-body sensation following surgery with this common modality of anesthesia.

Emergency management of corneal injuries

Corneal injuries account for a significant proportion of the ophthalmic workload of most emergency departments. Although the vast majority of cases are relatively minor, accurate diagnosis and appropriate management are vital to prevent potentially sight-threatening sequelae. We present a survey of corneal injury cases at a general emergency department.

INTRODUCTION

Corneal injuries are very common in both the adult and paediatric population and account for a significant proportion of the workload of most emergency departments. This survey assesses management of corneal injury cases at a general emergency department.

MATERIALS AND METHODS

A retrospective case study was performed of 100 patients consecutively diagnosed with a corneal abrasion by slit lamp examination at the emergency department of the Chelsea and Westminster Hospital, London. Each case was assessed to determine documentation of set criteria including visual acuity (VA), treatment and grade of examiner.

RESULTS

The commonest cause of injury was direct minor trauma (64% of cases) with contact lens related problems accounting for 12% of presentations. VA was documented correctly in 85 adult patients (90.4% of adults), incorrectly in 2 cases, and not documented at all in 7 adults (7.4%). VA was not recorded in paediatric cases. All cases were treated with topical chloramphenicol drops although frequency of treatment ranged from 2 to 5 times daily and duration of treatment ranged between 3 and 5 days and for 7 days. 6 cases (6%) were assessed by an emergency nurse practitioner and the remaining number were seen by a casualty officer.

DISCUSSION

VA must be accurately documented in all adult cases and should be documented in children of school age. A pinhole test should be performed in cases where VA is below 6/9. For analgesia, the use of topical nonsteroidal anti-inflammatory drugs, lubricants and bandage contact lens should be considered. Emergency nurse practitioners and general practitioners are ideally placed to follow-up uncomplicated cases.

Patient consultation survey in an ophthalmic outpatient department

INTRODUCTION

Consultation methods differ between medical practitioners depending on the individual setting. However, the central tenet to the doctor-patient relationship is the issue of confidentiality. This prospective survey highlights patient attitudes towards consultation methods in the setting of an ophthalmic outpatient department.

METHOD

Questionnaires were completed by 100 consecutive patients, who had been seen by an ophthalmologist in a single room, which had a joint doctor-patient consultation occurring simultaneously.

RESULTS

Each question of all 100 questionnaires was completed. 58% of patients were not concerned about sharing a consultation room with another patient or doctor. However, this did not equate to the 49% of patients who were indifferent to discussing issues in the joint consultation room. The most common factor was the general issue of confidentiality.

DISCUSSION

Ensuring total patient confidentiality may be deemed more necessary for certain medical specialties than for others, as seen in the practice of separate medical records in genitourinary medicine, for instance. However, with regard to patient consultations, the same level of confidentiality should be afforded across all specialties, and such factors should be borne in mind when planning outpatient clinics.

Ocular features of Sjogren?Larsson syndrome

Sjogren-Larson syndrome is a rare autosomal recessive neurocutaneous disorder characterized by a triad of intellectual disability, spastic diplegia or tetraplegia and congenital ichthyosis with associated ocular features, which include pigmentary changes in the retina. The usual presentation of crystalline maculopathy is from the age of 1-2 years onwards. Herein, a case of Sjogren-Larson syndrome in a 25-year-old woman is presented to highlight the ocular findings.

Cataract surgery for junior ophthalmologists: are there enough cases?

AIM

To evaluate those cases that are suitable for operation by the junior ophthalmic trainee.

METHODS

A prospective survey of 96 consecutive cases from five consultant lists for phacoemulsification over a 1 month period were preoperatively assessed for their suitability for the ophthalmic trainee using set criteria. A checklist was designed for all patients and criteria were marked with reference to suitability by a single examiner. The criteria chosen were arbitrary and had no bearing on a consultant's final decision to allow the junior to operate.

RESULTS

Twenty-two out of 96 cases (22.9%) were deemed to be suitable for operation by a junior ophthalmologist (ie 4.4 cases per consultant list). The three main reasons for exclusion were first eye case, eye for operation with visual acuity 6/12 or better, and mature cataract.

DISCUSSION

Using our results, if 4.4 cases were suitable for a junior ophthalmologist per month, this would allow for adequate exposure during the early stages of training. However, if the number of relatively straightforward cases on training lists were to be reduced owing to unavailability on hospital waiting lists, this could potentially compromise ophthalmic training in the future.