Most ophthalmic surgeons have used available needles without customisation ranging in size from 22 gauge (G) to 30G, with the 25G needle being the most commonly used.
Detailed longitudinal evaluation of corneal and other ophthalmological features of patients with lipoid proteinosis (LP).
Ophthalmological examinations, chart review, ultrasound biomicroscopy, corneal confocal microscopic examinations with Nidek confoScan 4 and direct sequencing of the extracellular matrix protein 1 gene in individuals from three consanguineous Saudi families with LP.
Seven individuals affected with LP (four female and three male subjects) were evaluated together with nine unaffected parents and siblings. All affected individuals had homozygous mutations in extracellular matrix protein 1. Four patients were examined frequently (every 6 months) beginning in infancy and early childhood. Globe and vision were normal in all individuals, and moniliform blepharosis always appeared after the age of 4 years. Prominent corneal nerves were detected in all patients regardless of age and were more apparent in patients with more severe genetic mutations. Conversely, the severity of moniliform blepharosis seemed age-dependent rather than genotype-related.
Prominent corneal nerves can be helpful in the early diagnosis of LP and should be added to the list of LP ophthalmological diagnostic features.
All experiments were conducted in accordance with the principles set forth in the Declaration of Helsinki. The expression of FP was examined by X-gal staining in ocular tissues of FP knockout mice carrying the β-galactosidase gene at the FP loci (Ptgfr–/– mice)
First, FP localisation was examined using Ptgfr–/– mice in which the β-galactosidase gene was ‘knocked-in’ at the FP gene. In the Ptgfr–/– mice, X-gal staining of ocular tissue revealed...]]>
Our experiments are based on monolayers of endothelial cells (ECs) grown under similar conditions for comparison. The results show significant differences between retinal and choroidal microvascular ECs and HUVEC. This is not surprising as particular diseases have particular predilection for specific vascular beds even within the same organ. The investigation of proliferation and IGF signalling in the microvascular ECs was confirmatory to our microarray studies. It was not directed at testing the potential of IGF to act as a costimulatory factor for somatic cell reprogramming.
We are of the opinion that postmortem artefact, including cessation of circulation, cannot be postulated as an explanation for the increased expression of pro-inflammatory genes in the...]]>
To investigate the retinal nerve fibre layer (RNFL) with optical coherent tomography (OCT) in prematurely-born children.
62 children born with a gestational age of ≤32 weeks, and a control group of 54 children born at term with normal birth weight (BW) were included in the study. 28 of the preterm children had retinopathy of prematurity (ROP) in the neonatal period; eight of them had severe ROP (stages 3–4). RNFL thickness was measured with Stratus OCT 3. Mean age at examination was 8.6 years in the preterm children and 10.1 years in the control group.
There was a significant difference between the children born preterm and those born at term, regarding RNFL thickness in the superior (right eye (RE), p=0.043; left eye (LE), p=0.048) and the nasal quadrants (RE, p=0.006; LE, p<0.001), as well as average RNFL thickness (RE, p=0.016; LE, p=0.029). This difference was caused by the thinner RNFL in children with previous severe ROP (stages 3 and 4). Within the preterm group, the average RNFL thickness increased with larger BW (RE, p=0.050; LE, p=0.028), but there was no correlation with gestational age at birth.
The RNFL was reduced in prematurely-born children with severe ROP when compared to children born at term. It is hypothesised that severe retinopathy as well as ablation of the retina with laser treatment or cryotherapy may affect the axons of the ganglion cells and thus reduce RNFL thickness. Prematurely-born children with low BW had a thinner RNFL, suggesting a negative effect of low birth weight on neural development.
To report the outcomes of a high-volume, multi-surgeon, multicentre LASIK corporation between 1998 and 2001.
46 708 eyes of 24 138 consecutive patients with myopic astigmatism had undergone LASIK using the Bausch & Lomb Technolas 217C excimer laser and Hansatome microkeratome. The study included 38 surgeons operating at 11 surgical centres. 31 surgeons underwent standardised training regardless of previous experience, which included didactic, observership and proctorship components. Mean attempted spherical equivalent refraction correction was –4.02±1.93 D (range –0.50 to –12.00 D). Mean attempted cylinder correction was 0.78±0.69 D (range 0.00 to 3.50 D). Median follow-up was 3 months.
Postoperative data with at least 1 month follow-up was available in 35 360 eyes (76%) of 18 195 patients. Predictability: mean deviation from intended spherical equivalent refraction correction was –0.21±0.47 D with 81% of eyes within ±0.50 D and 95% of eyes within ±1.00 D. Efficacy: uncorrected distance visual acuity was 20/20 in 71% of eyes and 20/40 in 95% of eyes. Safety: two or more lines of corrected distance visual acuity were lost in 0.57% of eyes. Postoperative corrected distance visual acuity was worse than 20/40 in 0.029% of eyes.
The short-term results of a high-volume, multi-surgeon LASIK Corporation were comparable with those reported in the Food and Drug Administration clinical trials during the same period.
Mathur et al
The cornea is largely considered to be an immune privileged site. There are several attributes that contribute to this notion such as the compact architecture of the corneal stroma, which is believed to retard migration of immune cells; the physiological blood–aqueous barrier that prevents any immunogenic mediators and cells entering the ocular tissue;
In addition to the study by Jung et al,
Vascularisation of the macula takes place between 24 and 27 weeks post-conception. Preterm birth may affect the formation of the foveal avascular zone (FAZ) and foveal depression, and displacement of inner retinal layers away from the incipient fovea.
To examine whether vascular abnormalities accompany an inner retinal abnormality, and whether they are coincident.
High-density spectral domain optical coherence tomography volume scans were obtained from 24 preterm children and 34 full-term controls (5–16 years). Matlab programs were used to quantify total retinal thickness, thickness of individual retinal layers and metrics of foveal morphology. Summed voxel projections for the ganglion cell layer–inner nuclear layer were used to identify the FAZ.
Preterm children had significantly smaller FAZ diameters than controls (p<0.0001). The foveal pits of preterm children were significantly shallower and less steep (p<0.0001) and total retinal thickness at the fovea was significantly increased (p<0.0001) compared to controls. The ganglion cell layer–inner plexiform layer and outer nuclear layer were significantly (p≤0.0001) thicker in preterm children than in controls.
Preterm birth results in abnormal foveal vascularisation, a failure of the inner retinal neurons to migrate away from the fovea, and an elevated outer nuclear layer ratio. The spatial coincidence of inner retinal and vascular abnormalities in preterm children supports the hypothesis that aspects of foveal development are interdependent.
Complex mechanisms make the eye an immunologically privileged site.
Retinal endothelial cells are crucially involved in the genesis of diabetic retinopathy which is treated with vascular endothelial growth factor (VEGF) inhibitors. Of these, ranibizumab can completely restore VEGF-induced effects on immortalised bovine retinal endothelial cells (iBREC). In most experiments supporting diabetic retinopathy therapy with bevacizumab, only non-retinal EC or retinal pigment epithelial cells have been used. Also, bevacizumab but not ranibizumab can accumulate in retinal pigment epithelial cells.
To investigate the effects of bevacizumab on VEGF-induced changes of iBREC properties and potential uptake and accumulation of both inhibitors.
Uptake of VEGF inhibitors by iBREC with or without pretreatment with VEGF165 was visualised by immunofluorescence staining and western blot analyses. Measured transendothelial resistance (TER) of iBREC (±VEGF165) showed effects on permeability, indicated also by the western blot-determined tight junction protein claudin-1. The influence of bevacizumab on proliferation and migration of iBREC was studied in the presence and absence of VEGF165.
Bevacizumab strongly inhibited VEGF-stimulated and basal migration, but was less efficient than ranibizumab in inhibiting VEGF-induced proliferation or restoring the VEGF-induced decrease of TER and claudin-1. This ability was completely lost after storage of bevacizumab for 4 weeks at 4°C. Ranibizumab and bevacizumab were detectable in whole cell extracts after treatment for at least 1 h; bevacizumab accumulated during prolonged treatment. Ranibizumab was found in the membrane/organelle fraction, whereas bevacizumab was associated with the cytoskeleton.
Both inhibitors had similar effects on retinal endothelial cells; however, some differences were recognised. Although barrier properties were not affected by internalised bevacizumab in vitro, potential adverse effects due to accumulation after repetitive intravitreal injections remain to be investigated.
To determine the efficacy of a remotely operated computer-based logarithmic (logMAR) visual acuity chart.
Visual acuity was tested using a laptop or computer-based logMAR chart (COMPlog) for all subjects by two different methods. The methods differed by the physical presence and absence (remote) of an optometrist and in the mode of instructions provided. Remote access was obtained through the internet, using Teamviewer software to control the system linked to COMPlog and instructions were provided by telephone. The order of measurements and the eye to be tested was randomised. logMAR visual acuity and time taken were recorded. A questionnaire was used to assess the participant's feedback.
Intraclass correlation for visual acuity between the two methods (α=0.964, 95% CI 0.937 to 0.979). There was no statistically significant difference (p=0.648) in the median visual acuity measurement between the two methods (median difference 0.00, IQR 0.20 logMAR). The time taken between the two methods was not statistically significant (p=0.457). There was no significant difference in the responses to the questionnaire between the study methods (p=0.119).
Tele (remotely controlled) visual acuity measurement is as reliable as that measured with the physical presence of an optometrist.
A significant proportion of paediatric keratoplasties are performed for endothelial dysfunction due to failed graft, congenital hereditary endothelial dystrophy
This study reports the indications, surgical technique and early outcomes of DSEK in children <14 years of age.
All children who underwent DSEK at our centre between January 2008 and January 2010 were included. Under general anaesthesia, an appropriate sized superior or temporal fornix based conjunctival flap was reflected and a 4–5 mm long, self-sealing scleral tunnel was made. The Descemet's membrane was scored using a reverse Sinskey hook and then stripped (except in cases of failed grafts). An anterior...]]>
It should be pointed that a great deal of literature has shown little or no foundation for the idea that low cerebrospinal fluid pressure is related to optic neuropathy.
To investigate the prevalence of, and demographic associations with, uncorrected refractive error (URE) in an older British population.
Data from 4428 participants, aged 48–89 years, who attended an eye examination in the third health check of the European Prospective Investigation into Cancer-Norfolk study and had also undergone an ophthalmic examination were assessed. URE was defined as ≥1 line improvement of visual acuity with pinhole-correction in the better eye in participants with LogMar presenting visual acuity (PVA) <0.3 (PVA <6/12). Refractive error was measured using an autorefractor without cycloplegia. Myopia was defined as spherical equivalent ≤–0.5 dioptre, and hypermetropia ≥0.5 dioptre.
Adjusted to the 2010 midyear British population, the prevalence of URE in this Norfolk population was 1.9% (95% CI 0.6% to 3.1%). Lower self-rated distance vision was correlated with higher prevalence of URE (ptrend<0.001). In a multivariate logistic regression model adjusting for age, gender, retirement status, educational level and social class, independent significant associations with URE were increasing age (ptrend<0.001) and having hypermetropic or myopic refractive error. Wearing distance spectacles was inversely associated with URE (OR 0.34, 95% CI 0.21 to 0.55, p<0.001). There were 3063 people (69.2%) who wore spectacles/contact lenses for distance vision. Spectacle wear differed according to type of refractive error (p<0.001), and use rose with increasing severity of refractive error (ptrend<0.001).
Although refractive error is common, the prevalence of URE was found to be low in this population reflecting a low prevalence of PVA<0.3.
To assess the effect of ranibizumab treatment for neovascular age-related macular degeneration (nvAMD) on patients' preferences and vision-related quality of life (VRQoL) in a routine clinical setting.
55 treatment naïve patients were examined before and after the initial upload of three monthly injections of 0.5 mg ranibizumab. VRQoL was assessed using a Rasch-adjusted NEI-VFQ-25. Time trade-off (TTO), standard gamble, a visual analogue scale and the European Quality of Life Questionnaire (EQ-5D) were used to calculate utilities, and multiple logistic regression models were conducted to determine independent factors associated with utilities.
Mean±SD age was 75±7 years, and 40 patients (73%) were female. Mean±SD best-corrected visual acuity of the treated eye increased from 20/80 at baseline (logMAR 0.60±0.35) to 20/63 (logMAR 0.52±0.36; p=0.020) at follow-up after three injections. Utility score increases ranged from 2 utils (standard gamble anchored for death) up to 6.6 utils (EQ-5D German TTO, p=0.023) and visual functioning improved (Rasch adjusted composite NEI-VFQ score 50±21 to 54±21, p=0.042). Whether the worse or better eye was treated was not significantly associated with improvements in utility or VRQoL, whereas VA improvement in the treated eye was associated with an increase in utility (TTO, p=0.020).
TTO performed best in this sample of elderly nvAMD patients undergoing anti-VEGF therapy. Better or worse eye treatment was not associated with a change in reported utilities or visual functioning in patients with newly diagnosed nvAMD. Directly elicited, vision-specific utilities gained with TTO seem to be sensitive to a change in vision status.
We read the paper by Minassian et al with great interest and thought that figures we have derived from the Certifications Office, London, on the incidence of new certifications for diabetic eye disease would be a useful resource alongside the prevalence figures provided.
To identify aspects of daily living affected by nystagmus.
Semistructured interviews were conducted at the University of Leicester, UK with participants with acquired and infantile nystagmus. In total 21, participants were purposively sampled and recruited. Transcript analysis was conducted using constant comparative technique, based upon the grounded theory, to identify specific areas of living affected by nystagmus.
Analysis identified six domains that were adversely affected by nystagmus; visual function, restriction of movement, standing out/not fitting in, feelings about the inner self, negativity about the future and relationships. Cosmetic appearance of nystagmus, including others' avoidant response to this, was described (n=18), as was others' failure to recognise what it is like to have nystagmus (n=18). Driving issues were frequently raised (n=19) and restrictions in occupation choice/opportunities (n=17) were highlighted. Reliance on others (n=16) also emerged. Additional to other categories was an overarching and universal distress arising from nystagmus affecting every aspect of everyday life.
Interviews revealed universally negative experiences of living with nystagmus that are previously unreported. Findings are similar to studies conducted for strabismus, in particular with respect to cosmetic impact. This study provides the content that is required to develop a nystagmus-specific quality of life tool.
Tachyphylaxis is a phenomenon describing an acute and sudden decrease in drug response, which depends on the rate at which the stimulus is administered. Tachyphylaxis can be overcome by increasing the interval between doses. Typically, tachyphylaxis occurs in the central nervous system when stores of either neurotransmitters or receptors available for a drug are depleted or occupied, respectively, after a high-intensity prolonged stimulus (desensitisation).
In tolerance, the responsiveness...]]>
To investigate the day-to-day repeatability of intraocular pressure (IOP) measurements.
A prospective cohort study of untreated patients presenting with primary open-angle glaucoma or ocular hypertension presenting with IOP>21 mm Hg. IOP was measured by masked Goldmann tonometry at 08:00, 11:00 and 16:00 at each of the three weekly visits. After starting travaprost (0.004%) to both eyes, the measurements were repeated for a further three weekly visits. Day-to-day repeatability was estimated before and after commencing medication and reported as the coefficient of repeatability and coefficient of variability.
At the 8:00 time point, mean IOPs were 26.1 and 17.9 mm Hg in the eye with higher pressure before and after starting treatment, respectively. Coefficient of repeatability and coefficient of variability were 6.8 mm Hg and 10.0%, respectively, before treatment, and 4.6 mm Hg and 10.5% on treatment. Therefore, before treatment and after starting medication the IOP lay within a range of ±20% of the mean IOP with 95% confidence.
The non-therapeutic variability from day to day significantly undermines the precision of IOP estimation and of the estimation of medication effectiveness even when the time of day is standardised in patients with primary open-angle glaucoma/ocular hypertension.
The syndrome of childhood blepharokeratoconjunctivitis (BKC) is frequently underestimated. While prevalent and aggressive among Indo-Pakistani/Middle-Eastern populations, we observe a recalcitrant destructive phenotype in white children/adolescents that persists into early adulthood and may require systemic immunosuppression.
A cohort of 10 white patients (20 eyes), median age 15.2 (range 6–27) years were identified among 62 patients with BKC attending a tertiary referral centre. Clinical features were graded and lid/conjunctiva swabs were performed, before instituting a hierarchical therapeutic protocol comprising lid hygiene, topical/systemic antibiotics, intensive topical glucocorticoids and systemic immunosuppression.
The median duration of symptoms prior to presentation was 4.3 (range 1.2–16.3) years, with 14 eyes (nine patients) demonstrating 360° peripheral corneal vascularisation associated with encroachment/involvement of the visual axis in 10 eyes (six patients). Corneal perforation(s) occurred in three eyes (two patients). Intensive topical glucocorticoids enabled disease control in 10 eyes (seven patients). In six eyes (three patients), persistent active disease necessitated systemic immunosuppression (azathioprine (2), mycophenolate mofetil (1), prednisolone (1)) achieving disease remission within three months with no adverse events reported.
Suboptimal treatment of BKC in white children may permit a progressively destructive sight-threatening phenotype, which may last into adulthood and require immunosuppression. Appropriate aggressive steroid-based and steroid-sparing strategies are vital for disease remission.
To describe a new method of removing dislocated nuclear fragments smaller than one-fourth the size of the lens nucleus through the sclerocorneal incision made for cataract surgery.
Dislocated lens nuclear fragments on the surface of the retina were removed from six eyes of six consecutive patients. An anterior vitreous cutter with a 27-gauge chandelier endoilluminator (Twinlight illumination) tied to its sleeve was inserted into the eye through the incision made for cataract surgery and used for core vitrectomy. A fragmatome with another 27-gauge chandelier endoilluminator (Twinlight illumination) fibre was used to grasp and move the larger dislocated nuclear fragments into the anterior chamber where they were divided and removed.
All dislocated nuclear fragments were removed through the incision for cataract surgery, and a posterior chamber lens was implanted in each patient without major complications.
The procedure can be used to remove dislocated lens nuclear fragments from the surface of the retina through the incision for cataract surgery. Neither a second surgery, which would require three ports, nor the body of instruments for vitreal surgery are needed with this procedure.
Cytoplasm of superficial squamous cells strongly expressed CK3 with no expression of Muc5AC, CK19 or CK15. Nuclear expression of BMI1, p63 α and and C/EBP was seen in a majority of cells on EI specimens tested. BCRP/ABCG2 was expressed on the cell membrane and in the cytoplasm and in the nucleus...]]>
First, when selecting the patient and control groups, measuring blood levels of vitamin B12 and folate might be beneficial and very important to eliminate the deficiency of these vitamins, which may increase the levels of blood homocysteine. Although the main aim of the study is to measure homocysteine levels, there was no vitamin B12 or folate measurement. The individuals having low vitamin B12 and folate levels could be excluded from the study. Thus, the authors...]]>
To investigate the effect of corneal collagen cross-linking (CCL) on tonopen measurements of intraocular pressure (IOP).
CCL with 0.1% riboflavin solution and 30 min of ultraviolet A radiation was performed on the right eye of 15 New Zealand albino adult rabbits (1.8–2.4 kg) (15 eyes). The left eye served as control. IOP was measured by a pressure transducer system (true IOP) and by the tonopen hand-held device (corneal applanation tonometer) before treatment, at 1 week, 1 month and 3 months following CCL. Reference pressure in the globe was increased by increments of 10 mm Hg from 10 to 40 mm Hg, using an anterior chamber infusion on a stand with variable height, and tonopen IOP measurements were recorded for each reference pressure in both eyes.
Before CCL, tonopen readings were similar between the two eyes (p>0.05). Tonopen underestimated the true IOP in all cases. Following CCL treatment, IOP measurements were significantly higher in the treated eye, at all time intervals (0.005<p<0.03). The most significant difference between true and measured IOP was noted at a reference pressure of 20 mm Hg.
IOP measurements following CCL are overestimated by the tonopen, probably due to increased stiffness of the treated cornea.
Regarding the cost of these systems, we agree that these are currently restrictive (although we have already witnessed a substantial drop in price). We think that, for this reason, simulation based training works better on a regional training basis rather than individual hospitals investing heavily for a limited number of trainees. However, the increased demand caused by higher trainee to machine ratios will raise issues regarding how much minimum training will be required and for how long. Studies plotting learning curves required to reach standards set by validation trials are thus...]]>
Into this mix enters aflibercept (VEGF Trap-eye (VTE); Eylea, Regeneron, Tarrytown, New York, USA), for which the US Food and Drug Administration granted approval for the treatment of subfoveal choroidal neovascularisation due to AMD on 18 November 2011. In contrast to the antibody-based VEGF binding strategy used by ranibizumab and bevacizumab, the VTE incorporates the second binding domain of the VEGFR-1 receptor and the third domain of the VEGFR-2 receptor.
To evaluate the clinical findings and visual outcomes of deep anterior lamellar keratoplasty (DALK) using an original manual dissection technique.
288 eyes (268 patients) with corneal pathologies without endothelial involvement were treated by DALK using an original manual dissection technique guided by a calibrated knife incision based on ultrasonic pachimetry values. Clinical records were examined retrospectively at 2 months, 6 months, 1 year and 2 years. The following outcomes were measured: visual acuity, topographic parameters, endothelial cell density and recipient stromal residue thickness.
At the 2-year postoperative follow-up, the mean logarithm of the minimum angle of resolution best spectacle corrected visual acuity (BSCVA) was 0.131±0.087 and topographic astigmatism was 2.87±1.57 diopters. In 12 cases (4.2%) a perforation of Descemet's membrane required conversion of the procedure to penetrating keratoplasty. Mean optical coherence tomography (OCT) residue thickness (measured in 82 eyes with OCT Visante) was 31.63±24.57 μm; lower values of recipient residue thickness were significantly associated with higher BSCVA (Spearman coefficient 0.635, p< 0.001).
DALK using a dry manual dissection technique provides visual, refractive and clinical results comparable to other deep lamellar techniques. Eyes with lower values of recipient residue thickness are associated with better visual acuity.
Several studies have demonstrated...]]>
Some eyes require long-term silicone oil tamponade. Problems arise in aphakic eyes with iris defects or hypotony, because an inferior iridectomy can not prevent silicone oil from entering the anterior chamber causing keratopathy and glaucoma. The artificial iris diaphragm was developed to prevent these complications.
In this retrospective case series, 94 consecutive aphakic eyes of 94 patients received an artificial iris diaphragm and a silicone oil tamponade. All eyes had hypotony or iris defects. The primary outcome measure was the retention of silicone oil behind the iris diaphragm. Secondary outcome measures included visual acuity, intraocular pressure and surgical revisions.
The mean follow-up time was 586 days. No silicone oil in the anterior chamber at the last follow-up visit was found in 58 cases (61.7%). The Kaplan–Meier survival analysis returned a mean survival time for a functional diaphragm of 1227 days. Keratopathy improved in 55.3% at least temporarily, and vision improved or remained stable in 38.2% until last follow-up. The diaphragm was more successful when the underlying disease was trauma or congenital malformation.
The artificial iris diaphragm often retained silicone oil from the anterior chamber in severely damaged eyes. It can be useful to prevent phthisis and preserve vision.
The preservation of globe integrity has always been a major concern during the treatment of retinoblastoma for fear of extraocular or metastatic spread. Intravitreal chemotherapy has been attempted as a desperate salvage therapy only for eyes with refractory retinoblastoma. Published data on the safety and efficacy of this route are, however, limited.
A modified technique of intravitreal injection in eyes with retinoblastoma is described. All children with retinoblastoma who received one or more intravitreal injections using this technique were retrospectively reviewed concerning ocular complications of the injection procedure as well as clinical or histopathological evidence of tumour spread.
30 eyes of 30 children with retinoblastoma received a total of 135 intravitreal injections, with a median follw-up duration of 13.5 months. No extraocular spread was seen on clinical follow-up in any patients and there was no tumour contamination of the retrieved entry sites histopathologically analysed among the five enucleated eyes. No significant ocular side effects were observed except transient localised vitreous haemorrhage (3/135).
This technique is potentially safe and effective at a low cost and may play a promising role, especially in the treatment of recurrent and/or resistant vitreous disease in retinoblastoma, as an alternative to enucleation and/or external beam radiotherapy. However, this treatment should not replace the primary standard of care of retinoblastoma and should not be considered in group E eyes. Its application should be approved by an ophthalmological-oncological team and it should be performed by an experienced eye surgeon in a tertiary referral centre after careful selection of a tumour-free injection site.
To describe the technique of intravitreal chemotherapy preceded by subconjunctival chemotherapy for the treatment of vitreous seeds in advanced stage retinoblastoma.
This non-comparative interventional case series retrospectively reviewed the medical records and postenucleation histopathological findings of two patients who presented within weeks of each other with bilateral retinoblastoma, Reese–Ellsworth (R-E) stage Vb in the worse eye. Both patients had failed systemic chemotherapy prior to receiving a single treatment of 0.5 ml (5 mg per 0.5 ml) of subconjunctival carboplatin, through which 0.05 ml (3 mcg per 0.05 ml) of carboplatin was injected into the vitreous (Case 2 received 0.1 ml of intravitreal carboplatin). The subconjunctival chemotherapy was given to reduce the risk of orbital tumour seeding following intravitreal injection. Following enucleation, ocular toxicity and the presence or absence of viable tumour cells at the intravitreal injection site were recorded.
Histopathological examination did not reveal patency of the pars plana intravitreal penetration site in either case at 6 weeks post-treatment nor was malignant seeding detected in the area of injection. Examination of the two enucleated eyes did not demonstrate structural toxicity to the cornea, anterior segment, iris or retina. Additionally, both cases were followed for over 37 months post-treatment, without the occurrence of orbital malignancy.
Injecting a bleb of subconjunctival chemotherapy prior to intravitreal drug delivery appeared to mitigate the risk of orbital tumour seeding in two patients with advanced stage retinoblastoma. Incorporating this technique may allow further investigation of intravitreal chemotherapy for the treatment of vitreous seeds in retinoblastoma.
Regarding assessment of operative performance using video-based methods, we have found the major impediment is time. For an attending to review a single cataract surgery...]]>
To examine the influence of cloudy media on the slow double-stimulation multifocal electroretinogram (mfERG).
Slow double-stimulation mfERG responses were measured from 26 subjects with normal ocular health under normal and light scattering conditions (induced using acrylic sheets) (Experiment 1) and another nine cataract patients before and after cataract surgery (Experiment 2). The amplitudes and implicit times of the first (M1) and second (M2) stimulation were compared under normal and light scattering conditions in Experiment 1 and they were compared under precataract and postcataract surgery in Experiment 2.
Compared with control conditions (normal and postcataract surgery), the M1 amplitude in the central region was significantly reduced in light scattering conditions (acrylic sheets and precataract surgery); the M2 amplitude and both M1 and M2 implicit times of all regions examined were moderately affected in precataract surgery. The M1:M2 amplitude ratio and implicit time ratio were virtually unaffected in cloudy media for either central or mid-peripheral regions.
Cloudy media affects the mfERG amplitude and implicit time in the slow double-stimulation, but does not affect the response ratio (ie, M1:M2 amplitude ratio and implicit time ratio) between the two stimulations. This suggests that the ratio analysis can be applied in patients with mild to moderately cloudy ocular media to evaluate the functional integrity of the retina.
To investigate the incidence of late onset bleb-related infection (BRI) following Mitomycin C (MMC) augmented trabeculectomy procedures at a single institution.
This was a retrospective case series analysis of late onset BRI, defined as either blebitis or endophthalmitis occurring at least 1 month following a glaucoma filtration procedure. Data collected from hospital charts included the position of the conjunctival flap base. Two cohorts were examined: the first a sample of 194 intraoperative MMC augmented trabeculectomies undertaken over a 4-year period from 1993 to 1997, and the second a sample of 764 MMC trabeculectomies performed in a 4-year period between the years 1999 and 2005.
A total of 11 cases of BRI (cumulative incidence 5.7%) were identified in the cohort from 1993 to 1997. BRI cases had trabeculectomies performed with a limbus-based conjunctival flap and presented at a median IQR 14.8 (9.4–42.9) months after surgery. In the 1999–2005 cohort, nine cases of BRI were identified (cumulative incidence 1.2%). All these BRI cases had a fornix-based conjunctival flap and presented at a median IQR 19.2 (6.1–44.1) months after trabeculectomy surgery.
This study found that the incidence of BRI was higher in MMC augmented trabeculectomy shortly after the introduction of MMC, but subsequently reduced to a lower level. While many changes in surgical technique had occurred in the intervening period, the most significant change was from limbus-based to fornix-based conjunctival flap. However, the retrospective nature of the study prevents the authors from concluding that there is a causative relationship between changes in surgical technique and BRI.
The authors aimed to review published data on uncorrected refractive error (URE) as a cause of blindness and visual impairment in adults aged ≥40 years in sub-Saharan Africa (SSA).
Data were extracted from population-based prevalence surveys measuring presenting visual acuity (PVA). Results from 11 surveys performed in 10 countries in SSA, encompassing 39 458 people aged ≥40 years and older, are presented.
The prevalence of blindness (PVA<3/60 in better eye) ranged from 1.1% in an urban district of Cameroon to 7.9% in a rural district in Ethiopia. More than half of studies (6/11) reported no blindness due to URE. The proportion of moderate visual impairment (PVA ≤6/60 and >6/18) due to URE ranged from 12.3% to 57.1%. Excluding two studies that included uncorrected aphakia as part of URE, the highest proportion of blindness and severe visual impairment due to uncorrected aphakia was found in Gambia (15.2%) and Nigeria (15.8%), respectively.
Although URE is a leading cause of visual impairment, it does not represent a major cause of blindness in SSA.
Retinitis pigmentosa (RP) is the commonest form of retinal dystrophy and is usually inherited as a monogenic trait but with remarkable genetic heterogeneity. RP1 is one of the earliest identified disease genes in RP with mutations in this gene known to act both recessively and dominantly although the mutational mechanism remains unclear. This study is part of our ongoing effort to characterise RP in Saudi Arabia at the molecular level.
Homozygosity mapping and candidate gene analysis.
The authors have identified four novel mutations, all recessive, in a number of families with a typical RP phenotype.
The distribution of these novel and previously reported RP1 mutations makes it challenging to describe a unifying mutational mechanism for dominant versus recessive RP1-related RP.
We propose that pigtail probing would better serve this purpose than standard bi-canalicular stenting because the Crawford stent is tied to itself and the knot is left loose inside the nasal cavity. The tension that is achieved at the conclusion of surgery may not be sustained.
In case of pigtail probing, the required tension can be easily titrated by judiciously shortening the length of the silicone tube used until the desired anatomical result is reached...]]>
We were interested to learn more about the good work Landers et al are doing.
They seem to have overlooked the work of Robin and others who have shown that when combined with a simple history and the measurement of visual acuity, frequency doubling technology threshold testing has a sensitivity of 89.5% and a specificity of 98.6% for the detection of glaucoma in population-based testing.
The classification of glaucoma purely on disc cup proportion is useful, but simplistic. It depends heavily on disc...]]>
We thought your readership may be interested in the following graph:
The above graph represents the price in British pounds by volume. Lucentis is available in 0.2 ml phials, although the treatment dose is only 0.05 ml (0.05 mg). Some of the liquid is lost in transfer between containers, and it is standard practice to discard the remainder between patients. According to the figures quoted in the British Medical Journal,
Eighty-eight out of 111 randomised patients returned for review, that is, 23 patients dropped out. The authors should consider performing intention-to-treat analysis. The authors did not analyse those who did not return for follow-up. Those who dropped out might have done so due to discomfort after using dexamethasone and might have gone elsewhere for other treatment.
Topical steroids may have the potential side effect of promoting viral replication...]]>
We used SOCT Copernicus HR to obtain three-dimensional...]]>
We are aware that most vitreoretinal surgeons currently employ wide-field viewing systems and peripheral indentation during their search for retinal breaks at the end of surgery. The existing literature on this subject, however, often mentions indirect funduscopy or does not specify search methods. And from personal communications we still encounter practices of search using indirect ophthalmoscopy, confinement of search to sclerotomy sites or confinement of search only to cases where a posterior vitreous detachment is induced. A recent large series focusing on break incidence in 20-gauge pars plana vitrectomy also found a high number of breaks.
Drs Raizada and Al...]]>
We did not completely understand what the authors mean by ‘intensified search strategy’ and ‘enhanced 360° internal search’. Are they proposing any new technique which is different from what is a common practice? It is a common practice to check for peripheral retinal breaks after PPV and we have been doing this in a similar fashion with the help of the Binocular Indirect Ophthalmol Microscope (BIOM) for the last 10 years. This is in fact a routine teaching in all surgical retina fellowship programmes. The authors reported a very high incidence of retinal breaks. Breaks were seen in 53...]]>