A systemic review of the literature indexed by Ovid MEDLINE was performed for the following medical subject headings: central retinal artery occlusion, thrombolysis, intra-arterial, fibrinolysis. Studies were analysed individually and categorised by study type, and extracted data grouped together for statistical analysis. Only studies with five patients or more were included in the review.

Twenty-three studies were identified in the original search; eight were selected for the analysis. Of these studies, 158 patients were represented, in which treatment was instituted within an average of 8.4 (SD 4) h of symptom onset. In these patients, visual improvement occurred on average in 93% of patients, with 13% achieving 20/20 or better, 25% achieving 20/40 or better, and 41% achieving 20/200 or better. Complications occurred in 4.5% of cases.

IAT may produce superior visual outcomes compared with conventional treatments for CRAO when instituted in certain situations. At the moment, there is insufficient evidence to support the routine use of IAT to treat CRAO. Well-designed prospective, randomised trials remain to be done.

A retrospective, non-comparative interventional case series of 22 consecutive patients with syphilitic uveitis who were managed in the Ocular Inflammation and Immunology Services of the Singapore National Eye Centre between 1995 and 2006.

Twenty-two patients (mean age 52.7 years, range 18–78) with a positive serum fluorescent treponemal antibody absorption test (100%) and negative HIV serology were reviewed. Non-granulomatous anterior uveitis was the commonest presenting finding (18/29 eyes, 62.06%). Posterior uveitis was seen in four (13.7%), intermediate uveitis in three (10.3%) and panuveitis was seen in eight (27.5%) eyes at presentation. Vitritis (19 eyes, 65.4%) was the commonest posterior segment finding. The majority (86.4%) had latent syphilis at the time of ocular involvement. An increasing trend in the number of cases of ocular syphilis in the past decade was not observed.

Despite resurgence in infectious syphilis, this centre did not see a dramatic rise in cases of syphilitic uveitis. Ocular syphilis presented most frequently as a non-granulomatous inflammation. Therefore, syphilis serology should be sought even for cases of anterior uveitis.

Patients undergoing cataract surgery in at least one eye by local surgeons in a rural setting between 8 August and 31 December 2005 were examined with slit lamp grading of PCO 10–14 months after surgery. Subjects with any PCO associated with best-corrected visual acuity of 6/7.5 or worse, or with grade 2+ or worse PCO without visual decrement, were offered YAG laser capsulotomy. Vision and self-reported visual function were assessed, and various demographic and clinical factors potentially associated with PCO were recorded.

Of 313 patients operated on within the study window, 239 (76%) could be contacted by telephone; study examinations were performed on 176 (74%). Examined subjects had a mean (SD) age of 69.4 (10.5) years, 116 (67%) were female, and 149 (86%) had been blind (presenting visual acuity <=6/60) in the operated eye before surgery. PCO of grade 1 or above was present in 34 of 204 operated eyes (16.7%). Those with PCO had significantly worse presenting vision (p = 0.007) but not visual function (p>0.3) than those without PCO. Women had a significantly higher prevalence of PCO (20.9%) than did men (8.6%, p<0.05). Of 19 eyes undergoing capsulotomy with best-corrected visual acuity measured the next day, 13 (68%) improved by one or more lines, and seven (37%) improved by two or more lines. Despite a higher uptake of capsulotomy (95%) as opposed to refraction (35%) in this cohort, the yield in terms of eyes with poor presenting visual acuity (<6/18) that could be improved was higher for refraction (26% = 9/35) than for capsulotomy (9% = 3/35).

The prevalence of PCO and impact on vision and visual function in this cohort was modest 1 year after surgery. However, PCO prevalence increases with time. Follow-up of this cohort is underway to determine the effectiveness of this early intervention in identifying and treating subjects who will eventually experience clinically significant PCO.

Cross-sectional case series.

Patients undergoing cataract surgery by local surgeons in a government, village-level facility in Sanrao, Guangdong between 8 August and 31 December 2005 were examined and had standardised interviews an average of 12 months after surgery.

Of 313 eligible patients, 239 (76%) completed the questionnaire. Subjects had a mean (SD) age of 69.9 (10.2) years, 36.4% (87/239) were male, and 87.0% (208/239) had been blind (presenting visual acuity <=6/60) before surgery. Word-of-mouth advertising was particularly important: 198 (85.0%) of the subjects knew a person who had undergone cataract surgery, of whom 191 (96.5%) had had cataract surgery at Sanrao itself. Over 70% of subjects (166/239) watched TV daily, whereas 80.0% (188/239) "never" read the newspaper. Nearly two-thirds of suggestions from participants (n = 211, 59.6%) favoured either TV advertisements or word-of-mouth to publicise the programme. While the son or daughter had paid for surgery in over 70% of cases (164/233), the patient’s having paid without help was the sole predictor of undergoing second-eye surgery (OR 2.27 (95% CI 1.01 to 5.0, p = 0.04)).

Strategies to increase uptake of cataract surgery in rural China may benefit from enhancing word-of-mouth advertising (such as with pseudophakic motivators), using television advertising where affordable, and micro-credit or other programmes to enable patients to pay their own fees, thus increasing uptake of second-eye surgery.

Forty-eight samples of generic chloramphenicol eye-drops were collected form Delhi and Chennai (Madras) in India. Conditions of storage of chloramphenicol eye-drops were recorded at the time of purchase. Concentrations of a hydrolytic degradation product of chloramphenicol were measured using validated high-pressure liquid chromatography. Results were compared with accepted UK standards.

Significantly higher levels of chloramphenicol thermal breakdown product were found in collected samples. All samples purchased were being stored in unrefrigerated conditions in the chemists sampled. Shelf lives exceeded UK equivalents, varying considerably between manufacturers.

Inadequate refrigeration and prolonged shelf lives of chloramphenicol generics collected from Delhi and Chennai are associated with very high levels of chloramphenicol thermal breakdown product. These levels substantially exceed UK quality-assurance standards undermining product reliability, possibly contributing to the positive selection of resistant organisms and product toxicity effects. The principals of quality-assurance breakdown described are particularly relevant to Europe, following recent deregulation of chloramphenicol eye-drops purchased over the counter.

Four hundred and fifty-three (22.3%) of the respondents reported impairment for distant vision, 377 (18.4%) reported near vision, and 312 (15.2) reported impairment for both far and near. Impairment of near vision had a significant impact on all domains of quality of life. Distant vision had less impact, with a significant decrement only in the domain of environment. After adjusting for the possible effects of age, sex, and co-occurring chronic physical illness, near-vision impairment accounted for 3.92% decrement in the overall quality of life of elderly persons.

Impairment of vision is associated with significant decrement in diverse areas of quality of life in this elderly sample. Problems with near vision were nevertheless more likely than those of distant vision to affect quality of life.

Non-comparative case series.

51 consecutive patients.

Standard fundus photography and autofluorescence photography (580 nm excitation, 695 nm barrier filter) were performed on all patients. Clinical features were correlated with autofluorescence features.

Autofluorescence features of choroidal melanoma and overlying retinal pigment epithelium (RPE).

The mean patient age was 59 years. The choroidal melanoma was a mean of 3.6 mm from the optic disc and 2.6 mm from the foveola. The mean tumour basal dimension was 11 mm and the mean tumour thickness was 4 mm. The choroidal melanoma showed intrinsic hypoautofluorescence (39%), isoautofluorescence (6%) and hyperautofluorescence (55%). Slightly increased hyperautofluorescence of the melanoma was found in pigmented tumours (versus non-pigmented), those with greater thickness and basal dimensions, and those with overlying disrupted RPE. Related RPE hyperplasia and atrophy showed hypoautofluorescence, drusen, RPE detachment and subretinal fluid showed slight hyperautofluorescence, and orange pigment displayed the brightest hyperautofluorescence.

Choroidal melanoma generally shows slight intrinsic hyperautofluorescence and the brightness increases with pigmented tumours, larger tumours, and those associated with disrupted RPE. Overlying orange pigment shows remarkably bright hyperautofluorescence.

A complete history and ophthalmic examination, including fundus photography and autofluorescence imaging, was performed on twelve probands harbouring the A3243G point mutation.

Four patients had diabetes, 10/12 hearing loss, and 7/12 were visually symptomatic. A positive family history was present in 5/12. Fundus findings consisted of two primary phenotypes: discontinuous circumferentially oriented perifoveal atrophy (9/12) or an appearance consistent with pattern dystrophy (3/12). In both phenotypes pale deposits and pigment clumping were seen at the level of the retinal pigment epithelium, with occasional changes also noted outside the arcades and nasal to the optic nerve. Fundus AF imaging revealed decreased autofluorescence in areas of atrophy and increased AF of the pale subretinal deposits. In areas of the retina that appeared normal clinically, variable sized flecks of increased and decreased AF were present.

The mitochondrial DNA A3243G point mutation can result in disease with a variable presentation. Fundus autofluorescence reveals a recognisable phenotype in most cases that is different from other macular dystrophies.

In a case–control study of Japanese men aged >=50 years (67 controls without ophthalmic disease and 148 with ARM), those with ARM were separated into groups of early (n = 75) and late (n = 73) ARM. Facial wrinkle length and area of hyperpigmentation, which are considered to be associated with exposure to sun, were measured using imaging with computer-based image analysis. Skin tone was also measured on the upper inner arm, which is not exposed to sun. Early and late ARM association with skin measurements was then evaluated.

Significantly more facial wrinkling (p = 0.047, odds ratio 3.8; 95% CI 1.01 to 13.97) and less facial hyperpigmentation (p = 0.035, odds ratio 0.3; 95% CI 0.08 to 0.92) was present in late ARM cases. The relationship between skin tone and ARM risk was not statistically significant.

This objective method showed that lifetime exposure to sunlight is an important factor in the progression of late ARM. An individual’s reaction to sunlight exposure may have a role in ARM progression in addition to total lifetime exposure to sunlight.

The files on 50 eyes of 46 consecutive patients diagnosed by OCT as having a foveal defect with residual retinal tissue at the bottom were reviewed. Retinal thickness was measured at the foveal centre and 750 µm temporally and nasally to differentiate further MPH and LMH. The corresponding corrected AF images were then evaluated. Eyes with either macular pucker or stage 1a impending macular hole served as controls.

OCT measurements allowed the classification of two different profiles: 28 eyes classified with MPH had macular centres and perifoveal retinas that were significantly thicker than the 22 eyes classified with LMH. The corrected value of the foveal AF intensity was not significantly different between the two groups. In addition, the AF did not correlate with the thickness of the retinal tissue at the base of either MPH or LMH eyes. None of the control eyes showed foveal AF.

The findings suggest that OCT data must be interpreted with caution when differentiating between MPH and LMH. In this series, the two groups showed similar foveal AF. AF imaging may add useful information to the differential diagnosis of MPH from LMH: the presence of foveal AF is consistent with a loss of foveal tissue and therefore a diagnosis of LMH.

46 eyes from 46 patients with a diagnosis of MH were included in this study. In all cases, a pars plana 25-gauge vitrectomy with peeling of the internal limiting membrane was performed. Before and after surgery, a complete clinical examination and a detailed macular analysis, which included the MH minimum and base diameter, the MH height, the Macular Hole Index (MHI), Diameter Hole Index (DHI) and Tractional Hole Index (THI), were performed. Predictive factors for visual prognosis after surgery were obtained by receiver operating characteristic curve analysis.

Minimum and base diameter as well as THI and MHI correlated significantly (p<0.01, p = 0.01, p = 0.04, p = 0.03, respectively) with postoperative best spectacle corrected visual acuity at 3 months, but DHI and MH height did not. Cut-off values of 311 µm and 1.41 were obtained for the minimum diameter and THI, respectively, from receiver operating characteristic curve analysis, providing an acceptable sensitivity and specificity.

An MH minimum diameter of <311 µm or a THI >1.41 are predictive factors for a good visual prognosis after MH surgery.

Retrospective, interventional, non-comparative consecutive case series.

Thirty eyes in 30 patients (30 eyes) with unilateral full-thickness macular hole (stage II–IV).

All eyes underwent PPV, ILM peeling and fluid–air exchange followed by postoperative face-down positioning for 2 days.

Best corrected visual acuity, optical coherence tomography (OCT) assessment of macular integrity, and biomicroscopy at days 3 and 7, and months 1, 3, 6 and 12.

On postoperative day 3, OCT demonstrated macular hole closure in 28 eyes (93%). One eye required vitrectomy 7 weeks after initial surgery due to retinal detachment.

In the present case series, PPV with Trypan Blue-assisted ILM peeling, short-acting internal tamponade and thus shorter face-down positioning was associated with a 93% macular hole closure rate.

The study included 144 patients diagnosed as having RP. The mean age of the patients was 38.5 (SD 13.3) years, and 42% of the subjects were women. They answered the National Eye Institute Visual Function Questionnaire (NEI-VFQ) to assess the vision-related quality of life and the Beck Depression Inventory (BDI) to assess depressive symptoms. Patients were classified into groups with and without depression according to the BDI score. The NEI-VFQ composite and subscale scores were compared between groups. The correlations between the BDI and the NEI-VFQ, weighted visual acuity (WVA) and functional vision score (FVS) were investigated.

The depressed group had significantly less subjective visual function compared with the non-depressed group. A negative correlation was observed between the BDI and the NEI-VFQ scores, while no correlation was found between the BDI score and WVA or FVS.

The RP patients with depression had poorer vision-related functions compared with those patients without depression, which cannot be explained by the visual acuity. Interventions to diagnose and treat depression are necessary to enhance the overall quality of life in RP patients.

In 16 eyes of 16 consecutive patients aged 30 years or younger, prospective open-label PDT was performed. Outcomes of visual acuity as well as changes in CNV lesion parameters were evaluated.

The mean patient age at first PDT was 19.7 (SD 8.7) years (range 6–30). 81% of the patients retained stable vision within two lines or exceedingly improved vision during follow-up of 34 (24) months. Significant vision gain was denoted in seven paediatric patients (2.7 (1.4) lines, mean (SD); p = 0.019) as well as in a subgroup of 12 patients not affected by active uveitis (2.6 (2.0) lines, p = 0.0005). Two patients with multifocal choroiditis and panuveitis (MCP) experienced vision losses of five and 11 lines after four PDT sessions despite receiving additional steroidal treatment. Except for one patient with MCP and two patients who dismissed follow-up, a mean of 2.2 (1.3) PDTs per patient sufficiently inactivated CNV lesions during follow-up. In the area of the former PDT spot, alterations of the pigment epithelium increased by 40% without correlation to changes in vision.

The results indicate good PDT efficacy and tolerability most promising in a subgroup of patients with vision-impairing CNV not associated with active uveitis. PDT in young patients with CNV remains a valuable treatment with good risk–benefit profile over the long term.

Fifteen eyes of 15 patients with symptomatic PCV who received three monthly intravitreal bevacizumab were retrospectively reviewed. Subsequent retreatments with intravitreal bevacizumab and/or PDT were performed in patients with recurrent or persistent polypoidal lesions on indocyanine green angiography (ICGA), and persistent or recurrent subretinal fluid.

The mean follow-up duration was 12.8 months. At 3 months, the mean logMAR BCVA improved from 0.61 to 0.51 (p = 0.014), and the mean CFT reduced from 347 µm to 247 µm (p = 0.015). Despite the visual and anatomical improvements, persistent polyps were present in ICGA of all eyes at 3 months. At the last follow-up, mean BCVA remained at 0.51 after additional treatment with intravitreal bevacizumab and/or PDT (p = 0.022). Patients who had subsequent PDT were less likely to have persistent polypoidal lesions on ICGA at the last visit (p = 0.041).

Intravitreal bevacizumab appeared to result in stabilisation of vision and reduction of exudative retinal detachment in PCV patients. However, intravitreal bevacizumab monotherapy had limited effectiveness in causing regression of the polypoidal lesions in ICGA, and additional PDT appeared to be useful for treating these lesions.

Intravitreal half-lives and relative equimolar VEGF-binding activities of VEGF Trap and ranibizumab were incorporated into a first-order decay model. Time-dependent VEGF Trap activities (relative to ranibizumab) for different initial doses (0.5, 1.15, 2 and 4 mg) were calculated and plotted.

Seventy-nine days after a single VEGF Trap (1.15 mg) injection, the intravitreal VEGF-binding activity would be comparable to ranibizumab at 30 days. After injection of 0.5, 2 and 4 mg VEGF Trap, the intravitreal VEGF-binding activities (comparable to ranibizumab at 30 days) would occur at 73, 83 and 87 days, respectively

On the basis of this mathematical model, VEGF Trap maintains significant intravitreal VEGF-binding activity for 10–12 weeks after a single injection.

Prospective interventional case study.

19 patients, 18 of whom had suffered previous filter or glaucoma implant failure. Seventeen had open-angle glaucoma, and two had neovascular glaucoma. Seventeen patients were black and two were Asian.

All patients underwent supra-Tenon’s capsule placement of a single-plate Molteno implant. Goldmann applanation tensions and Snellen visual acuities were determined before the operation and at the last follow-up visit. The numbers of preoperative and postoperative adjunctive drugs were compared before and after surgery.

Success was defined as intraocular pressure <=18 mm Hg with or without anti-glaucoma drugs.

Mean age was 62 years. Mean pressure before and after surgery was 31 and 16 mm Hg, respectively. Mean follow-up was 22 months (range 12–48). Vision returned to within 2 lines of preoperative vision, except in one patient who lost light perception. Surgery was regarded as a failure in four patients, including both patients with neovascular glaucoma. The difference between the median number of drugs used before (three) and after (one) the operation was significant (p<0.001). Complications were minimal, characterised by small choroidal effusions in three patients; all resolved spontaneously.

Supra-Tenon’s capsule placement of Molteno implants in eyes with previously failed glaucoma surgery is an effective method for controlling intraocular pressure.

This is a retrospective case–control study. The study population consisted of all patients with positive blood cultures for Klebsiella, admitted to Changi General Hospital (Singapore) from August 2004 to July 2005. The cases were patients who developed Klebsiella endophthalmitis, and the controls were those who did not. The potential risk factors analysed included age, sex, race and total white cell count at presentation, maximum temperature response, co-morbid pathologies, presence of severe infection, site of primary infection, antibiotic sensitivity of the bacterial strain, and systemic antibiotics treatment regimen.

133 consecutive patients with Klebsiella bacteraemia confirmed by blood culture were included. Five (3.8%) developed endophthalmitis. Klebsiella endophthalmitis was significantly associated with liver abscess as the primary site of infection (p<0.001) and disseminated intravascular coagulation (p = 0.010) on both univariate and multivariate analysis. Diabetes mellitus and other co-morbid pathologies, race and maximum temperature response were not risk factors for the occurrence of endophthalmitis.

Liver abscess and disseminated intravascular coagulation are risk factors for endogenous endophthalmitis in patients with Klebsiella sepsis.

The right eye of 75 New Zealand White rabbits was inoculated in the vitreous cavity with strains of Staphylococcus epidermidis, Staphylococcus aureus or Pseudomonas aeruginosa. The study evaluated treatment with 1.5% levofloxacin compared with 1% vancomycin plus 2.2% ceftazidime, and a control group. At 24 h after treatment, 100 µl vitreous and aqueous humor were harvested, and the number of colony-forming units (CFU) per ml was determined. The microbiological status of the vitreous and aqueous humor samples was tested at day 2, 3, 5 and 8. The Peyman classification was used to assess the severity of endophthalmitis.

For the S epidermidis endophthalmitis model, levofloxacin treatment produced an approximately 3 log decrease in CFU/ml of vitreous relative to that in untreated eyes (p = 0.023), whereas vancomycin plus ceftazidime produced a 5 log reduction in CFU/ml (p = 0.023). However, in the S aureus model, levofloxacin treatment produced an approximately 4 log reduction in CFU/ml, whereas vancomycin plus ceftazidime produced an approximately 2 log reduction in CFU/ml relative to that of the control (p = 0.018 and p = 0.019, respectively). Treatment of P aeruginosa-infected rabbit eyes with levofloxacin produced a 5 log reduction in CFU/ml of vitreous, whereas vancomycin plus ceftazidime produced an approximately 3–4 log reduction in CFU/ml relative to that of the control (p = 0.001). However, there was no significant difference between levofloxacin and vancomycin plus ceftazidime on comparing the reduction of CFU/ml of vitreous for any of the bacterial strains studied.

Levofloxacin appears to be effective in treating experimental endophthalmitis in the rabbit model. Further studies, especially on the toxicity of intravitreal levofloxacin, are required before a clinical role for the drug in postoperative therapy can be determined.

Unilateral chronic ocular hypertension was induced in C57BL6/J mice by laser ablation of the limbal episcleral veins. Scotopic flash electroretinograms were recorded after 5, 10, 20, and 40 days to isolate specific outer and inner retinal responses. Inner retinal function was correlated with the pressure differential between treated and non-treated eyes at the time of electroretinographic recording, and with the cumulative IOP insult (the integral of the IOP.time profile). Peripheral and central ganglion cell densities were quantified by Brn-3 immunohistochemistry.

Elevated IOP induced a preferential deficit in inner retinal function. The positive scotopic threshold response (pSTR) was suppressed by 68% on day 5, by 50% on day 10, by 54% on day 20 and by 46% on day 40 after laser treatment. Inhibition of the STR correlated with the pressure differential between treated and non-treated eyes but not with the IOP.time integral. Inner retinal dysfunction preceded the progressive death of ganglion cells. Ganglion cell loss occurred preferentially in peripheral retina and correlated with the cumulative IOP insult.

We have demonstrated specific inner retinal dysfunction in an inducible mouse glaucoma model. STRs are sensitive to elevated IOP per se, and their early suppression reflects ganglion cell dysfunction rather than cell death. The correlation between IOP elevation and suppression of inner retinal function, in the context of the temporal progression of ganglion cell death, suggests that a portion of the IOP-mediated ganglion cell dysfunction may be reversible.

Blood samples of 63 preterm infants born at a postmenstrual age (PMA) of 23–32 weeks were obtained between 5 days and 15 weeks after birth. 42 infants had no ROP, two had stage 1, nine stage 2 and 10 stage 3. Of these, four infants were treated with retinal photocoagulation. VEGF-A, sVEGFR-1, sVEGFR-2, and sTie2 were measured in the plasma with a sandwich enzyme immunoassay using factor-specific monoclonal mouse antibodies. The time course of concentrations plotted by kernel smoothing in infants with and without ROP were compared and a paired subgroup with analysis of variance was analysed.

ROP patients had raised plasma levels of sVEGFR-2 and sTie2 compared with premature infants without ROP. VEGF-A and sVEGFR-1 levels were similar in both groups. Analysis of a subgroup with pairs of measurements, one before 32 weeks and one after 36 weeks, showed a significant increase in sTie2 after 36 weeks of PMA independent of ROP (p = 0.03).

This is the first study to measure plasma levels of angiogenic factors in ROP. Similar VEGF-A plasma levels in infants with and without ROP suggest that pathogenic retinal angiogenesis in ROP is mainly driven by local VEGF-A synthesis. Elevated plasma levels in active ROP were observed for sVEGFR-2 and sTie2. These increases have yet to be confirmed as predictive values for ROP.

EIU was produced in immunosuppressed iNOS^–/– mice and C57BL/6 (normal) mice by footpad injection of lipopolysaccharide. Leukocytes were labelled with acridine orange. Leukocyte rolling in the retinal microcirculation was evaluated in vivo with acridine orange digital fluorography. The number of migrated leukocytes was counted in flat-mounted retina.

Both leukocyte rolling and migration peaked at 48 h after lipopolysaccharide injection. The maximal numbers of rolling leukocytes in the immunosuppressed iNOS^–/– mouse retina decreased by 98.2% (p<0.001) compared with that in the normal mouse retina at 48 h after lipopolysaccharide injection. In addition, the maximal numbers of migrated leukocytes in the immunosuppressed iNOS^–/– mouse retina decreased by 74.0% (p<0.001) compared with that in the normal mouse retina at 24 h after lipopolysaccharide injection. Furthermore, the diameters of major retinal veins of the immunosuppressed iNOS^–/– group were smaller at both 24 and 48 h after lipopolysaccharide injection than were those of the normal group (p<0.001, respectively).

A lack of iNOS suppresses leukocyte–endothelial cell interactions in the retinas of mice with EIU. This suggests that iNOS may play a role in the management of patients with uveitis and other inflammatory conditions.

Sixteen membranes were studied by immunohistochemical techniques.

Cells expressing -smooth-muscle actin (-SMA), a marker of differentiation of fibrocytes into myofibroblasts, were present in all membranes. Cells expressing the haematopoietic stem-cell antigen CD34, the leucocyte common antigen CD45, CCR7, CXCR4, CCL21 and CXCL12 were noted in 50%, 75%, 68.8%, 100%, 80% and 93.8% of the membranes, respectively. Double immunohistochemistry indicated that all cells expressing CD34, CD45, CCR7, CXCR4, CCL21 and CXCL12 co-expressed -SMA. The number of cells expressing CD34 correlated significantly with the numbers of cells expressing CXCL12 (r_s = 0.567; p = 0.022) and CCL21 (r_s = 0.534; p = 0.04).

Circulating fibrocytes may function as precursors of myofibroblasts in PVR membranes.

A rugate structure was electrochemically etched into a highly doped p-type silicon substrate to create a porous silicon film that was subsequently removed and ultrasonically fractured into particles. To stabilise the particles in aqueous media, the silicon particles were modified by surface alkylation (using thermal hydrosilylation) or by thermal oxidation. Unmodified particles, hydrosilylated particles and oxidised particles were injected into rabbit vitreous. The stability and toxicity of each type of particle were studied by indirect ophthalmoscopy, biomicroscopy, tonometry, electroretinography (ERG) and histology.

No toxicity was observed with any type of the particles during a period of >4 months. Surface alkylation led to dramatically increased intravitreal stability and slow degradation. The estimated vitreous half-life increased from 1 week (fresh particles) to 5 weeks (oxidised particles) and to 16 weeks (hydrosilylated particles).

The porous silicon photonic crystals showed good biocompatibility and may be used as an intraocular drug-delivery system. The intravitreal injectable porous silicon photonic crystals may be engineered to host a variety of therapeutics and achieve controlled drug release over long periods of time to treat chronic vitreoretinal diseases.