The effect of patient symptom awareness on the visual outcome in retinal detachment.

PURPOSE: To explore whether a patient's prior knowledge of the symptoms associated with rhegmatogenous retinal detachment (RRD) relates to the visual outcome after treatment. METHODS: We performed a prospective survey study on 126 patients receiving treatment for primary RRD between March and July 2021. RESULTS: Thirty-seven per cent (n = 47) of patients responded that they were aware of the RRD symptoms prior to the detachment. A history of RRD in the fellow eye or knowledge of family members treated for RRD was frequently reported as a reason for the patient's awareness of RRD symptoms. Patients aware of RRD symptoms presented significantly more often with an attached macula (χ2 , p = 0.002) and a better visual outcome following surgery (Mann-Whitney U, p = 0.028) compared to patients who were not aware of RRD-related symptoms. Among 76 patients with a myopic refractive error, only 15% (n = 11) indicated that they had been warned about the increased RRD risk related to myopia, suggesting that three-quarters of patients were not actively informed by their eye care professionals. CONCLUSION: RRD symptom awareness is significantly related to a higher rate of macula-on RRDs and better visual outcomes after treatment. There is limited awareness of increased RRD risk in myopic RRD patients. These findings suggest that counselling individuals at high risk of RRD about related symptoms is inadequate and better counselling may improve visual outcomes following RRD treatment.

A technical protocol for an experimental ex vivo model using arterially perfused porcine eyes.

Ex vivo ocular perfused models have been described in the past and were applied in different mammalian species as platforms to test drug delivery systems and surgical techniques. However, reproduction of those methods is challenging because extensive and precise description of the protocols used is lacking. In this technical paper we provide a detailed description of all the steps to be followed from the enucleation of porcine eyes to cannulation of the ophthalmic artery and perfusion. This model can contribute to the reduction of use of living animals in ophthalmology research, whereas as opposed to in vitro models, it preserves tissue complexity and integrity.

Baerveldt glaucoma implant in paediatric patients.

AIM: To evaluate the Baerveldt glaucoma implant (BGI) in paediatric glaucoma treatment. METHODS: In a retrospective non-comparative case series 55 eyes of 40 consecutive paediatric patients (< or =16 years) with primary or secondary glaucoma underwent Baerveldt (350 mm2) implantation. Surgical outcome was evaluated by Kaplan-Meier table analysis. RESULTS: The overall success rate was 80% at last follow up, with a mean follow up of 32 (range 2-78) months. Cumulative success was 94% at 12 months and 24 months, 85% at 36 months, 78% at 48 months, and 44% at 60 months. 11 eyes (20%) failed postoperatively because of an IOP >21 mm Hg (eight eyes), persistent hypotony (two eyes), and choroidal haemorrhage following cataract surgery (one eye). The most frequent complication needing surgery was tube related (20%). A new observation was mild to moderate dyscoria in 22% of the eyes, all buphthalmic, caused by entrapment of a tuft of peripheral iris in the tube track. CONCLUSIONS: The BGI is effective and safe in the management of primary and secondary glaucoma. When angle surgery has proved to be unsuccessful or inappropriate in paediatric patients, a BGI is a good treatment option. One must be prepared to deal with the tube related problems.

Ocular toxicity study of trypan blue injected into the vitreous cavity of rabbit eyes.

BACKGROUND: To evaluate the ocular toxicity of trypan blue (TB) injected into the vitreous cavity of rabbit eyes. TB is a dye that could be useful for staining epiretinal membranes during vitrectomy surgery. METHODS: Ten New Zealand White (NZW) rabbits underwent gas-compression vitrectomy. Rabbits were divided into three groups to receive injections of 0.1 ml basic salt solution, 0.1 ml of a 0.06% TB solution or 0.1 ml of a 0.2% TB solution. Ocular toxicity was assessed by slit-lamp biomicroscopy, ophthalmoscopy, electroretinography and histology. RESULTS: Transient posterior capsule opacification was noted in all animals. No significant reductions in a-wave or b-wave amplitudes were found in any of the animals. Light and electron microscopic examination of the inferior retina in the 0.2% TB-treated eyes showed damaged photoreceptors and marked disorganization. Immunohistochemical staining for rhodopsin was strongly reduced in those sections and staining for proliferation with Ki-67 was positive. No histological abnormalities were found in the upper retina of the 0.2% TB-treated eyes or in any part of the retina of the 0.06% TB-treated or control eyes. No histological abnormalities were found in any of the anterior chamber angle specimens. CONCLUSIONS: Although no signs of toxicity were found after the prolonged presence of TB at a concentration of 0.06% in the vitreous cavity of rabbit eyes, marked damage occurred in the lower retina of 0.2% TB-treated eyes. The short-term presence of TB at a concentration of 0.06% in the vitreous cavity is harmless to the rabbit eye but a higher concentration of TB could be unsafe.

Symptoms predictive for the later development of retinal breaks.

OBJECTIVE: To identify symptoms in patients with isolated posterior vitreous detachment predictive for the later development of retinal breaks. METHODS: Two hundred eighty consecutive patients seen with symptoms of posterior vitreous detachment were prospectively asked to complete a questionnaire detailing their symptoms. At the time of presentation and follow-up, all patients had a full ophthalmologic examination including slitlamp biomicroscopy with Goldmann 3-mirror contact lens after maximal pupil dilatation. Two hundred fifty patients with an isolated posterior vitreous detachment were included and reexamined 6 weeks after the onset of symptoms. If small retinal or vitreous hemorrhages were detected, patients were reexamined after 2 weeks. RESULTS: In 13 patients (5.2%) a retinal break was detected at reexamination. Logistic regression analysis with backward elimination revealed that symptoms of flashes in combination with clouds or multiple (>10) small dots at the time of the initial examination or an increase of floaters after the initial examination were statistically significantly (P<.001) related to the development of new breaks. These symptoms had a predictive value for the presence or absence of a new retinal break of 75.0% and 99.6%, respectively. CONCLUSIONS: Specific symptoms can identify patients at risk for the development of new retinal breaks after an initial examination in which no abnormalities were found and may obviate the need for follow-up appointments of patients not at risk.

Randomized clinical trial of cryotherapy versus laser photocoagulation for retinopexy in conventional retinal detachment surgery.

PURPOSE: To investigate whether the method of retinopexy influences the visual recovery rate and the breakdown of the blood-ocular barrier after conventional retinal detachment surgery. METHODS: Forty-eight patients (48 eyes) with primary rhegmatogenous retinal detachment entered into the study. All eyes were phakic, had an attached macula, and were scheduled for conventional scleral buckling surgery. Patients were randomly assigned to have either laser or cryotherapy for retinopexy. All visual acuity and flare measurements were performed by a masked observer. The interventional procedure was cryopexy at the time of scleral buckling surgery or postoperative (4 weeks) laser photocoagulation. Visual acuity testing with ETDRS chart and aqueous flare measurement with laser flare photometry were performed by a masked observer at standard intervals: preoperatively and 1 day, 7 days, 4 weeks, and 10 weeks postoperatively. Analysis of covariance by multiple linear regression was used for statistical evaluation. RESULTS: Postoperative flare values from patients receiving cryotherapy were significantly higher at each measurement point in time (P < or =.001). The visual recovery was slower in the patients receiving cryotherapy (1 week, P =.003; 4 weeks, P =.03; 10 weeks, P =.081). CONCLUSION: Laser flare photometry proved sufficiently sensitive to quantify an increase in aqueous flare after limited external retinal cryotherapy. Postoperative flare, as a measure of blood-ocular barrier breakdown, was significantly higher and visual recovery slower in the cryotherapy group. Visual acuity after 10 weeks was not significantly different between both groups.

Negligible role for NK cells and macrophages in delayed xenograft rejection.

Hyperacute rejection (HAR) of a discordant xenograft can be avoided by complement manipulation, but delayed xenograft rejection (DXR) still leads to graft loss. It is generally assumed that macrophages and NK cells play key roles in DXR. In the present study the survival times and cellular infiltrate following guinea pig to rat heart transplantation was analyzed in the course of DXR, following aspecific and specific manipulation of macrophages and NK cells. HAR was overcome by a single injection of cobra venom factor 1 day before heart transplantation. To aspecifically reduce the inflammatory response dominating DXR, dexamethasone (DEXA) was given. Treatment with DEXA markedly reduced infiltration by NK cells, macrophages, and granulocytes. It also led to prolonged graft survival times (median survival of 0.4 days, n = 10, P < 0.05). In the second series of experiments the specific roles of NK cells and macrophages in DXR were further assessed. Monoclonal antibody 3.2.3 was used to selectively deplete NK cells. Liposome-encapsulated dichloromethylene biphosphonate was given to achieve macrophage depletion. Neither of these specific treatments, alone or combined, led to prolonged graft survival. Immunohistology revealed that at day 2 after transplantation no NK cells or macrophages were present in grafts from the combined treatment group. Only a mild infiltration of granulocytes was observed. Collectively, these results strongly suggest that NK cells and macrophages are not likely to be pivotal cell types in DXR.