A novel eye drop application monitor to assess patient compliance with a prescribed regimen: a pilot study.

PURPOSE: To assess the ability of a novel imaging device to allow physicians to personalize therapeutic regimens based on objective patient drop administration data. METHODS: A novel imaging system was used to record video of the drop technique of subjects in clinic (n=25) or at home (n=17) for 1 week. Video assessment by a reading center was compared with patient reporting and their prescribed regimen with respect to how many drops were applied and how many landed in the eye. RESULTS: Reading center assessment of both drops dispensed and drops landing in the eye was significantly different from the prescribed regimen in the clinic (Pd=0.005, Pi<0.001, respectively) and at-home arms (Pd=0.003, Pi<0.001, respectively). CONCLUSIONS: This imaging system is a powerful tool to help physicians tailor patient therapy more accurately, to help researchers evaluate new drop therapies with objective rather than subjective data, and to potentially facilitate better patient training for improved drug delivery.

The adjunctive use of perfluoroperhydrophenanthrene (Vitreon) in diabetic vitrectomy.

OBJECTIVE: To evaluate the utility and efficacy of perfluoroperhydrophenanthrene in the management of retinal detachments secondary to severe proliferative diabetic retinopathy. PATIENTS AND METHODS: Forty consecutive patients with proliferative diabetic retinopathy and retinal detachments were entered into the study at nine participating clinical centers. Perfluoroperhydrophenanthrene (Vitreon) was used as an adjunct to pars plana vitrectomy and membranectomy. RESULTS: Preoperative diagnoses included combined traction and rhegmatogenous retinal detachments in 23 eyes (57.5%), traction retinal detachments in 13 eyes (32.5%), and recurrent rhegmatogenous retinal detachments in 4 eyes (10). Vitreous hemorrhage was present in 17 eyes (42.5%). Preoperative visual acuity ranged from light perception or hand motion in 28 eyes (70%) to 5/200 or greater in 12 eyes (30%). Vitreon was primarily used to flatten the retina following relaxing retinotomy in 12 eyes (30%), to displace subretinal fluid in a posterior-to-anterior direction without performing a drainage retinotomy in 15 eyes (37.5%), and to manage intraoperative complications such as iatrogenic tears in 8 (20%) and retinal dialysis in 5 eyes (12.5%). The retina flattened intraoperatively in all cases, facilitating administration of laser photocoagulation. Patients were followed for a minimum of six months (mean 13.2 months). At last follow up, the macula remained attached in 37 eyes (92.5%), including 31 (77.5%) in which the retina was totally attached. The retina remained detached in 3 eyes (7.5%). Visual acuity improved postoperatively in 20 patients (50%), was unchanged in 13 patients (32.5%), and worsened in 7 patients (17.5%). CONCLUSIONS: Perfluoroperhydrophenanthrene is a useful and effective intraoperative tool for the management of complex retinal detachments secondary to severe proliferative diabetic retinopathy.

The management of giant retinal tears using perfluoroperhydrophenanthrene. A multicenter case series. Vitreon Collaborative Study Group.

OBJECTIVE: The purpose of the study was to determine the predictors of success and evaluate the use of perfluoroperhydrophenanthrene as an intraoperative and postoperative tool in the management of giant retinal tears in a multicentered collaborative study. DESIGN: Multicentered prospective case series. PARTICIPANTS: Twenty-three centers consecutively enrolled 162 eyes of 161 patients with retinal tears 90 degrees or greater in circumferential extent. INTERVENTION: Perfluoroperhydrophenanthrene was used as an intraoperative surgical adjunct in all cases and left after surgery in 16 eyes (9.9%). MAIN OUTCOME MEASURES: Retinal reattachment and visual acuity. RESULTS: Intraoperative reattachment was achieved in 158 eyes (97.5%); 147 eyes (90.7%) remained attached at their most recent follow-up. Seventy-nine eyes (48.8%) experienced an improvement in their visual acuity, 26 eyes (16.0%) remained unchanged, and 57 (35.2%) worsened. Recurrent retinal detachment occurred in 80 patients (49.4%). Other significant postoperative complications included cataract formation in 20 (39.2%) of 51 eyes, macular pucker in 12 (7.4%), corneal decompensation in 10 (6.2%), and hypotony (intraocular pressure equal to or less than 5 mmHg) in 9 (5.6%). A chi-square analysis of preoperative characteristics showed that hypotony (P = 0.007), macular detachment (P = 0.020), a history of cataract extraction (P = 0.003), poor visual acuity (P = 0.000), giant tear extent greater than 180 degrees (P = 0.004), and higher grade proliferative vitreoretinopathy (P = 0.000) all predicted a poor visual outcome. Vitreon (Vitrophage, Inc., Lyons, IL) was left in 16 eyes (9.9%) for an extended postoperative retinal tamponade for between 3 and 1034 days (mean, 87.2 days). The Vitreon was well tolerated, and these eyes experienced a similar outcome and rate of retinal reattachment to the rest of the group. CONCLUSIONS: Vitreon is a safe and useful adjunct to pars plana vitrectomy in the management of giant retinal tears and may, additionally, be the perfluorocarbon liquid that can be used most safely as a temporary postoperative tool for extended retinal tamponade, reinforcing its role as a useful adjunct in the management of these complex retinal detachments.

Surgical closure of macular hole using an absorbable macular plug.

BACKGROUND: The surgical management of macular holes has been a subject of controversy in recent years. Various techniques such as vitrectomy, membrane peeling, and gas tamponade with or without transforming growth factor-beta 2, and recently the use of autologous platelets have produced closure rates from 58% to 96%, depending on the stage of the hole. METHODS: The authors present preliminary results in a study of 19 consecutive patients with stage 3 or stage 4 macular hole who underwent vitrectomy followed by placement of an absorbable partially cross-linked gelatin plug in the macular hole. The vitreous cavity was filled with a nonexpanding gas or air alone; the patient was instructed to maintain prone positioning for 2-3 days. RESULTS: Anatomic attachment of the edges of the macular hole was achieved in 19 out of 19 patients with a minimum follow-up period of 6 months (average 11.5 months). CONCLUSIONS: A cross-linked gelatin plug can effectively reattach the edges of macular holes of stages 3 and 4. Its use is recommended only in macular holes in high myopes with posterior staphyloma or recurrent macular hole.

Surgical management of traumatic retinal detachment with perfluorocarbon liquid. The Vitreon Study Group.

BACKGROUND: To evaluate the effect of perfluoroperhydrophenanthrene on the outcome of traumatic retinal detachment with proliferative vitreoretinopathy, a retrospective study of 111 patients was performed at 35 tertiary care centers, both private practice and institutional. We believed that perfluoroperhydrophenanthrene would assist in manipulating the retina during surgery, removing intraocular foreign bodies, draining suprachoroidal hemorrhage, and reattaching the retina because of the perfluorocarbon's high specific gravity. METHODS: Of the 700 patients in the Vitreo study group, 111 with a history of trauma (109 had retinal detachment, 50 had proliferative vitreoretinopathy) were chosen for this study. Perfluoroperhydrophenanthrene was used intraoperatively to manipulate the retina hydrokinetically, remove intraocular foreign bodies, drain suprachoroidal hemorrhage, and to reattach the retina in the case of giant tears. RESULTS: Logistic multiple regression analysis was used to identify factors as being predictive of poor visual outcome. Factors predictive of poor visual outcome were: type of trauma (p = 0.0065) (ruptured globe); presence of giant retinal tear (p = 0.0253); and low preoperative visual acuity (p = 0.044). At the last follow-up examination, the reattachment rate was 75.6% (i.e., 84 eyes). Of those 84 eyes, 55 (49.5%) had achieved a visual acuity of > or = 5/200 and 34 (30.6%) had a visual acuity of > or = 20/200. In cases complicated by proliferative vitreoretinopathy, the final reattachment rate was 66%, with 40% of the eyes studied obtaining a visual acuity of > or = 5/200. CONCLUSIONS: Perfluoroperhydrophenanthrene has been used intraoperatively in the management of traumatic retinal detachments without any apparent ill effects.

A new instrument (forceps/scissors) for preretinal membrane peeling, segmentation.

This new intraocular instrument has been developed to aid vitreoretinal surgeons in the removal of preretinal membranes. It functions as both a forceps for membrane peeling and scissors for cutting.

Experimental retinopathy by hyperbaric oxygenation.

Retinopathy of prematurity (ROP) usually occurs after a prolonged exposure to normobaric hyperoxia in newborn mammals and infants. We hypothesized that experimental ROP also could develop after acute exposures to hyperbaric oxygenation (HBO), providing that a severe and maintained retinal vasoconstriction occurred during HBO exposure. Five- to seven-day-old, Long Evans Sprague-Dawley rats were exposed for 5 h either to 5 atm abs oxygen or to 5 atm abs O2 with 190 mmHg inspired PCO2 (hypercapnia). Control rats breathed air at atmospheric pressure. Two months after exposures, rats were anesthetized, perfused intraventricularly with India ink, and retinal images were obtained. Retinal vascular density (RVD) in each image was calculated as the number of pixels in the retinal vessel area divided by the total number of pixels in the image (retinal tissue and vessels). The RVD was significantly increased from 0.0112 +/- 0.004 in the air-exposed controls to 0.0417 +/- 0.029 in the HBO-exposed rats (mean +/- SD; n = 4 in each group). HBO with hypercapnia produced a nonsignificant increase in RVD (0.0255 +/- 0.007; n = 4), reducing the HBO-induced increase in RVD by 39%. These results are consistent with the hypothesis that a sustained HBO-induced retinal vasoconstriction in newborn rats, followed by a hypoxic-ischemic injury, might result in vascular proliferation, thereby initiating ROP development on return to air. Hypercapnia does not completely prevent HBO-induced retinal vasoproliferation, probably because possible vasodilation, induced by hypercapnia, can greatly elevate retinal tissue PO2 and promote oxidative damage.

An analysis of posterior segment complications after vitrectomy using the perfluorocarbon perfluoroperhydrophenanthrene (Vitreon). Vitreon Collaborative Study.

We report posterior segment complications encountered with the use of the liquid perfluorocarbon, perfluoroperhydrophenanthrene (Vitreon) as an intraoperative adjunct to vitreoretinal surgery in 640 patients participating in the Vitreon Collaborative Study. We also evaluated postoperative complications in 60 patients in whom Viteron was intentionally left inside the vitreous cavity for periods ranging from 5 days to 4 weeks as a short-term retinal tamponade. The five most common postoperative complications among these patients as a whole were recurrent retinal detachment, with or without proliferative vitreoretinopathy (11.28%); macular pucker (5.85%); fibrinous reaction (4%); residual Vitreon (3.85%); and vitreous hemorrhage (2.57%).

Experimental retinal tolerance to very low viscosity silicone oil (100 cs) as a vitreous substitute compared to higher viscosity silicone oil (5000 cs).

We evaluated the toxicity of very low viscosity (100 centistokes) and higher viscosity silicone oil (5000 centistokes) in rabbit eyes as a short-to-long-term postoperative vitreous substitute (6 weeks to 5 months). Emulsification of 100-cs and 5000-cs silicone oil did not occur in eyes which were followed for as long as 5 months. No toxic effects to retinal cells were detected by light or electron microscopy. Because no toxic effects were seen with 100-cs silicone oil, it can be used in an outpatient setting as a short-term postoperative tamponading agent. Electroretinographic responses of silicone-injected eyes were normal.

A new knife handle with a safe blade-release design for surgical and laboratory use.

This new knife handle is designed for all Bard-Parker blades. It safely releases the blade through a mechanism that is intended to reduce the risk of injury and subsequent infection by blood-borne pathogens.

Postoperative chronic pressure abnormalities in the vitreon study.

Perfluoroperhydrophenanthrene (Vitreon) was used as an intraoperative hydrokinetic retinal manipulator, followed by C3F8 or SF6 gases, silicone oil, or Vitreon as postoperative tamponading agents in 234 eyes. Two chronic intraoperative pressure abnormalities were defined: hypotony (5 mm Hg or less) and elevated intraocular pressure (IOP) (25 mm Hg or more at three or more postoperative visits). Postoperatively, 28 eyes (12%) had chronically elevated IOP, and 41 (18%) had chronic hypotony. There was no significant difference in the incidence of abnormal IOP among the groups of eyes in which the various tamponading agents had been used. In particular, the use of Vitreon as an intraoperative tool or as a short-term tamponade did not affect the incidence of chronic abnormal IOP any more than did the use of silicone oil, C3F8, or SF6 as tamponading agents.

Contact diode laser: high power application through fiberoptic cutting tips.

Diode laser energy has been applied through a fiberoptic probe using a power setting of 2.5 watts (W) in the continuous mode. In this study we employed high-power diode laser energy (4 to 12 W, continuous wave) to incise ocular tissue through a fiberoptic probe using 100 microns and 300 microns tips. The retina was photocoagulated with a 300 microns orb tip. No bleeding occurred at the incision sites. Histologic evaluation revealed coagulation into the healthy tissue ranging from 10 to 50 microns.

Hyperbaric oxygen tolerance in newborn mammals--hypothesis on mechanisms and outcome.

Newborn mammals, compared to adults, are extremely resistant to the CNS effects of hyperbaric oxygenation (HBO) induced by excessive generation of reactive oxygen species. This tolerance to HBO may be related to either physiological responses or the chemical characteristics of the immature brain, including a low cerebral blood flow and energy metabolism, and a low concentration of polyunsaturated fatty acids. In adult mammals the main protective mechanism against CNS oxygen toxicity, besides endogenous antioxidants, is a transient HBO-induced cerebral vasoconstriction. How cerebral vasculature reacts to HBO in the immature brain is not known. We present indirect evidence suggesting that HBO in newborn rats induces a persistent cerebral vasoconstriction concurrently with a severe and maintained reduction in ventilation. It is speculated that the outcome of these physiologic responses to hyperoxic exposures may be: (a) extension of tolerance to both CNS and pulmonary oxygen poisoning; (b) creation of a profound hypoxic-ischemic condition in vulnerable neural structures; and (c) impairment of the circulatory and ventilatory responses to hypoxic stimuli on return to air with consequent development of a secondary hypoxic-ischemic condition. These hypothetical pre- and post-HBO events may set the stage for the development of some delayed neurological disorders, including the retinopathy of prematurity and the retardation of brain development in fetuses or prematurely-born infants subjected to oxygen therapy.

Use of vancomycin in vitrectomy infusion solution and evaluation of retinal toxicity.

The retinal toxicity of vancomycin in infusion solution used in vitrectomy and lensectomy was investigated in rabbit eyes by means of electroretinography and histologic study (light microscopy). Concentrations of 8 micrograms/ml, 16 micrograms/ml, and 32 micrograms/ml of vancomycin in balanced salt solution caused no abnormal ERG or histologic changes. However, ERG amplitude depression and abnormal histologic changes occurred when the concentration of 100 micrograms/ml of vancomycin was used.