Biomedical subjects

D V Alfaro

Publications and source records attributed to D V Alfaro.

At least 19 recordsLinked to original sources

PubMed2001

Quantification of optic nerve axon loss associated with a relative afferent pupillary defect in the monkey.

OBJECTIVE: To quantify the amount of optic nerve axonal loss associated with the presence of a mild relative afferent pupillary defect (RAPD) in an experimental monkey model. METHODS: The right macula of 5 rhesus monkeys (Macaca mulatta) was treated with concentrically enlarging diode laser burns until an RAPD was detected using a transilluminator light and measured with neutral density filters. Intervals between treatments were 3 to 7 days over a period of 2 months. Pupillary responses to light stimulation were recorded with a monocular infrared television pupillometer. Two months after detection of an RAPD, 5 treated and 4 control monkeys underwent euthanasia and enucleation. Histopathologic analysis and quantification of optic nerve axon counts using an image analysis system were performed. RESULTS: No RAPD was observed despite an estimated ganglion cell loss of up to 26%. A 0.6 log unit RAPD was present in 5 monkeys when the laser scar incorporated the entire macula within the temporal vascular arcades. One eye had progressive vitreomacular traction with worsening of the RAPD to 1.8 log units without further laser treatment. Histopathologic evaluation disclosed complete loss of the normal retinal architecture within the macula. The average fiber loss for the 4 treated eyes with 0.6 log unit RAPDs compared with fellow eyes was 53.3% (95% confidence interval [CI], 45.0%-61.6%). The average difference in axon counts between untreated pairs of optic nerves was 12.8% (95% CI, 10.0%-15.6%). Optic nerve axon loss between pairs of experimental and control eyes was statistically significant (P<.001). CONCLUSION: In rhesus monkeys, an RAPD develops after an approximate unilateral loss between 25% and 50% of retinal ganglion cells. CLINICAL RELEVANCE: Owing to redundancy in the anterior visual pathways, unilateral retinal ganglion cell loss may occur prior to the observation of an RAPD. The presence of an RAPD measuring 0.6 log units implies that significant retinal ganglion cell injury has occurred.

Animals↗

PubMed1997

Shatter resistance of spectacle lenses.

OBJECTIVE: To evaluate the relative strength and shatter resistance of spectacle lenses currently used in sunglasses and dress, sports, and industrial eyewear. DESIGN: Seven lenses that met the US American National Standards Institute (ANSI) Z80 standards for dress glasses (made of high-index plastic, allyl resin plastic, heat tempered glass, chemically tempered glass, and polycarbonate, and with center thickness ranging from 1 mm to 2.2 mm) and 4 lenses that met ANSI Z87 standards for industrial safety eyewear (allyl resin plastic, heat-tempered glass, chemically tempered glass, and polycarbonate, all with 3.0-mm center thickness) were tested for impact resistance to 5 projectiles (air gun pellets, golf balls, tennis balls, lacrosse balls, and baseballs). MAIN OUTCOME MEASURES: Impact energy required to shatter spectacle lenses. RESULTS: Based on 348 lens impacts, dress and industrial lenses made from glass, allyl resin plastic, and high-index plastic shattered at impact energies less than those expected to be encountered from the test projectiles during their routine use. Polycarbonate lenses demonstrated resistance to impact for all tested projectiles exceeding the impact potential expected during routine use. CONCLUSIONS: Under the test conditions of this study, polycarbonate lenses demonstrated greater impact resistance than other commonly used spectacle lenses that conform to prevailing eyewear standards. These findings suggest that current ANSI Z80 and ANSI Z87 standards should be reevaluated.

Eye Protective Devices↗

PubMed1997

Experimental preretinal neovascularization by laser-induced venous thrombosis in rats.

PURPOSE: Retinal ischemia and neovascularization (NV) are important components of many retinal disorders. To facilitate further investigation of retinal ischemia and neovascularization, we sought to develop a reproducible in vivo experimental model of venous occlusion by photodynamic thrombosis in rats. METHODS: After anesthesia, 27 eyes of pigmented rats received an intraperitoneal injection of 0.2 ml of, 10% sodium fluorescein 15 minutes prior to laser treatment. With a blue-green argon laser, selected venous sites next to the optic nerve head were photocoagulated indirectly with a 78 diopter lens. Venous occlusion was accomplished using laser parameters of 1.0 second, 50 microns, and 50-100 mW. For a control group, 10 eyes were coagulated on the retina between major vessels using the same parameters after fluorescein injection. For a second control group, 1% sodium hyaluronate was injected into the subretinal space to make a long-standing retinal detachment in 5 eyes. RESULTS: With 1-8 laser impulses, each venous occlusion was obtained and was associated with extreme venous constriction and tortuousity. Retinal edema became evident 10-30 minutes after treatment in the sectors associated with the occluded veins. This edema became a bullous retinal detachment (RD) within 12 hours and intra-retinal hemorrhage was observed. The retinal edema continued for 3-10 days and the retinas reattached spontaneously. Prior to or after retinal reattachment 70% (19/27) of eyes developed retinal NV and tractional RD. Of these, 11 developed NV of the optic disc (NVD), 6 developed NV elsewhere (NVE), and 2 developed NVD and NVE. In 30% (8/27) of the eyes, retinal edema resolved without evidence of NV. In control groups no eyes showed either circulatory disorders or evidence of NV. CONCLUSIONS: This is a new model of retinal ischemia and associated neovascularization established by venous thrombosis that is easily reproducible. Many aspects of rat retinal physiology are known and this model has promise as an avenue for further investigation.

Animals↗

PubMed1997

Intravenous gentamicin and ceftazidime in penetrating ocular trauma: a swine model.

PURPOSE: A swine model of ocular trauma was used to determine the extent of penetration of systematically administered gentamicin and ceftazidime to the vitreous cavity of traumatized and normal eyes. METHODS: Forty-six pigs received a scleral laceration to the right eye and then underwent surgical repair. Thirty-six animals received intravenous gentamicin, and 10 pigs were given ceftazidime. RESULTS: The level of gentamicin in the vitreous of traumatized and nontraumatized eyes did not achieve the minimum inhibitory concentrations (MIC) for Pseudomonas and Haemophilus species despite multiple and large intravenous doses. Ceftazidime concentrations in traumatized eyes were above the minimum inhibitory concentration for these organisms. CONCLUSIONS: Ceftazidime achieves an intravitreal concentration 33 times the minimum inhibitory concentration of Haemophilus species and twice that of Pseudomonas species in traumatized eyes after systemic administration, a finding that lends support to its use as a prophylactic agent in the management of penetrating ocular trauma. Gentamicin does not appear to enter the traumatized eye at appreciable levels after systemic administration, and, therefore, it is not recommended for use as a prophylactic agent in the management of penetrating ocular trauma.

Animals↗

PubMed1997

Experimental pseudomonal posttraumatic endophthalmitis in a swine model. Treatment with ceftazidime, amikacin, and imipenem.

PURPOSE: To compare the intravitreal efficacy of three separately administered antibiotics (imipenem, ceftazidime, and amikacin) in limiting the intraocular inflammation and tissue destruction caused by posttraumatic pseudomonal endophthalmitis. METHODS: Thirty-three Yorkshire pigs each received a surgically induced scleral injury to the right eye. After repair, each eye was injected with 22,000 colony-forming units of live Pseudomonas aeruginosa. Pigs then were randomly grouped into a natural-history-of-infection group in which no treatment was given (n = 9) or into groups treated with the following: intravitreal imipenem (n = 6), ceftazidime (n = 6), amikacin (n = 6), or normal saline (n = 6). Pigs then were observed clinically for 18-24 hours after surgery and enucleated for histopathologic examination. RESULTS: Clinical examinations revealed significantly less posterior segment inflammation in pigs treated with amikacin and imipenem than in pigs in the natural history or saline control groups, based on the Wilcoxon rank sum test (P < .05). Histopathologic examinations showed similar results, with less intraocular inflammation and retinal destruction in pigs treated with amikacin and imipenem, whereas the inflammation in pigs treated with ceftazidime did not differ significantly from that in control pigs. CONCLUSION: Intravitreal antibiotic treatment with imipenem or amikacin appears to limit intraocular inflammation and retinal tissue damage when given early in the course of posttraumatic pseudomonal endopthalmitis. Results with ceftazidime are less conclusive.

Amikacin↗

PubMed1996

The effect of trauma on the ocular penetration of intravenous ciprofloxacin.

PURPOSE: To study the intraocular pharmacokinetics of intravenously administered ciprofloxacin following eye trauma. METHODS: Twenty-three New Zealand albino rabbits and 12 Yorkshire pigs each received a surgically induced scleral injury to the right eye. Following repair, each rabbit received a single 30-mg intravenous infusion of ciprofloxacin. Each pig received either two 200-mg doses or two 400-mg doses of intravenous ciprofloxacin given 12 hours apart. Vitreous and serum samples were harvested at 0.5, 1, 4, 6, and 12 hours after antibiotic administration in rabbits and 1 hour after the second dose in pigs. Bioassays for ciprofloxacin were performed on each sample, and results were statistically compared by t test. The untraumatized left eye in each animal served as a control. RESULTS: The mean vitreous concentration of ciprofloxacin in traumatized rabbit eyes was 0.37 microgram/ml. This level was sustained above levels in control eyes (0.18 microgram/ml) for at least 4 hours following antibiotic administration. In control eyes, intravitreal levels peaked at 1 hour. Mean vitreous concentrations +/- SD in traumatized pig eyes were 0.091 +/- 0.017 microgram/ml in swine that had received 200-mg doses of ciprofloxacin vs 0.312 +/- 0.153 microgram/ml in swine that had received 400-mg doses (P = .02). Mean vitreous concentrations of ciprofloxacin in control eyes were not affected by increasing dosage. CONCLUSION: In both animal models, experimental surgical trauma increased intravitreal ciprofloxacin delivery. In addition, systemically administered ciprofloxacin achieved intravitreous levels exceeding minimum inhibitory concentrations for common ocular pathogens, suggesting a role for ciprofloxacin in the prophylaxis of posttraumatic endophthalmitis.

Absorption↗

PubMed1996

Intravenous cefazolin in penetrating eye injuries. A swine model.

PURPOSE: A swine model of penetrating ocular trauma was used to determine the delivery of systemically administered cefazolin to the vitreous cavity of traumatized and nontraumatized eyes. METHODS: Thirty-one pigs received a scleral laceration to the right eye under anesthesia and then were given intravenous cefazolin every 8 hours. Seven pigs received nine doses at 17 mg/kg. Seven animals received three doses of 36 mg/kg, and six others received nine doses of this regimen. Six pigs received three doses of 79 mg/kg and five others received three doses of 190 mg/kg. RESULTS: Vitreous levels of cefazolin averaged 15.6 micrograms/mL in traumatized eyes but were less than 1 microgram/mL in control eyes of animals receiving three doses at 190 mg/kg (P < or = 0.025). Mean serum concentration in these animals was 49.3 micrograms/mL. Vitreous levels were less than 1 microgram/mL in traumatized and control eyes in animals given lower doses of cefazolin (range, 17-79 mg/kg) despite multiple treatments over 2 and 3 days. CONCLUSIONS: These data demonstrate that systemically delivered cefazolin achieves levels ten times the minimum inhibitory concentration for Staphylococcus epidermidis in injured eyes. Therapeutic intraocular levels can be obtained through intravenous dosing, provided that therapeutic serum concentrations are achieved.

Animals↗

PubMed1996

Experimental posttraumatic Bacillus cereus endophthalmitis in a swine model. Efficacy of intravitreal ciprofloxacin, vancomycin, and imipenem.

PURPOSE: The authors compare the intravitreal efficacy of ciprofloxacin, vancomycin and imipenem, in treating experimental Bacillus cereus endophthalmitis. METHODS: Thirty-three Yorkshire pigs received a surgically induced injury to the right eye, which was then repaired and injected with 8400 colony forming units of live B. cereus. Nine pigs received no therapy and served as a natural history group. Twenty-four other pigs then were randomized into a treatment group with ciprofloxacin (n = 6), vancomycin (n = 6), imipenem (n = 6), or normal saline (n = 6). Eyes were examined clinically 1, 2, 3, 4, 5, 6, 8, 12, and 24 hours after inoculation. After 24 hours, the eyes were enucleated for histologic study. RESULTS: Experimental disease was characterized by an aggressively developing endophthalmitis, with retinitis and vitritis developing at 4 hours. Histologic examination showed vitreous abscess and retinal necrosis. Both vancomycin- and imipenem-treated group had less inflammation and tissue destruction than control animals, based on the Wilcoxon rank sum test (P < 0.05). Ciprofloxacin-treated animals showed significantly more intraocular destruction and were indistinguishable from controls. CONCLUSION: Vancomycin and imipenem appear to limit inflammation and tissue destruction when given early in the course of experimental posttraumatic endophthalmitis caused by B. cereus. Results with ciprofloxacin are less conclusive and warrant further investigation.

Animals↗

PubMed1996

Experimental Bacillus cereus post-traumatic endophthalmitis and treatment with ciprofloxacin.

BACKGROUND: Bacillus species remain an important cause of post-traumatic endophthalmitis, often causing permanent visual loss. METHODS: Twenty two rabbits were used to evaluate the clinical and histological findings of Bacillus cereus experimental post-traumatic endophthalmitis. Eyes that had received a scleral laceration and surgical repair were inoculated with Bacillus cereus. Thirty four other rabbits were used to evaluate the efficacy of intravitreal ciprofloxacin in treating experimental disease. RESULTS: Animals developed a post-traumatic endophthalmitis that closely mimicked human disease, characterised by a rapidly progressive and destructive endophthalmitis. Histological evaluation revealed retinal detachment, retinal necrosis, and the infiltration of inflammatory cells into the subretinal space. Intravitreal ciprofloxacin (100 micrograms) prevented the development of disease when given 1 hour and 6 hours after trauma and inoculation. CONCLUSIONS: Clinical and histological examination of experimental Bacillus cereus post-traumatic endophthalmitis suggests that retinal detachment and retinal necrosis play important roles in visual loss. Ciprofloxacin may be of benefit in the management of certain intraocular infections following penetrating injury.

Animals↗

PubMed1995

Paediatric post-traumatic endophthalmitis.

AIMS: A retrospective analysis of children with post-traumatic endophthalmitis was performed to determine if microbiological differences exist between this disease in the paediatric population compared with this disease in adults. METHOD: Twelve cases of post-traumatic endophthalmitis in children were analysed to determine characteristics of this disease in youth. Patient ages varied from 18 months to 13 years; the mean age was 8 years. Gram positive organisms were isolated in eight eyes, Gram negative organisms from four eyes, fungus from one eye, and negative cultures in three eyes. The most common isolates were streptococcal species (56.6%) and staphylococcal species (22.2%). Vitrectomy was performed on eight (66.7%) eyes. RESULTS: Visual acuity of 20/200 or better was obtained in eight eyes (66.7%). Three eyes had vision less than 5/200. One eye developed phthisis bulbi. Nine (75%) patients were younger than 10 years of age, and six (66.7%) of these nine obtained a final visual acuity of 20/200 or better. CONCLUSION: Useful vision can be obtained in children with post-traumatic endophthalmitis with early, aggressive treatment. The microbiology of paediatric post-traumatic endophthalmitis differs from adult disease with streptococcal species as the most common infecting organisms.

Adolescent↗

PubMed1994

Intravenous cefazolin in penetrating eye injuries. I. Effects of trauma and multiple doses on intraocular delivery.

The poor intraocular penetration of systemically administered antibiotics has raised questions regarding their usefulness as prophylactic agents in the management of penetrating eye injuries. Cefazolin was administered intravenously to rabbits with penetrating eye injuries to determine the influence of trauma on ocular pharmacokinetics. Following a standardized penetrating eye injury in 27 New Zealand white rabbits, animals were divided into three groups that received either three, six, or nine doses of intravenous cefazolin every 8 h. Cefazolin levels were then measured in the traumatized eye, the non-traumatized (control) fellow eye, and in the serum of each animal. In the three treatment groups vitreous concentrations of cefazolin were significantly higher in traumatized eyes than in the non-injured eyes. After three doses, vitreous concentrations of cefazolin in traumatized eyes averaged 9.1 mg/l; mean concentrations of cefazolin in non-injured eyes were 0.6 mg/l (P < 0.0002). After six doses of intravenous cefazolin, vitreous concentrations in traumatized eyes averaged 7.3 mg/l; cefazolin levels in non-injured eyes were 0.6 mg/l in the non-traumatized eyes (P < 0.0005). After nine doses, vitreous cefazolin concentrations in traumatized eyes averaged 9.7 mg/l, while mean levels in the non-traumatized eyes were all 0.05 mg/l (P < 0.0002). This work suggests that penetrating injuries of the eye alter ocular pharmacokinetics, resulting in high intraocular concentrations of systemically administered cefazolin.

Animals↗

PubMed1994

Penetrating eye injuries in young children.

BACKGROUND: Penetrating eye injuries remain an important cause of blindness among children. METHODS: Thirty consecutive children, nine years of age or younger, were treated for penetrating eye injuries. Twenty-two (73%) of those patients studied were male and 8 (17%) were female. The average age of the patients was 4.6 years. Sharp objects accounted for the majority of injuries (83%). Twenty (66%) eyes required only primary repair and 10 (33%) eyes required secondary lensectomy and vitreous surgery, which was done within 10 days of the primary repair. Length of follow-up ranged from 6 months to 48 months, and 5 patients were lost to follow-up. RESULTS: Visual acuity of 20/40 or better was achieved in 13 (72%) of the 18 patients requiring only primary repair. Stereopsis was present in 13 (87%) of these patients. Of those patients that underwent secondary lensectomy with anterior or pars plana vitrectomy, 42% had visual acuity of 20/100 or better. None had stereopsis. CONCLUSION: Young children with penetrating eye injuries requiring only primary repair may achieve excellent visual recovery, whereas those with traumatic cataract necessitating lensectomy and vitreous surgery have a less favorable outcome because of more severe injury and subsequent amblyopia.

Amblyopia↗

PubMed1994

Posttraumatic endophthalmitis. Causative organisms, treatment, and prevention.

BACKGROUND: Posttraumatic endophthalmitis is a rare complication of penetrating eye injuries that results in blindness in potentially salvageable eyes. METHODS: 36 cases of posttraumatic endophthalmitis were evaluated retrospectively to determine which factors were associated with visual loss. All cases were treated with intravenous and intraocular antibiotics. Pars plana vitrectomy was performed in 15 (41.7%) cases as an adjunct to treatment. RESULTS: Patients ranged in age from 18 months to 83 years, and included 30 men (83%) and 6 women (17%). Intraocular foreign bodies were present in 6 patients (16.7%), 9 (25%) had corneal lacerations, 13 (36.1%) had corneoscleral or scleral lacerations, and 8 (22.2%) had ocular trauma of unknown type. Of the 36 eyes, 21 (58.3%) had positive culture results, and 10 of these (27.8%) had multiple organisms. The most common isolates were Staphylococcus species (26.5%), Streptococcus species (20.6%), and Bacillus species (14.7%). In 4 cases the diagnosis was made 6 or more years after injury. Final visual acuity was 20/200 in 8 eyes (22.2%) and 20/300 in 1 eye. In 17 cases (47.2%), the eye was salvaged but visual acuity was 5/200 or worse, and 10 eyes (27.8%) were lost to enucleation or phthisis bulbi. CONCLUSION: Prompt diagnosis and early treatment with intraocular and systemic antibiotics are important in the successful management of posttraumatic endophthalmitis. The use of pars plana vitrectomy was associated with a good visual outcome when used in select cases.

Adolescent↗

PubMed1993

Intravenous cefazolin in penetrating eye injuries. Treatment of experimental posttraumatic endophthalmitis.

The use of intravenous antibiotics as prophylaxis in penetrating eye injuries is strictly empiric and not based on scientific data supporting their use. To determine the efficacy of prophylactic intravenous cefazolin in penetrating eye injuries, a rabbit model of posttraumatic endophthalmitis was developed. Forty rabbits received penetrating eye injuries followed immediately by an intravitreal inoculum of live Staphylococcus epidermidis. The rabbits then were randomly divided into four groups: group 1 received three doses of intravenous cefazolin; group 2 received six doses, and group 3 received nine doses; group 4 received no treatment and served as controls. All control rabbits developed 4+ vitreitis; rabbits receiving three doses of the antibiotic developed 2+ vitreitis, and those receiving six or nine doses of cefazolin showed no vitreous inflammation (P < or = 0.0001). Histologic examination of control eyes showed an exuberant reaction with formation of retrolental membranes, vitreous abscess, and retinal detachment. Eyes treated with nine doses of cefazolin were devoid of inflammatory cells. These findings suggest that intravenous cefazolin is effective in preventing the development of posttraumatic endophthalmitis in a rabbit model.

Animals↗

PubMed1992

Vitrectomy for perforating eye injuries from shotgun pellets.

Pars plana vitrectomy and scleral buckling were performed on 22 eyes of 19 patients for treatment of perforating eye injuries from shotgun pellets. We reviewed the intraoperative findings at the time of vitrectomy to determine what factors might influence final visual acuity. The presence of a total retinal detachment at vitrectomy portended a poor prognosis when compared with eyes without total retinal detachment, as only one of ten eyes with total retinal detachment obtained useful vision (P = .002). Preoperative separation of the posterior vitreous was associated with a favorable outcome when compared with the absence of posterior vitreous detachment (P = .035), as ten of 16 eyes with posterior vitreous detachment at the time of vitrectomy ultimately achieved functional vision. The locations of the exit wounds did not affect visual success in the overall series of patients. However, in the patients who achieved visual success, exit wounds outside the vascular arcades were more likely to be associated with final visual acuities of, or better than, 20/70 than were those within the arcades (P = .022). Other prognostic factors, such as the number of perforations and the use of cryotherapy, were also examined for their effects on final visual outcome. However, these factors did not appear to affect visual outcome statistically.

Adolescent↗

PubMed1992

Systemic antibiotic prophylaxis in penetrating ocular injuries. An experimental study.

Intraocular concentrations of systemically administered gentamicin and cefazolin in eyes after a standard penetrating ocular injury were measured to determine the effect of eye injury on ocular pharmacokinetics. Twenty pigmented rabbits were divided into two groups. A standard, 8-mm wound was made at the pars plana of one eye in each animal. Group 1 consisted of 10 rabbits that were treated with cefazolin (75 mg/kg), and Group 2 consisted of 10 rabbits that were given gentamicin (2 mg/kg). Fellow eyes, which sustained no trauma, served as control eyes. All groups received intravenous injections every 8 hours for 72 hours, beginning immediately after repair of the wound. After 72 hours, samples were obtained from the anterior chamber, vitreous cavity, and serum. Standardized bioassays for detection of gentamicin or cefazolin were performed. Significant concentrations of intravitreal cefazolin (9.6 micrograms/ml) and gentamicin (0.60 micrograms/ml) were found in the traumatized eyes in comparison to control eyes (P = 0.0001; P = 0.006). Cefazolin exhibited excellent penetration, achieving concentrations well above minimum inhibitory concentration values for most organisms. Gentamicin levels, however, were well below acceptable therapeutic levels. This study suggests that systemically administered cefazolin can achieve significant intravitreal penetration at minimum inhibitory concentrations after penetrating injury.

Animals↗

PubMed1992

Subretinal perfluorocarbon liquids. An experimental study.

Perfluorocarbon liquids (PFCL) are fully fluorinated, synthetic, transparent compounds with a high specific gravity. These compounds are being increasingly used as an intraoperative tool for repair of complicated retinal detachments. A known complication of their use, however, is liquid entering the subretinal space via a retinal break. The purpose of this study was to evaluate the effects of two of these liquids when placed subretinally in the rabbit eye. Vitrectomy, retinotomy, and subretinal injection of 0.03 cc of either perfluoroctane, perfluorotributylamine, or balanced salt solution (control eyes) were performed on 36 rabbit eyes. Animals were monitored clinically by indirect ophthalmoscopy and fundus photography for up to 21 days. After the 21-day observation period, electroretinograms (ERG) were taken before the rabbits were killed. Histopathologic studies were done at 3 hours, 24 hours, 3 days, 7 days, 14 days, and 21 days after injection. Three eyes demonstrated tearing of the retinotomy site due to downward migration of the PFCL droplet. Results of the ERGs were normal in all animals tested. Phagocytosis of PFCL droplets by the retinal pigment epithelium (RPE) was observed in 1 eye 3 hours after injection. Three of the eyes that received PFCL injections and all of the control eyes demonstrated moderate intracellular edema of both inner and outer nuclear layers as early as 24 hours after injection. In one eye injected with PFCL, these changes progressed to swelling and cystic formation of the inner nuclear layer and mild degeneration of the outer photoreceptor segments 3 days after injection. It was assumed that these effects occurred on a mechanical basis and were not related to PFCL toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

A clinical comparison of the Oculab Tono-Pen with the Goldmann applanation tonometer in eyes filled with silicone oil.

Intraocular pressure in 21 eyes filled with silicone oil was measured with two different instruments: the Oculab Tono-Pen and a Goldmann applanation tonometer mounted to a slit lamp biomicroscope. Intraocular pressure ranged from 2 mmHg to 28 mmHg, and the mean difference between readings obtained from the two instruments was 0.64, which was not statistically significant. These results suggest that the Oculab Tono-Pen is an effective instrument with which to measure intraocular pressure in silicone-filled eye.

Cataract Extraction↗