Dexamethasone sodium phosphate loaded nanoparticles for prevention of nitrogen mustard induced corneal injury

Nitrogen mustard (NM) is a potent vesicating chemical warfare agent that is primarily absorbed through skin, inhalation, or ocular surface. Ocular exposure of NM can cause acute to chronic keratopathy which can eventually lead to blindness. There is a current lack of effective countermeasures against ocular exposure of NM despite their imperative need. Herein, we aim to explore the sustained effect of Dexamethasone sodium phosphate (DSP)-loaded polymeric nanoparticles (PLGA-DSP-NP) following a single subconjunctival injection in the management and prevention of corneal injury progression upon exposure to NM. DSP is an FDA approved corticosteroid with proven anti-inflammatory properties. We formulated PLGA-DSP-NP with zinc chelation ion bridging method using PLGA polymer, with particles of approximately 250 nm and a drug loading of 6.5 wt%. Under in vitro sink conditions, PLGA-DSP-NP exhibited a sustained drug release for two weeks. Notably, in NM injured cornea, a single subconjunctival (SCT) injection of PLGA-DSP-NP outperformed DSP eyedrops (0.1%), DSP solution, placebo NP, and saline, significantly mitigating corneal neovascularization, ulceration, and opacity for the two weeks study period. Through PLGA-DSP-NP injection, sustained DSP release hindered inflammatory cytokine recruitment, angiogenic factors, and endothelial cell proliferation in the cornea. This strategy presents a promising localized corticosteroid delivery system to effectively combat NM-induced corneal injury, offering insights into managing vesicant exposure.

Retinal burns from laser pointers: a risk in children with behavioural problems

OBJECTIVE

To explore self-inflicted retinal burns from laser pointers in children.

METHODS

Literature review of laser pointer retinal injuries in childhood and online survey of UK Consultant Ophthalmologists. A cohort of local children with self-inflicted injury is described. The matter is topical. We review progress in recent legislation and policy change in the UK.

RESULTS

Four of 77 case reports of laser burns in childhood analysed reported psychological or behavioural issues. Three of four children in our cohort had such issues. Delay in diagnosis occurred in two of our patients. Structural retinal damage persisted for over 12 months in all four children (seven eyes). Our survey of UK ophthalmologists found 159 cases of injury (85% male), 80% under 20 years of age. The majority of the laser pointers were purchased online. Many patients (36%) suffered moderate vision loss (6/18 to 6/60 Snellen), while 17% (at least 11 patients) suffered severe vision loss (<6/60 Snellen).

CONCLUSION

We highlight the risk of macular damage and vision loss from handheld lasers specifically in children with behavioural, learning or mental health issues. The diagnosis may be difficult or delayed in such children. In children with uncertain macular changes, ophthalmologists should explore the history for possible instances of exposure to handheld lasers pointers. Regulatory authorities and manufacturers of handheld lasers need to be aware of the risk to children. Furthermore, there is a need to better inform parents, carers and teachers of the risk of ocular self-injury from such lasers pointers.

UV damage of the anterior ocular surface - microstructural evidence by in vivo confocal microscopy

PURPOSE

To evaluate and describe the microstructural changes at the ocular surface in response to habitual ocular sun exposure, correlate them with the UV protection habits and follow their dynamics using in vivo confocal microscopy(ICM).

METHODS

For a period of minimum 4 months 200 subjects (400 eyes), aged 28 ± 7.3 years, were recruited with the agreement that they will spend their summer exclusively in the region of the Black Sea coast at 43 °N latitude and will be examined before and after the summer. All subjects filled in a questionnaire about habitual UV protection and were examined clinically and by ICM.

RESULTS

Questionnaire results demonstrated that 83.5% (167 participants) of the subjects considered the sun dangerous for their eyes, but 78% (156 subjects) believed that there is danger exclusively during the summer period. Although no clinical changes were detected, microstructural analysis of the cornea demonstrated statistically significant (p = 0.021) decrease of the basal epithelial density - from 6167 ± 151 cells/mm² before to 5829 ± 168 cells/mm² after the summer period. Microstructural assessment of the conjunctiva demonstrated characteristic cystic lesions with dark centres and bright borders encountered in only 25 eyes(6%) before, and affecting 118 eyes(29.5%) after the summer. The total area of the cysts after the summer increased fivefold. Spearman analysis proved negative correlation between sun protection habits and number of cysts.

CONCLUSION

Summer sun exposure for one season leads to clinically undetectable, microstructural changes affecting the cornea, bulbar and palpebral conjunctiva with transient, but possibly cumulative nature.

Thermodynamic measurement after cooling the cornea with intact epithelium and lid manipulation

PURPOSE

To characterize the rate of change of ocular surface temperature (OST) under lid manipulation after cooling the intact cornea with balanced salt solution (BSS).

METHODS

In a patient for refractive surgery, prior to the ablation, the temperature of the cornea was continuously recorded with a high speed infrared (350Hz) camera. Two millilitre of chilled BSS with a temperature of 8.6°Celsius (°C) was instilled for about 3s. Using exponential functions, the three contributions have been determined, subjacent corneal layers, environment, and chilled BSS.

RESULTS

The mean temperature of the cornea preoperatively was 34.5°C. After applying the chilled BSS the temperature decreased about 14°C down to an OST of 20°C and the time needed afterwards to get the normal (OST) temperature of about 30°C was 40s. Due to the inserted speculum and missing blink, OST did not reach the original OST of 34.5°C and faded at about 32.5°C. According to our best fitted model, absolute value of each contributing component was 31.4°C (subjacent corneal layers), 26.8°C (environment) and 8.6°C (BSS).

CONCLUSIONS

Applying chilled BSS to the cornea quickly reduces the temperature of the cornea with a thermal relaxation time of 3s and a amplitude decrease of 8.6°C. This together with a relaxation time of 7s for subjacent corneal layers, and 184s for environment after instillation of BSS combined with a well-controlled environment provides a period of 40s of corneal temperature below baseline, which may be of clinical benefit when applying chilled BSS immediately before or immediately after ablation.

Efficient eye-safe neodymium doped composite yttrium gallium garnet crystal laser

We report a laser-diode pumped continuous-wave (cw) and passively Q-switched eye-safe laser at about 1.42 μm with the neodymium-doped yttrium gallium garnet (Nd:YGG) crystal for the first time to our knowledge. The composite Nd:YGG crystal was developed originally. A systematic comparison of laser performance between the homogeneously doped and composite Nd:YGG crystal was made, which showed that the composite Nd:YGG manifested less thermally induced effects. Cw output power of 2.06 W was obtained with the slope efficiency of 20.7%. With a V:YAG as a saturable absorber, the passive Q-switching at 1.42 μm was gotten with the pulse width, pulse energy, and peak power of 34 ns, 46.7 μJ, and 1.4 kW, respectively. The present work should provide a potential candidate for the generation of eye-safe lasers.

Prevention of ocular firework injuries

DOI: http://dx.doi.org/10.3126/nepjoph.v4i1.5842 NEPJOPH 2012; 4(1): 3-4

Corneal burns associated with phacoemulsification

Corneal burns can have devastating surgical results. The surgical team in an ophthalmic operating room needs to be well trained on the phacoemulsification equipment and ophthalmic procedures.

Laser safety in dentistry

Although many regulations and standards relating to laser safety are in effect, there continue to be an average of 35 laser injuries per year. Laser safety professionals believe that this number under-represents the actual number of injuries and that many more accidents per year occur that are not documented with federal agencies. A review of these accidents has determined that failing to wear available eye protection is one of the most frequent contributing factors to laser injuries. As the purchase and use of lasers in dentistry continues to grow, so must concern for laser safety. This article provides basic information to advance the safe use of lasers in dentistry and to help establish laser safety protocols for the dental office.

Determination of eye safety filter protection factors associated with retinal thermal hazard and blue light photochemical hazard for intense pulsed light sources

An assessment is provided of protection factors afforded for retinal thermal hazard and blue light photochemical hazard for a range of filters used with intense pulsed light sources (IPLs). A characteristic IPL spectrum based on black body radiation at 5000 K with a low cut filter at 515 nm was identified as suitable for such estimations. Specific filters assessed included types with idealized transmission properties and also a range of types whose transmission characteristics were measured by means of a Bentham DMc150 spectroradiometer. Predicted behaviour based on these spectra is outlined which describes both the effectiveness of protection and the level of luminous transmittance afforded. The analysis showed it was possible to describe a figure of merit for a particular filter material relating the degree of protection provided and corresponding value of luminous transmittance. This consideration is important for providing users of IPL equipment with safety eyewear with adequate level of visual transmittance.

Quantitative thermographic analysis of viscoelastic substances in an experimental study in rabbits

PURPOSE

To measure the temperature parameters on the corneal surface during the delivery of standardized ultrasound energy assisted with ophthalmic viscosurgical devices (OVDs) or different temperatures of irrigating solutions in an experimental animal model.

SETTING

Department of Ophthalmology and Visual Rehabilitation, Medical University of Lodz, and Central Institute for Labor Protection, National Research Institute, Warsaw, Poland.

METHODS

Thirty rabbits (60 eyes) were randomly divided into 6 groups in which different OVD or balanced salt solutions (BSS) were used: group 1: Viscoat (sodium hyaluronate 3%-chondroitin sulfate); group 2: Provisc (sodium hyaluronate 1%); group 3: soft-shell technique; group 4: Celoftal (hydroxypropyl methylcellulose 2%); group 5: BSS 22 degrees C; and group 6: BSS 4 degrees C. After the nucleus and lens cortex were removed, the anterior chamber was filled with OVD or BSS and a phaco tip was introduced into the pupillary plane and switched on. The same phaco tip parameters were used in all groups. For thermographic measurements (ie, maximal temperature [MT], dynamic rise in temperature [DRT], and time when the maximal level of temperature [TMLT] was achieved), a thermocamera was used.

RESULTS

Mean preoperative temperature on the rabbit corneal surface was 22.76 degrees C +/- 1.48 degrees C (SD). Working with a phaco tip increased the temperature in each group. A significantly higher MT was observed in group 5 (27.85 degrees C +/- 0.52 degrees C), followed by group 2 (27.75 degrees C +/- 0.54 degrees C), group 3 (27.74 degrees C +/- 0.46 degrees C), and group 4 (27.25 degrees C +/- 0.60 degrees C), than in group 6 (26.81 degrees C +/- 0.34 degrees C) and group 1 (26.52 degrees C +/- 0.48 degrees C) (P<.05). Significantly higher values of DRT and shorter TMLT values were observed in group 5 (1.16 degrees C/s +/- 0.42 degrees C/s, 4 seconds) and group 6 (0.91 degrees C/s +/- 0.13 degrees C/s, 5 seconds) than in groups 2, 3, 1, and 4 (0.09 degrees C/s +/- 0.07 degrees C/s, 30 seconds; 0.08 degrees C/s +/- 0.04 degrees C/s, 40 seconds; 0.07 degrees C/s +/- 0.03 degrees C/s, 45 seconds; 0.06 degrees C/s +/- 0.02 degrees C/s, 50 seconds, respectively) (P<.0001).

CONCLUSIONS

Currently used OVDs potentially offer different levels of protection against the increase in temperature that occurs during phacoemulsification. Therefore, the surgeon should consider this aspect when choosing an OVD, particularly in difficult cases (ie, hard nucleus, shallow anterior chamber, endothelial abnormalities).

Corneal endothelial cells' protection against thermal injury: influence of ophthalmic viscoelastic substances in experimental study on rabbits

PURPOSE

To quantify the maximal level of temperature and the time the maximal temperature is achieved and correlate the temperature parameters to the mean rate of endothelial cell loss after standardized ultrasound delivery assisted with four viscoelastic substances or different temperature of balanced salt solution (BSS).

METHODS

Thirty rabbits (60 eyes) were divided into six groups in which different viscoelastic substances or different temperature of BSS were used: Group 1, Viscoat; 2, Provisc; 3, soft shell technique; 4, Celoftal; 5, BSS 22 degrees C; and 6, BSS 4 degrees C. The same parameters of ultrasound energy were delivered by standard phaco tip introduced into pupillary plane. Thermocamera was employed for measurements of temperature parameters. Endothelium cell count was measured before surgery and 1 month postoperatively.

RESULTS

Maximal level of temperature was measured as follows: Group 5, 27.85 +/- 0.52 degrees C; Group 2, 27.75 +/- 0.54 degrees C; Group 3, 27.74 +/- 0.46 degrees C; Group 4, 27.25 +/- 0.60 degrees C; Group 6, 26.81 +/- 0.34 degrees C; Group 1, 26.52 +/- 0.48 degrees C (p<0.05). The time the maximal temperature is achieved was statistically shorter in Groups 5 and 6: 4 seconds, 5 seconds, respectively, p<0.0001, as compared with Group 2 (30 seconds), Group 3 (40 seconds), Group 1 (45 seconds), and Group 4 (50 seconds). The mean rate of endothelial cell loss was calculated as follows: Group 1, 4.35%+/-2.55%; Group 2, 8.43%+/-5.2%; Group 3, 6.25%+/-4.20%; Group 4, 6.53%+/-4.65%; Group 5, 14.3%+/-3.85%; and Group 6, 8.78%+/-4.45%.

CONCLUSIONS

Viscoelastic substances offer different levels of endothelial cell protection against temperature increase during phacoemulsification. The mean rate of endothelial cell loss correlates with the time the maximal temperature is achieved rather than with the value of maximal level of temperature. This implicates that surgical strategy should consider the choice of the most effective viscoelastic substances, particularly in difficult cases, e.g., hard nucleus, shallow anterior chamber, primary endothelial abnormality.

Ocular emergency--a case report

BACKGROUND

Ocular emergencies are not uncommon and one of the causes is chemical burns. Irrigation is the major emergency therapeutic measure of such burns and this also has an impact on the prognosis. We hereby present a case report of chemical burns.

METHOD/RESULT

The case report of a 33year old factory worker presenting with history of visual loss following splash of cement dust unto his face is hereby presented with literature review.

CONCLUSION

We conclude that people working in high-risk industries for chemical injuries should wear protective devices and be given health education as to what they can do in cases of accident.

[Total eclipse of the sun in August 11, 1999: a program of prevention and surveillance of ocular complications]

Watching directly at the sun without appropriate protection, particularly during a solar eclipse, can cause severe retinal injuries. On 11 August 1999, a total solar eclipse crossed France. The Direction Générale de la Santé implemented a prevention strategy. A formal agreement was developed with manufacturers and importers of protective glasses and more than 30 million glasses, conformed with safety standards, were distributed in France. Information campaign reach the whole population in France. In order to evaluate the impact of this campaign, The National Institute of Public Health in France implemented a nation-wide surveillance of ocular complications related to the eclipse. Information on patients was collected using a standardised questionnaire. The questionnaire was sent to the 5,600 private and public sector ophthalmologists practising in France and to five hundred hospital emergency units. A total of 147 patients were reported to have had a retinal injury associated with viewing the eclipse. Seventeen cases were severe (visual acuity < 2/10th) of whom 7 had bilateral injury. Forty-four per cent of patients were aged 15 to 29 years and 46% viewed the eclipse in three regions in the south of France which were sunny on 11th August. One hundred and six patients (67% aged 30 years and more) presented with keratitis. Thirty-six per cent occurred in 2 northern regions of France, which were overcast on the day. A hundred patients watched the whole eclipse without any protection, 74 reported to have removed their EC glasses, and 32 used non-appropriate devices. Only 4 patients presenting with retinal injury reported having used the EC glasses the whole time whilst viewing the eclipse. France is the only country in Europe to have implemented an exhaustive prospective surveillance of ocular injuries related to the solar eclipse. According to current data, the quality and availability of EC glasses did not contribute significantly to ocular injuries. Clinical and epidemiological studies are being conducted in order to further document the evolution of patients presenting with retinal injuries, the circumstances of observation, and their comprehension of preventive messages.

Safe exposure times for slit-lamp fundus biomicroscopy with high plus lenses

PURPOSE

The purpose of this study was to calculate the retinal irradiance and maximum permissible exposure time (MPE) using high plus fundus biomicroscopy lenses.

METHODS

Four Volk handheld condensing lenses (+78 D, +90 D, Superfield NC, and Super 66) were tested with biomicroscopes from three manufacturers (Nikon, Topcon, and Zeiss) on both high and medium illumination. Using the conservation of radiance theorem, the retinal irradiance was calculated and. with guidelines from the American National Standard Institute (ANSI). the maximum permissible exposure time was determined.

RESULTS

The range of MPE time across all lenses and biomicroscopes was from 23 seconds to 74 seconds on high illumination setting. The average MPE times were: for the +78 D, 36 seconds; the Superfield NC, 57 seconds; the Super 66, 32 seconds; and the +90 D, 52 seconds.

CONCLUSION

Retinal irradiances and safe exposure times are useful guidelines in both the clinical and academic setting. Fundus biomicroscopy with non-contact high plus condensing lenses produced calculated retinal irradiances and MPE times similar to those of other commonly used ophthalmic equipment. Awareness of the maximum permissible exposure time increases the safety of this valuable technique.

Protecting the retina during MemoryLens insertion

BACKGROUND

To determine the light-scattering power of the folded MemoryLens(R).

SETTING

Department of Ophthalmology, University of Utah, Salt Lake City, Utah, USA.

METHODS

The focusing power of 10 unfolded MemoryLenses (Mentor Ophthalmics) was measured using an optical bench. The IOLs were then unfolded in a 37 degrees C distilled water bath and reexamined within 15 seconds of removal from the bath. Resolutions were read after the lenses were dried for 1 hour and cooled to room temperature and again after they were rehydrated and reheated in the water bath.

RESULTS

In the rolled state, all lenses diffused the illumination of the light source. After the IOLs were unfolded in the water bath at 37 degrees C, they gave readings of acceptable to high resolution. After the lenses were air dried for 1 hour and cooled to room temperature, the resolution of all lenses decreased. However, after the IOLs were rehydrated and reheated for 1 more hour, resolution was similar to that of the original hydrated lenses.

CONCLUSION

When folded, at a low temperature, or dehydrated, the MemoryLens may provide protection from the operating microscope by scattering light.

Direct measurement of wound temperature during phacoemulsification

We developed a method to measure wound temperature during phacoemulsification with a thermometer and compared the temperature between pulse and nonpulse modes. In cases with partial or complete obstruction of the aspiration port, wound temperature was significantly lower in the pulse mode versus the nonpulse mode. It was ascertained that pulse mode phacoemulsification prevents thermal burn of the wound in the hard nucleus during cataract surgery. This method is useful to evaluate wound temperature during phacoemulsification under various conditions.

Serious fireworks-related eye injuries

OBJECTIVE

To analyze and compare epidemiological and clinical information on serious fireworks-related eye injuries from two affiliates of the United States Eye Injury Registry.

METHOD

Retrospective review.

RESULTS

In the Eye Injury Registry of Alabama (EIRA) database, 185 of the 4150 injuries (4.4%) were caused by fireworks. In the Hungarian Eye Injury Registry database, only two of the 1245 cases (0.1%, p=0.000001) were fireworks-related. In the EIRA, 79% of patients were males and 87% were under 31 years. A bystander was injured in 67% of the cases, being an average of 23 feet away; 39% of bystanders had a final vision < or =19/200. No injured person wore eye protection. Bottle rockets caused 80% of the 185 injuries. Overall, 20% of eyes had <5/200 final visual acuity. Twenty-five percent of bottle rocket-injured eyes, compared to 64% of those injured by other devices, had > or =20/40 final vision (p=0. 000004). CONCLUSIONS. The rate of fireworks-related serious eye injuries has not decreased in Alabama in the last 16 years; most patients are young males. Since bystanders are at a measurable risk even at a distance of 100 feet, wearing eye protection is recommended to both bystanders and operators. Bottle rockets cause most of the injuries and the more severe ones, and should be the prime target for prevention. The benefit of a strict and enforced legislative ban on private fireworks displays is demonstrated by the much lower incidence figure in Hungary. Such a ban should be considered in other countries where fireworks-related eye injuries are common.

Eye injuries from fireworks in Western Sweden

PURPOSE

To investigate the extent and type of as well as the circumstances connected with, ocular injuries caused by pyrotechnical products in the Western region of Sweden (1 750 000 inhabitants).

METHODS

A three-year prospective observational study was carried out to register, interview and follow-up all patients with ocular injuries caused by fireworks. The patients were reported by all ophthalmologists in the area.

RESULTS

52 patients (72 injured eyes) were reported, 49 males and 3 females. 39 of 52 (75%) were younger than 18 years. 15 patients (including the three females) were bystanders. The injuries ranged from conjunctivitis to complete loss of the eye. The pyrotechnical device had been manipulated or misused in 19 (37%) of the 52 accidents. Seriousness of injury could not be correlated to type of device or to whether the injured person was active in launching the firework or not. 20 (38%) of the 52 patients had permanent damage to the eye.

CONCLUSION

Ocular injuries from fireworks remain a problem. Preventive measures such as protective glasses and legislation are being discussed.

Chemical injuries to the eye in Benin City, Nigeria

Chemical injury to the eye is still an important cause of blindness and serious complications in Benin City, Nigeria. Twelve patients were seen with chemical injury to the eye over a five year period. They were all male patients. Ten were assault cases and two were accidental cases. The most common injurious agent was ammonia. Complications seen were corneal opacification in ten patients, symblepharon in nine patients, entropion, ectropion, cataract and staphyloma developed in some of the patients. There were four cases of bilateral blindness and six cases of unilateral blindness. Late presentation to hospital and failure to initiate adequate first aid treatment were contributing factors to the poor outcome. Health education of the public about the importance of prompt, prolonged irrigation of the chemically injured eye and early presentation to the hospital is advised.

Dodick laser phacolysis: thermal effects

PURPOSE

To gather experimental data on whether Dodick laser phacolysis leads to corneal or scleral burns.

SETTING

The Eye Department, County Hospital Salzburg, Salzburg, Austria.

METHODS

The study was done using a pulsed neodymium:YAG (Nd:YAG) laser with a wavelength of 1064 nm; energy, 10 mJ; and duration of pulses, 14 ns. The light pulse is carried by a 400 microns quartz fiber to the laser phacolysis probe. The laser light hits a titanium target inside the tip, causing an optical breakdown and thus a shock wave. The generation of both plasma and the shock disrupt the nuclear material. The temperature at the ultrasonic phaco and laser phacolysis tip was measured under air and balanced salt solution (BSS) in a test chamber and in the anterior chambers of eye-bank eyes.

RESULTS

Ultrasonic phacoemulsification led to a difference in temperature up to 55.3 degrees C under air, 12 degrees C in BSS, and 10.9 degrees C in the anterior chamber. There was no clinical significant heat generated by the laser phacolysis tip.

CONCLUSION

This initial in vitro study demonstrates that the well-known risk of the tissue heating (i.e., phaco burn) does not occur with Dodick laser phacolysis, even when the irrigation flow is slow or discontinued.

Laser injuries of the eye

With the increasing use of lasers in the military and industry, a moderate number of significant retina injuries have occurred. These injuries have been due to lasers in the visible and near-infrared spectrum primarily, with a pulse duration in the nanosecond range. Use of lasers in the ophthalmic community has resulted also in structural damage to the cornea, lens, IOL, and retina. Because we have no proven treatment for most injuries to the retina, we must continue to strongly emphasize the use of wavelength-specific protective goggles to try to prevent future eye injuries.

Transmittance of tinted and UV-blocking disposable contact lenses

PURPOSE

Tinted and ultraviolet (UV)-blocking disposable contact lenses have become increasingly popular over the last decade. Wearers of UV-blocking contact lenses could benefit greatly by protecting their eyes from potential UV radiation damage. A Uvikon 930 dual beam spectrophotometer was used to measure three enhancement-tinted lenses (royal blue, evergreen, and aqua), two types of UV-blocking lenses, and two types of non-UV-blocking lenses. Enhancement-tinted lenses did show a decrease in transmittance at certain wavelengths on the visible spectrum, but they did not reduce the transmittance of UV radiation to the extent of the UV-blocking lenses designed specifically for this purpose.

[An analysis of 148 outpatient treated occupational accidents]

BACKGROUND

The most common eye injuries are non-perforating. Eye injuries in the workplace are a major cause of socioeconomical damage, morbidity and disability, despite well publicised standards for industrial eye protection. This study investigates the epidemiological and clinical aspects of 148 occupational cases.

PATIENTS

At the University Eye Clinic of Tübingen, 709 non-perforating eye injuries were registered as occupational accidents between 1995 and 1996. Of these cases, 148 were analysed retrospectively per random.

RESULTS

The 5 most common injuries of 148 patients (m/f = 138/10; mean age 33.4 +/- 12 years) were related to corneal foreign body injuries (35%), chemical burns (15.5%), sub-conjunctival foreign bodies (12%), thermal/ultraviolet injuries (11%) and contusions (7.4%). Of these patients, 22.3% were employed as construction workers and 16.2% as metal workers. At the time of examination the visual acuity of the traumatic eye was 0.9 +/- 0.3. The interval between the beginning of work and accident was 6.2 +/- 6.4 hours in average (0.5-13.5 h). Of all accidents, 8.5% were caused during the first hour of work; in contrast 45.5% of all accidents were caused after 6 hours of work. Another 12.4 +/- 14.5 hours (5min.-72 h; median 7 h) passed by until the patients arrived for eye examination at the Eye Clinic of Tübingen. Only 6% of all patients arrived within the first hour, and 29.7% after 12 hours. Of all cases, 30.4% received first-aid treatment in their company by the factory doctor or by the eye doctor before examination at the Eye Clinic. Only 6.8% of all patients had protective spectacles during work. Incapacity was seen in 30.4%; the average in total was 5.5 +/- 10 days.

CONCLUSION

Despite the late examination at the Eye Clinic the functional loss was mostly little except after chemical burns. Nevertheless, most occupational accidents can be avoided with better protective devices in order to reduce the incidence of injuries and socioeconomical damage. Therefore an intense campaign about protective devices at the place of employment should be required. We conclude that education about safety glasses in the workplace by tradespeople and trades assistants during tasks for which goggles are recommended could considerably reduce the rate of occupational eye traumata. The data of the University Eye Clinic of Tübingen are useful to identify strategies to prevent eye injuries such as wider and better use of safety glasses and improvement in engineering controls.

Personal defense sprays: effects and management of exposure

BACKGROUND

Most personal defense sprays contain o-chlorobenzylidene malononitrile (CS), w-chloroacetophenone (CN), oleoresin capsicum (OC), or a combination of these ingredients as the active agent. They are designed to incapacitate by causing acute ocular irritation, lacrimation, conjunctivitis, blepharospasm, and mild to moderate respiratory distress.

METHODS

To assess the ocular effects of sprays containing OC as the active agent. Snellen visual acuities and anterior segment appearances of 22 police officers were determined before and after spray exposure. To assess the effects of OC spray contamination on soft contact lenses, four brands of lenses were sprayed and cleaned twice with an alcohol-based cleaner. Gas chromatography was used to search for residual OC in the lenses.

RESULTS

All officers experienced intense blepharospasm, lacrimation, conjunctivitis, and incapacitation as the result of spray exposure. Acute effects lasted about 5 to 10 min, with relatively complete recovery occurring in about 30 to 60 min. All had significant conjunctivitis, and some had water-drop-shaped corneal defects that stained with fluorescein. These defects resolved within 24 hours without treatment. OC residue was found to be present in the soft lenses that had been sprayed and cleaned twice.

CONCLUSIONS

Optometrists can manage uncomplicated spray exposure patients by directing at-home irrigation with water, and following up with an in-office examination. Soft lenses contaminated by OC spray should be discarded.

Poor prognosis of severe chemical and thermal eye burns: the need for adequate emergency care and primary prevention

The epidemiology and wound healing following medical and surgical treatment of 101 patients with 131 severely burnt eyes due to chemical or thermal agents have been analyzed. Most of the accidents occurred at work (72.3%); the majority of the burns were chemical (84.2%), of which 79.8% were caused by alkalis. The long average duration of treatment on ward (5.2 +/- 4.1 months) and the high number of surgical interventions (8.0 +/- 8.0) indicate the difficulties in treatment and the delayed recovery of the affected eyes. Despite improved possibilities of immuno-suppression after keratoplasty (cyclosporin A) and new methods of surgery (Tenon plasty), the possibilities of an optical rehabilitation are still limited. A visual acuity of 6/60 or better was achieved in 39 eyes (32.2%). Immediate irrigation was reported in 56.1% of accidents at the place of work and in 42.8% of accidents sustained at home. There was a significant difference with respect to the extent of damage, the treatment on ward and the number of surgical interventions. The visual prognosis for eyes which received immediate irrigation was significantly improved. Eye protection was not used in any of the 101 cases. Spread of information is necessary for adequate emergency care for eye burns as well as for permanent employment of protective glasses in high-risk occupations.

[Means of individual protection in cleaning-up consequences of accidents at chemical industries]

The authors considered protective efficiency and physiologic acceptability to compare various types of individual protective means applied in some industries. The article presents general principles and methodic approaches to use of various individual protective means for eyes and respiratory organs. The important notion is that besides individual protective means also pharmacologic agents, various norms and regulations (MAC) should be used to protect humans from chemical hazards. Some revealed common features for chemical enterprises could serve to forecast occupational diseases and therefore determine individual protective means for respiratory organs and define the application of those means. To make quick and correct choice of the individual protective means for respiratory organs during accidents at chemical enterprises, one should refer to PC data bases.