Eye Contact Case Study

On April 26, 2005, between 8:00 and 9:00 pm, Janet Abaroa was preparing to go to bed, according to her husband, Raven Abaroa. In court documents, Mr. Abaroa stated that he then left their home to attend a nearby soccer game. When he returned home at 10:45 pm, he discovered his pregnant wife's bloody corpse and called 911. The North Carolina Office of the Chief Medical Examiner concluded that the cause of death was two stab wounds to the front torso. The victim's parents chose to bury her on their family plot at Brown's Mill Cemetery in Antrim Township, Pennsylvania, in May 2005.

The husband immediately became a key person of interest in the case. However, the murder became a “cold case” due to a lack of physical evidence connecting him to the crime. During an inventory check years later, a new detective noted that the victim's contact lenses were not in their storage case. Family members told police that the victim always removed her contact lenses before going to sleep. A police investigator testified that Raven Abaroa told him that Janet removed her contact lenses before bed and was wearing her glasses when Raven left the home. Due to this discrepancy, an exhumation was requested by the District Attorney's Office to determine whether the contact lenses were still on Janet Abaroa's eyes.

Defense attorney Amos Tyndall wrote in a statement obtained by the Herald-Mail that “Mr. Abaroa had objected to the Commonwealth's petition to exhume Mrs. Abaroa's body… to conduct experiments that have no scientific validity, will be performed without a specific or established protocol, and are designed to support conclusions the analysts have already reached about the case” [1].

On July 20, 2010, as the result of an order signed by Judge Douglas Herman, the remains of Janet Abaroa were exhumed from the Brown's Mill Cemetery so that the District Attorney's Office of Durham, North Carolina, could determine whether the decomposed body had contact lenses in the eyes. The exhumed eye contents remained in the custody of the crime investigation unit of Durham, North Carolina, from July 2010 until February 2013, pending a forensic examination by an ophthalmologist.

On February 28, 2013, material evidence item number IR: 05-10185, obtained from the exhumation of Janet Abaroa, was delivered to Charles Zwerling, MD, for forensic evaluation. The purpose of this examination was to determine whether this material evidence represented or contained contact lens remnants. All of the material evidence was returned undamaged and intact to the District Attorney's Office on March 22, 2013, to allow for possible examination by the defense.

On March 30, 2013, Judge Orlando Hudson declared a mistrial due to a hung jury. On March 12, 2014, Raven Abaroa agreed to plead guilty to a charge of voluntary manslaughter. Abaroa entered an Alford Plea, in which he did not admit guilt but agreed that prosecutors likely had sufficient evidence to obtain a conviction. He was sentenced to 95 to 123 months in prison [2].

A Brief History of Contact Lenses: Composition and Use

The idea of creating a contact lens for the human eye was first proposed by Leonardo Da Vinci in 1508. In his Manual D, Codex of the Eye, he described a method for altering the refractive power of the cornea by submerging the eye in a bowl of water to change the refraction of the light (see Fig. 1) [3]. In 1636, René Descartes suggested a similar idea for altering the refractive power of the human cornea, using a glass tube filled with liquid in contact with the eye [4, 5].

In 1887, the German glassblower F.E. Muller unsuccessfully produced the first actual contact lens for the human eye. This contact was made entirely of glass and covered the entire eye. In the same year, Adolph Fick constructed and fitted the first successful hard contact lens for use. Fick published his work, “Contactbrille,” in the journal Archiv für Augenheilkunde in March 1888.

In 1936, contact lenses were manufactured for the first time using a plastic material known at the time as polymethyl methacrylate (PMMA) [6, 7]. Optometrist William Feinbloom combined this new plastic material with existing hard contact glass material and created the first hybrid rigid lenses. With improved lathe manufacturing techniques and smaller designs, hard PMMA contact lenses became very popular in the 1960s [8]. Despite their popularity, there were limitations in wearing time and comfort as these PMMA lenses did not allow the passage of oxygen through the lens [9]. The development of rigid gas-permeable (RGP) lenses represented the next advancement in design and wear time for contacts, with enhanced permeability of oxygen [10].

In 1971, the US Food and Drug Administration (FDA) approved the first soft contact lens: Softlens was comprised of a flexible hydrogel material made from a monomer solution of 2-hydroxyethyl methacrylate (HEMA). The new soft contact lens was well-accepted by the American public due to the increased comfort level [11]. In 1981, the FDA approved the first overnight or extended wear contact lens. In 1998, the first soft silicone hydrogel contact lenses entered the market, with increased oxygen permeability properties [12]. Since that time, numerous companies, such as Vistakon and Ciba, have manufactured newer generations of silicone hydrogels. These silicone contact lenses have higher water content for improved flexibility and comfort, in addition to increased oxygen permeability [13-15].

Methods and Observational Results

Because no accepted scientific protocol existed, an examination procedure was created specifically for the examination of the exhumed orbital material in the Abaroa case. This new procedure allowed a scientific and systematic approach (Table 1).

  1. Collect Evidence
  2. Morphology
    1. Size
    2. Shape
    3. Weight
    4. Color
    5. Markings
      1. Inversion markings
      2. Alignment/toric lines
      3. Manufacturer identification marks
  3. Physical Properties
    1. Transparency
    2. Flexibility
      1. Rigid
        1. Hard
        2. Semi-soft
      2. Soft
    3. Refractive Prescription
      1. Sphere ±; Cylinder ±; Axis
      2. Base curve
      3. Diameter
      4. Tint
    4. Chemical composition by gas chromatography–mass spectrometry
    5. Water properties
      1. Hydrophilic
      2. Hydrophobic
  4. Data Base
    1. Use of electronic medical records (EMR)
      1. Correlate refractive Rx with specific patient
      2. Identify prescribing medical care provider
    2. Identify specific manufacturer
  5. Simulation Studies
    1. Reproduce physical environment
    2. Reproduce physical conditions
    3. Special computer software to extrapolate contact lens dimensions from remnants

Moreover, simulated dehydration and burial experiments were performed using new contact lenses from various optical companies. On March 12, 2013, the exhumed specimens were examined at the Pathology Lab of Wayne Memorial Hospital. The material trace evidence was removed from the cardboard container. The numerous trace samples were contained in a plastic bottle with liquid formalin preservative fluid.

Using sterile precautions to minimize any additional contamination, the specimens were removed from the vial and placed onto surgical gauze to eliminate the formalin fluid. Next, all of the samples were gently washed in physiologically normal saline to remove any residual liquid preservative. Then, all of the samples were weighed on a Mettler Toledo analytical scale to determine that the overall total weight of all 8 specimens was 0.024 g.

All of the samples were placed on a glass surface and examined with a stereomicroscope. The specimens were separated and measured using surgical calipers and blunt-tip surgical forceps, and these processes were documented using a Sony Cybershot digital camera.

Nomenclature

For organizational purposes, the specimens were separated into two groups: Group 1, which consisted of 4 larger specimens; and Group 2, which consisted of 4 smaller specimens. Group 1 was designated as containing Samples A, B, C, and D. Group 2 was designated as simply containing 4 small samples, consisting of irregular fragmented shapes <0.1 cm in size (see Fig. 2). All of the specimens in Groups 1 and 2 had the same color and consistency. Both groups were photographed using macro-settings and the automatic flash of the Sony Cybershot digital camera.

Evaluation of Case Materials

Samples A, B, C, and D all demonstrated varying degrees of transparency. All of the samples were hydrophilic and became more pliable and flexible with the slow addition of sterile normal physiologic saline solution. All of the irregular samples had smooth curvilinear surfaces with concave and convex shapes. Samples A, B, and D demonstrated beveled outer edges. Samples A, B, C, and D were then measured using surgical calipers to determine the greatest length and width of each sample. Samples A, B, C, and D were also photographed to demonstrate the transparency of each of the specimens. Below is a summary of the physical findings and measurements (Table 2).

A1.0 × 0.6YellowConvexPliableTransparentHomogenous
B0.6 × 0.5YellowConvexPliableTransparentHomogenous
C0.5 × 0.5YellowConvexSemi-PliableTransparentHomogenous
D0.4 × 0.3YellowConvexSemi-PliableSemi-transparentHomogenous

The 4 remaining smaller samples in Group 2 were <0.1 cm in dimension but were of the same homogenous pliable, yellow, semi-transparent material.

Under stereomicroscopic viewing, none of the samples demonstrated human histology consistent with epithelial, connective, muscular, and/or nervous human tissue. With the exception of Sample A, all of the sample surfaces were shown to be identical in appearance and consistency (see Fig. 3). Sample A exhibited a pattern of embossed spherical markings that appeared to be manufactured. Using additional normal physiologic saline solution and microsurgical forceps with smooth edges, Sample A was unfolded to reveal an improved appearance of the markings. Sample A was photographed on the convex and concave sides for better evaluation of the embossed markings. The markings clearly demonstrated the whole numbers 1, 2, and 3. Embossed markings are typical of inversion marks placed on the surface of contact lenses by various contact lens companies [16]. The inversion marks 1, 2, and 3 are the proprietary markings found on Acuvue 2 soft contact lenses, which are manufactured by Vistakon [17].

To confirm the similarities seen in color patterns and fracture results of the victim's contact lenses, simulation studies were needed. The simulation studies could not test all of the variables in this case, but they serve as a baseline to explain how the contact lenses came to be fractured and discolored.

Contact Lens Fracture Simulation Study and Results

The contact lens fracture simulation study was performed using an Acuvue® 2 manufactured by Vistakon®, with +1.50 power, an 8.7 base curve and a diameter of 14.0 mm. The contact was removed from its manufacturer's packaging and photographed using the Sony Cybershot digital camera.

The digital photograph clearly demonstrates the same whole numbers 1, 2, and 3 as previously noted and demonstrated on Sample A of the trace material evidence. Moreover, these same inversion marks were located at the outer border of the contact lenses. The inversion marks 1, 2, and 3 are proprietary and are used to orient correct placement of the contact (see Fig. 4). This new Acuvue® 2 contact lens was then dehydrated using a hair blow dryer without heat on the contact lens for 30 min.

The contact lens exhibited marked brittleness and was easily fractured into smaller fragments in a similar pattern to that of the exhumed material. This fracture pattern was consistent with natural dehydration of the hydrophilic substrate of a soft contact lens. Moreover, the dehydrated fractured contact lenses were able to be rehydrated using physiologic normal saline solution.

Contact Lens Burial Simulation Study and Results

A contact lens burial simulation study was performed to reproduce the yellow discoloration patterns noted on Sample A from the material evidence. Acuvue 2 soft contact lenses were used as the controls throughout the simulation study. Soft contact lenses from other manufacturers were added to the burial simulation study as variables for comparison. Variable factors that could affect the outcomes of this simulation study included different soil conditions, water tables, burial depths, and temperatures.

Soft contact lenses were applied to two sets of enucleated pig eyes. Following standard North Carolina funeral protocols [18], the pig eyes with applied contact lenses were then embalmed and buried to determine the effects of the environment and postmortem ocular bio-degeneration. The pig eyes were obtained from a local swine processing plant after the animals had been euthanized under veterinary supervision.

The first wooden casket was prepared and contained a pair of soft contact lenses: Acuvue 2 (−2.25) 8.7, 14.0 (right eye), and Air Optix (−2.50) 8.4, 13.8 (left eye). The two contact lenses were placed on two freshly enucleated pig eyes [19, 20]. The pig eyes and contact lenses were then exposed to “Dodge Dis Spray,” a chemical used to slow the biodegradation process per the standard funeral protocols in the state of North Carolina. Plastic lens caps were placed over the pig eyes/contact lenses according to usual funeral preparations (see Fig. 5).

A second casket was prepared in the same manner, containing an Acuvue 2 (−2.25) 8.7, 14.0 (right eye) and a Proclear (−11.00) 8.5, 14.0 (left eye) (see Fig. 6).

In both wooden miniature caskets, the contact lenses and pig eyes were covered with funeral quality burial linen. The caskets were then buried six feet below the ground surface within a brick and cement burial vault on July 1, 2013, in Goldsboro, North Carolina. The vault protected the casket from both the weight of the earth and the heavy maintenance equipment that can pass over a typical grave.

The first wooden casket was exhumed 6 months later on January 11, 2014, and the second casket was exhumed 12 months later on June 30, 2014 (see Figs. 5 and 6). Both caskets were brought to Goldsboro Eye Clinic for forensic evaluation. Each opened casket was photograph-documented, revealing two decomposed enucleated pig eyes covered with lens caps. The lid caps were removed, revealing the partially decomposed pig eyes. The contact lens on each pig eye was carefully inspected, removed with microsurgical forceps, and photographed (see Fig. 7).

In every case, all of the contacts partially adhered to the degenerative cornea and required the use of physiologically normal saline solution to separate the contact lens from the cornea (see Fig. 8).

All of the soft contact lenses demonstrated thinning, micro-tears, fractures, and a distinctive yellow color change. The soft contacts developed partial and irregular areas of yellowish deposits throughout the entire thickness of the lenses, with loss of the usual transparency (see Figs 7 and 8). The intensity of the yellowish color on the control Acuvue® 2 contact lenses increased from the sixth month to the twelfth month exhumations and were similar to the yellow spoilage that was noted in the exhumed samples (see Table 3).

Acuvue 2®61025N/A
Air Optix®6510100%
Acuvue 2®123020N/A
Proclear®123520100%

Discussion

The contact lens remnants obtained from the exhumed body and the contact lenses used in the simulation experiments (see Table 3) both demonstrated the same yellowish discoloration, decomposition, and loss of transparency.

Most contact lenses are comprised of monomers and cross-linked materials that have charges on the monomers. This charge distribution results in the attraction of proteins and/or lipids that possess charged surfaces [5]. The protein and/or lipid materials create a biofilm made of deposits within the contact lens. This biofilm of deposits results in the contact lens losing its optical properties and transparency as well as assuming a yellow color. Thus, the yellow color or lens spoilage is the result of the diffusion of proteins and lipids into the contact lens substrate [21, 22].

The spherical-embossed markings on Sample A were identical to the proprietary inversion mark, or inside-outside markings, of Vistakon®, which manufactures the Acuvue® brand contact lenses. The purpose of this type of marking is to assist the patient in determining whether the contact lens is in the correct orientation for safe insertion onto the cornea [23]. Vistakon® was contacted and provided a table delineating the variations with which Acuvue® contact lens manufactured in 2005 (at the time of the murder) exhibited the inversion mark (see Table 4).

Acuvue 2 brand (with 123 inversion marks)Etafilcon ADaily wear and extended wear
Acuvue brand bifocalEtafilcon ADaily wear and extended wear
1-Day Acuvue brandEtafilcon ADaily wear
1-Day Acuvue moist brandEtafilcon ADaily wear
Acuvue advance brandGalyfilcon ADaily wear
Acuvue Oasys Brand (with 123 inversion marks)Senofilcon ADaily wear and extended wear

As noted in Table 4, the chemical substrate is etafilcon A or senofilcon A (proprietary name), which is a hydrophilic form of a soft contact lens and is a three dimensional, amorphous material with cross-linked substrates [24]. The lenses are soft because the temperature of the polymer is greater than its glass transition temperature [25, 26]. These soft contacts are still manufactured by Acuvue® using cast molding, with embossing of the 1, 2, and 3 inversion marks [5, 27].

The scientists at Vistakon® offered to perform gas chromatography–mass spectrometry (GC/MS) on one or more of the samples to further clarify the chemical substrate of the contact lens material. In Table 3, the only two variations that exhibited the 1, 2, 3 inversion marks are the Acuvue 2 and the Acuvue Oasys. GC/MS would have identified the material as etafilcon A or senofilcon A. However, this destructive analysis was not performed on the Abaroa exhumed case samples, thus enabling the defense to obtain expert opinions on all of the original sample material. GC/MS, as well as other nondestructive techniques, should be considered additional tools for future investigations.

Conclusion

Material evidence from an exhumed body was collected and examined, maintaining a strict chain of custody. The embossed inscription marks 1, 2, and 3 on Sample A represented a fragment of a hydrophilic soft contact lens, which was further identified as a specific product of an Acuvue® Brand Contact Lens manufactured by Vistakon® (see Fig. 9).

After an exhaustive search of the literature, this case appeared to be the first published identification and use of a contact lens from an exhumed body in a murder investigation [5]. This key piece of material evidence was instrumental in providing factual proof refuting the defendant's testimony in the murder trial. Simulation studies provided further verification and science-based proof for these findings.

A procedure for examining recovered contact lenses from crime scenes is important for ensuring objective conclusions. Moreover, contact lenses should be preserved in conditions that allow for additional examination of original material by other experts [28]. The guidelines created in this investigation are offered as an operating procedure for future cases involving contact lenses as forensic evidence.

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