PMC6652071_01
Ophthalmic reexamination six months after the initial examination in 2010.
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A mature cataract was found in the right eye (Figure 1(a)) and a nuclear incipient cataract was found in the left eye (Figure 1(b)).
B-mode ocular ultrasonography of the elephant's right eye revealing a hyperechoic nuclear lens. Despite the clinical diagnosis of a mature cataract, the lens cortex appears to be less significantly affected in the ultrasound image. The crystalline lens thickness (A: 12.2 mm), crystalline lens diameter (B: 17.9 mm), and the vitreal chamber depth (C: 21.4 mm) are visible in this image, as well. Note that D is not a valid measurement and that the caliper measurements were inadvertently saved.
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Transcorneal B-scan ultrasonography revealed hyperechoic lens in both eyes, consistent with cataractous changes (Figure 2).
The original plan was to perform surgery on the right eye, if possible, but the elephant went into right lateral recumbency and could not be maneuvered into left lateral recumbency. As a result, surgery was performed on his left eye.
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However, right lateral recumbency was achieved (Figure 3) and the decision to continue with phacoemulsification of the left eye, rather than the right eye, was made.
A size 30 endotracheal tube is being placed, under manual control, along the left arm of this veterinarian.
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A size 30 endotracheal tube (ET) was used for intubation (Figure 4). The elephant was intubated with a 30 mm endotracheal tube and breathing was controlled via the same leaf blower apparatus described previously (Figures 4 and 5).
A modified Y-piece apparatus and electric leaf blower were attached to the endotracheal tube to provide intermittent positive pressure ventilation (IPPV) and supplemental oxygen to the elephant bull during the duration of the anesthesia.
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Intermittent positive pressure ventilation (IPPV) and supplemental oxygen were provided with a modified Y-piece apparatus and electric leaf blower (Figure 5). The elephant was intubated with a 30 mm endotracheal tube and breathing was controlled via the same leaf blower apparatus described previously (Figures 4 and 5).
A modified retrobulbar block was performed using a slightly bent, 19-gauge, 2.5-inch needle to deposit approximately 25 ml of 2% mepivacaine (Pharmacia & Upjohn Company, Pfizer Inc. NY, NY, USA) through the ventral and dorsal bulbar conjunctiva behind the globe.
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NY, NY, USA) was deposited behind the globe from both dorsal and temporal conjunctival access points (Figure 6).
Manual digital pressure was applied simultaneously to the upper and lower eyelids to displace the globe anteriorly, thereby providing better access to the sites of injection for the modified retrobulbar block described and shown in Figure 6.
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Access to these regions was facilitated by slight manual depression of the upper and lower eyelids (Figure 7).
Due to the unconventional surgical location and positioning of the elephant, a head-mounted microscope (Varioscope M5 , Acrivet, Veterinary Division of S&V Technologies AG, Hennigsdorf, Germany) was utilized to facilitate visualization for the procedures.
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Acrivet, Veterinary Division of S&V Technologies AG, Hennigsdorf, Germany) was utilized (Figure 8). A trilaminar, clear corneal incision (CCI) was created.
Phacoemulsification was performed using a 45-degree, 4 cm long handpiece designed specifically for horses (Acrivet, Veterinary Division of S&V Technologies AG, Hennigsdorf, Germany).
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fig9
Phacoemulsification with a 45-degree, 4 cm equine-specific system was utilized to remove the cataract (Figure 9).
A series of images illustrating the use of an overhead hoist attached to a sling that was placed under his thorax prior to induction (see Figure 3).
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He was moderately disoriented and unable to rise on his own, requiring assistance with an overhead hoist (Figures 10(a)-10(d)).
The elephant bull was photographed during a training session where he was practicing to lie down in left lateral recumbency on command, with the hope that he would end up in the appropriate position to perform phacoemulsification of his right eye.
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To prevent the elephant from going down into right lateral recumbency, it was trained to stretch out in left lateral recumbency (Figure 11).
A small piece of what appears to be lens nuclear material can be visualized within the ventromedial pupil at approximately the 4 o'clock position.
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At the 8-week recheck, a small lens remnant was discovered in the vitreous in the right eye that could only be visualized when the pupil was fully dilated (Figure 12).
A corrective contact lens (+ 9.00 diopters) has been placed in the elephant's right eye in an attempt to correct the marked hyperopia due to his being left aphakic (Acrivet, Veterinary Division of S&V Technologies AG, Hennigsdorf, Germany). Note the smaller circular area within the center of the lens (this is most readily visible along the ventromedial pupil extending from approximately 2:30 to 9:00 o'clock) that represents the corrective portion of the lens. The four black dots at the 12, 3, 6, and 9 o'clock edges of the corrective contact lens are to make it easier to visualize during subsequent examinations.
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Technologies AG, Hennigsdorf, Germany) was placed in the right eye (Figure 13). Due to waning cooperation of the elephant, a corrective lens was not placed in the left eye.