Glaucoma

Glaucoma is a serious ocular condition characterized by elevated intraocular pressure that damages the optic nerve and internal structures of the eye, ultimately leading to vision loss if left untreated. In guinea pigs, glaucoma can occur as a primary condition or secondary to other ocular diseases such as uveitis, lens luxation, or intraocular tumors. The condition causes significant pain and progressive deterioration of vision, making early detection and management essential for maintaining quality of life. Advanced cases may develop buphthalmos, an enlargement of the entire globe that results from chronic elevated pressure stretching the eye structures.

Glaucoma occurs with moderate frequency in guinea pigs, though precise prevalence data is limited compared to more commonly studied species. The condition may be underdiagnosed because guinea pigs hide signs of discomfort effectively and owners may not recognize the subtle early symptoms. Primary glaucoma, where the condition arises spontaneously without other underlying eye disease, appears to occur in guinea pigs and may have genetic components in certain individuals or lines. Secondary glaucoma, resulting from other ocular pathology that impairs normal fluid drainage from the eye, is also recognized and may be more amenable to treatment when the underlying cause can be addressed.

The impact of glaucoma on guinea pig health extends beyond vision to significantly affect comfort and quality of life. Elevated intraocular pressure causes substantial pain that guinea pigs may hide through their prey animal instincts until the condition becomes severe. This chronic pain can suppress appetite, leading to weight loss and potentially triggering life-threatening gastrointestinal stasis. Progressive vision loss affects the guinea pig's ability to navigate their environment, find food, and interact normally with cage mates. The psychological stress of living with chronic pain and disability compounds the physical effects of the disease. In advanced cases, the enlarged eye becomes vulnerable to injury and may develop corneal ulceration from exposure.

The treatability of glaucoma in guinea pigs focuses on management rather than cure, as damage to the optic nerve and retina from elevated pressure is typically irreversible. Medical management with pressure-lowering medications can slow disease progression and improve comfort when initiated early. However, guinea pigs often present with advanced disease due to delayed recognition of symptoms, limiting treatment options and effectiveness. In cases where medical management fails or the eye is blind and painful, surgical options including enucleation may be recommended to eliminate pain and improve quality of life. Early detection through regular veterinary examinations and owner awareness of warning signs offers the best opportunity for successful management.

The primary cause of glaucoma is impaired drainage of aqueous humor, the fluid produced within the eye that normally flows through specific structures before draining through the iridocorneal angle. In primary glaucoma, abnormalities of the drainage angle itself prevent normal fluid outflow, leading to accumulation of aqueous humor and elevated intraocular pressure. The precise causes of primary glaucoma in guinea pigs are not fully characterized, but structural anomalies of the drainage apparatus similar to those seen in other species are likely involved. Some cases may have congenital origins, with affected animals born with abnormal drainage structures that eventually cause clinical disease.

Genetic and hereditary factors appear to play a role in some cases of guinea pig glaucoma, though the inheritance patterns have not been extensively studied in this species. Observations of familial clustering in some breeding groups suggest that genetic predisposition exists. Primary glaucoma affecting both eyes, often with onset within a similar timeframe, supports genetic etiology in these cases. Breeders who observe recurring glaucoma in their lines should consider this when making breeding decisions and may benefit from excluding affected animals and their close relatives from breeding programs. The potential for heritable glaucoma means that affected guinea pigs ideally should not be bred.

Secondary glaucoma develops as a consequence of other ocular conditions that physically obstruct aqueous humor drainage or alter the drainage structures. Uveitis, or inflammation inside the eye, represents a common cause of secondary glaucoma through multiple mechanisms including inflammatory debris blocking the drainage angle and scarring that permanently impairs outflow. Lens luxation, where the lens becomes displaced from its normal position, can physically obstruct aqueous drainage pathways. Intraocular tumors may block drainage directly or cause secondary inflammation leading to glaucoma. Hemorrhage within the eye from trauma or disease can obstruct outflow. Chronic untreated cataracts may lead to lens-induced uveitis and secondary glaucoma.

Risk factors for developing glaucoma include advancing age, with older guinea pigs showing increased incidence of both primary glaucoma and the conditions that cause secondary glaucoma. History of eye trauma or previous ocular disease increases risk for secondary glaucoma development. Guinea pigs from lines with known glaucoma occurrence may carry genetic predisposition. Poor general health and immune function may predispose to inflammatory conditions that can lead to secondary glaucoma. Environmental factors have not been definitively linked to glaucoma development, though overall health maintenance through proper husbandry likely supports ocular health.

The disease mechanism of glaucoma involves a destructive cascade initiated by elevated intraocular pressure. Normal intraocular pressure in guinea pigs is maintained through balanced production and drainage of aqueous humor. When drainage is impaired, pressure rises progressively, compressing and damaging the delicate structures at the back of the eye. The optic nerve head is particularly vulnerable, with pressure-induced damage interrupting transmission of visual signals to the brain. Retinal ganglion cells, the neurons that form the optic nerve, are progressively destroyed by elevated pressure. The outer coats of the eye may stretch under chronic pressure, leading to the globe enlargement known as buphthalmos. This stretching can thin and weaken the cornea, predisposing to ulceration and potential rupture.

Early warning signs of glaucoma in guinea pigs are often subtle and challenging to detect without experience and careful observation. Initial symptoms may include slight changes in eye appearance that are difficult to characterize, such as a dull or hazy quality to the eye surface. The pupil may appear slightly dilated compared to the other eye or may respond sluggishly to light. Mild behavioral changes including slight reduction in activity or subtle reluctance to approach food dishes may indicate developing discomfort. Some guinea pigs show mild photophobia, preferring darker areas of their enclosure or squinting in bright light. Changes in appetite may precede obvious eye changes as the guinea pig responds to chronic discomfort.

As glaucoma progresses, symptoms become increasingly apparent and easier for owners to recognize. The affected eye develops a noticeably dilated pupil that may no longer respond to light changes. Corneal cloudiness or haziness develops as edema forms from elevated pressure affecting the corneal endothelium. The eye may appear larger than the unaffected eye as the globe begins to stretch under chronic pressure. Redness of the conjunctiva and sclera indicates inflammation and congestion associated with elevated pressure. The eye may develop a blue or blue-green discoloration from corneal edema. Increased tearing or discharge may occur as the eye surface becomes compromised.

Behavioral changes associated with glaucoma reflect the pain and vision impairment caused by this condition. Affected guinea pigs often become quieter and more withdrawn, spending increased time hiding rather than engaging in normal activities. Appetite reduction is common as pain suppresses normal feeding behavior. Guinea pigs may hold the affected eye partially closed or blink excessively. Head positioning may change, with the guinea pig appearing to guard or protect the affected side. Responses to visual stimuli approaching from the affected side may be diminished or absent as vision deteriorates. Social interactions frequently decrease, with affected animals showing less engagement with cage mates.

Physical examination findings provide crucial information for diagnosis and severity assessment. Measurement of intraocular pressure using tonometry reveals elevated readings compared to normal values for guinea pigs. The cornea appears edematous with loss of normal clarity. In advanced cases, the globe is visibly enlarged compared to the opposite eye or to normal guinea pig eye size. The pupil is typically widely dilated and unresponsive to light. Examination of the internal eye structures may be limited by corneal cloudiness but may reveal changes in the lens position or evidence of underlying conditions causing secondary glaucoma. The optic nerve head, when visible, may show cupping or pallor indicating damage.

Symptom progression in untreated glaucoma follows a course of progressive worsening. Intraocular pressure continues to rise as drainage remains impaired, accelerating damage to the optic nerve and retina. Globe enlargement becomes increasingly pronounced, eventually reaching dramatic proportions in severely affected eyes. Complete blindness develops in the affected eye as the optic nerve is destroyed. The enlarged cornea becomes vulnerable to injury and may develop ulceration from exposure or trauma. Secondary complications including lens luxation and intraocular hemorrhage may develop. Pain typically increases with disease progression, significantly affecting quality of life.

Certain symptoms indicate emergency situations requiring immediate veterinary attention. Acute severe increase in intraocular pressure causes intense pain manifested by complete eye closure, dramatic behavior changes, and apparent distress. Any visible corneal ulceration on an eye with glaucoma requires urgent treatment to prevent perforation of the already compromised tissue. Signs of sudden complete vision loss suggest acute pressure spike requiring emergency intervention. Evidence of globe rupture, including fluid leakage or sudden softening of the eye, constitutes an emergency. Systemic signs of severe pain including complete appetite loss, lethargy, and evidence of gastrointestinal stasis require immediate attention.

Diagnosis of glaucoma requires examination by a veterinarian experienced in exotic animal medicine, ideally one with ophthalmology expertise or access to appropriate equipment for measuring intraocular pressure. The examination begins with careful observation of both eyes, comparing size, clarity, and overall appearance between sides. Pupil size and light responses are evaluated, with the dilated, unresponsive pupil characteristic of glaucoma noted. External structures including the conjunctiva, sclera, and cornea are assessed for signs of inflammation, edema, and damage. Overall physical examination evaluates general health status and identifies any concurrent conditions affecting management decisions.

Tonometry, the measurement of intraocular pressure, is essential for confirming glaucoma diagnosis and monitoring treatment response. Various tonometry methods can be used in guinea pigs, with rebound tonometry devices being commonly employed due to their ease of use and minimal patient restraint requirements. Normal intraocular pressure values in guinea pigs provide reference ranges, though individual variation exists. Significantly elevated readings confirm glaucoma, while the degree of elevation helps guide treatment urgency and intensity. Serial pressure measurements over time monitor disease progression or treatment response.

Additional diagnostic procedures help characterize the type and severity of glaucoma and identify underlying causes in cases of secondary glaucoma. Gonioscopy, examination of the drainage angle, may be possible with appropriate equipment and can reveal structural abnormalities causing primary glaucoma or scarring from previous inflammation. Ophthalmoscopy evaluates the optic nerve head for changes associated with glaucoma, including cupping and pallor, when corneal clarity permits visualization. Ultrasonography can evaluate internal eye structures when corneal opacity prevents direct visualization, identifying lens position abnormalities, masses, or other causes of secondary glaucoma. Electroretinography, if available, can assess retinal function independent of corneal clarity.

Differential diagnosis considers other conditions that may present similarly to glaucoma. Buphthalmos from other causes, including congenital abnormalities, must be distinguished from glaucomatous enlargement. Uveitis without secondary glaucoma causes eye redness and cloudiness but without elevated pressure. Corneal disease may cause cloudiness resembling glaucomatous edema. Exophthalmos from retrobulbar disease causes apparent eye enlargement but the globe itself is not larger. Cataracts cause lens opacity that may be confused with corneal edema. Distinguishing primary from secondary glaucoma is important for treatment planning, as addressing underlying causes may improve outcomes in secondary cases.

Emergency treatment for acute glaucoma or sudden pressure spikes focuses on rapidly lowering intraocular pressure to prevent further optic nerve damage and relieve severe pain. Systemic and topical medications that reduce aqueous humor production or improve drainage are administered urgently. Osmotic agents may be used to draw fluid from the eye and provide rapid pressure reduction in severe cases. Pain management with appropriate analgesics improves immediate comfort. Supportive care including fluid therapy and nutritional support maintains overall health while aggressive medical management is implemented. Close monitoring of pressure response guides treatment intensity and decisions about additional interventions.

Medical management of glaucoma relies on medications that lower intraocular pressure through various mechanisms. Topical carbonic anhydrase inhibitors such as dorzolamide reduce aqueous humor production and are commonly used in guinea pig glaucoma management. Beta-blockers may provide additional pressure reduction in some cases. Prostaglandin analogs used extensively in other species have uncertain efficacy in guinea pigs and are not typically first-line choices. Combination therapy using multiple medication classes may be needed to achieve adequate pressure control. Treatment must be continued indefinitely, as pressure typically rises when medications are discontinued. Owner ability to administer topical medications multiple times daily is essential for successful medical management.

Surgical intervention may be considered when medical management fails to control pressure adequately or is not feasible due to practical constraints. Surgical options for glaucoma in guinea pigs are limited compared to larger species, and specialized expertise is typically required. Laser procedures to reduce aqueous production or improve outflow have been described but require specialized equipment. Drainage implant surgery has been performed in guinea pigs but carries technical challenges related to their small eye size. Cyclodestructive procedures that reduce aqueous production by destroying portions of the ciliary body may provide pressure control when other options fail. These advanced procedures require referral to veterinary ophthalmologists with exotic animal experience.

Enucleation, or surgical removal of the affected eye, represents a definitive treatment option that eliminates pain and prevents complications from blind, glaucomatous eyes. This option is particularly appropriate when the eye is completely blind, when medical management fails to provide adequate comfort, when owners cannot maintain intensive medical treatment schedules, or when the eye develops complications such as corneal ulceration. Guinea pigs adapt very well to monocular vision and typically experience substantial improvement in comfort and quality of life following removal of painful glaucomatous eyes. The decision for enucleation should be made collaboratively between the veterinary team and owner, with quality of life as the primary consideration.

Supportive care throughout glaucoma management addresses overall health and comfort regardless of the specific treatment approach employed. Vitamin C supplementation at adequate doses supports general health and tissue integrity. Pain management with appropriate analgesics improves comfort and helps maintain appetite. Environmental modifications including reduced bright lighting may improve comfort for eyes with corneal edema. Monitoring for gastrointestinal stasis and intervening early with syringe feeding if appetite decreases protects against this life-threatening complication. Concurrent treatment of any underlying conditions contributing to secondary glaucoma improves overall outcomes.

Treatment decisions are guided by multiple factors including disease severity and stage at presentation, whether the eye retains any vision, patient comfort level, owner ability to provide intensive ongoing treatment, availability of specialist referral, and financial considerations. Early-stage disease with retained vision may warrant aggressive medical management attempts. Advanced disease with complete blindness and significant discomfort may be best served by enucleation to restore quality of life. Bilateral disease creates additional complexity, as maintaining even one seeing eye significantly affects the guinea pig's function and wellbeing. Honest discussion of prognosis and realistic expectations helps owners make appropriate decisions for their individual situations.

Recovery and management timeline for glaucoma reflects the chronic nature of this condition and the goals of treatment. Guinea pigs started on medical management typically require several weeks of monitoring and medication adjustment to determine optimal treatment protocols. Frequent rechecks during this period assess pressure control and refine medication regimens. Once stable management is achieved, ongoing monitoring at regular intervals, typically every few months, ensures continued control. Medical management is indefinite, with most guinea pigs requiring lifelong treatment to maintain pressure control. Response to treatment varies, with some guinea pigs achieving good control and others requiring escalating therapy or alternative approaches.

Post-treatment care for guinea pigs undergoing enucleation follows a more defined recovery course. The surgical site typically heals well within two to three weeks, with most guinea pigs returning to normal activity and appetite within days of surgery. Pain management continues during the healing period to ensure comfort. The surgical site is monitored for appropriate healing without signs of infection or dehiscence. Activity restriction during initial healing prevents trauma to the surgical site. Once healed, no ongoing treatment related to the removed eye is needed, representing a significant advantage over chronic medical management for eyes that cannot be saved.

Prognosis for glaucoma in guinea pigs depends on multiple factors influencing treatment success and quality of life outcomes. Early detection before significant optic nerve damage occurs offers the best opportunity for vision preservation, though even early treatment may not prevent eventual vision loss in progressive cases. Secondary glaucoma where the underlying cause can be addressed may have better prognosis than primary glaucoma with inherent drainage dysfunction. Unilateral disease has better functional prognosis than bilateral involvement, as the seeing eye compensates for vision loss in the affected eye. Response to medical management varies individually, with some guinea pigs achieving stable control and others progressing despite treatment.

Long-term outlook for guinea pigs with glaucoma requires realistic expectations about disease progression and quality of life. Most guinea pigs with glaucoma eventually lose vision in the affected eye despite treatment, though the timeline varies considerably. Guinea pigs adapt remarkably well to monocular vision or even complete blindness when other senses remain intact and their environment is appropriately managed. Quality of life can be excellent even for blind guinea pigs when pain is controlled and proper accommodations are made. The goal of treatment should focus on maintaining comfort and function rather than necessarily preserving vision that may be inevitably lost. Establishing ongoing care with an experienced veterinarian ensures appropriate monitoring and timely intervention as the disease progresses.

Primary prevention of glaucoma presents challenges because the fundamental causes, particularly genetic factors in primary glaucoma, are not fully understood or easily controlled. However, certain strategies may reduce risk or enable early detection when disease does develop. Breeding decisions represent the most direct prevention opportunity, with affected guinea pigs and their close relatives ideally excluded from breeding programs to reduce the propagation of genetic predisposition. Breeders observing recurring glaucoma in their lines should carefully evaluate their breeding stock and consider outcrossing to unrelated lines. Purchasing guinea pigs from breeders without histories of ocular disease in their animals reduces the risk of acquiring genetically predisposed individuals.

Prevention of secondary glaucoma focuses on managing or preventing the conditions that can lead to impaired aqueous drainage. Prompt treatment of uveitis and other inflammatory eye conditions reduces the risk of scarring and permanent drainage impairment. Eye injuries should receive immediate veterinary attention to minimize complications that could lead to secondary glaucoma. Regular monitoring of guinea pigs with cataracts allows early detection if lens-induced inflammation develops. Maintaining overall good health through proper husbandry, nutrition, and preventive care supports ocular health and reduces the risk of conditions that could secondarily cause glaucoma.

Early detection through regular health monitoring provides the best opportunity for successful management when glaucoma does develop. Annual wellness examinations with a veterinarian experienced in guinea pig care should include basic eye assessment. Owners should perform daily observations of their guinea pigs' eyes, noting any changes in size, clarity, pupil appearance, or behavior suggesting visual problems or discomfort. Any suspected eye abnormality should prompt prompt veterinary evaluation, as early intervention in glaucoma significantly affects outcomes. Guinea pigs from lines with known glaucoma occurrence may benefit from more frequent eye examinations or periodic tonometry screening.

Vitamin C supplementation and overall nutritional management support general health in ways that may benefit ocular health. Adequate vitamin C intake is essential for guinea pig health given their inability to synthesize this nutrient. Fresh vegetables high in vitamin C provide natural supplementation while adding dietary variety. Commercial supplements offer consistent dosing when produce availability is limited. A foundation of unlimited timothy hay supports digestive health and overall wellbeing. Proper hydration through clean, fresh water supports all body systems including the eyes.

Environmental management reduces the risk of eye trauma and supports overall health in ways that benefit ocular function. Safe cage design without sharp edges or protruding elements prevents eye injuries. Appropriate bedding without sharp or dusty components reduces eye irritation. Good lighting without excessively bright conditions provides comfortable viewing. Avoiding sudden environmental changes reduces stress that could affect immune function and overall health. Maintaining consistent, appropriate temperatures and humidity supports general health. Peaceful social groupings minimize aggressive interactions that could result in eye injuries.

Daily management of guinea pigs with glaucoma requires dedication to medication administration and monitoring protocols. Topical eye medications must be applied at prescribed intervals, often multiple times daily, throughout the guinea pig's life. Proper application technique ensures medication reaches the eye surface effectively while minimizing stress. Recording medication administration times helps ensure consistency and allows tracking of any doses that might be missed. Observation during medication administration provides opportunity to note any changes in eye appearance that might indicate disease progression or complications. Establishing a consistent daily routine makes medication administration a predictable part of the guinea pig's day, reducing stress associated with handling.

Environmental modifications accommodate vision impairment and support comfort for guinea pigs with glaucoma. Consistent cage layout allows guinea pigs to navigate by memory, with food, water, and hiding areas maintained in constant locations. Single-level housing eliminates fall risks associated with compromised depth perception or blindness. Soft, dust-free bedding prevents irritation to sensitive or compromised eyes. Reduced ambient lighting may improve comfort for eyes with corneal edema. Avoiding sudden environmental changes or rearrangements reduces confusion and stress for visually impaired guinea pigs. Providing multiple food and water sources throughout the enclosure ensures easy access regardless of vision status.

Quality of life maintenance focuses on comfort, engagement, and monitoring for complications that could affect wellbeing. Pain management assessment should be ongoing, with any signs of increased discomfort prompting veterinary consultation about adjusting analgesic protocols. Syringe feeding supplementation may be needed if appetite decreases, preventing weight loss and gastrointestinal stasis. Favorite foods offered regularly encourage eating and provide enrichment. Gentle handling and vocal interaction provide stimulation that does not depend on vision. Cage mates can provide important social support, though monitoring ensures interactions remain positive. Weight monitoring identifies appetite problems early, allowing intervention before significant decline.

Ongoing monitoring enables early detection of disease progression, treatment failure, or complications requiring intervention. Daily observation should note eye size, clarity, comfort level indicated by whether the eye is held open normally, and any discharge or surface abnormalities. Behavioral indicators including appetite, activity level, and social engagement provide information about overall comfort and wellbeing. Regular veterinary examinations with intraocular pressure measurements monitor treatment effectiveness and disease progression. Any sudden changes in eye appearance, behavior, or comfort level should prompt immediate veterinary evaluation. Recording observations in a health log helps track trends and provides valuable information for veterinary consultations.

Caregiver support and resources help ensure successful long-term management of this chronic condition. Understanding that glaucoma requires indefinite management with uncertain outcomes allows realistic expectations. Training in medication administration technique from the veterinary team ensures effective treatment delivery. Emotional support is important when facing the reality of managing a chronic, progressive condition with potential for vision loss. Financial planning for ongoing medication costs and regular veterinary visits reduces stress. Connecting with online communities of guinea pig owners managing similar conditions provides practical tips and emotional support. Recognizing that quality of life can remain excellent even with vision loss helps maintain positive perspective throughout management.

All guinea pig breeds can develop glaucoma, and no specific breed has been definitively identified as having significantly elevated risk compared to others. The condition appears to occur across breeds without strong breed predilection based on currently available information. However, the genetic component of primary glaucoma means that risk may be elevated in certain family lines regardless of breed. Guinea pigs from families with known glaucoma occurrence should be considered higher risk and may benefit from enhanced monitoring or screening. The limited research specifically examining guinea pig glaucoma makes definitive breed risk statements difficult.

Certain population characteristics may correlate with elevated glaucoma risk independent of specific breed. Older guinea pigs have higher incidence of glaucoma, making age a more significant risk factor than breed in most cases. Guinea pigs from breeding operations with histories of eye problems in their animals may carry genetic predisposition passed through multiple generations. Show guinea pigs do not appear to have elevated glaucoma risk specifically, though the stress of showing could theoretically affect animals predisposed to the condition. Animals with histories of eye inflammation, trauma, or other ocular conditions face elevated risk for secondary glaucoma development.

Breeder recommendations for reducing glaucoma occurrence in guinea pig populations center on responsible breeding practices. Affected guinea pigs should ideally be removed from breeding programs to avoid propagating genetic predisposition. Close relatives of affected animals warrant careful consideration before breeding, as they may carry glaucoma genes even without expressing the condition themselves. Maintaining detailed health records allows identification of family lines with elevated disease occurrence. Outcrossing to unrelated animals may reduce risk in lines where glaucoma has occurred. Pre-breeding eye examinations by experienced veterinarians could identify subtle abnormalities in potential breeding stock, though practical implementation may be challenging.

Glaucoma in guinea pigs is closely related to several conditions that may occur concurrently, share similar presentations, or directly cause secondary glaucoma. Uveitis, or inflammation inside the eye, frequently leads to secondary glaucoma through scarring of drainage structures and inflammatory debris obstruction. The relationship is bidirectional, as chronic glaucoma can itself trigger inflammatory changes within the eye. Cataracts may be associated with glaucoma development, particularly when mature cataracts cause lens-induced uveitis affecting aqueous drainage. Lens luxation, where the lens becomes displaced from normal position, can physically obstruct drainage pathways and cause acute pressure elevation.

Several conditions produce symptoms similar to glaucoma and must be differentiated through appropriate examination. Exophthalmos from retrobulbar disease causes apparent eye prominence that may be confused with glaucomatous buphthalmos, but pressure measurement distinguishes these conditions. Corneal disease from various causes produces cloudiness resembling glaucomatous edema. Conjunctivitis causes eye redness that may mimic the conjunctival hyperemia of glaucoma. Anterior uveitis without secondary glaucoma causes pupil abnormalities and eye changes that overlap with glaucoma presentation. Intraocular tumors may present with eye enlargement before glaucoma develops as a secondary complication.

Potential complications of glaucoma extend the impact of this condition beyond initial pressure elevation. Corneal ulceration develops as the stretched, edematous cornea becomes vulnerable to minor trauma or exposure damage. Lens luxation may occur as zonular fibers holding the lens in position are stretched and weakened by globe enlargement. Retinal detachment can result from traction as the eye stretches or from ischemic damage related to elevated pressure. Complete blindness is the expected outcome for most untreated or poorly controlled glaucomatous eyes. Chronic pain from uncontrolled glaucoma significantly diminishes quality of life and can trigger secondary complications including gastrointestinal stasis from reduced food intake. Globe rupture represents an end-stage complication of severely enlarged, compromised eyes.