**4. Results analysis**

## **4.1 Storage and evacuation processes of intraocular metabolic residue**

This paper presents four states of metabolic residue accumulation during the process of stimulating eye movements for rehydration and drainage. In the first state, metabolic residues form droplet agglutinations without significant variations of their forms. In the second state, metabolic residue forms agglutinations in droplets with important variations in their forms. In the third state, metabolic residues are in suspension. In the fourth state, metabolic residues form films impregnated in the intraocular layers.

In the first state, the residue droplets maintain their different dimensions (constant volume), shapes, refractions, opacities, and high viscosities, so they form small lenses that can project the same image to the retina in different regions, with different dimensions, shapes, and intensities. This pathology was first observed in Scheiner's experiments in 1619, *apud* [12]. The drops, depending on their positions and shapes, in relation to incident light can cause chromatic scattering. The moving medium circulation between the drops can rehydrate them and transfer them to the second state.

In the second state, the droplets of the residues keep their different volumes fixed but vary their dimensions, shapes, opacities, and viscosities, so they form small, variable refractive lenses that can project radial beams with periodic expansions and reductions. These movements have different frequencies, depending on the movements of different drops, and can cause chromatic dispersion, depending on their shapes and positions, in relation to the incident light. Depending on the circulation of the moving medium, there may be dehydration of the droplets, and they may lose their movement, that is, move to the first state, or there may be rehydration of the droplets, and they may pass to the third state in suspension.

In the third state, the metabolic residues are in suspension. The residues in suspension diffuse the intraocular light. Intraocular diffusion can cause visual discomfort if there is pupillary constriction, a tendency in older people. Stimulated mydriasis enhances this discomfort. Miosis and prolonged stay of suspended residues stimulate upper eyelid ptosis to reduce the opening for light penetration. Depending on the

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*Intraocular Forced Convection Mechanism Defect as Probable Cause of Normal-Tension…*

in the drainage process, depending on the moving medium circulation.

requires an impulsive movement of the mobile mass.

on the symptoms.

metabolic residue.

circulation of the mobile medium, the suspended residues may become dehydrated or rehydrate. If dehydrated, the viscosity increases and is agglutinated into droplets, passing to a second state (droplets in different shapes). If rehydrated, the viscosity is reduced and eliminated through the nasal and oral routes or by the trabecular mesh. Elimination through the nasal and oral routes may cause tearing, burning in the cornea, obstruction of the nostril, and mild inflammation in the throat. The trabecular route can obstruct and increase intraocular pressure. From this state there may be migration to the first state through thin-layer deposits on the cornea or lens layers. This is the initial state of the metabolic residue storage process as well as the final state

In the fourth state, the metabolic residues are stored as films in the intraocular layers. Symptoms can be perceived through the visualized sinuosities while moving the eye, observing a flat visual field. The mere circulation of the mobile medium is insufficient to rehydrate the metabolic residue films and transform them into aqueous suspension of the third state. To rehydrate the metabolic residue in this state

The four states of intraocular storage are always present, but there are alternations between symptoms, although they may appear together. Thus visual acuity depends on the state predominance, the amount, and the way metabolic residue is accumulated. The rehydration exercises and drainage of metabolic residue depend

**4.2 Influence of bilateral upper eyelid blepharoplasty on cornea curvature**

**Table 1** shows, chronologically, the patient's intraocular pressure, on several dates, and, in addition, important information to show the situations experienced by the patient during the time while drainage work of intraocular metabolic residues was being analyzed. To renew the driver's license using corrective lenses in February 2014, the patient had to exercise his left eye for 10, 2 days apart, and then rest for 2 days, because there was little chance of approval, mainly because of the left eye. On the day of the exam, the left eye was fine, but the contralateral eye was in minimal approval condition. When an eye improves, the contralateral worsens. Five years later, in March 2019, the patient's driver's license was renewed with corrective lenses without any special attention, but 133 days later the patient's acuity was assessed with DV 20/50 OR, wearing corrective lenses. Visual acuity is not an important parameter to assess the drainage status of accumulated intraocular

The patient noticed that his eyelid opening was compromised by corneal topography in April 2016, **Figure 4a**. The patient had never worn contact lenses. In May 2017 a bilateral upper blepharoplasty was performed. **Table 1** shows the highest pressure in the series was recorded in June, 2017, 49 days after surgery. 135 days later, lower intraocular pressure values were recorded. Upper blepharoplasty allows the light incidence in the region hidden by the upper eyelid ptosis and stimulates rehydration of metabolic residue stored in the region hidden by upper eyelid ptosis. Rehydration of a large volume of stored residue causes significant increase in drainage of metabolic residue through the oral and nasal routes, as well as through the trabecular meshwork. Intense passage of residue through the trabecular meshwork may obstruct the passage of aqueous humor and increase pressure. With the continuity of the exercises, obstruction can be removed from the trabecular meshwork and intraocular pressure reduced. Increased intraocular pressure should be observed in many patients after cataract surgery. Cataract reduces the light incidence on the retina and favors metabolic residue accumulation. A cataract surgery allows a higher light incidence in the retina, thus contributing to the rehydration

*DOI: http://dx.doi.org/10.5772/intechopen.89934*

#### *Intraocular Forced Convection Mechanism Defect as Probable Cause of Normal-Tension… DOI: http://dx.doi.org/10.5772/intechopen.89934*

circulation of the mobile medium, the suspended residues may become dehydrated or rehydrate. If dehydrated, the viscosity increases and is agglutinated into droplets, passing to a second state (droplets in different shapes). If rehydrated, the viscosity is reduced and eliminated through the nasal and oral routes or by the trabecular mesh. Elimination through the nasal and oral routes may cause tearing, burning in the cornea, obstruction of the nostril, and mild inflammation in the throat. The trabecular route can obstruct and increase intraocular pressure. From this state there may be migration to the first state through thin-layer deposits on the cornea or lens layers. This is the initial state of the metabolic residue storage process as well as the final state in the drainage process, depending on the moving medium circulation.

In the fourth state, the metabolic residues are stored as films in the intraocular layers. Symptoms can be perceived through the visualized sinuosities while moving the eye, observing a flat visual field. The mere circulation of the mobile medium is insufficient to rehydrate the metabolic residue films and transform them into aqueous suspension of the third state. To rehydrate the metabolic residue in this state requires an impulsive movement of the mobile mass.

The four states of intraocular storage are always present, but there are alternations between symptoms, although they may appear together. Thus visual acuity depends on the state predominance, the amount, and the way metabolic residue is accumulated. The rehydration exercises and drainage of metabolic residue depend on the symptoms.

#### **4.2 Influence of bilateral upper eyelid blepharoplasty on cornea curvature**

**Table 1** shows, chronologically, the patient's intraocular pressure, on several dates, and, in addition, important information to show the situations experienced by the patient during the time while drainage work of intraocular metabolic residues was being analyzed. To renew the driver's license using corrective lenses in February 2014, the patient had to exercise his left eye for 10, 2 days apart, and then rest for 2 days, because there was little chance of approval, mainly because of the left eye. On the day of the exam, the left eye was fine, but the contralateral eye was in minimal approval condition. When an eye improves, the contralateral worsens. Five years later, in March 2019, the patient's driver's license was renewed with corrective lenses without any special attention, but 133 days later the patient's acuity was assessed with DV 20/50 OR, wearing corrective lenses. Visual acuity is not an important parameter to assess the drainage status of accumulated intraocular metabolic residue.

The patient noticed that his eyelid opening was compromised by corneal topography in April 2016, **Figure 4a**. The patient had never worn contact lenses. In May 2017 a bilateral upper blepharoplasty was performed. **Table 1** shows the highest pressure in the series was recorded in June, 2017, 49 days after surgery. 135 days later, lower intraocular pressure values were recorded. Upper blepharoplasty allows the light incidence in the region hidden by the upper eyelid ptosis and stimulates rehydration of metabolic residue stored in the region hidden by upper eyelid ptosis. Rehydration of a large volume of stored residue causes significant increase in drainage of metabolic residue through the oral and nasal routes, as well as through the trabecular meshwork. Intense passage of residue through the trabecular meshwork may obstruct the passage of aqueous humor and increase pressure. With the continuity of the exercises, obstruction can be removed from the trabecular meshwork and intraocular pressure reduced. Increased intraocular pressure should be observed in many patients after cataract surgery. Cataract reduces the light incidence on the retina and favors metabolic residue accumulation. A cataract surgery allows a higher light incidence in the retina, thus contributing to the rehydration


#### **Table 1.**

*Chronological presentation of medical examinations and surgery.*

of an important volume of metabolic residue that can obstruct the trabecular meshwork and increase intraocular pressure. Since cataract surgeries and upper blepharoplasty are not followed by orthoptic exercises, in the postoperative period, it is important to develop a trabecular meshwork cleaning procedure to resolve cases in which intraocular pressure does not return to preoperative levels. Intraocular pressure should always be evaluated during residue drainage work, as well as in the postoperative period of cataract surgery and upper blepharoplasty.

**Figure 4** shows, in four corneal topographies, the evolution of the anterior corneal surface curvature recovery, produced by the rehydration and drainage exercises of intraocular metabolic residues. The rehydration and drainage of intraocular metabolic residue can solve different pathologies related to anterior surfaces of the cornea. Although not the best way to evaluate the eyelid opening, this was the way available to the authors, in search of parameters that could evaluate the evolution of

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**Figure 4.**

*Intraocular Forced Convection Mechanism Defect as Probable Cause of Normal-Tension…*

the work. The ocular region was recorded in the same laboratory on the dates presented in **Table 1** and **Figure 4**. The diameters, horizontal and vertical, were found for each mapping, in relation to their own scales. **Figure 4** shows, with dashed lines, how scales and diameters were evaluated. **Table 2** shows that the horizontal diameters of the two eyes did not show significantly different percentages (OD 14.3%,

*Four corneal topography exams from the same patient. (a) On April 5, 2016 (before superior blepharoplasty -* 

*OU, on May 8, 2017). (b) On September 4, 2017. (c) On March 5, 2018. (d) On October 23, 2018.*

*DOI: http://dx.doi.org/10.5772/intechopen.89934*

*Intraocular Forced Convection Mechanism Defect as Probable Cause of Normal-Tension… DOI: http://dx.doi.org/10.5772/intechopen.89934*

the work. The ocular region was recorded in the same laboratory on the dates presented in **Table 1** and **Figure 4**. The diameters, horizontal and vertical, were found for each mapping, in relation to their own scales. **Figure 4** shows, with dashed lines, how scales and diameters were evaluated. **Table 2** shows that the horizontal diameters of the two eyes did not show significantly different percentages (OD 14.3%,

**Figure 4.**

*Four corneal topography exams from the same patient. (a) On April 5, 2016 (before superior blepharoplasty - OU, on May 8, 2017). (b) On September 4, 2017. (c) On March 5, 2018. (d) On October 23, 2018.*


**Table 2.**

*Diameters and errors relative to a pattern.*

OS 15.5%) but the vertical diameters of the two eyes show significantly different percentages (OD 20.9%, OS 30.2%), that is, their evolution had not yet stabilized. The vertical diameter of both eyes exposed to the instrument was reduced because of simultaneous eyelid ptosis. The percentage error was calculated using as default the values cited in [6]. The percentage value is a referential error, serving only to compare the respective eye diameters. As such, the vertical diameter of the left eye is still far from the dimension of the collateral eye, i.e., the vertical limits had not yet fully recovered. The evolution shown in **Figure 4** shows the need for orthoptic exercises after upper eyelid blepharoplasty to recover eyelid opening and probably after cataract surgery.

#### **4.3 Current state of intraocular cleansing**

Although the results presented do not seem encouraging, there are interpretations that minimize the apparent divergence of the successful progress of the work. At the beginning of the study, the patient had presbyopia, had had eyelid ptosis in both eyes for over 15 years, and had no cataract. Blepharoplasty in both eyes was performed in 2017, when the cataract was at an advanced stage. This shows that the patient spent 17 years trying to rehydrate and drain metabolic residue with serious upper visual field constraints [8]. That is, the patient did not have the opportunity to recover the mechanisms of intraocular mass transfer by forced convection and, as a result, developed cataracts. Cataract is the storage of dehydrated metabolic residue in the lens due to a defect in the mechanism of mass transfer in the lens by forced convection [3, 8]. Even so, it was possible to recover from some pathologies described in the works [9, 14]. Rehydration of intraocular metabolic residue is a slow and difficult process to perform because it does not require any external physical effort or any agent that reduces the viscosity of dehydrated residue. It does, however, require changes in habits and a lot of sleep, and success may depend on acquired physiology, congenital and hereditary, as well as diet, among others. The intermediate stages of intraocular cleaning indicate that rehydration of the concentrated metabolic residue reduces its concentration and viscosity due to the increase in mobile mass added to the stagnant residue. Thus increasing its stagnant volume may represent an increase in the extent of the stagnant area, resulting in cataract evolution, if any, but with lower density and viscosity, which are not evaluated. Due to the rehydration and drainage process, the patient showed signs in the cycle of improving and degrading visual acuity. The patient did not have access to any test that evaluated the storage of intraocular metabolic residue. **Figure 4** shows the evolution of corneal curvature in several tests. The patient has already overcome two

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mass stagnation.

that excrete intraocular metabolic residue.

*Intraocular Forced Convection Mechanism Defect as Probable Cause of Normal-Tension…*

pathologies, dark adaptation, for which there is no measurement standard and can read a text right after looking at the sun. It is important to know that activities in the dark stimulate rehydration of intraocular metabolic residue (sleeping in the dark), fixation instability favors dehydration of intraocular metabolic residue, and eyelid ptosis impairs the mechanism of intraocular mass transfer by forced convection. It is worth noting that headache and its immediate recovery through eye alignment, without medication, are symptoms of suffering caused in the oculomotor support system of the eyeball and an important sign of displacement in its support base, due

With much simplification, the eye can be described as having three power supplies and four excretory paths, controlled by two forced convection systems [10]. There are three sources of food: tear fluid (feeds the corneal epithelium and excretes through the nasal and mouth cavities as well as the digestive system), aqueous humor (feeds the lens and corneal stroma and excretes through the venous system), and through Bruch's membrane (the circulatory system feeds and excretes the retina). There are two systems of forced convection, the intrinsic muscles (the crystalline and Schlemm canal) and the extrinsic muscles (cornea, trabecular mesh, and retina), which drive mass transfer. The physical properties of a cleaning sponge can be used as a metaphor for four greatly simplified mass transfer models. The four adaptations are these: a cleaning sponge to represent bidirectional movements on its sides, for the feeding and excretion of the lens; a cleaning sponge with its closed sides, to represent the bidirectional movements on its two other sides for feeding and excretion of the retina (Bruch's membrane) [6]; a cleaning sponge with closed sides to represent the unidirectional passage on both sides for the passage of aqueous humor and metabolic residue (trabecular meshwork) [1, 11]; and finally, two cleaning sponges, juxtaposed to closed flat surfaces, to represent bidirectional movements on their free sides for feeding and excretion of the epithelium and corneal stroma (epithelium, Bowman's membrane, and stroma) [1, 6]. Intraocular metabolic residues are stored when mass transfer mechanisms are insufficient to maintain constant, concentration, and agitation of dissolved or suspended metabolic residue components in the moving mass. An insufficiency of these mechanisms causes the mobile mass to stagnate in both forced convection systems and to store the metabolic residue due to dehydration. Dehydrated residues are stored simultaneously in the cornea, trabecular mesh, Schlemm's canal, lens, and retina. Vicious and frequent habits can cause mobile

Metabolic residue is released if there is a physical work of forced convection systems capable of excreting concentrated metabolic residue in solution or suspension in the mobile medium. The release of fixed metabolic residue depends on its rehydration to transform it into a solution or suspension. The cornea, trabecular mesh, lens, Schlemm's canal, and retina simultaneously excrete accumulated residues. Orthoptic exercises can stimulate the physical effort to excrete metabolic residue, as well as rehydrate the fixed residues; these, however, cause sleep. Cataract surgery stimulates the forced convection system because it unbalances the efforts of the extrinsic muscle due to increased light transmission and change in refractive power resulting from intraocular lens implantation. Therefore, postoperative symptoms caused by cataract surgery are similar to those caused by orthoptic exercises

*DOI: http://dx.doi.org/10.5772/intechopen.89934*

**5. Conclusion**

to the disposition intraocular storage of metabolic residues.

*Intraocular Forced Convection Mechanism Defect as Probable Cause of Normal-Tension… DOI: http://dx.doi.org/10.5772/intechopen.89934*

pathologies, dark adaptation, for which there is no measurement standard and can read a text right after looking at the sun. It is important to know that activities in the dark stimulate rehydration of intraocular metabolic residue (sleeping in the dark), fixation instability favors dehydration of intraocular metabolic residue, and eyelid ptosis impairs the mechanism of intraocular mass transfer by forced convection. It is worth noting that headache and its immediate recovery through eye alignment, without medication, are symptoms of suffering caused in the oculomotor support system of the eyeball and an important sign of displacement in its support base, due to the disposition intraocular storage of metabolic residues.
