**2. Epidemiology**

Advancements in acute medical therapies have led to the reduction of mortality due to acute ischemic or hemorrhagic stroke [5]. Studies have shown that 10% of patients recover without any residual deficits, a quarter have mild residual deficits, while 50% are severely disabled or require skilled nursing care within a medical facility able to manage their needs [6]. Along with severe physical disability, patients that suffer from a stroke also experience neuropsychiatric changes. The most common neuropsychiatric sequelae, post-stroke, are depression and anxiety [7]. Patients that survive stroke often experience anxiety and depression related to making adjustments to their new reality [7]. With more patients surviving stroke, quality of life becomes an area of focus. Poststroke depression has been regarded as one of the most important measures for quality of life after an acute stroke. The presence of depression after stroke results in impaired recovery, decreased participation in rehab efforts, impaired cognition, and even increased mortality. The majority of the expressed concern from patients is related to their ability to work and provide financial stability for themselves/their families, the ability to manage their activities of daily living, and the loss of their functional independence [7].

The term poststroke depression puts a focus on ischemic rather than hemorrhagic strokes, which is mostly due to the fact that ischemic strokes have been studied more in the literature, and thus will be the focus of this chapter [8]. Poststroke depression can occur anywhere from days to years after an acute ischemic event with the peak incidence of poststroke depression occurring between 3 months and 2 years, even if the patient's symptoms are improving [9]. Patients that experience the onset of poststroke depression at or after 7 weeks from the acute event are less likely to have a spontaneous remission of this depression [9]. In the acute phase, patients that had a longer inpatient hospital stay were seen to score higher on the Beck Depression Inventory than those that were in the community or in a rehabilitation facility. However, many of these studies have excluded patients that are aphasic, have cognitive impairment, or experienced pre-stroke depression. This may be one of the main reasons that poststroke depression may be underdiagnosed and undertreated [10].

#### **2.1 Demographics associated with poststroke depression**

Patients younger than 60 are seen to have higher depression scores poststroke. In the general population, major depression is more prevalent in patients younger than 65 years old [11]. In multiple studies that adjusted for pre-stroke depression it was found that more than 30% of the patients younger than 65 could be diagnosed as having clinical depression using the Center for Epidemiologic Studies Depression Scale (CES-D). It was found that within this younger age group there was a higher rate of depression associated with lower socioeconomic status, familial stress, and the ability to provide financial stability [7, 11]. However, having good social support has been found to be protective against poststroke depression [7, 11]. Adults over the age of 65 represent the majority of stroke patients, which can skew the data.

**259**

*Post Stroke Depression*

*DOI: http://dx.doi.org/10.5772/intechopen.86935*

and more obvious depressive phenotype [6, 11].

gender is a definitive predictor of poststroke depression.

their risk of stroke, and thus their risk for poststroke depression.

**3. Comorbidities associated with poststroke depression**

Comorbid conditions prior to a stroke can affect the development of depression after an acute ischemic event. Conditions such as diabetes, and preexisting psychiatric disorders like depression, anxiety, and bipolar disorder can all have an effect on poststroke depression [17, 18]. One meta-analysis has demonstrated that patients that have vascular risk factors such as diabetes are at a higher risk for developing poststroke depression [17]. This is not thought to be related to the vascular depression theory, which will be discussed later in this chapter. In a Chinese study, it was

However, multiple meta-analyses have shown that when controlling for other variables such as sex, patients younger than 65 experienced more poststroke depression,

Biologic sex and poststroke depression is a controversial issue. Numerous meta-analyses have looked at the relationship between 'gender' and how it affects or predicts poststroke depression. The results were mixed when looking at data from across the globe. In some studies, women have been found to experience double the risk of poststroke depression compared to men [12, 38]. The gender disparity may be related to how each sex reacts to stressful life events. Women have been demonstrated to have more stress in reaction to negative life events, such as a stroke, which results in feelings of depression [12]. On self-reported survey, women were seen to indicate they have more depressive symptoms, compared to men, when age was controlled for [12]. The risk factors for women developing depression after an acute stroke were: pre-stroke psychiatric comorbidity, age younger than 65, and impairment in cognition [13]. Similarly, men with higher level of physical disability after a stroke had more depressive symptoms than women, or men with less physical disability. In multicenter analysis from China, and India, these studies found that male sex had a higher correlation with poststroke depression [10, 15]. However, there may be confounding factors when evaluating sex differences and poststroke depression. For example, in China there may be a higher number of men in the general population [14]. In the Indian study there were more men in the study [10]. In the USA, it is possible that there is a higher rate of self-reporting by women, as well as under reporting of depressive symptoms in men, based on their level of physical disability [14]. Therefore, more studies need to be done in this area to determine if

Socioeconomic status and education related to poststroke depression is also difficult to measure, due to multiple confounders and conflicting data. However, reviewing the meta-analysis of patient demographics and poststroke depression has shown that patients with lower overall education levels have an increased risk for poststroke depression with mild depressive symptoms [13]. A large meta-analysis of the literature found that there is an association between more years of education and lower risk for depression after a stroke. This study demonstrated that on average the participants in the study without poststroke depression had 0.32 years of education more than those that did have depressive symptoms after their stroke [16]. The symptoms that were seen in this data set were defined as mild depressive symptoms, but could not be classified as clinically depressed. However, this may also have confounding factors in this category. Patients that have lower socioeconomic status have been shown to have lower levels of education [16]. They may also be exposed to environmental factors that put them at increased risk for stroke, such as unhealthy diet, unhealthy lifestyle, more perceived stress, exposure to second hand smoke, and pollution in urban areas [10, 13, 16]. These factors may increase

#### *Post Stroke Depression DOI: http://dx.doi.org/10.5772/intechopen.86935*

*New Insight into Cerebrovascular Diseases - An Updated Comprehensive Review*

scale (CES-D), Zung self-rating depression scale and the Hamilton Depression Rating Scale (HDRS) [5]. Post stroke depression has a great impact on the healthcare system as well as on the individual patient. In this chapter, we will examine all aspect of depression as it relates to stroke by using these scales and large metaanalyses to define post-stroke depression, and assess how it relates to stroke and

Advancements in acute medical therapies have led to the reduction of mortality due to acute ischemic or hemorrhagic stroke [5]. Studies have shown that 10% of patients recover without any residual deficits, a quarter have mild residual deficits, while 50% are severely disabled or require skilled nursing care within a medical facility able to manage their needs [6]. Along with severe physical disability, patients that suffer from a stroke also experience neuropsychiatric changes. The most common neuropsychiatric sequelae, post-stroke, are depression and anxiety [7]. Patients that survive stroke often experience anxiety and depression related to making adjustments to their new reality [7]. With more patients surviving stroke, quality of life becomes an area of focus. Poststroke depression has been regarded as one of the most important measures for quality of life after an acute stroke. The presence of depression after stroke results in impaired recovery, decreased participation in rehab efforts, impaired cognition, and even increased mortality. The majority of the expressed concern from patients is related to their ability to work and provide financial stability for themselves/their families, the ability to manage their activities of daily living, and the loss of their functional independence [7]. The term poststroke depression puts a focus on ischemic rather than hemorrhagic strokes, which is mostly due to the fact that ischemic strokes have been studied more in the literature, and thus will be the focus of this chapter [8]. Poststroke depression can occur anywhere from days to years after an acute ischemic event with the peak incidence of poststroke depression occurring between 3 months and 2 years, even if the patient's symptoms are improving [9]. Patients that experience the onset of poststroke depression at or after 7 weeks from the acute event are less likely to have a spontaneous remission of this depression [9]. In the acute phase, patients that had a longer inpatient hospital stay were seen to score higher on the Beck Depression Inventory than those that were in the community or in a rehabilitation facility. However, many of these studies have excluded patients that are aphasic, have cognitive impairment, or experienced pre-stroke depression. This may be one of the main reasons that poststroke depression may be underdiagnosed

**258**

and undertreated [10].

**2.1 Demographics associated with poststroke depression**

Patients younger than 60 are seen to have higher depression scores poststroke. In the general population, major depression is more prevalent in patients younger than 65 years old [11]. In multiple studies that adjusted for pre-stroke depression it was found that more than 30% of the patients younger than 65 could be diagnosed as having clinical depression using the Center for Epidemiologic Studies Depression Scale (CES-D). It was found that within this younger age group there was a higher rate of depression associated with lower socioeconomic status, familial stress, and the ability to provide financial stability [7, 11]. However, having good social support has been found to be protective against poststroke depression [7, 11]. Adults over the age of 65 represent the majority of stroke patients, which can skew the data.

recovery.

**2. Epidemiology**

However, multiple meta-analyses have shown that when controlling for other variables such as sex, patients younger than 65 experienced more poststroke depression, and more obvious depressive phenotype [6, 11].

 Numerous meta-analyses have looked at the relationship between 'gender' and how it affects or predicts poststroke depression. The results were mixed when looking at data from across the globe. In some studies, women have been found to experience double the risk of poststroke depression compared to men [12, 38]. The gender disparity may be related to how each sex reacts to stressful life events. Women have been demonstrated to have more stress in reaction to negative life events, such as a stroke, which results in feelings of depression [12]. On self-reported survey, women were seen to indicate they have more depressive symptoms, compared to men, when age was controlled for [12]. The risk factors for women developing depression after an acute stroke were: pre-stroke psychiatric comorbidity, age younger than 65, and impairment in cognition [13]. Similarly, men with higher level of physical disability after a stroke had more depressive symptoms than women, or men with less physical disability. In multicenter analysis from China, and India, these studies found that male sex had a higher correlation with poststroke depression [10, 15]. However, there may be confounding factors when evaluating sex differences and poststroke depression. For example, in China there may be a higher number of men in the general population [14]. In the Indian study there were more men in the study [10]. In the USA, it is possible that there is a higher rate of self-reporting by women, as well as under reporting of depressive symptoms in men, based on their level of physical disability [14]. Therefore, more studies need to be done in this area to determine if gender is a definitive predictor of poststroke depression.

Socioeconomic status and education related to poststroke depression is also difficult to measure, due to multiple confounders and conflicting data. However, reviewing the meta-analysis of patient demographics and poststroke depression has shown that patients with lower overall education levels have an increased risk for poststroke depression with mild depressive symptoms [13]. A large meta-analysis of the literature found that there is an association between more years of education and lower risk for depression after a stroke. This study demonstrated that on average the participants in the study without poststroke depression had 0.32 years of education more than those that did have depressive symptoms after their stroke [16]. The symptoms that were seen in this data set were defined as mild depressive symptoms, but could not be classified as clinically depressed. However, this may also have confounding factors in this category. Patients that have lower socioeconomic status have been shown to have lower levels of education [16]. They may also be exposed to environmental factors that put them at increased risk for stroke, such as unhealthy diet, unhealthy lifestyle, more perceived stress, exposure to second hand smoke, and pollution in urban areas [10, 13, 16]. These factors may increase their risk of stroke, and thus their risk for poststroke depression.


**5. Intraoperative complications**

It has been reported that cataract extraction in eyes with previous vitrectomy is often more complicated because of various anatomic changes in the eye. In the vitrectomized eye, whose vitreous cavity was filled with air, gas or liquid solutions, the aqueous humor is the one that ends up occupying said space, so the lens does not have the counter pressure of the vitreous, which is a semi-solid and viscous substance, and during cataract surgery can occur significant variations in the depth of the anterior chamber that make the procedure difficult. Potential complications that may arise from this situation include bad pupil dilatation, zonule damage, posterior synechia, posterior capsule tears, increase mobility of complex lens-iris and altered intraocular fluid dynamics as a result of the absence of the anterior hyaloid face. Thus, cataract surgery (phacoemulsification) in vitrectomized eyes has been reported to be associated with an increased rate of complications. [74–77]

Cataract surgery in the vitrectomized eye can be performed under topical anesthesia, or in complex cases local anesthesia. When surgery was performed under topical anesthesia, the anterior chamber was irrigated with lidocaine 0.5% before it was filled with an ophthalmic viscosurgical device. There are ophthalmologists who prefer peri- or retrobulbar anesthesia, since when the anterior chamber is deepened, oscillations of the irido-crystalline diaphragm occur with variation in pupillary diameter that generates discomfort to the patient. If the surgery is performed using local anesthesia (retrobulbar), it is necessary to be cautious with the pressure exerted by the Honan balloon. Excessive pressure exerted by this balloon could damage or increase damage to a compromised zonule, increasing the risk of intraoperative drop of the nucleus into the vitreous cavity. For this reason, the use of topical anesthesia is preferable for cataract surgery in previously vitrectomized eyes. Finally, general anesthesia will be reserved for children, neurological and psychiatric patients and bad collaborators.

Biro et al. reported posterior capsule tears and dropped nucleus in 7,3% in 41 vitrectomized patiens. [78]

Nevertheless, others authors suggest that eyes with and without prior pars plana vitrectomy (PPV) have a similar likelihood of having intraoperative complications. These authors reported that recognize the differences in the physiologic state of the vitrectomized eye compared with that of non-vitrectomized eyes reduced the frequency of intraoperative complications. [79]

A clear corneal incision for performing the phacoemulsification was recommended, avoiding the conjuntival-scleral scarring from previous retinal surgery. [80]

No intraoperative wound-related problems have been described using this clear corneal approach, with a 3-step wound construction with a 50% vertical groove.

In patients with inadequate dilation of the pupil, the use of intracamerular phenylephrine or the insertion of iris retractors or pupillary elongation maneuvers will be evaluated, and if there are posterior synechiae, synechiolysis will be performed with the help of viscoelastics.

In the case of severe crystalline opacities that do not allow the visualization of the background orange reflex, the use of trypan blue in the staining of the anterior capsule, facilitating capsulorhexis, will be considered. In vitrectomized eyes, trypan

**45**

(**Figures 3** and **4**).

*Cataract Surgery in Post-Vitrectomized Eyes DOI: http://dx.doi.org/10.5772/intechopen.95467*

rupture of the posterior capsule.

event of significant ocular collapse. [81]

level before any phaco manipulation.

length and greater anterior chamber depth. [82]

blue must be introduced into the anterior chamber slowly to avoid its diffusion to the vitreous chamber through zonular dehiscences. If this happens, phacoemulsification can be very complicated by the loss of the foveal reflex, increasing the risk of

If possible, very small capsulorhexis should be avoided to avoid capsular phimosis that later hinders the evaluation of the retinal periphery. Both cohesive viscoelastics that have expansive property allowing the management of mydriasis,

Phacoemulsification with a constant pressure minimizes complications in the

In a study of 75 vitrectomized eyes, this blockage was observed in 53.3% of the cases during cataract surgery, especially in younger patients, with greater axial

Infusion deviation syndrome occurs when fluid migrates backward through the zonule and it increases the volume of the vitreous and causes flattening of the anterior chamber. Titiyal et al. [83] presented this complication in 12.3% of the 89 vitrectomized eyes during cataract surgery. To prevent this, it is recommended to carry out the hydration maneuvers carefully, reduce the flow of fluid within the anterior chamber (lowering the height of the bottles if possible or reducing the flow/aspiration rate). Once this complication appears, it is very useful to place in the pars plana a vitrectomy trocar without a valve to allow the pressure to escape from the poste-

rior chamber and to be able to continue performing phacoemulsification.

Maneuvers that push the lens during phacoemulsification and cause zonular tension should be avoided. Thorough careful hydrodissection, confirmation of adequate lens rotation before phacoemulsification and gentle nucleus manipulation help to avoid unnecessary zonular damage and posterior capsule tears. If there is a fall of the nucleus or fragments to the vitreous cavity after the rupture of the posterior capsule, aggressive maneuvers should not be carried out when trying to recover them since they can generate ruptures in the retina and subsequent retinal detachment. The appropriate management in these cases is to perform a posterior approach to the complication through pars plana vitrectomy. In general, it is recommended to complete the vitrectomy if necessary, ensure by direct visualization that retinal tears have not been generated, removal of all fragments (either using the vitreotome or using the posterior chamber phacoemulsifier). In these cases, exploration of the peripheral retina to detect tears by indentation is highly recommended

If there is good capsular support, a lens can be placed in the capsular bag remnants or in the sulcus if the anterior capsule remains intact. In the latter case, it is highly recommended to perform the Gimbel maneuver, which consists of dislocating the optic of the intraocular lens through the opening of the anterior capsule, keeping the haptics of the lens in sulcus. With this maneuver great stability in the implanted intraocular lens is obtained. The technique provides stability and

Fluctuations in the anterior chamber, such as the antero and retropulsion phenomenon, can be minimized by keeping the infusion bottle low, although sometimes there are unavoidable intraoperative mioses that make surgery difficult. Accurately sized wounds, including the clear corneal incision for the phaco tip and the side port for the nucleus manipulator, help to maintain a relatively sealed chamber during surgery and minimize fluctuation of the anterior chamber depth. In the case of having a reverse pupillary blockage, produced when the iris contacts the anterior capsule, preventing the flow from reaching the posterior chamber, it can be solved either by lifting the iris with a second instrument from the paracentesis or using the phaco tip lifting the iris and put the foot pedal in the irrigation

and dispersives that protect the corneal endothelium can be used.

#### *Cataract Surgery in Post-Vitrectomized Eyes DOI: http://dx.doi.org/10.5772/intechopen.95467*

*Current Cataract Surgical Techniques*

**5. Intraoperative complications**

refractive target of zero.

complications. [74–77]

psychiatric patients and bad collaborators.

frequency of intraoperative complications. [79]

performed with the help of viscoelastics.

vitrectomized patiens. [78]

Different from phacoemulsification in previously vitrectomized cases and faced with the variability of published results, our recommendation in cases of phacovitrectomy combined surgery would be to calculate the intraocular lens with a

It has been reported that cataract extraction in eyes with previous vitrectomy is often more complicated because of various anatomic changes in the eye. In the vitrectomized eye, whose vitreous cavity was filled with air, gas or liquid solutions, the aqueous humor is the one that ends up occupying said space, so the lens does not have the counter pressure of the vitreous, which is a semi-solid and viscous substance, and during cataract surgery can occur significant variations in the depth of the anterior chamber that make the procedure difficult. Potential complications that may arise from this situation include bad pupil dilatation, zonule damage, posterior synechia, posterior capsule tears, increase mobility of complex lens-iris and altered intraocular fluid dynamics as a result of the absence of the anterior hyaloid face. Thus, cataract surgery (phacoemulsification) in vitrectomized eyes has been reported to be associated with an increased rate of

Cataract surgery in the vitrectomized eye can be performed under topical anesthesia, or in complex cases local anesthesia. When surgery was performed under topical anesthesia, the anterior chamber was irrigated with lidocaine 0.5% before it was filled with an ophthalmic viscosurgical device. There are ophthalmologists who prefer peri- or retrobulbar anesthesia, since when the anterior chamber is deepened, oscillations of the irido-crystalline diaphragm occur with variation in pupillary diameter that generates discomfort to the patient. If the surgery is performed using local anesthesia (retrobulbar), it is necessary to be cautious with the pressure exerted by the Honan balloon. Excessive pressure exerted by this balloon could damage or increase damage to a compromised zonule, increasing the risk of intraoperative drop of the nucleus into the vitreous cavity. For this reason, the use of topical anesthesia is preferable for cataract surgery in previously vitrectomized eyes. Finally, general anesthesia will be reserved for children, neurological and

Biro et al. reported posterior capsule tears and dropped nucleus in 7,3% in 41

A clear corneal incision for performing the phacoemulsification was recommended, avoiding the conjuntival-scleral scarring from previous retinal surgery. [80] No intraoperative wound-related problems have been described using this clear corneal approach, with a 3-step wound construction with a 50% vertical groove. In patients with inadequate dilation of the pupil, the use of intracamerular phenylephrine or the insertion of iris retractors or pupillary elongation maneuvers will be evaluated, and if there are posterior synechiae, synechiolysis will be

In the case of severe crystalline opacities that do not allow the visualization of the background orange reflex, the use of trypan blue in the staining of the anterior capsule, facilitating capsulorhexis, will be considered. In vitrectomized eyes, trypan

Nevertheless, others authors suggest that eyes with and without prior pars plana vitrectomy (PPV) have a similar likelihood of having intraoperative complications. These authors reported that recognize the differences in the physiologic state of the vitrectomized eye compared with that of non-vitrectomized eyes reduced the

**44**

blue must be introduced into the anterior chamber slowly to avoid its diffusion to the vitreous chamber through zonular dehiscences. If this happens, phacoemulsification can be very complicated by the loss of the foveal reflex, increasing the risk of rupture of the posterior capsule.

If possible, very small capsulorhexis should be avoided to avoid capsular phimosis that later hinders the evaluation of the retinal periphery. Both cohesive viscoelastics that have expansive property allowing the management of mydriasis, and dispersives that protect the corneal endothelium can be used.

Phacoemulsification with a constant pressure minimizes complications in the event of significant ocular collapse. [81]

Fluctuations in the anterior chamber, such as the antero and retropulsion phenomenon, can be minimized by keeping the infusion bottle low, although sometimes there are unavoidable intraoperative mioses that make surgery difficult.

Accurately sized wounds, including the clear corneal incision for the phaco tip and the side port for the nucleus manipulator, help to maintain a relatively sealed chamber during surgery and minimize fluctuation of the anterior chamber depth.

In the case of having a reverse pupillary blockage, produced when the iris contacts the anterior capsule, preventing the flow from reaching the posterior chamber, it can be solved either by lifting the iris with a second instrument from the paracentesis or using the phaco tip lifting the iris and put the foot pedal in the irrigation level before any phaco manipulation.

In a study of 75 vitrectomized eyes, this blockage was observed in 53.3% of the cases during cataract surgery, especially in younger patients, with greater axial length and greater anterior chamber depth. [82]

Infusion deviation syndrome occurs when fluid migrates backward through the zonule and it increases the volume of the vitreous and causes flattening of the anterior chamber. Titiyal et al. [83] presented this complication in 12.3% of the 89 vitrectomized eyes during cataract surgery. To prevent this, it is recommended to carry out the hydration maneuvers carefully, reduce the flow of fluid within the anterior chamber (lowering the height of the bottles if possible or reducing the flow/aspiration rate). Once this complication appears, it is very useful to place in the pars plana a vitrectomy trocar without a valve to allow the pressure to escape from the posterior chamber and to be able to continue performing phacoemulsification.

Maneuvers that push the lens during phacoemulsification and cause zonular tension should be avoided. Thorough careful hydrodissection, confirmation of adequate lens rotation before phacoemulsification and gentle nucleus manipulation help to avoid unnecessary zonular damage and posterior capsule tears. If there is a fall of the nucleus or fragments to the vitreous cavity after the rupture of the posterior capsule, aggressive maneuvers should not be carried out when trying to recover them since they can generate ruptures in the retina and subsequent retinal detachment. The appropriate management in these cases is to perform a posterior approach to the complication through pars plana vitrectomy. In general, it is recommended to complete the vitrectomy if necessary, ensure by direct visualization that retinal tears have not been generated, removal of all fragments (either using the vitreotome or using the posterior chamber phacoemulsifier). In these cases, exploration of the peripheral retina to detect tears by indentation is highly recommended (**Figures 3** and **4**).

If there is good capsular support, a lens can be placed in the capsular bag remnants or in the sulcus if the anterior capsule remains intact. In the latter case, it is highly recommended to perform the Gimbel maneuver, which consists of dislocating the optic of the intraocular lens through the opening of the anterior capsule, keeping the haptics of the lens in sulcus. With this maneuver great stability in the implanted intraocular lens is obtained. The technique provides stability and

**Figure 3.** *Posterior capsule tear (yellow arrow) in a post-vitrectomized cataract surgery.*

#### **Figure 4.**

*Subluxated fragments of the lens (yellow arrow) to the retina in a complicated post-vitrectomized cataract surgery.*

long-term centration of the IOL and prevents vitreous from extending anterior to the IOL. [84]

If there is no capsular support, other alternatives must be chosen to place the intraocular lens, such as the sulcus-sutured lens or the iris fixation lenses.

The use of multifocal lenses in eyes with retinal pathology remains controversial, so it is generally preferred to implant single vision lenses.

### **6. Postoperative complications**

Vitrectomized patients after cataract surgery have a higher risk of postoperative complications. In patients with previous macular surgery and diabetic eyes, a higher incidence of cystic macular edema has been observed. It was reported after a mean time of 42 days after cataract surgery. [85] Nevertheles, there are other studies which have not found CME however, OCT was not routinely used. Therefore, it is important to monitor these patients with fundus and OCT postoperatively since some are refractory cases and require subtenon or intravitreal treatment (**Figure 5**). [86, 87]

Patients with a history of retinal detachment or high myopia surgery may have a higher incidence of retinal detachment, so the peripheral retina should be evaluated throughout the postoperative period. The incidence of RD has been reported between 2% and 8% in different studies [88–90]. Cataract surgery in these patients

**47**

**Author details**

these eyes.

**Figure 5.**

Olivia Esteban\*, Javier Mateo, Paula Casas, Javier Lara and Javier Ascaso

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

can no have intra-operative complication which may predispose to RD. Therefore, this complication was a consequence of the previous posterior segment pathology in

*Asymptomatic cystic macular edema four weeks after cataract surgery in a vitrecomized patient (A). Resolution of macular cystics after topical non-steroidal anti-inflammatory treatment (B).*

The incidence of posterior capsular opacification (PCO) was higher in vitrectomized eyes compared with nonvitrectomized eyes. [91, 92] It is ranging between

Finally, another complication in vitrectomized patients undergoing cataract surgery may be long-term subluxations or dislocations of the lens to the vitreous cavity. High myopia was the most frequent predisposing factor in 18.1% of the

In summary, cataract development and progression are known as frequent complications of PPV. Because of the application of vitreoretinal surgical techniques to a broader range of posterior segment diseases and because cataract surgery is frequently performed in postvitrectomy eyes, cataract surgeons should be familiar with the challenges of cataract extraction in vitrectomized eyes.

2.2% and 19.9% [15–17] within the first year after surgery. [88–90].

Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain

provided the original work is properly cited.

\*Address all correspondence to<EMAIL_ADDRESS>
*Cataract Surgery in Post-Vitrectomized Eyes DOI: http://dx.doi.org/10.5772/intechopen.95467*

83 eyes with this complication. [93]

*Cataract Surgery in Post-Vitrectomized Eyes DOI: http://dx.doi.org/10.5772/intechopen.95467*

**Figure 5.**

*Current Cataract Surgical Techniques*

**46**

**Figure 4.**

**Figure 3.**

*surgery.*

the IOL. [84]

*Subluxated fragments of the lens (yellow arrow) to the retina in a complicated post-vitrectomized cataract*

long-term centration of the IOL and prevents vitreous from extending anterior to

If there is no capsular support, other alternatives must be chosen to place the

The use of multifocal lenses in eyes with retinal pathology remains controversial,

Vitrectomized patients after cataract surgery have a higher risk of postoperative complications. In patients with previous macular surgery and diabetic eyes, a higher incidence of cystic macular edema has been observed. It was reported after a mean time of 42 days after cataract surgery. [85] Nevertheles, there are other studies which have not found CME however, OCT was not routinely used. Therefore, it is important to monitor these patients with fundus and OCT postoperatively since some are refractory cases and require subtenon or intravitreal

Patients with a history of retinal detachment or high myopia surgery may have a higher incidence of retinal detachment, so the peripheral retina should be evaluated throughout the postoperative period. The incidence of RD has been reported between 2% and 8% in different studies [88–90]. Cataract surgery in these patients

intraocular lens, such as the sulcus-sutured lens or the iris fixation lenses.

so it is generally preferred to implant single vision lenses.

*Posterior capsule tear (yellow arrow) in a post-vitrectomized cataract surgery.*

**6. Postoperative complications**

treatment (**Figure 5**). [86, 87]

*Asymptomatic cystic macular edema four weeks after cataract surgery in a vitrecomized patient (A). Resolution of macular cystics after topical non-steroidal anti-inflammatory treatment (B).*

can no have intra-operative complication which may predispose to RD. Therefore, this complication was a consequence of the previous posterior segment pathology in these eyes.

The incidence of posterior capsular opacification (PCO) was higher in vitrectomized eyes compared with nonvitrectomized eyes. [91, 92] It is ranging between 2.2% and 19.9% [15–17] within the first year after surgery. [88–90].

Finally, another complication in vitrectomized patients undergoing cataract surgery may be long-term subluxations or dislocations of the lens to the vitreous cavity. High myopia was the most frequent predisposing factor in 18.1% of the 83 eyes with this complication. [93]

In summary, cataract development and progression are known as frequent complications of PPV. Because of the application of vitreoretinal surgical techniques to a broader range of posterior segment diseases and because cataract surgery is frequently performed in postvitrectomy eyes, cataract surgeons should be familiar with the challenges of cataract extraction in vitrectomized eyes.


*3.11. Modelling and Simulation Tools*

Table 5 presents a summary of the most popular simulation tools, wherein tools such as Matlab/Simulink (MathWorks, Natick, MA, USA) and MATPOWER have particular importance. Matlab is a numerical computing environment of 4th generation programming language, it can interface with other languages such as C, C++, C#, Java, Fortran, and Python. MATPOWER is an open-source tool that is used to simulate optimal power flows, which uses Monte Carlo to evaluate the performance of MG. Alternately, other tools such as GAMS, which is an optimization language for linear, nonlinear, and mixed programming, have been used by many authors to solve the uncertainty problem in energy management and for optimal dimensioning of the microgrid. Other tools such as CPLEX have been employed, which is an optimizer based on the C language and is compatible with other languages like C++, Java, and Python.

**Table 5.** Simulation software and tools used in the management of microgrids.

The simulation and modeling of microgrids has been analyzed with programs such as Simulink and PSCAD/EMTDC (Manitoba Hydro International Ltd., Winnipeg, Manitoba, Canada). Both tools are used for power control and energy management in microgrids.

Software such as HOMER (Pro Version, HOMER Energy LLC, Boulder, CO, USA), HOGA (or its updated version iHOGA) (Pro+ Version, University of Zaragoza, Zaragoza, Spain), or HYBRID2 (University of Massachusets, NREL/NWTC, Golden, CO, USA) also deserve a mention, which can be used to optimize the operation and energy management of hybrid systems with renewable energies.


**1. Introduction**

Tuberculosis (TB) has traditionally been one of the major causes of pleural disease and until the earlier decades of the past century held as a principal paradigm of "pleuritis". Indeed in the presence of a distinctly exudative effusion and a compatible clinical presentation the widely used term "pleuritis exudativa" insinuated a tuberculous aetiology and has therefore been understood to be synonymous with "pleuritis exudativa tuberculosa". Whilst in the era of TB decline in the Western hemisphere the term "pleuritis exudativa" (which actually is a tautol‐ ogy!) has largely survived but should now describe exudative effusions in general, the full and precise term "pleuritis exudativa tuberculosa" is therefore suggested whenever the possibility of a tuberculous background is addressed. Otherwise the term "tuberculous pleurisy" or "tuberculous pleuritis" is used to describe this entity, in some countries also the term "specific pleurisy" is common. Apart from acute pleuritis exudative tuberculosa, TB of the pleura may however rarely present as a rather chronic disease state in terms of caseous pleurisy or specific (i. e. tuberculous) empyema, respectively. The following chapter reviews the different features and mechanisms of tuberculous pleural involvement as well as their diagnostic and thera‐ peutic implications.