**8. Treatment**

Slit lamp examination – assessment of the depth of the anterior chamber shows that there is axial (central and peripheral) shallowing of the anterior chamber and, unlike in pupil block, the iris is not typically bowed forwards, and anterior lens movement is noted. Patency of the iridotomy, if such exists, should be evaluated – if there is no iridotomy or the patency is in doubt, laser iridotomy can be performed or repeated to rule out pupil block, but it does not cause resolution of the condition. Seidel test should be performed to exclude filtering bleb leaking after filtration surgery. Biomicroscopy assessment of the posterior segment is neces‐ sary for the purpose of ruling out choroidal detachment or suprachoroidal hemorrhage

Ultrasonography – conducted for the purpose of determining the axial length of the eyeball (which tends to be shorter than normal) and to determine the position and size of the ciliary body and its processes [25]. Moreover, information on the thickness of the choroid may be

Ultrabiomicroscopy (UBM) – this test gives images of the iris, the intraocular lens and ciliary body as well as their relative positions before and after the occurrence of malignant glauco‐ ma. The rotation of the ciliary body to the front and shallowing of the anterior chamber may be subject to normalization after tearing of the anterior hyaloid [24]. This test enables visual‐ ization of the structures of the anterior segment, although the capability of conducting tests

**Figure 3.** OCT of the anterior segment in malignant glaucoma – shallowing of the anterior chamber, peripheral irido‐

Anterior segment OCT *(optical coherence tomography)* – a non-invasive high resolution techni‐ que that can be used for the purpose of objective imaging of the iridocorneal angle structure as well as for qualitiative and quantitative assessment. Parameters such as: AOD – *anterior chamber opening distance,* ACA – *anterior chamber angle* have been adapted from ultrasound biomicroscopy for the OCT method. Measurements of scleral thickness, CCT – *central corneal thickness*, and central depth of the anterior chamber during an episode of malignant glauco‐ ma can also be conducted. Marked displacement of the structures of the anterior segment, peripheral irido-corneal touch, and forward shift of the lens may be noted Examination may reveal a decreased anterior chamber angle with extreme shallowing of the anterior chamber

in the early postoperative period is limited due to the immersion technique

Tonometry – usually reveals increased IOP

428 Glaucoma - Basic and Clinical Aspects

obtained through ultrasonographic examination

corneal touch, forward shift of the IOL.

#### **8.1. Conservative treatment**

The goal of conservative treatment is to decrease the production of aqueous humour and shrink the vitreous while simultaneously decreasing resistance in the path of aqueous hu‐ mour flow to the anterior chamber through applied cycloplegia.

The active mechanism of the drugs used in the treatment of malignant glaucoma is as fol‐ lows:

**Mydriatics – cycloplegics** – paralysis of the ciliary muscle, widening of the ciliary processes ring, tightening of the zonule apparatus, backwards movement of the lens.

**Osmotically active agents** – increase of blood osmolality causing movement of water from the eyeball in the direction of hyperosmotic plasma, which results in a decrease of the hy‐ dration of the vitreous body and makes it possible to retract the iris-lens diaphragm and deepen the anterior chamber.

**β-blockers** – suppression of aqueous humour production, as a result of which the volume of humour directed towards the vitreous is reduced.

**Carbonic anhydrase inhibitors** – reduction of secretion of aqueous humour by inhibiting carbonic anhydrase activity in the epithelium of the ciliary body.

**Corticosteroids** – by limiting inflammation, they reduce edema in the area of the ciliary body and help to minimize inflammatory adhesions of the lens or vitreous body with the ciliary body [20].

According to data from the literature, approximately 50% of patients react to medical thera‐ py [3]. In the work of Debrouwere et al., however, the percentage of recurrences after con‐ servative treatment of patients with malignant glaucoma was equal to 100%, despite an initially good response to such therapy [49]. Also, in own experience, a lack of success in re‐ versing the pathogenic mechanism by means of conservative treatment in malignant glauco‐ ma concerns the great majority of cases. In own material, reactions to conservative treatment were observed in 5 eyes with malignant glaucoma out of 22 of those tested [22.7%), howev‐ er, ultimately, a surgical procedure was necessary in three of them due to the recurrence of typical symptoms and no control over IOP. Permanent improvement after pharmacological treatment was achieved in only 2 eyes [9.1%). The observations of other authors also confirm transient effectiveness of medical therapy during the initial period [11,42]. Even if IOP con‐ trol is achieved as a result of such treatment, long-term cycloplegia is necessary to maintain this effect in many eyes [25]. In some cases, when medications are discontinued or changed, tendencies of recurrence of malignant glaucoma symptoms are observed [50]. Therefore, medical treatment is thought to be of temporary effect and is used until definite treatment with laser iridotomy, posterior capsulotomy and hyaloidotomy is performed. The currently valid regimen for conservative treatment includes locally applied: atropine, phenylephrine, β-blockers, acetazolamide, and generally administered 50% glicerol solution in oral doses and intravenously administered mannitol. Locally applied corticosteroids play the role of limiting the accompanying inflammatory process. If improvement has been achieved, the dosage of hyperosmotic agents can be decreased, followed by carbonic anhydrase inhibitors, however treatment with mydriatic-cycloplegic agents should be continued [3]. The follow‐ ing treatment schedule can also be applied: mannitol 2 g per kg intravenously once or twice a day, acetazolamide 250 mg tid, and locally: 1% Tropicamide qid, Cosopt (dorzolamide hy‐ drochloride-timolol maleate ophthalmic solution) bid, 0.1 % Dexamethasone phosphate tid. This regimen is usually successful until laser treatment is performed.

ing is achieved. 5-15 bursts with an energy of 1-3 mJ through iridotomy or iridectomy are usually effective in achieving communication. An immediate effect of such a procedure is often observed in the form of deepening of the anterior chamber. If there is no access to the iridectomy, communication can be achieved through the lens capsule in a pseudophakic eye using an energy of 1 mJ near the edge of the IOL. Such a procedure may be preceded by decompressing the vitreous chamber by puncturing it with a 25 gauge needle through pars plana. The above scheme may be repeated. The magnitude and patency of communication between the anterior and posterior segments of the eye are decisive to the distribution of pressure between the anterior and posterior segment of the eyeball. Recurrences may occur even when communication is present but is not effective enough to decrease the force shift‐ ing the iridolenticular diaphragm forward. In the case of difficult access to the circumferen‐ tial part of the lens capsule in the area of iridectomy, the effect of deepening of the anterior chamber is to be achieved by creating a capsulotomy within the pupil or outside the edges of the artificial lens, after which a capsulotomy in the area of the iridectomy that is as large

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The goal of Nd-YAG laser hyaloidotomy, in turn, is to tear the anterior hyaloid face, as a result of which the depth of the anterior chamber is normalized [24]. Epstein and others treated aphakic and pseudophakic eyes with an energy of 3 to 11 mJ delivered to the anteri‐ or hyaloid face [53]. This treatment can be conducted through surgical iridectomies or laser iridotomies, often in many places. It is carried out centrally, to the back of the lens capsule,

**Figure 4.** Anterior segment OCT in eye with malignant glaucoma – complication after Nd-Yag laser capsulotomy with hyaloidotomy - hyaloid gets across the iridotomy into the anterior chamber (white arrow); note shallow anterior

Transscleral cyclophotocoagulation is a procedure with different applications. The laser beam causes ablation of the ciliary body, which causes reduction of aqueous humour se‐ cretion. Energy absorption by melanine leads to thermal coagulation and destruction of

or in combination with capsulotomy in pseudophakic patients [46].

chamber, forward movement of the IOL and iridocorneal touch at considerable area.

as possible should be created.

#### **8.2. Surgical treatment**

#### *8.2.1. Laser treatment*

Laser therapy is usually used together with conservative treatment and should be per‐ formed as early as possible because postponement of this therapy may lead to increased IOP with injury to the optic nerve and loss of visual field as a consequence, flattening of the anterior chamber, corneal-lens touch, and corneal decompensation. This method of management can also be used after malignant glaucoma surgery, and then can serve to sustain or restore the effects of the operation. The main limitation of laser techniques – excluding transscleral cyclophotocoagulation with a diode laser – is their dependency on corneal transparency. Topical glycerol may lead to temporary clearance of corneal edema and make the procedure viable.

In cases of suspected malignant glaucoma, pupillary block should be eliminated as a pos‐ sible contributory element to the shallow anterior chamber by assessing the size and pa‐ tency of iridotomy, when present, or by the creation of a patent iridotomy, if necessary [51]. Surgeons may prefer to use the Nd-YAG laser alone or argon laser pre-treatment fol‐ lowed by the Nd-YAG laser. With an Nd-YAG laser energy of 2-5 mJ, 1-3 pulses per burst are usually used.

Currently, as the treatment of choice in aphakic and pseudophakic eyes, several laser effects are used in combination: laser iridotomy with anterior hyaloidotomy and posterior capsu‐ lotomy, all through the same location. In this case, a positive effect of laser therapy is the creation of direct communication between the vitreous, the posterior chamber, and the ante‐ rior chamber, and such a procedure can restore normal dynamics of aqueous humour flow in malignant glaucoma [52]. If needed, it may be applied in more than one location.

Capsulotomy is usually performed using an energy of 1 to 4 mJ per pulse. The energy and pulses may be increased gradually according to the thickness of the capsule until an open‐ ing is achieved. 5-15 bursts with an energy of 1-3 mJ through iridotomy or iridectomy are usually effective in achieving communication. An immediate effect of such a procedure is often observed in the form of deepening of the anterior chamber. If there is no access to the iridectomy, communication can be achieved through the lens capsule in a pseudophakic eye using an energy of 1 mJ near the edge of the IOL. Such a procedure may be preceded by decompressing the vitreous chamber by puncturing it with a 25 gauge needle through pars plana. The above scheme may be repeated. The magnitude and patency of communication between the anterior and posterior segments of the eye are decisive to the distribution of pressure between the anterior and posterior segment of the eyeball. Recurrences may occur even when communication is present but is not effective enough to decrease the force shift‐ ing the iridolenticular diaphragm forward. In the case of difficult access to the circumferen‐ tial part of the lens capsule in the area of iridectomy, the effect of deepening of the anterior chamber is to be achieved by creating a capsulotomy within the pupil or outside the edges of the artificial lens, after which a capsulotomy in the area of the iridectomy that is as large as possible should be created.

trol is achieved as a result of such treatment, long-term cycloplegia is necessary to maintain this effect in many eyes [25]. In some cases, when medications are discontinued or changed, tendencies of recurrence of malignant glaucoma symptoms are observed [50]. Therefore, medical treatment is thought to be of temporary effect and is used until definite treatment with laser iridotomy, posterior capsulotomy and hyaloidotomy is performed. The currently valid regimen for conservative treatment includes locally applied: atropine, phenylephrine, β-blockers, acetazolamide, and generally administered 50% glicerol solution in oral doses and intravenously administered mannitol. Locally applied corticosteroids play the role of limiting the accompanying inflammatory process. If improvement has been achieved, the dosage of hyperosmotic agents can be decreased, followed by carbonic anhydrase inhibitors, however treatment with mydriatic-cycloplegic agents should be continued [3]. The follow‐ ing treatment schedule can also be applied: mannitol 2 g per kg intravenously once or twice a day, acetazolamide 250 mg tid, and locally: 1% Tropicamide qid, Cosopt (dorzolamide hy‐ drochloride-timolol maleate ophthalmic solution) bid, 0.1 % Dexamethasone phosphate tid.

Laser therapy is usually used together with conservative treatment and should be per‐ formed as early as possible because postponement of this therapy may lead to increased IOP with injury to the optic nerve and loss of visual field as a consequence, flattening of the anterior chamber, corneal-lens touch, and corneal decompensation. This method of management can also be used after malignant glaucoma surgery, and then can serve to sustain or restore the effects of the operation. The main limitation of laser techniques – excluding transscleral cyclophotocoagulation with a diode laser – is their dependency on corneal transparency. Topical glycerol may lead to temporary clearance of corneal edema

In cases of suspected malignant glaucoma, pupillary block should be eliminated as a pos‐ sible contributory element to the shallow anterior chamber by assessing the size and pa‐ tency of iridotomy, when present, or by the creation of a patent iridotomy, if necessary [51]. Surgeons may prefer to use the Nd-YAG laser alone or argon laser pre-treatment fol‐ lowed by the Nd-YAG laser. With an Nd-YAG laser energy of 2-5 mJ, 1-3 pulses per

Currently, as the treatment of choice in aphakic and pseudophakic eyes, several laser effects are used in combination: laser iridotomy with anterior hyaloidotomy and posterior capsu‐ lotomy, all through the same location. In this case, a positive effect of laser therapy is the creation of direct communication between the vitreous, the posterior chamber, and the ante‐ rior chamber, and such a procedure can restore normal dynamics of aqueous humour flow

Capsulotomy is usually performed using an energy of 1 to 4 mJ per pulse. The energy and pulses may be increased gradually according to the thickness of the capsule until an open‐

in malignant glaucoma [52]. If needed, it may be applied in more than one location.

This regimen is usually successful until laser treatment is performed.

**8.2. Surgical treatment**

430 Glaucoma - Basic and Clinical Aspects

and make the procedure viable.

burst are usually used.

*8.2.1. Laser treatment*

The goal of Nd-YAG laser hyaloidotomy, in turn, is to tear the anterior hyaloid face, as a result of which the depth of the anterior chamber is normalized [24]. Epstein and others treated aphakic and pseudophakic eyes with an energy of 3 to 11 mJ delivered to the anteri‐ or hyaloid face [53]. This treatment can be conducted through surgical iridectomies or laser iridotomies, often in many places. It is carried out centrally, to the back of the lens capsule, or in combination with capsulotomy in pseudophakic patients [46].

**Figure 4.** Anterior segment OCT in eye with malignant glaucoma – complication after Nd-Yag laser capsulotomy with hyaloidotomy - hyaloid gets across the iridotomy into the anterior chamber (white arrow); note shallow anterior chamber, forward movement of the IOL and iridocorneal touch at considerable area.

Transscleral cyclophotocoagulation is a procedure with different applications. The laser beam causes ablation of the ciliary body, which causes reduction of aqueous humour se‐ cretion. Energy absorption by melanine leads to thermal coagulation and destruction of the pigment epithelium and accompanying vessels. Deep coagulative necrosis of the pig‐ ment epithelium, pathological reconstruction of collagen fibers in the stroma, and intra‐ vascular coagulation in the blood vessels of the ciliary body take place [43]. Significant complications include postoperative inflammation, pain, cystoid macular edema, and phthisis. Thus, indications for cyclophotocoagulation are generally limited to patients whose glaucoma has been resistant to medical and surgical therapies, with no potential for improvement in visual acuity.

three steps will usually result in complete resolution of the condition. Pars plana vitrectomy is reserved for cases that did not respond to the procedure above, and in any case, it should be combined with opening of the anterior hyaloid face. Thus, in refractory malignant glau‐ coma, partial PPV should be performed and supplemented by procedures making it possi‐ ble to achieve communication between the anterior chamber and the vitreous cavity. Achievement of correct flow and equalization of pressure between the posterior and anteri‐ or segment of the eyeball is decisive for the effectiveness of the surgery. Partial PPV should be conducted conservatively, preferably using trocars and a 25 gauge vitrectome. Communi‐ cation between the anterior chamber and vitreous cavity may be achieved by cutting out the lens capsule using a vitrectome or puncturing it through the cornea with a needle, alterna‐ tively by cutting the anterior and posterior capsules with cystotome from the side of the an‐

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**Figure 6.** Combined partial pars plana vitrectomy with capsulotomy communicating anterior chamber and vitreous cavity in surgical treatment of malignant glaucoma: A. The trocar is inserted through pars plana 3.5 mm posteriorly to the corneal limbus before PPV. B. Achieving communication between the anterior chamber and vitreous cavity using a

Malignant glaucoma remains a difficult clinical problem that results in irreversible blindness if treatment is delayed and not adequate. The surgeon should be aware preoperatively of eyes at risk and observe them closely during follow-up visits. Early recognition is the most important step to prevent irreversible loss of vision. The prognosis depends on the duration and the severity of the malignant glaucoma attack. In patients with glaucoma in its early stage, the prognosis can be good if the attack is discontinued and IOP is well controlled. The problem is that malignant glaucoma is often resistant to conservative treatment, and laser procedures are not always effective as well. Partial pars plana vitrectomy combined with capsulotomy communicating the anterior chamber and vitreous cavity in such cases is an ef‐ ficacious method of intervention when it comes to IOP control, postoperative BCVA, and re‐ duction of the number of antiglaucoma medications. The prognosis after laser and surgical

terior chamber within iridectomy.

vitrectome.

**9. Prognosis**

#### *8.2.2. Surgical treatment*

The indication for surgical intervention is a lack of effectiveness of conservative and laser treatment [11,36]. An operative procedure should not be conducted too late due to the de‐ velopment of complications resulting from the persistence of the malignant process.

**Figure 5.** A,B: Advanced stage of malignant glaucoma - shallow anterior chamber, corneal oedema and posterior syn‐ echiae in pseudophakic eye.

Currently used methods of surgical treatment were introduced when the role of the patholo‐ gy of the anterior segment and the vitreous body in the pathogenesis of the malignant proc‐ ess were discovered. As of now, surgical intervention in malignant glaucoma is directed towards lowering IOP, achieving correct anatomical relationships between the vitreous body, lens, and ciliary body, and additionally enabling correct flow of aqueous humour from the posterior segment to the anterior chamber of the eye. Achievement of communica‐ tion seems to be necessary, because the disruption of aqueous humour flow in malignant glaucoma can last even after PPV [54]. The concept of such a procedure is based on the ob‐ servation of regression of the symptoms of malignant glaucoma in the case of direct commu‐ nication between the vitreous cavity and anterior chamber being ensured [25]. The iridectomy may be performed using Vannas scissors or a vitrectomy tip, whereas the poste‐ rior capsulotomy and hyaloidotomy may be done with a vitrectomy tip. The anterior cham‐ ber may be reformed with air. All of these procedures should be performed in one setting through the same location. Additionally synechiolysis may be performed if the iridocorneal angle is completely closed using a spatula or a viscoelastic agent. The performance of all three steps will usually result in complete resolution of the condition. Pars plana vitrectomy is reserved for cases that did not respond to the procedure above, and in any case, it should be combined with opening of the anterior hyaloid face. Thus, in refractory malignant glau‐ coma, partial PPV should be performed and supplemented by procedures making it possi‐ ble to achieve communication between the anterior chamber and the vitreous cavity. Achievement of correct flow and equalization of pressure between the posterior and anteri‐ or segment of the eyeball is decisive for the effectiveness of the surgery. Partial PPV should be conducted conservatively, preferably using trocars and a 25 gauge vitrectome. Communi‐ cation between the anterior chamber and vitreous cavity may be achieved by cutting out the lens capsule using a vitrectome or puncturing it through the cornea with a needle, alterna‐ tively by cutting the anterior and posterior capsules with cystotome from the side of the an‐ terior chamber within iridectomy.

**Figure 6.** Combined partial pars plana vitrectomy with capsulotomy communicating anterior chamber and vitreous cavity in surgical treatment of malignant glaucoma: A. The trocar is inserted through pars plana 3.5 mm posteriorly to the corneal limbus before PPV. B. Achieving communication between the anterior chamber and vitreous cavity using a vitrectome.
