Treatment of primary open angle glaucoma

The purpose of monitoring patients with primary open-angle glaucoma is to maintain or improve the condition. The doctor and the patient are interested in the functional preservation of the patient's vision organ throughout his life. To start or change the treatment, one should prove the presence or absence of the possibility of developing functional disorders due to glaucoma in this patient. For this, the doctor should know the stage of glaucoma, the severity of the changes at that stage of glaucoma and the estimated duration of glaucoma. For this purpose, it is recommended to use a diagram of glaucoma.

The stage of glaucoma is determined with the nomograph of the disc state. The degree of disruption is determined by carrying out serial estimates of the history, visual field and condition of the optic nerve disc. The duration of the damaging effect of primary open-angle glaucoma is determined by a reasonable assumption about the patient's lifespan.

A diagram of glaucoma and an explanation of the diagram of glaucoma by Dr. George Spefe. The diagram of glaucoma allows to define and understand the clinical course of glaucoma in each patient.

On the y axis, the diagrams postpone the stage of glaucoma, along the x-axis - the expected life span. Each line has a certain slope and bend, they are displayed in different ways:

• dotted lines reflect the slope and flexure of graphs obtained as a result of serial studies, such as repeated annual photographic registration of the optic nerve disk or repeated perimetry;
• solid lines reflect the clinical course of the disease according to anamnesis;
• the dotted lines show the expected changes in the future.

These hypothetical extrapolated courses in the future are based on the nature of previous courses and on knowing what happened to the patient from a certain point in the treatment process.

The chart shows the treatment courses for 7 patients with different manifestations of glaucoma.

• The patient at point "A" glaucomatous changes are weak, in front of supposedly another third of life.
• The patient at point "B" expressed glaucoma, about a third of the life ahead.
• The patient at point "C" glaucomatous changes are poorly expressed, there are several years of life.
• The patient at the point "D" expressed glaucoma, left a few years of life.

Patient number 1 at the point "A" ahead of a third of life, there is an early stage of glaucoma. Approximately one-third of life back in the patient there was an increase in intraocular pressure, treatment was prescribed. After the withdrawal of treatment, damage to the optic disc or visual field deterioration was not noted. It is logical to assume that if the intraocular pressure is maintained at the nasal level, the schedule will continue accordingly to line No. 1. At the end of life, the patient will not develop any glaucomatous lesions.

Patient number 2 at point "A". Minimal glaucoma changes, there is still a third of life ahead. A constant increase in intraocular pressure was observed in this patient. Early lesion of the optic nerve disk and visual field disturbance developed. With the continuation of the course of the disease, according to the dotted line No. 2, no apparent asymptomatic damage develops without treatment. However, until the end of life the patient will not go blind.

Patients # 3 and # 4 at point "B". A marked glaucoma, about a third of life ahead. In patient number 3 rapid progression of changes, blindness will come long before the end of life. Patient №4. Who received a trauma to his eye in childhood and who then had a decrease in vision as a result of steroid-induced glaucoma, has stable eyesight for most of his life, so it is logical to expect that the condition will continue to remain stable.

Patients at the points "C" and "D" for the rest of their lives remained several years, but patients in the "C" (as in patients number 1 and number 2 in the "A") observed minimal glaucoma changes, and in patients at the point "D" (as in patient number 4 in the "B") there is a pronounced glaucoma.

Patient # 5 has a clinical course consistent with the course of the disease in patient # 3 (severe glaucoma with rapid progression of changes), but approximately midway through the life of the glaucoma process, the course of the glaucoma process became less severe. Nevertheless, without effective intervention, blindness will come to the end of the patient's life. Compare patients number 4 and number 5, who have the same degree of glaucoma changes at the point "D" and the same life expectancy (expressed glaucoma and several years before the end of life). Patient # 4 has a clinical course of the disease stable, so there is no need to change the treatment. And patient # 5 urgently needs to reduce intraocular pressure.

Patient number 6 near the point "C" also left a few years of life, but the progression of glaucoma is somewhat slower, heme in patients number 2 and number 5. Patient # 6 has too little change of nakedness, treatment is not required, despite the progression of the disease. Severe glaucoma damage or loss of vision will not develop even if there is no treatment, so the patient will not feel any functional disturbance throughout his life.

The expected life expectancy of patient number 7 at point "C" is several years, but glaucoma progresses so quickly that. Despite the short expected life expectancy, blindness will come long before death.

The use of a glaucoma chart to identify and describe the type of clinical course of the disease allows the enemy and the patient to realize that:

Patients №1,4 and 6 treatment is not required. Patient # 1 will never develop any damage, patient # 4 has marked damage, but without deterioration, and patient # 6 is experiencing a slow progression of the disease. That throughout his life the patient will not feel it.

Patients 3, 5 and 7 urgently need treatment to prevent the onset of blindness long before the end of life.

The need for treatment of patient number 2 is ambiguous. Since this patient does not have glaucoma, it is possible that treatment is not required. However, some damage will develop, therefore, if damage is undesirable, it is recommended to prescribe therapy.

Adequate management of the patient with primary open-angle glaucoma is to maintain an equilibrium between the risk factors for the onset of pain or loss of function in the absence of intervention, the possible benefits of intervention (slowing or stabilizing visual impairment and significant improvement), and possible risks of intervention.

The only proven effective way to treat primary open-angle glaucoma is to decrease intraocular pressure. Recommendations have been developed to determine the value by which intraocular pressure should be reduced in each case to prevent deterioration, stabilization or improvement.

Risk and benefit of treatment

Risk associated with lack of intervention	The risk associated with the intervention	Benefits of Intervention
Pain	Local side effects: pain; redness; cataract; infection; bleeding; allergic reactions; outbreaks; increased pigmentation, etc.	Improved visual function
Loss of visual function: the minimum; moderate; complete	Systemic side effects: Fatigue; Malaise; Cardiovascular changes; Neurological changes; Psychological changes; Pulmonary changes, etc.	Stabilization of the course of the disease
-	-	Slowdown in the development of pathological processes

Risk of loss of function in the absence of intervention

Low

• The absence of changes in the optic nerve
• No cases of blindness due to glaucoma in the family
• Ability to self-service
• High-quality care is available
• Estimated life expectancy is less than 10 years
• Intraocular pressure is below 15 mm Hg.
• The absence of exfoliation and changes characteristic of the pigment dispersion syndrome
• Absence of cardiovascular diseases

Tall

• Changes in the optic nerve
• The presence of cases of blindness due to glaucoma in the family or the identification of a "gene" of glaucoma
• Inability to self-service
• Lack of affordable quality care
• Estimated life expectancy over 10 years
• Intraocular pressure is above 30 mm Hg.
• Exfoliative Syndrome
• Presence of cardiovascular diseases

Expected benefit of treatment *

• The estimated benefit is high with a decrease in intraocular pressure by more than 30%
• Presumed benefit is possible with a decrease in intraocular pressure by 15-30%
• The absence of the intended benefit with lowering the intraocular pressure by less than 15%

* In some cases, only the stabilization of intraocular pressure is considered beneficial.

The effectiveness of reducing intraocular pressure and the risk of side effects

A typical decrease in intraocular pressure
In response to drug therapy	about 15% (range 0-50%)
In response to argon-laser trabeculoplasty	about 20% (range 0-50%)
In response to an operation aimed at increasing the filtration	about 40% (range 0-80%)
The likelihood of side effects resulting from treatment
Medication Therapy	thirty%
Argon-laser trabeculoplasty	almost absent
Operation aimed at increasing filtration	60% *

* The lower the final intraocular pressure, the higher the probability of side effects of the operation.

Some doctors recommend achieving the target intraocular pressure - a level of intraocular pressure, in which no further damage occurs. It must be remembered that the target intraocular pressure is only a rough guide to treatment. The only effective way to monitor a patient with primary open-angle glaucoma is to assess the stability of the condition of the optic disc, the visual fields, or both. Thus, if the condition of the optic nerve and the field of vision is stable, despite a higher level of intraocular pressure than the calculated target, it is incorrect to reduce the pressure to the target intraocular pressure. Conversely, if the target pressure is reached and the deterioration of the optic nerve and the visual field continues, then the target pressure is too high, there is another cause of impairment not related to glaucoma, or neuronal damage is already so severe that the progression of the process continues regardless of the intraocular level pressure.

Thus, primary open-angle glaucoma is one of the main causes of irreversible blindness throughout the world. Diagnosis, in the first place, is to identify the lesion of the optic nerve. The goal of the treatment is to maintain the patient's health by means of minimal interventions necessary to slow the deterioration of visual functions and keep them at a sufficient level throughout the life of the patient. For this, the attending physician should know the stage of glaucoma, the level of glaucoma changes and the expected life expectancy of the patient.