Prognostic factors for predicting progression of open angle glaucoma in adults: Cochrane Prognostic Review Protocol

Objectives: This is a protocol for a Cochrane Review (prognosis). The objectives are as follows:
Primary objective: To identify prognostic risk factors for progression of functional visual outcomes of primary open angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXFG) in adults.

Table 1. PICOTS of the primary objective
Population - Adults ≥ 18 years of age of any ethnicity with open angle glaucoma (restricted to POAG and PXFG types) diagnosed as having open angle and evidence of glaucomatous damage. We will exclude studies evaluating risk factors on those who have already undergone surgical treatment for glaucoma.

Index prognostic factors - Prognostic factors associated with the progression of open angle glaucoma (restricted to POAG and PXFG types), evaluated in primary studies. Specific prognostic factors of interest will include, but are not restricted to: patient demographic information, such as age, sex, ethnicity, and socio‐economic status; clinical data, such as comorbidities (presence or absence of cardiovascular disease, diabetes, hypothyroidism, obstructive sleep apnoea, etc.) and variations in systemic blood pressure (diastolic blood pressure, systolic blood pressure, mean arterial pressure); and functional and structural biomarkers in the prognostic context of the POAG or PXFG. We will also consider the stage of glaucoma at baseline (mild, moderate, severe types). We expect that prognostic factors will generally be measured at the time that participants enter the study, and after the diagnosis of POAG or PXFG has been made.

Comparator - Not applicable

Outcomes - Primary outcome: progression of glaucoma that has been ascertained by visual fields (VF) (functional assessment), or by VF plus imaging test (e.g. OCT) will be the main outcome of interest for the primary objective. We will exclude studies that have assessed structural outcomes using optical coherence tomography (OCT) only.

Timing - We will include studies that present the above outcome with at least 2 years follow‐up after diagnosis. Ideally, the period of follow‐up should be 5 years or more.

Setting - We will include studies undertaken in any care setting, with no geographical limitations.

Secondary objectives: To identify prognostic risk factors for progression of structural outcomes of POAG and PXFG in adults.

Table 2. PICOTS of the secondary objective

Population - Adults ≥ 18 years of age of any ethnicity with open angle glaucoma (restricted to POAG and PXFG types) diagnosed as having open angle and evidence of glaucomatous damage. We will exclude studies evaluating risk factors on those who have already undergone surgical treatment for glaucoma.

Index prognostic factors - We anticipate that there will be fewer studies that have assessed glaucoma progression using OCT. However, the prognostic factors that we will consider and expect to be measured in the included studies are similar to those for the primary objective.

Comparator - Not applicable

Outcomes - Progression of glaucoma that has been ascertained by OCT or any other imaging test (structural assessments) will be the outcome of interest for the secondary objective.

Timing - We will include studies that present the above outcome with at least 2 years follow‐up after diagnosis. Ideally, the period of follow‐up should be 5 years or more.

Setting - Studies undertaken in any care setting, with no geographical limitations.