Toward Value Based Health Care in pituitary surgery: application of a comprehensive outcome set in perioperative care

Quality of life in Prolactinoma: A systematic review

BACKGROUND

Prolactinomas are common tumours that significantly reduce quality-of-life (QOL) due to sellar mass effect, secondary hypogonadism, and the peripheral effects of prolactin. Understanding the factors that influence QOL would provide insights into therapeutic targets to optimise patient outcomes and improve wellbeing in prolactinoma.

METHODS

A systematic review was performed in accordance with the PRISMA statement. Studies that reported patient QoL using validated metrics were included. Bias and methodological rigour were assessed using the MINORS criteria.

RESULTS

A total of 18 studies were identified studies were available for review, comprising 877 patients. Most were small cross-sectional studies at high risk of bias. Prolactinoma exhibit worse QOL than healthy controls, particularly mental and psychosocial wellbeing. QOL is also worse than patients with non-functional adenomas, but better than those with Cushing's disease and acromegaly. QOL correlates with prolactin levels, and approaches population baseline with prolonged biochemical control. Dopamine agonists and surgery both improve overall QOL, however improvements are more rapid with surgery.

CONCLUSION

Poor quality of life in prolactinoma is multifactorial, related to biochemical control, side effects of therapy, and sellar mass effect. Targeting persistent symptoms, reducing healthcare costs, and reducing side-effects of therapy are avenues to improving QOL in patients with prolactinoma.

Prospective Integrated Individualized Clinical Decision-making and Outcome Evaluation for Surgery in Patients with Acromegaly: A New Paradigm?

BACKGROUND

Growth-hormone-producing pituitary adenomas have variable likelihood for biochemical remission (BR). During preoperative counseling, individual estimated surgical likelihoods/risks should be balanced against alternative (medical) treatments, which is necessary for accurate outcome presentation. Preoperative estimation of BR or total resection (TR) likelihoods have not been reported, resulting in extrapolation of individual outcomes.

AIMS

To share an innovative outcome reporting paradigm by integrating surgical decision-making, and expected/realized results, resulting from the Value-Based Health Care (VBHC) care path with periodical performance evaluation and care innovation cycle.

METHODS

Prospective cohort study of consecutive patients with acromegaly undergoing surgery (January 2016-December 2020; postoperative follow-up ≥6 months) reporting on both classic, and novel innovative outcome evaluations.

RESULTS

Fifty eight patients (66 procedures) were included. Intended TR was achieved in 34/50 procedures, whereas intended debulking was achieved in 15/16 procedures. 38/66 procedures resulted in BR, and 4 procedures resulted in permanent complications. Achieving intended surgical goal was estimated preoperatively as likely in 33 (goal achieved (GA) in 28/33), potentially in 27 (GA in 19/27), and unlikely in 6 procedures (GA in 2/6). Integrated Outcome Square 1 (IOQ1) -intended effect achieved without complications- was achieved in 46/66 patients.

CONCLUSION

Implementation of the developed quality process positively affects preoperative individual shared decision-making, resulting in improved (individual) outcomes, particularly in complex patients for whom preoperative chances are not fully reflected by tumor size and KNOSP grade, e.g., reoperations, or other challenging circumstances identified during preoperative counseling. Through repeated evaluations, our own team's knowledge increased, allowing for improved individualized treatment strategies.

Efficacy and Safety of Endoscopic Transsphenoidal Resection for Prolactinoma: A Retrospective Multicenter Case-series

BACKGROUND

Endoscopic transsphenoidal surgery (ETSS) for prolactinoma is reserved for dopamine agonist (DA) resistance, intolerance, or apoplexy. High remission (overall 67%, microprolactinoma up to 90%), low recurrence (5-20%) rates highlighted that surgery might be first-line treatment.

AIMS

To report on outcomes of ETSS in a cohort of prolactinomas.

METHODS

Multicenter retrospective cohort of 137 prolactinoma patients (age 38.2 ± 13.7 years; 61.3% female, median follow-up 28.0 [15.0-55.5] months) operated between 2010-2019 with histopathological confirmation.

RESULTS

Median preoperative prolactin levels were 166 (98-837 µg/L; males 996 [159-2145 µg/L] vs. females 129 [84-223 µg/L], p <0.001). 56 (40.9%) microprolactinomas, 69 (50.4%) macroprolactinomas, and 7 (5.1%) giant prolactinomas were included, whereas no adenoma was detected in 5 (3.6%) patients. Males had larger tumors (macroprolactinomas: 38, 71.7%) vs. 31 (36.9%), p <0.001; giant prolactinomas: 7 (13.2%) vs. 0 (0.0%), (p <0.001). Prolactinomas were graded as KNOSP-3 in 15 (11.5%), and KNOSP-4 in 20 (15.3%) patients. Primary indication was DA intolerance (59, 43.1%); males 14 (26.4%) vs. females 45 (53.6%), p = 0.006. Long-term remission (i.e., DA-free prolactin level <1xULN) was achieved in 87 (63.5%) patients, being higher in intended complete resection (69/92 [75.0%]), and lower in males (25 [47.2%] vs. 62 females [73.8%], p = 0.002). Transient DI (n = 29, 21.2%) was the most frequent complication.

CONCLUSIONS

Despite high proportions of macroprolactinoma and KNOSP 3-4, long-term remission rates were 63.5% overall, and 83.3% in microprolactinoma patients. Males had less favorable remission rate compared to females. These findings highlight that ETSS may be a safe and efficacious treatment to manage prolactinoma.

Care trajectories of surgically treated patients with a prolactinoma: why did they opt for surgery?

PURPOSE

To describe care trajectories in patients with prolactinoma, aiming to clarify the rationale for surgery.

METHODS

Retrospective observational cohort study of consecutive patients with prolactinoma undergoing surgery from 2017 to 2019 at the referral center (RC), prior to surgery being considered a viable treatment option (i.e. PRolaCT study). Demographics and clinical data (type and duration of pretreatment and surgical indications, goals, and outcomes) were collected from patient records. Care trajectories were divided into three phases: (1) diagnosis and initial treatment, (2) endocrine treatment at the RC, and (3) surgical treatment.

RESULTS

40 patients were included (31 females (77.5%), median age 26.5 (14-63) years. Indications for surgery were dopamine agonist (DA) intolerance (n = 31, 77.5%), resistance (n = 6, 15.0%), and patient/physician preference (n = 3, 7.5%). Patients were pretreated with DA (n = 39 (97.5%)), and surgery (n = 3 (7.5%)). Median disease duration at surgery was 4 (0-27) years. Primary surgical goal was total resection in 38 patients (95.0%), of which biochemical remission was achieved 6 months postoperatively in 23 patients (62.2%), and clinical remission in 6 patients (16.2%), missing data n = 1.

CONCLUSION

Care trajectories were highly individualized based on patient and tumor characteristics, as well as the multidisciplinary team's assessment (need for alternative treatment, surgical chances and risks). Most patients were pretreated pharmacologically and had broad variation in timing of referral, undergoing surgery as last-resort treatment predominantly due to DA intolerance. High quality imaging and multidisciplinary consultations with experienced neurosurgeons and endocrinologists enabling treatment tailored to patients' needs were prerequisites for adequate counseling in treatment of patients with prolactinoma.

Patient-reported outcomes in refractory hormone-producing pituitary adenomas: an unmet need

PURPOSE

To describe quality and outcomes of patient-reported outcome (PRO) measures (PROMs) used in patients with refractory hormone-producing pituitary adenomas, and to provide an overview of PROs in these challenging pituitary adenomas.

METHODS

Three databases were searched for studies reporting on refractory pituitary adenomas. For the purpose of this review, refractory adenomas were defined as tumors resistant to primary therapy. General risk of bias was assessed using a component approach and the quality of PROM reporting was assessed using the International Society for Quality of Life Research (ISOQOL) criteria.

RESULTS

20 studies reported on PROMs in refractory pituitary adenomas, using 14 different PROMs, of which 4 were disease specific (median general risk of bias score: 33.5% (range 6-50%) and ISOQOL score: 46% (range 29-62%)). SF-36/RAND-36 and AcroQoL were most frequently used. Health-related quality of life in refractory patients (measured by AcroQoL, SF-36/Rand-36, Tuebingen CD-25, and EQ-5D-5L) varied greatly across studies, and was not always impaired compared to patients in remission.

CONCLUSION

There is a scarcity of data on PROs in the subset of pituitary adenomas that is more difficult to treat, e.g., refractory and these patients are difficult to isolate from the total cohort. The patients' perspective on quality of life, therefore, remains largely unknown in refractory patients. Thus, PROs in refractory pituitary adenomas require adequate analysis using properly reported disease specific PROMs in large cohorts to enable appropriate interpretation for use in clinical practice.

Time taken to resume activities of daily living after transsphenoidal surgery for pituitary tumors

Postoperative management after transsphenoidal surgery (TSS) is important; however, the guidelines for resuming daily activities after TSS are insufficient. This study aimed to examine the time to return to activities of daily living (ADL) after TSS for pituitary tumors. A 4-month prospective data collection was completed for 114 of 117 patients who underwent TSS for pituitary tumors from April to July 2021. The time when the patient returned to ADL after surgery was measured using the self-recording sheet. More than 97% and 92% of the patients returned within 1 month (median: within 7 days) for the elements of basic ADL and within 2 months (median: within 15 days) for the elements of instrumental ADL, excluding a few. Notably, 73.3% of patients returned to work within 4 months. The median time for the activities included 64 days for washing hair head down, 44 days for blowing nose, 59 days for lifting heavy objects, and 102 days for sexual activity. For patients who received extended-TSS or had postoperative problems, the time to return was delayed. Based on these results, it will be possible to provide practical information and guidelines on the time to return to ADL after TSS in pituitary tumor patients.

Health-Related Quality of Life in Intracranial Meningioma: Current Evidence and Future Directions

Historically, largely due to the good prognosis for survival, there has been little attention paid to the possible impact of meningiomas and their treatment on health-related quality of life (HRQoL). However, in the last decade there has been increasing evidence that patients with intracranial meningiomas suffer from long-term decreases in their HRQoL. Compared with controls and normative data, meningioma patients have worse HRQoL scores both before and after intervention and continuing long term (even after >4 years of follow-up). Overall, surgery results in improvements in many aspects of HRQoL. The limited available studies investigating the impact of radiotherapy suggest that this type of treatment decreases HRQoL scores, especially in the long term. There is however only limited evidence on additional determinants of HRQoL. Patients with anatomically complex skull base meningiomas and severe comorbidities, including epilepsy, report the lowest HRQoL scores. Other tumor and sociodemographic characteristics have shown weak associations with HRQoL. Furthermore, about one-third of caregivers of meningioma patients report caregiver burden, warranting interventions to improve caregiver HRQoL. As antitumor interventions may not improve HRQoL scores to be comparable to those of the general population, more attention should be paid to the development of integrative rehabilitation and supportive care programs for meningioma patients.

Cost-effectiveness of direct surgery versus preoperative octreotide therapy for growth-hormone secreting pituitary adenomas

PURPOSE

The objective of this study was to compare the cost-effectiveness of preoperative octreotide therapy followed by surgery versus the standard treatment modality for growth-hormone secreting pituitary adenomas, direct surgery (that is, surgery without preoperative treatment) from a public third-party payer perspective.

METHODS

We developed an individual-level state-transition microsimulation model to simulate costs and outcomes associated with preoperative octreotide therapy followed by surgery and direct surgery for patients with growth-hormone secreting pituitary adenomas. Transition probabilities, utilities, and costs were estimated from recent published data and discounted by 3% annually over a lifetime time horizon. Model outcomes included lifetime costs [2020 United States (US) Dollars], quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs).

RESULTS

Under base case assumptions, direct surgery was found to be the dominant strategy as it yielded lower costs and greater health effects (QALYs) compared to preoperative octreotide strategy in the second-order Monte Carlo microsimulation. The ICER was most sensitive to probability of remission following primary therapy and duration of preoperative octreotide therapy. Accounting for joint parameter uncertainty, direct surgery had a higher probability of demonstrating a cost-effective profile compared to preoperative octreotide treatment at 77% compared to 23%, respectively.

CONCLUSIONS

Using standard benchmarks for cost-effectiveness in the US ($100,000/QALY), preoperative octreotide therapy followed by surgery may not be cost-effective compared to direct surgery for patients with growth-hormone secreting pituitary adenomas but the result is highly sensitive to initial treatment failure and duration of preoperative treatment.

Quality measurement for cardiovascular diseases and cancer in hospital value-based healthcare: a systematic review of the literature

BACKGROUND

This systematic literature review identifies hospital value-based healthcare quality measures, measurement practices, and tools, as well as potential strategies for improving cardiovascular diseases and cancer care.

METHODS

A systematic search was carried out in the PubMed, Embase, CINAHL, and MEDLINE (OvidSP) databases. We included studies on quality measures in hospital value-based healthcare for cardiovascular diseases and cancer. Two reviewers independently screened titles and abstracts, conducted a full-text review of potentially relevant articles, assessed the quality of included studies, and extracted data thematically. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and four validated tools were used for methodological quality assessment.

RESULTS

The search yielded 2860 publications. After screening the titles and abstracts, 60 articles were retrieved for full-text review. A total of 37 studies met our inclusion criteria. We found that standardized outcome sets with patient involvement were developed for some cardiovascular diseases and cancer. Despite the heterogeneity in outcome measures, there was consensus to include clinical outcomes on survival rate and disease control, disutility of care, and patient-reported outcome measures such as long-term quality of life.

CONCLUSION

Hospitals that developed value-based healthcare or are planning to do so can choose whether they prefer to implement the standardized outcomes step-by-step, collect additional measures, or develop their own set of measures. However, they need to ensure that their performance can be consistently compared to that of their peers and that they measure what prioritizes and maximizes value for their patients.

TRIAL REGISTRATION

PROSPERO ID: CRD42021229763 .

Implementation of functional imaging using 11C-methionine PET-CT co-registered with MRI for advanced surgical planning and decision making in prolactinoma surgery

PURPOSE

To report the first experience of our multidisciplinary team with functional imaging using ¹¹C-methionine positron emission tomography-computed tomography (¹¹C-methionine PET-CT) co-registered with MRI (Met-PET/MRI^CR) in clinical decision making and surgical planning of patients with difficult to treat prolactinoma.

METHODS

In eighteen patients with prolactinoma, referred to our tertiary referral centre because of intolerance or resistance for dopamine agonists (DA), Met-PET/MRI^CR was used to aid decision-making regarding therapy.

RESULTS

Met-PET/MRI^CR was positive in 94% of the patients. MRI and Met-PET/MRI^CR findings were completely concordant in five patients, partially concordant in nine patients, and non-concordant in four patients. In five patients Met-PET/MRI^CR identified lesion(s) that were retrospectively also visible on MRI. Met-PET/MRI^CR was false negative in one patient, with a cystic adenoma on conventional MRI. Thirteen patients underwent transsphenoidal surgery, with nine achieving full biochemical remission, two clinical improvement and near normalized prolactin levels, and one patient clinical improvement with significant tumour reduction. Hence, nearly all patients (94%) were considered to have a positive outcome. Permanent complication rate was low. Three patients continued DA, two patients have a wait and scan policy.

CONCLUSION

Met-PET/MRI^CR can provide additional information to guide multidisciplinary preoperative and intraoperative decision making in selected cases of prolactinoma. This approach resulted in a high remission rate with a low rate of complications in our expert centre.

Effects of a transsphenoidal surgery quality improvement program on patient outcomes and hospital financial performance

OBJECTIVE

A comprehensive quality improvement (QI) program aimed at all aspects of patient care after pituitary surgery was initiated at a single center. This initiative was guided by standard quality principles to improve patient outcomes and optimize healthcare value. The programmatic goal was to discharge most elective patients within 1 day after surgery, improve patient safety, and limit unplanned readmissions. The program is described, and its effect on patient outcomes and hospital financial performance over a 5-year period are investigated.

METHODS

Details of the patient care pathway are presented. Foundational elements of the QI program include evidence-based care pathways (e.g., for hyponatremia and pain), an in-house research program designed to fortify care pathways, patient education, expectation setting, multidisciplinary team care, standard order sets, high-touch postdischarge care, outcomes auditing, and a patient navigator, among other elements. Length of stay (LOS), outcome variability, 30-day unplanned readmissions, and hospital financial performance were identified as surrogate endpoints for healthcare value for the surgical epoch. To assess the effect of these protocols, all patients undergoing elective transsphenoidal surgery for pituitary tumors and Rathke's cleft cysts between January 2015 and December 2019 were reviewed.

RESULTS

A total of 609 adult patients who underwent elective surgery by experienced pituitary surgeons were identified. Patient demographics, comorbidities, and payer mix did not change significantly over the study period (p ≥ 0.10). The mean LOS was significantly shorter in 2019 versus 2015 (1.6 ± 1.0 vs 2.9 ± 2.2 midnights, p < 0.001). The percentage of patients discharged after 1 midnight was significantly higher in 2019 versus 2015 (75.4% vs 15.6%, p < 0.001). The 30-day unplanned hospital readmission rate decreased to 2.8% in 2019 from 8.3% in 2015. Per-patient hospital profit increased 71.3% ($10,613 ± $19,321 in 2015; $18,180 ± $21,930 in 2019), and the contribution margin increased 42.3% ($18,925 ± $19,236 in 2015; $26,939 ± $22,057 in 2019), while costs increased by only 3.4% ($18,829 ± $6611 in 2015; $19,469 ± $4291 in 2019).

CONCLUSIONS

After implementation of a comprehensive pituitary surgery QI program, patient outcomes significantly improved, outcome variability decreased, and hospital financial performance was enhanced. Future studies designed to evaluate disease remission, patient satisfaction, and how the surgeon learning curve may synergize with other quality efforts may provide additional context.

Impact of patient-reported nasal symptoms on quality of life after endoscopic pituitary surgery: a prospective cohort study

PURPOSE

Endoscopic transsphenoidal surgery causes nasal morbidity and negatively affects health-related quality of life (HRQoL). Knowledge on actionable symptoms that could improve postoperative HRQoL is therefore important. This study assessed the impact of nasal symptoms on postoperative HRQoL.

METHODS

This perioperative cohort study included 103 adult patients undergoing endoscopic pituitary adenoma resection (August 2016-December 2018), with measurements preoperatively, and 5 days, 6 weeks and 6 months after surgery. Nasal symptoms were measured with the Anterior Skull base nasal inventory-12, and HRQoL with the Short Form-36 (SF-36) physical (PCS) and mental component scores (MCS). Linear regression analysis was used to assess (1) determinants of postoperative nasal morbidity, (2) associations between number of symptoms or (3) individual symptoms and HRQoL, and (4) the percentage of variance of HRQoL explained by nasal symptoms.

RESULTS

The number of nasal symptoms transiently increased after surgery. No significant treatment- or disease-related determinants of nasal morbidity were identified. The number of nasal symptoms was significantly associated with a lower PCS (β = - 1.0; 95%CI - 1.5, - 0.4), but not with MCS at 6 weeks. Similar results were observed at 6 months. Headaches (42.2%), problems with smell (42.0%), and taste (36.0%) were the most prevalent symptoms, while sense of smell and taste, and nasal discharge showed the strongest associations with HRQoL.

CONCLUSIONS

Postoperative nasal symptoms, in particular problems with smell and taste, significantly affect pituitary patients' physical HRQoL. Monitoring of these symptoms may aid in determining which patients may benefit from intensified follow-up and treatment, aiming to optimize HRQoL.

Costs and Its Determinants in Pituitary Tumour Surgery

PURPOSE

Value-based healthcare (VBHC) provides a framework to improve care by improving patient outcomes and reducing healthcare costs. To support value-based decision making in clinical practice we evaluated healthcare costs and cost drivers in perioperative care for pituitary tumour patients.

METHODS

We retrospectively assessed financial and clinical data for surgical treatment up to the first year after surgery of pituitary tumour patients treated between 2015 and 2018 in a Dutch tertiary referral centre. Multivariable regression analyses were performed to identify determinants of higher costs.

RESULTS

271 patients who underwent surgery were included. Mean total costs (SD) were €16339 (13573) per patient, with the following cost determinants: surgery time (€62 per minute; 95% CI: 50, 74), length of stay (€1331 per day; 95% CI 1139, 1523), admission to higher care unit (€12154 in total; 95% CI 6413, 17895), emergency surgery (€10363 higher than elective surgery; 95% CI: 1422, 19305) and postoperative cerebrospinal fluid leak (€14232; 95% CI 9667, 18797). Intradural (€7128; 95% CI 10421, 23836) and combined transsphenoidal/transcranial surgery (B: 38494; 95% CI 29191, 47797) were associated with higher costs than standard. Further, higher costs were found in these baseline conditions: Rathke's cleft cyst (€9201 higher than non-functioning adenoma; 95% CI 1173, 17230), giant adenoma (€19106 higher than microadenoma; 95% CI 12336, 25877), third ventricle invasion (€14613; 95% CI 7613, 21613) and dependent functional status (€12231; 95% CI 3985, 20477). In patients with uncomplicated course, costs were €8879 (3210) and with complications €17551 (14250).

CONCLUSIONS

Length of hospital stay, and complications are the main drivers of costs in perioperative pituitary tumour healthcare as were some baseline features, e.g. larger tumors, cysts and dependent functional status. Costs analysis may correspond with healthcare resource utilization and guide further individualized care path development and capacity planning.

SF-12 or SF-36 in pituitary disease? Toward concise and comprehensive patient-reported outcomes measurements

PURPOSE

Pituitary diseases severely affect patients' health-related quality of life (HRQoL). The most frequently used generic HRQoL questionnaire is the Short Form-36 (SF-36). The shorter 12-item version (SF-12) can improve efficiency of patient monitoring. This study aimed to determine whether SF-12 can replace SF-36 in pituitary care.

METHODS

In a longitudinal cohort study (August 2016 to December 2018) among 103 endoscopically operated adult pituitary tumor patients, physical and mental component scores (PCS and MCS) of SF-36 and SF-12 were measured preoperatively, and 6 weeks and 6 months postoperatively. Chronic care was assessed with a cross-sectional study (N = 431). Mean differences and agreement between SF-36 and SF-12 change in scores (preoperative vs. 6 months) were assessed with intraclass correlation coefficients (ICC) and limits of agreement, depicting 95% of individual patients.

RESULTS

In the longitudinal study, mean differences between change in SF-36 and SF-12 scores were 1.4 (PCS) and 0.4 (MCS) with fair agreement for PCS (ICC = 0.546) and substantial agreement for MCS (ICC = 0.931). For 95% of individual patients, the difference between change in SF-36 and SF-12 scores varied between -14.0 and 16.9 for PCS and between -7.8 and 8.7 for MCS. Cross-sectional results showed fair agreement for PCS (ICC = 0.597) and substantial agreement for MCS (ICC = 0.943).

CONCLUSIONS

On a group level, SF-12 can reliably reproduce MCS in pituitary patients, although PCS is less well correlated. However, individual differences between SF-36 and SF-12 can be large. For pituitary diseases, alternative strategies are needed for concise, but comprehensive patient-reported outcome measurement.

Endoscopic Surgery for Pituitary Tumors

Endoscopic transsphenoidal surgery for pituitary adenoma is a safe and highly effective first-line treatment that is well tolerated by patients. Potential complications are plenty, and there is a large variation in complexity of surgery. This article presents the philosophy, surgical techniques, and outcomes of a high-volume pituitary adenoma center. Three surgical videos illustrate some procedures. The experience has reinforced the authors' belief that experience and surgical volume are key to high quality of care.

Quality of care evaluation in non-functioning pituitary adenoma with chiasm compression: visual outcomes and timing of intervention clinical recommendations based on a systematic literature review and cohort study

PURPOSE

Surgery in patients with non-functioning pituitary macroadenomas (NFMA) is effective in ameliorating visual function. The urgency for decompression, and preferred timing of surgery related to the preoperative severity of dysfunction is unknown.

METHODS

Systematic review for evidence to provide clinical guidance for timing of surgical decompression of the optic chiasm, and a cohort study of 30 NFMA patients, in whom mean deviation (MD), and severity of visual dysfunction was assessed.

RESULTS

Systematic review 44 studies were included with a total of 4789 patients. Postoperatively, visual field defects improved in 87.0% of patients, stabilized in 12.8% and worsened in 1.0%. Specific protocols regarding timing of surgery were not reported. Only seven studies (16.7%) reported on either the duration of visual symptoms, or diagnostic, or treatment delay. Cohort study 30 NFMA patients (50% female, 60 eyes, mean age 58.5 ± 14.8 years), had a median MD of - 5.3 decibel (IQR - 3.1 to - 10.1). MD was strongly correlated with clinical severity (r =  - 0.94, P < 0.0001), and were used for severity of defects cut-off values: (1) normal >  - 2 dB, (2) mild - 2 dB to - 4 dB, (3) moderate - 4 to - 8 dB, (4) severe - 8 to - 17 dB, (5) very severe <  - 17 dB.

CONCLUSION

Surgical decompression is highly effective in improving visual function. Uniform, quantitative grading of visual dysfunction was lacking. MD is a promising quantitative outcome measure. We provide recommendations for the evaluation of timing of surgery, considering severity of visual impairment, which will need further validation based on expert clinical practice.