-  Participant Eligibility Criteria

        The participant must meet all of the eligibility criteria and none of the exclusion
        criteria below.

        INCLUSION CRITERIA:

          1. Participant must understand and sign the informed consent.

          2. Participant must be 18 years of age or older.

          3. Participant must have a diagnosis of VHL disease. In accordance with established
             criteria for diagnosis, any one of the following will be considered sufficient
             evidence that VHL disease is present:

               -  A family history of VHL disease plus one or more of the following lesions: RCH,
                  spinal or cerebellar hemangioblastoma, pheochromocytoma, multiple pancreatic
                  cysts, epididymal or broad ligament cystadenomas, multiple renal cysts or renal
                  cell carcinoma before age 60 years.

               -  Presence of two or more hemangioblastomas of the retina or brain or a single
                  hemangioblastoma in association with a visceral manifestation such as kidney or
                  pancreatic cysts; renal cell carcinoma; adrenal or extra-adrenal
                  pheochromocytomas; endolymphatic sac tumors; papillary cystadenomas of the
                  epididymis or broad ligament; or neuroendocrine tumors of the pancreas.

               -  Presence of a known disease-causing germline mutation in the VHL gene.

          4. Any female participant of childbearing potential must not be pregnant or
             breast-feeding, must have a negative pregnancy test at screening and must be willing
             to undergo pregnancy testing immediately prior to each treatment.

          5. Any female participant of childbearing potential and any male participant able to
             father children must have (or have a partner who has) had a hysterectomy or vasectomy,
             be completely abstinent from intercourse or must agree to practice two effective
             methods of contraception throughout the course of the study and for at least two
             months following the last administration of combination investigational treatment.
             Acceptable methods of contraception include:

               -  hormonal contraception (i.e., birth control pills, injected hormones, dermal
                  patch or vaginal ring),

               -  intrauterine device,

               -  barrier methods (diaphragm or condom) with spermicide, or

               -  surgical sterilization (hysterectomy, tubal ligation or vasectomy).

        EXCLUSION CRITERIA:

          1. Participant has a history or evidence of significant cardiac disease (for example, use
             of cardiac medications aside from agents to control blood pressure, past acute
             coronary syndrome, past myocardial infarction, past revascularization procedure or
             arrhythmias requiring past or present treatment).

          2. Participant has a history of stroke or transient ischemic attack.

             Note: cerebrovascular manifestations and/or complications of central nervous system
             hemangioblastomas are not exclusionary, in the absence of past stroke or transient
             ischemic attack.

          3. Participant has used systemic medication with significant anti-VEGF or anti-PDGF
             activity within 30 days of study entry or expects use of such a medication within 12
             months of study entry.

          4. Participant is medically unable to comply with study procedures or follow-up in the
             judgment of the investigator.

          5. Participant has a diagnosis of diabetic mellitus (type 1 or type 2). Any one of the
             following will be considered sufficient evidence that diabetes is present:

               -  Current regular use of insulin for the treatment of diabetes,

               -  Current regular use of oral anti-hyperglycemia agents for the treatment of
                  diabetes,

               -  Hemoglobin A1C of greater than or equal to 6.5%, or

               -  Documented diabetes by the American Diabetes Association (ADA) and/or World
                  Health Organization (WHO) criteria.

        Study Eye Eligibility Criteria

        The participant must have at least one eye meeting all inclusion criteria and none of the
        exclusion criteria listed below.

        INCLUSION CRITERIA:

          1. Participant has at least one RCH secondary to VHL disease in the study eye that
             fulfills the following criteria:

               1. The RCH must exhibit growth potential with consequent threat to vision. Growth
                  potential with consequent threat to vision is defined by AT LEAST ONE of the
                  following:

                    -  Associated intra- or sub-retinal exudation or lipid deposition that, in the
                       judgment of the investigator, reflects ongoing vascular incompetence and is
                       not solely reflective of residual changes following previous treatment or
                       solely secondary to coexistent retinal traction.

                    -  Increased size of the tumor compared to a previous time point as assessed by
                       fundus photography or FA.

                    -  Associated intra-, sub- or pre-retinal hemorrhage not secondary to previous
                       treatment, as assessed by fundus photography or FA.

                    -  The presence of dilated and/or tortuous feeder vessels.

                    -  Vitreous cell or haze indicative of vitreous exudation, in the absence of
                       other ocular features potentially responsible for such findings.

               2. The RCH, in the judgment of the investigator, is NOT readily treatable using
                  thermal laser because of its size, posterior location, poor previous response to
                  conventional therapy, association with significant exudation, epiretinal
                  proliferation, associated vascular abnormalities such as vascular proliferation
                  or diffusely incompetent retinal vessels, or other factors predictive of a poor
                  response to standard of care approaches.

          2. The study eye must have clarity of ocular media and degree of pupil dilation
             sufficient to permit adequate fundus photography.

        EXCLUSION CRITERIA:

          1. The study eye has present or chronic ocular or periocular infection (including any
             history of ocular herpes zoster).

          2. The study eye has chronic glaucoma; OR has received anti-glaucoma medication at any
             time within 90 days of study entry; OR has significant ocular hypertension, defined as
             documented intraocular pressure of greater than or equal to 28 mmHg on any occasion in
             the absence of self-limited acute glaucoma, OR greater than or equal to 24 mmHg on at
             least two occasions in the absence of self-limited acute glaucoma.

             Note: History of self-limited acute glaucoma in a study eye, if now resolved and not
             expected to recur, is not exclusionary. History of glaucoma or ocular hypertension in
             the fellow eye, if not felt to significantly impact risk of glaucoma in the study eye,
             is not exclusionary.

          3. The study eye has undergone any surgical procedure within 60 days prior to study entry
             (inclusive of cryotherapy or thermal laser).

          4. The study eye has a history of intravitreal injection of an anti-VEGF agent (such as
             bevacizumab, ranibizumab or aflibercept) within 42 days prior to study entry.

          5. The study eye has a history of intravitreal or periocular injection of long-acting
             corticosteroids (such as triamcinolone acetonide) within 90 days of study entry or
             history of any sustained-release ocular drug delivery device with reasonable
             expectation of residual activity in the study eye.

        Choice of Study Eye in Cases of Bilateral Eligibility

        If both eyes of a participant meet the criteria described above, the investigator will
        choose to enroll one eye in consultation with the participant.